Electrode sheet, electrode assembly, battery cell, battery, and electric device

Abstract

An electrode sheet, an electrode assembly, a battery cell, a battery, and an electric device. The electrode sheet is applied to a battery. The electrode sheet comprises a current collector and an active material layer. The current collector defines a coated region coated with an active material layer and a tab region not coated with an active material layer. The coated region comprises a main body region and a perforated region provided between the main body region and the tab region, wherein one or more holes are formed in the portion of the current collector at the perforated region. By configuring the coated region to comprise a main body region and a perforated region located between the main body region and the tab region, and forming one or more holes in the portion of the current collector at the perforated region, in the process of cold-pressing the electrode sheet, the elongation rate of the perforated region can be reduced, and the mismatch between the elongation rate of the coated region and the elongation rate of the tab region is alleviated, thereby reducing the formation of the tab region into crescent curves and waves, and reducing the occurrence of folding or wrinkling on the tab region during electrode sheet winding.

Description

Electrode pieces, electrode assemblies, battery cells, batteries and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on the Chinese patent application with application number 202410129806.4, application date January 30, 2024, and invention name “Pole piece, electrode assembly, battery cell, battery and electrical equipment”, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into the present disclosure as a reference. Technical Field

[0003] The present disclosure relates to the field of battery technology, and in particular to pole pieces, electrode assemblies, battery cells, batteries, and electrical equipment. Background Art

[0004] This section is intended to provide a background or context for the embodiments of the present disclosure. No admission is made that the description herein is prior art by virtue of its inclusion in this section.

[0005] To achieve higher energy density, power batteries require cold pressing of the cell pole pieces to achieve a higher compaction density for the active materials on the pole pieces, thereby increasing the volumetric energy density of the cell. As compaction increases, the elongation of the cell pole pieces also increases significantly. During the cold pressing process, the thickness of the coating area (where the active material is applied) and the blank area (where no active material is applied) on the pole piece differ, which can easily lead to an elongation mismatch between the coating area and the blank area. This can cause crescent-shaped bends and waves in the blank area, resulting in folding or wrinkling of the pole tabs during winding.

[0006] Summary of the Invention

[0007] In view of this, the embodiments of the present disclosure hope to provide a pole piece, an electrode assembly, a battery cell, a battery and an electrical device, which can improve the situation where the pole tabs are folded or wrinkled during the winding process of the pole piece.

[0008] To achieve the above-mentioned object, a first aspect of the embodiments of the present disclosure provides a pole piece for use in a battery, the pole piece comprising a current collector and an active material layer, the current collector defining a coating region coated with the active material layer and a tab region not coated with the active material layer;

[0009] The coating area includes a main body area and a perforated area arranged between the main body area and the tab area, and one or more holes are opened on the current collector in the perforated area.

[0010] The electrode provided by the embodiment of the present disclosure includes a current collector and an active material layer, wherein the current collector defines a coating area coated with the active material layer and a tab area not coated with the active material layer. By setting the coating area to include a main body area and a perforated area located between the main body area and the tab area, one or more holes are opened on the current collector in the perforated area. In this way, during the cold pressing process of the electrode, the current collector in the perforated area can be extended into the hole, thereby reducing the elongation of the perforated area under a certain compressive stress. In addition, the active material layer near the hole is relatively loose, which can play a role in alleviating the elongation of the current collector, further reducing the elongation of the perforated area. That is, after cold pressing, the elongation of the main body area is greater than the elongation of the perforated area, and the elongation of the perforated area is greater than the elongation of the tab area, that is, a certain gradient of elongation is formed between the main body area, the perforated area and the tab area, thereby improving the mismatch of elongation between the coating area and the tab area, thereby improving the formation of crescent-shaped bends and wavy shapes in the tab area, and improving the folding or wrinkling of the tab area during the winding process of the electrode. In addition, the extension of the current collector in the perforated area into the hole can improve the strength of the perforated area, that is, make the strength of the perforated area close to the strength of the coating area. That is to say, while improving the mismatch in elongation between the coating area and the tab area, the impact on the strength of the perforated area can be minimized as much as possible.

[0011] Furthermore, during the production of electrodes, in order to improve the folding of the tab area, a pattern is usually pressed in the tab area to form a reinforcing rib. This requires the tab area to be stretched a certain amount more than the coating area to accommodate the pressing of the reinforcing rib. However, due to the greater elongation of the coating area, pressing a pattern in the tab area can easily lead to disconnection of the current collector. The electrode provided in the embodiment of the present disclosure, by configuring the coating area to include a main body area and a perforated area located between the main body area and the tab area, and by providing holes in the current collector in the perforated area so that the elongation of the perforated area is less than that of the main body area, can improve the situation in which pressing a pattern in the tab area can easily lead to disconnection of the current collector.

[0012] In some embodiments, the diameter of the holes formed on the current collector in the perforated region is D, and 0.1 μm ≤ D ≤ 400 μm.

[0013] By setting the pore size of the holes opened on the current collector in the punched area to 0.1μm-400μm, the holes with a diameter within this range can reduce the elongation of the punched area, so that a certain gradient of elongation is formed between the main area, the punched area and the tab area, thereby improving the elongation mismatch between the coating area and the tab area, and minimizing the impact on the strength of the punched area as much as possible.

[0014] In some embodiments, the diameter of the holes formed on the current collector in the perforated area is D, and 10 μm ≤ D ≤ 50 μm.

[0015] By setting the pore size of the holes opened on the current collector in the punched area to 10μm≤D≤50μm, the holes with a diameter within this range can effectively reduce the elongation of the punched area, so that a certain gradient of elongation is formed between the main area, the punched area and the tab area, effectively improving the elongation mismatch between the coating area and the tab area, and minimizing the impact on the strength of the punched area as much as possible.

[0016] In some embodiments, along the running direction of the pole piece, the distance between adjacent holes is L1, and 0.1 mm ≤ L1 ≤ 100 mm.

[0017] By setting the spacing between adjacent holes along the running direction of the pole piece to 0.1 mm-100 mm, the influence on the strength of the punched area can be reduced and the elongation of the punched area can be lowered.

[0018] In some embodiments, along the running direction of the pole piece, the spacing between adjacent holes is L1, 0.5 mm ≤ L1 ≤ 10 mm.

[0019] By setting the spacing between adjacent holes along the running direction of the pole piece to 0.5 mm-10 mm, the influence on the strength of the punching area can be reduced as much as possible, and the elongation of the punching area can be effectively reduced.

[0020] In some embodiments, along a direction perpendicular to the running direction of the pole piece, a distance between adjacent holes is L2, 2mm≤L2≤10mm.

[0021] By setting the spacing between adjacent holes in a direction perpendicular to the running direction of the pole piece to 2mm-10mm, the impact on the strength of the punched area can be minimized as much as possible, and the elongation of the punched area can be effectively reduced.

[0022] In some embodiments, the width of the punched area along the running direction of the pole piece is L3, 0mm<L3≤20mm.

[0023] By setting the width of the punching area along the running direction of the pole piece to 0mm<L3≤20mm, the impact on the strength of the punching area can be reduced, and the elongation of the punching area can be reduced, so that a certain gradient of elongation is formed between the main area, the punching area and the pole tab area, thereby improving the elongation mismatch between the coating area and the pole tab area.

[0024] In some embodiments, the width of the punched area along the running direction of the pole piece is L3, 1mm≤L3≤10mm.

[0025] By setting the width of the punching area along the running direction of the pole piece to 1mm≤L3≤10mm, the impact on the strength of the punching area can be minimized as much as possible, and the elongation of the punching area can be effectively reduced, so that a certain gradient of elongation is formed between the main area, the punching area and the pole tab area, thereby improving the elongation mismatch between the coating area and the pole tab area.

[0026] In some embodiments, a molten pool is formed at the edge of the hole.

[0027] The laser-formed hole forms a molten pool at the edge of the hole, which helps to improve the strength of the hole area.

[0028] In some embodiments, there are multiple holes, all of which are distributed on multiple track lines, each of the holes on a single track line is arranged in a straight line along the running direction of the pole piece, and multiple track lines are arranged in parallel along a direction perpendicular to the running direction of the pole piece.

[0029] By machining the holes on the current collector in the perforated area according to a predetermined arrangement rule, it is more conducive to controlling the strength of the perforated area.

[0030] A second aspect of an embodiment of the present disclosure provides an electrode assembly, which includes a first electrode plate, a second electrode plate and an isolation membrane, wherein the isolation membrane is used to isolate the first electrode plate and the second electrode plate, and at least one of the first electrode plate and the second electrode plate is the electrode plate described in any embodiment of the present disclosure.

[0031] The electrode sheet of the electrode assembly provided by the embodiment of the present disclosure includes a current collector and an active material layer. The current collector defines a coating area coated with the active material layer and a tab area not coated with the active material layer. By setting the coating area to include a main body area and a punched area located between the main body area and the tab area, one or more holes are opened on the current collector in the punched area. In this way, during the cold pressing of the pole piece, the current collector in the punched area can be extended into the hole, so that under a certain compressive stress, the elongation of the punched area can be reduced. In addition, the active material layer near the hole is relatively loose, which can alleviate the elongation of the current collector and further reduce the elongation of the punched area. That is to say, after cold pressing, the elongation of the main body area is greater than the elongation of the punched area, and the elongation of the punched area is greater than the elongation of the tab area, that is, a certain gradient of elongation is formed between the main body area, the punched area and the tab area, thereby improving the elongation mismatch between the coating area and the tab area, thereby improving the crescent-shaped and wavy bends in the tab area, and improving the folding or wrinkling of the tab area during the winding process of the pole piece. In addition, the extension of the current collector in the perforated area into the hole can improve the strength of the perforated area, that is, make the strength of the perforated area close to the strength of the coating area. That is to say, while improving the mismatch in elongation between the coating area and the tab area, the impact on the strength of the perforated area can be minimized as much as possible.

[0032] Furthermore, during the production of electrodes, in order to improve the folding of the tab area, a pattern is usually pressed in the tab area to form a reinforcing rib. This requires the tab area to be stretched a certain amount more than the coating area to accommodate the pressing of the reinforcing rib. However, due to the greater elongation of the coating area, pressing a pattern in the tab area can easily lead to disconnection of the current collector. The electrode provided in the embodiment of the present disclosure, by configuring the coating area to include a main body area and a perforated area located between the main body area and the tab area, and by providing holes in the current collector in the perforated area so that the elongation of the perforated area is less than that of the main body area, can improve the situation in which pressing a pattern in the tab area can easily lead to disconnection of the current collector.

[0033] A third aspect of the embodiments of the present disclosure provides a battery cell, comprising a packaging film and the electrode assembly described above, wherein the packaging film is wrapped around the outside of the electrode assembly.

[0034] The pole piece of the battery cell provided in the embodiment of the present disclosure includes a current collector and an active material layer. The current collector defines a coating area coated with the active material layer and a tab area not coated with the active material layer. By setting the coating area to include a main body area and a punched area located between the main body area and the tab area, one or more holes are opened on the current collector in the punched area. In this way, during the cold pressing of the pole piece, the current collector in the punched area can be extended into the hole, so that under a certain compressive stress, the elongation of the punched area can be reduced. In addition, the active material layer near the hole is relatively loose, which can alleviate the elongation of the current collector and further reduce the elongation of the punched area. That is to say, after cold pressing, the elongation of the main body area is greater than the elongation of the punched area, and the elongation of the punched area is greater than the elongation of the tab area, that is, a certain gradient of elongation is formed between the main body area, the punched area and the tab area, thereby improving the elongation mismatch between the coating area and the tab area, thereby improving the crescent-shaped and wavy bends in the tab area, and improving the folding or wrinkling of the tab area during the winding process of the pole piece. In addition, the extension of the current collector in the perforated area into the hole can improve the strength of the perforated area, that is, make the strength of the perforated area close to the strength of the coating area. That is to say, while improving the mismatch in elongation between the coating area and the tab area, the impact on the strength of the perforated area can be minimized as much as possible.

[0035] Furthermore, during the production of electrodes, in order to improve the folding of the tab area, a pattern is usually pressed in the tab area to form a reinforcing rib. This requires the tab area to be stretched a certain amount more than the coating area to accommodate the pressing of the reinforcing rib. However, due to the greater elongation of the coating area, pressing a pattern in the tab area can easily lead to disconnection of the current collector. The electrode provided in the embodiment of the present disclosure, by configuring the coating area to include a main body area and a perforated area located between the main body area and the tab area, and by providing holes in the current collector in the perforated area so that the elongation of the perforated area is less than that of the main body area, can improve the situation in which pressing a pattern in the tab area can easily lead to disconnection of the current collector.

[0036] A fourth aspect of the embodiments of the present disclosure provides a battery comprising at least one of the battery cells described above.

[0037] The battery electrode provided by the embodiment of the present disclosure includes a current collector and an active material layer. The current collector defines a coating area coated with the active material layer and a tab area not coated with the active material layer. By setting the coating area to include a main body area and a punched area located between the main body area and the tab area, one or more holes are opened on the current collector in the punched area. In this way, during the cold pressing of the pole piece, the current collector in the punched area can be extended into the hole, so that under a certain compressive stress, the elongation of the punched area can be reduced. In addition, the active material layer near the hole is relatively loose, which can alleviate the elongation of the current collector and further reduce the elongation of the punched area. That is to say, after cold pressing, the elongation of the main body area is greater than the elongation of the punched area, and the elongation of the punched area is greater than the elongation of the tab area, that is, a certain gradient of elongation is formed between the main body area, the punched area and the tab area, thereby improving the elongation mismatch between the coating area and the tab area, thereby improving the crescent-shaped and wavy bends in the tab area, and improving the folding or wrinkling of the tab area during the winding process of the pole piece. In addition, the extension of the current collector in the perforated area into the hole can improve the strength of the perforated area, that is, make the strength of the perforated area close to the strength of the coating area. That is to say, while improving the mismatch in elongation between the coating area and the tab area, the impact on the strength of the perforated area can be minimized as much as possible.

[0038] Furthermore, during the production of electrodes, in order to improve the folding of the tab area, a pattern is usually pressed in the tab area to form a reinforcing rib. This requires the tab area to be stretched a certain amount more than the coating area to accommodate the pressing of the reinforcing rib. However, due to the greater elongation of the coating area, pressing a pattern in the tab area can easily lead to disconnection of the current collector. The electrode provided in the embodiment of the present disclosure, by configuring the coating area to include a main body area and a perforated area located between the main body area and the tab area, and by providing holes in the current collector in the perforated area so that the elongation of the perforated area is less than that of the main body area, can improve the situation in which pressing a pattern in the tab area can easily lead to disconnection of the current collector.

[0039] A fifth aspect of the embodiments of the present disclosure provides an electrical device, comprising the battery cell or the battery described above, wherein the battery cell or the battery is used to store or provide electrical energy.

[0040] The electrode plate of the battery of the electric device provided in the embodiment of the present disclosure includes a current collector and an active material layer. The current collector defines a coating area coated with the active material layer and a tab area not coated with the active material layer. By setting the coating area to include a main body area and a punched area located between the main body area and the tab area, one or more holes are opened on the current collector in the punched area. In this way, during the cold pressing of the pole piece, the current collector in the punched area can be extended into the hole, so that under a certain compressive stress, the elongation of the punched area can be reduced. In addition, the active material layer near the hole is relatively loose, which can alleviate the elongation of the current collector and further reduce the elongation of the punched area. That is to say, after cold pressing, the elongation of the main body area is greater than the elongation of the punched area, and the elongation of the punched area is greater than the elongation of the tab area, that is, a certain gradient of elongation is formed between the main body area, the punched area and the tab area, thereby improving the elongation mismatch between the coating area and the tab area, thereby improving the crescent-shaped and wavy bends in the tab area, and improving the folding or wrinkling of the tab area during the winding process of the pole piece. In addition, the extension of the current collector in the perforated area into the hole can improve the strength of the perforated area, that is, make the strength of the perforated area close to the strength of the coating area. That is to say, while improving the mismatch in elongation between the coating area and the tab area, the impact on the strength of the perforated area can be minimized as much as possible.

[0041] Furthermore, during the production of electrodes, in order to improve the folding of the tab area, a pattern is usually pressed in the tab area to form a reinforcing rib. This requires the tab area to be stretched a certain amount more than the coating area to accommodate the pressing of the reinforcing rib. However, due to the greater elongation of the coating area, pressing a pattern in the tab area can easily lead to disconnection of the current collector. The electrode provided in the embodiment of the present disclosure, by configuring the coating area to include a main body area and a perforated area located between the main body area and the tab area, and by providing holes in the current collector in the perforated area so that the elongation of the perforated area is less than that of the main body area, can improve the situation in which pressing a pattern in the tab area can easily lead to disconnection of the current collector. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a schematic structural diagram of a vehicle provided by an embodiment of the present disclosure;

[0043] FIG2 is a perspective exploded schematic diagram of a battery provided in one embodiment of the present disclosure;

[0044] FIG3 is a schematic structural diagram of a pole piece provided in one embodiment of the present disclosure;

[0045] FIG4 is a top view of a pole piece located at a hole before cold pressing according to an embodiment of the present disclosure;

[0046] FIG5 is a front view of a pole piece provided by an embodiment of the present disclosure located at a hole before cold pressing;

[0047] FIG6 is a top view of a pole piece located at a hole after cold pressing according to an embodiment of the present disclosure;

[0048] FIG7 is a front view of a pole piece located at a hole after cold pressing according to an embodiment of the present disclosure;

[0049] FIG8 is a schematic diagram of elongation testing of a pole piece provided by an embodiment of the present disclosure and a pole piece of the prior art under tension, wherein the elongation of the pole piece along the tape running direction is shown;

[0050] FIG9 is a schematic diagram showing elongation tests of a pole piece provided by an embodiment of the present disclosure and a pole piece of the prior art under tension, wherein the elongation of the pole piece in a direction perpendicular to the tape running direction is shown;

[0051] FIG10 is a top view of a conventional pole piece before cold pressing;

[0052] FIG11 is a front view of a conventional electrode before cold pressing;

[0053] FIG12 is a top view of a pole piece of the prior art after cold pressing;

[0054] FIG13 is a front view of a pole piece in the prior art after cold pressing.

[0055] Description of Reference Numerals

[0056] 1. Pole piece; 1a. Coating area; 1b. Main body area; 1c. Perforated area; 1d. Tab area; 1e. Hole; 11. Current collector; 12. Active material layer; 10. Battery cell; 20. Case; 100. Battery; 200. Controller; 300. Motor; 1000. Vehicle. DETAILED DESCRIPTION

[0057] It should be noted that, unless there is a conflict, the embodiments and technical features in the embodiments of the present disclosure can be combined with each other, and the detailed description in the specific implementation methods should be understood as an explanation of the purpose of the present disclosure and should not be regarded as an improper limitation on the present disclosure.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this disclosure; the terms "including" and "having" and any variations thereof in this disclosure are intended to cover non-exclusive inclusions.

[0059] In the description of the embodiments of the present disclosure, technical terms such as "first," "second," and "third" are used solely to distinguish different objects and should not be understood to indicate or imply relative importance or to implicitly specify the quantity, specific order, or primary and secondary relationship of the technical features indicated. In the description of the embodiments of the present disclosure, "plurality" means more than two, unless otherwise specifically defined.

[0060] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] In the description of the embodiments of the present disclosure, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0062] In the description of the embodiments of the present disclosure, the orientations or positional relationships indicated by technical terms such as "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "circumferential", "height direction", "first direction", and "second direction" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present disclosure.

[0063] In the description of the embodiments of the present disclosure, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal connectivity between two components or interaction between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0064] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and can be direct contact, contact through an intermediate medium layer, contact with essentially no interaction force between the two contacting parties, or contact with interaction force between the two contacting parties.

[0065] With the development of clean energy, more and more devices are using electricity as a driving force. Consequently, power batteries, such as lithium-ion batteries, that can store large amounts of electricity and undergo multiple charge and discharge cycles are rapidly developing. These batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric vehicles, as well as in aerospace and other fields.

[0066] In the present disclosure, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, and the present disclosure is not limited thereto. Battery cells may be cylindrical, rectangular, or in other shapes, and the present disclosure is not limited thereto.

[0067] The battery referred to in the embodiments of this disclosure refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this disclosure may include a battery module or a battery pack. Batteries generally include a housing for enclosing one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0068] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The uncoated positive electrode collector protrudes from the coated positive electrode collector, and the uncoated positive electrode collector serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The uncoated negative electrode collector protrudes from the coated negative electrode collector, and the uncoated negative electrode collector serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon. To ensure high current flow without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0069] A battery cell also includes a wrapping film and a casing. The wrapping film is applied to the outside of the electrode assembly, and the casing encapsulates the wrapped electrode assembly to form a battery cell. The wrapping film can be Mylar film, and the casing can be aluminum. After the electrode assembly is wound, the Mylar film and casing are encapsulated through the Mylar wrapping and casing steps. The Mylar film seals and protects the electrode assembly, effectively insulating the electrode assembly and casing from each other, preventing internal short circuits in the battery cell. The casing also provides protection.

[0070] The process of preparing the pole piece usually includes pulping, coating, cold pressing, and tab die-cutting. The coating process includes applying the well-stirred active material to the current collector, so that the current collector has a coating area coated with an active material layer and a blank area that is not coated with an active material layer. The blank area is used as a tab after processing (for example, after the tab die-cutting process). Generally, in order to improve the coating efficiency, a roller coating process is often used. Roller coating uses a rotating roller as a carrier of the active material. The active material forms a wet film of a certain thickness on the surface of the roller, and then contacts the current collector with the help of the roller during rotation, and the active material is coated on the surface of the current collector. The cold pressing process is to roll the pole piece with the active material attached by a cold pressing device. On the one hand, it makes the coated material more compact, improves the energy density, and ensures the consistency of the thickness. On the other hand, it will further control dust and humidity.

[0071] During the cold pressing process, the thickness of the coating area on the electrode with active material and the blank area without active material is different, which can easily lead to an extension mismatch between the coating area and the blank area. The coating area on the electrode with active material will become longer along the tape direction under the action of compressive stress and tension in the tape direction, while the blank area without active material is not subjected to compressive stress, so the length direction does not become longer along the tape direction. This will cause the blank area to bear greater tension, easily break the tape, or form crescent-shaped bends and waves in the blank area, causing the pole ears to fold or wrinkle during the winding process.

[0072] In view of this, to improve the situation where the tabs of a pole sheet may fold or wrinkle during winding, the present disclosure provides a pole sheet for use in a battery. The pole sheet includes a current collector and an active material layer. The current collector defines a coating region coated with the active material layer and a tab region not coated with the active material layer. The coating region includes a main body region and a perforated region disposed between the main body region and the tab region. The current collector in the perforated region is provided with one or more holes.

[0073] The electrode provided by the embodiment of the present disclosure includes a current collector and an active material layer, wherein the current collector defines a coating area coated with the active material layer and a tab area not coated with the active material layer. By setting the coating area to include a main body area and a perforated area located between the main body area and the tab area, one or more holes are opened on the current collector in the perforated area. In this way, during the cold pressing process of the electrode, the current collector in the perforated area can be extended into the hole, thereby reducing the elongation of the perforated area under a certain compressive stress. In addition, the active material layer near the hole is relatively loose, which can play a role in alleviating the elongation of the current collector, further reducing the elongation of the perforated area. That is, after cold pressing, the elongation of the main body area is greater than the elongation of the perforated area, and the elongation of the perforated area is greater than the elongation of the tab area, that is, a certain gradient of elongation is formed between the main body area, the perforated area and the tab area, thereby improving the mismatch of elongation between the coating area and the tab area, thereby improving the formation of crescent-shaped bends and wavy shapes in the tab area, and improving the folding or wrinkling of the tab area during the winding process of the electrode. In addition, the extension of the current collector in the perforated area into the hole can improve the strength of the perforated area, that is, make the strength of the perforated area close to the strength of the coating area. That is to say, while improving the mismatch in elongation between the coating area and the tab area, the impact on the strength of the perforated area can be minimized as much as possible.

[0074] Furthermore, in the production process of the electrode, in order to improve the folding of the tab area, patterns are usually pressed in the tab area to form reinforcing ribs. In this way, the tab area needs to be stretched a certain amount more than the coating area for the pressing of the reinforcing ribs. Since the coating area has a larger elongation, pressing patterns in the tab area can easily lead to the disconnection of the current collector. The pole piece provided in the embodiment of the present disclosure is configured to include a main body area and a perforated area between the main body area and the tab area by setting the coating area to include a main body area and a perforated area between the main body area and the tab area, and by opening a hole in the current collector in the perforated area so that the elongation of the perforated area is less than that of the main body area. In this way, the situation that pressing patterns in the tab area can easily lead to the disconnection of the current collector can be improved. The technical solution described in the embodiment of the present disclosure is applicable to battery cells, batteries, and electrical equipment using batteries.

[0075] Electrical equipment can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present disclosure do not impose any special restrictions on the above-mentioned electrical equipment.

[0076] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0077] FIG1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. A controller 200, a motor 300, and a battery 100 may be provided inside the vehicle 1000, and the controller 200 is used to control the battery 100 to power the motor 300. For example, the battery 100 may be provided at the bottom, front, or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, for example, for the working power requirements of the vehicle 1000 during startup, navigation, and operation. In another embodiment of the present disclosure, the battery 100 may not only be used as an operating power source for the vehicle 1000, but may also be used as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0078] The battery 100 includes at least one battery cell 10. The number of battery cells 10 may be one or more.

[0079] Referring to Figure 2 , multiple battery cells 10 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to multiple battery cells 10 being connected both in series and in parallel. Multiple battery cells 10 can be directly connected in series, in parallel, or in a hybrid configuration, and the entire battery 10 can then be housed within a housing 20. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 10 in series, in parallel, or in a hybrid configuration to form a battery 100 module. The multiple battery modules 100 can then be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within the housing 20. The battery 100 can also include other structures. For example, the battery 100 can include a busbar for electrically connecting the multiple battery cells 10. Each battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery 100, a sodium-ion battery 100, or a magnesium-ion battery 100, but is not limited thereto. The battery cell 10 can be cylindrical, flat, rectangular, or have other shapes.

[0080] The battery cell 10 includes an electrode assembly and a packaging film wrapped around the outside of the electrode assembly.

[0081] The electrode assembly is a wound structure, comprising a first electrode sheet, a second electrode sheet, and a separator, wherein the separator is used to separate the first electrode sheet from the second electrode sheet. At least one of the first electrode sheet and the second electrode sheet is the electrode sheet 1 in any embodiment of the present disclosure.

[0082] At least one of the first pole piece and the second pole piece is the pole piece 1 in any embodiment of the present disclosure, which means that the first pole piece can be the pole piece 1 in any embodiment of the present disclosure, the second pole piece can be the pole piece 1 in any embodiment of the present disclosure, or both the first pole piece and the second pole piece can be the pole piece 1 in any embodiment of the present disclosure.

[0083] Taking sodium-ion batteries as an example, the future application of passenger cars and energy storage systems requires higher energy density, and it is usually necessary to improve the compaction of the electrode 1 to improve the energy density of the battery cell. In fact, the negative electrode commonly used in sodium-ion batteries is hard carbon with a higher specific energy density. As the compaction increases, the elongation of the coating area 1a also increases significantly (graphite generally has a cold pressing elongation of ≤0.1%, and hard carbon generally has a cold pressing elongation of >0.2%). Due to the different thicknesses of the tab area 1d and the coating area 1a (the tab area 1d has no active material layer 12), it is easy to cause the elongation of the coating area 1a and the tab area 1d to not match, resulting in crescent-shaped and wavy bending in the tab area 1d, causing the tab to fold or wrinkle during the winding process. At the same time, the active material layer 12 at the edge of the coating area 1a is likely to be thicker than the middle of the coating area 1a, which is prone to overpressure during cold pressing and causes edge collapse.

[0084] The reasons for the mismatch in elongation between the coating area 1a and the tab area 1d include: high cold pressing density (for high energy density), and the negative electrode material is hard and difficult to slide; the thickness of the coating area 1a and the tab area 1d are inconsistent, and the cold pressing elongation is inconsistent; the cold pressing elongation is large, basically reaching the upper limit of the elongation that the current collector 11 can withstand, and production fluctuations can easily lead to over-elongation or edge cracking; in the production process of the electrode, in order to improve the folding of the tab area 1d, patterns are usually pressed in the tab area 1d to form reinforcing ribs. In this way, the tab area 1d needs to be stretched a certain amount more than the coating area 1a (usually 0.3%) for the pressing of the reinforcing ribs. However, due to the large elongation of the coating area 1a, pressing patterns in the tab area 1d can easily cause the current collector 11 to break.

[0085] The electrode sheet 1 provided in the embodiment of the present disclosure is applied to a battery 100. Referring to Figures 3 to 7, the electrode sheet 1 includes a current collector 11 and an active material layer 12. The current collector 11 defines a coating region 1a coated with the active material layer 12 and a tab region 1d not coated with the active material layer 12. The coating region 1a includes a main body region 1b and a perforated region 1c disposed between the main body region 1b and the tab region 1d. One or more holes 1e are formed in the current collector 11 in the perforated region 1c.

[0086] The coating region 1 a includes a main body region 1 b and a perforated region 1 c disposed between the main body region 1 b and the tab region 1 d . That is, the main body region 1 b and the tab region 1 d are connected via the perforated region 1 c .

[0087] It should be noted that the main region 1 b refers to the region of the current collector 11 where no holes 1 e are formed, and the perforated region 1 c refers to the region of the current collector 11 where holes 1 e are formed.

[0088] It should be noted that the number of holes 1 e opened on the current collector 11 in the perforated area 1 c is not limited, that is, one or more holes 1 e are opened on the current collector 11 in the perforated area 1 c.

[0089] The specific type of the hole 1e is not limited here. For example, the hole 1e can be a through hole or a blind hole.

[0090] It can be understood that punching 1e in the punching area 1c can reduce the elongation of the punching area 1c, and the strength of the punching area 1c remains basically unchanged; the punching area 1c uses the collector 11 to punch 1e to reduce the upper limit of the elongation of the punching area 1c (by adjusting the distribution of holes 1e to achieve the difference in the upper limit of the elongation of the punching area 1c and the main area 1b), reserving a larger elongation processing range for the tab area 1d.

[0091] Figure 4 is a top view of a pole piece provided in an embodiment of the present disclosure, located at a hole before cold pressing; Figure 5 is a front view of a pole piece provided in an embodiment of the present disclosure, located at a hole before cold pressing; Figure 6 is a top view of a pole piece provided in an embodiment of the present disclosure, located at a hole after cold pressing; Figure 7 is a front view of a pole piece provided in an embodiment of the present disclosure, located at a hole after cold pressing; Figure 10 is a top view of a pole piece of the prior art before cold pressing; Figure 11 is a front view of a pole piece of the prior art before cold pressing; Figure 12 is a top view of a pole piece of the prior art after cold pressing; and Figure 13 is a front view of a pole piece of the prior art after cold pressing. It can be seen that the active material layer 12 near the hole 1e is relatively loose, which can alleviate the expansion of the current collector 11, further reducing the expansion rate of the punched area 1c.

[0092] The electrode 1 provided in the embodiment of the present disclosure includes a current collector 11 and an active material layer 12. The current collector 11 defines a coating area 1a coated with the active material layer 12 and a tab area 1d not coated with the active material layer 12. By setting the coating area 1a to include a main body area 1b and a punching area 1c located between the main body area 1b and the tab area 1d, one or more holes 1e are opened on the current collector 11 in the punching area 1c. In this way, during the cold pressing process of the electrode 1, the current collector 11 in the punching area 1c can be extended into the hole 1e, so that under a certain compressive stress, the elongation rate of the punching area 1c can be reduced. In addition, the active material layer 12 near the hole 1e is relatively loose, which can alleviate the elongation of the current collector 11, further The elongation of the perforated region 1c is reduced. That is, after cold pressing, the elongation of the main region 1b is greater than that of the perforated region 1c, and the elongation of the perforated region 1c is greater than that of the tab region 1d. That is, a certain gradient of elongation is formed between the main region 1b, the perforated region 1c, and the tab region 1d. This improves the elongation mismatch between the coating region 1a and the tab region 1d, thereby improving the crescent-shaped bends and wavy shapes formed in the tab region 1d, and improving the folding or wrinkling of the tab region 1d during the winding process of the pole piece 1. In addition, the extension of the current collector 11 in the perforated region 1c into the hole 1e can improve the strength of the perforated region 1c, that is, make the strength of the perforated region 1c close to that of the coating region 1a. That is, while improving the elongation mismatch between the coating region 1a and the tab region 1d, the impact on the strength of the perforated region 1c can be minimized.

[0093] Furthermore, in the production process of the electrode, in order to improve the folding of the tab area 1d, a pattern is usually pressed in the tab area 1d to form a reinforcing rib. In this way, the tab area 1d needs to be stretched a certain amount more than the coating area 1a to provide for the pressing of the reinforcing rib. Since the coating area 1a has a large elongation, pressing a pattern in the tab area 1d can easily cause the current collector 11 to break. The electrode 1 provided in the embodiment of the present disclosure is configured such that the coating area 1a includes a main body area 1b and a perforated area 1c located between the main body area 1b and the tab area 1d, and a hole 1e is opened on the current collector 11 in the perforated area 1c so that the elongation of the perforated area 1c is less than that of the main body area 1b. In this way, the situation that pressing a pattern in the tab area 1d can easily cause the current collector 11 to break can be improved.

[0094] For example, Figure 8 is a schematic diagram of the elongation test of the pole piece provided by an embodiment of the present disclosure and the pole piece of the prior art under tension, wherein the diagram shows the elongation of the pole piece along the tape running direction; Figure 9 is a schematic diagram of the elongation test of the pole piece provided by an embodiment of the present disclosure and the pole piece of the prior art under tension, wherein the diagram shows the elongation of the pole piece along the direction perpendicular to the tape running direction. In other words, by applying the same tensile force to the pole piece provided by the embodiment of the present disclosure and the pole piece of the prior art, for example, the pole piece is stretched at 50mm / min, to test the elongation of the pole piece provided by the embodiment of the present disclosure and the pole piece of the prior art. The dotted lines shown in Figures 8 and 9 are the elongation rates of the pole pieces of the prior art (equivalent to the control group), and the solid lines shown in Figures 8 and 9 are the elongation rates of the pole pieces provided by the embodiments of the present disclosure. It can be seen that under the same tensile force, the pole pieces provided by the embodiments of the present disclosure have lower elongation rates than the pole pieces in the prior art, whether along the tape-walking direction or in the direction perpendicular to the tape-walking direction. That is, the pole piece 1 provided by the embodiment of the present disclosure is configured such that the coating area 1a is configured to include a main body area 1b and a perforated area 1c located between the main body area 1b and the tab area 1d, and one or more holes 1e are provided on the current collector 11 of the perforated area 1c. In this way, during the cold pressing process of the pole piece 1, the current collector 11 of the perforated area 1c can be extended into the hole 1e. Therefore, under the condition of constant compressive stress, the elongation of the punching area 1c can be reduced. In addition, the active material layer 12 near the hole 1e is relatively loose, which can alleviate the elongation of the current collector 11, further reducing the elongation of the punching area 1c. That is, after cold pressing, the elongation of the main area 1b is greater than the elongation of the punching area 1c, and the elongation of the punching area 1c is greater than the elongation of the tab area 1d, that is, a certain gradient of elongation is formed between the main area 1b, the punching area 1c and the tab area 1d, which improves the elongation mismatch between the coating area 1a and the tab area 1d, thereby improving the crescent-shaped bend and wave-shaped formation of the tab area 1d, and improving the folding or wrinkling of the tab area 1d during the winding process of the pole piece 1.

[0095] In some embodiments, as shown in FIG3 , there are multiple holes 1e. All holes 1e are distributed along multiple track lines. The holes 1e on a single track line are arranged linearly along the running direction of the pole piece 1, while multiple track lines are arranged parallel to the running direction of the pole piece 1. In other words, the holes 1e have a specific arrangement pattern. This facilitates the processing of each hole 1e according to the predetermined arrangement pattern during the molding process and is more conducive to controlling the strength of the punched area 1c.

[0096] The main body region 1 b , the perforated region 1 c and the tab region 1 d are arranged in sequence along the running direction of the pole piece 1 .

[0097] The holes 1e on a single track line refer to single-row holes 1e, which are arranged in sequence along the running direction of the pole piece 1. Multiple track lines refer to multiple rows of holes 1e, which are arranged in parallel in a direction perpendicular to the running direction of the pole piece 1.

[0098] By machining the holes 1 e on the current collector 11 in the perforated area 1 c according to a predetermined arrangement rule, it is more advantageous to control the strength of the perforated area 1 c.

[0099] In some embodiments, referring to FIG. 4 , the diameter of the holes 1 e formed on the current collector 11 in the perforated region 1 c is D, and 0.1 μm≤D≤400 μm. For example, it is 0.1μm, 1μm, 5μm, 10μm, 20μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm, 210μm, 220μm, 230μm, 240μm, 250μm, 260μm, 270μm, 280μm, 290μm, 300μm, 310μm, 320μm, 330μm, 340μm, 350μm, 360μm, 370μm, 380μm, 390μm or 400μm, etc.

[0100] By setting the aperture of the hole 1e opened on the current collector 11 of the punching area 1c to 0.1μm-400μm, the hole 1e with an aperture within this range can reduce the elongation of the punching area 1c, so that a certain gradient of elongation is formed between the main area 1b, the punching area 1c and the tab area 1d, thereby improving the elongation mismatch between the coating area 1a and the tab area 1d, and minimizing the impact on the strength of the punching area 1c.

[0101] In some embodiments, referring to FIG4 , the pores 1e formed on the current collector 11 in the perforated region 1c have a pore diameter D, 10 μm ≤ D ≤ 50 μm, for example, 10 μm, 11 μm, 12 μm, 16 μm, 17 μm, 18 μm, 20 μm, 21 μm, 22 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 30 μm, 34 μm, 35 μm, 36 μm, 38 μm, 39 μm, 40 μm, 42 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, or 50 μm, etc.

[0102] By setting the aperture of the hole 1e opened on the current collector 11 of the punching area 1c to 10μm≤D≤50μm, the hole 1e with an aperture within this range can effectively reduce the elongation of the punching area 1c, so that a certain gradient of elongation is formed between the main area 1b, the punching area 1c and the tab area 1d, effectively improving the elongation mismatch between the coating area 1a and the tab area 1d, and can minimize the impact on the strength of the punching area 1c.

[0103] In some embodiments, referring to FIG3 , along the tape running direction of the pole piece 1 , the spacing between adjacent holes 1 e is L1, and 0.1 mm ≤ L1 ≤ 100 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 1 mm, 10 mm, 11 mm, 12 mm, 15 mm, 18 mm, 20 mm, 23 mm, 24 mm, 25 mm, 28 mm, 30 mm, 33 mm, 35 mm, 40 mm, 48 mm, 50 mm, 53 mm, 60 mm, 65 mm, 70 mm, 76 mm, 80 mm, 85 mm, 88 mm, 89 mm, 90 mm, 98 mm, or 100 mm, etc.

[0104] By setting the spacing between adjacent holes 1e along the running direction of the pole piece 1 to 0.1 mm-100 mm, the influence on the strength of the punched area 1c can be reduced, and the elongation of the punched area 1c can be lowered.

[0105] In some embodiments, referring to FIG3 , along the tape running direction of the pole piece 1 , the spacing between adjacent holes 1 e is L1, 0.5 mm ≤ L1 ≤ 10 mm, for example, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.8 mm, 3.0 mm, 3.3 mm, 3.5 mm, 4.0 mm, 4.8 mm, 5.0 mm, 5.3 mm, 6.0 mm, 6.5 mm, 7.0 mm, 7.6 mm, 8.0 mm, 8.5 mm, 8.8 mm, 9.0 mm, 9.5 mm, or 10 mm, etc.

[0106] By setting the spacing between adjacent holes 1e along the running direction of the pole piece 1 to 0.5mm-10mm, the influence on the strength of the punching area 1c can be reduced as much as possible, and the elongation of the punching area 1c can be effectively reduced.

[0107] In some embodiments, referring to FIG3 , along a direction perpendicular to the tape running direction of the pole piece 1 , the spacing between adjacent holes 1 e is L2, 2 mm ≤ L2 ≤ 10 mm, for example, 2.0 mm, 2.1 mm, 2.2 mm, 2.5 mm, 2.6 mm, 3.0 mm, 3.4 mm, 3.5 mm, 4.0 mm, 4.6 mm, 5.0 mm, 5.6 mm, 6.0 mm, 6.5 mm, 7.0 mm, 7.5 mm, 8.0 mm, 8.3 mm, 8.8 mm, 9.0 mm, 9.6 mm, or 10 mm, etc.

[0108] By setting the spacing between adjacent holes 1e in a direction perpendicular to the running direction of the pole piece 1 to 2mm-10mm, the influence on the strength of the punching area 1c can be minimized as much as possible, and the elongation of the punching area 1c can be effectively reduced.

[0109] In some embodiments, referring to FIG3 , the width of the perforated area 1 c along the tape-running direction of the electrode 1 is L3, where 0 mm < L3 ≤ 20 mm. For example, the width is 0.2 mm, 0.5 mm, 1 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm, 16 mm, 17 mm, 18 mm, 18.8 mm, 19 mm, 19.6 mm, or 20 mm.

[0110] By setting the width of the punching area 1c along the running direction of the pole piece 1 to 0mm<L3≤20mm, the impact on the strength of the punching area 1c can be reduced, and the elongation of the punching area 1c can be reduced, so that a certain gradient of elongation is formed between the main area 1b, the punching area 1c and the tab area 1d, thereby improving the elongation mismatch between the coating area 1a and the tab area 1d.

[0111] In some embodiments, referring to FIG3 , the width of the perforated area 1 c along the tape running direction of the electrode 1 is L3, 1 mm ≤ L3 ≤ 10 mm, for example, 1.0 mm, 1.2 mm, 1.3 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3.0 mm, 3.4 mm, 3.5 mm, 4.0 mm, 4.8 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.8 mm, 7.0 mm, 7.6 mm, 8.0 mm, 8.5 mm, 8.8 mm, 9.0 mm, 9.5 mm, or 10 mm, etc.

[0112] By setting the width of the punching area 1c along the running direction of the pole piece 1 to 1mm≤L3≤10mm, the impact on the strength of the punching area 1c can be minimized as much as possible, and the elongation of the punching area 1c can be effectively reduced, so that a certain gradient of elongation is formed between the main area 1b, the punching area 1c and the tab area 1d, thereby improving the elongation mismatch between the coating area 1a and the tab area 1d.

[0113] It should be noted that the specific method of forming the holes 1e is not limited here. For example, the holes 1e in the current collector 11 of the perforated area 1c are punched by laser, and a molten pool is formed at the edge of the holes 1e formed by the laser. This is beneficial to improving the strength of the perforated area 1c.

[0114] It should be noted that the aperture D of the hole 1e opened on the current collector 11 of the punched area 1c; the spacing between adjacent holes 1e along the running direction of the pole piece 1 is L1; the spacing between adjacent holes 1e along the direction perpendicular to the running direction of the pole piece 1 is L2; ​​the width of the punched area 1c along the running direction of the pole piece 1 is L3. The measurement method is not limited here. For example, it can be measured by an electron microscope, for example, by taking an electron microscope image and performing measurement on the electron microscope image.

[0115] In the description of the present disclosure, the descriptions with reference to the terms "in one embodiment", "in some embodiments", "in other embodiments", "in yet other embodiments", or "exemplary" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present disclosure. In the present disclosure, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine different embodiments or examples described in the present disclosure and the features of different embodiments or examples, unless they are contradictory.

[0116] The foregoing description is merely a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure are intended to be within the scope of protection of the present disclosure.

Claims

1. A pole piece for use in a battery, comprising a current collector and an active material layer, wherein the current collector defines a coating region coated with the active material layer and a tab region not coated with the active material layer; in, The coating area includes a main body area and a perforated area arranged between the main body area and the tab area. One or more holes are opened on the current collector in the perforated area.

2. The pole piece according to claim 1, wherein: The pores formed on the current collector in the perforated area have a pore diameter D, and 0.1 μm≤D≤400 μm.

3. The pole piece according to claim 2, wherein: The diameter of the holes formed on the current collector in the perforated area is D, and 10 μm≤D≤50 μm.

4. The pole piece according to any one of claims 1 to 3, wherein: Along the running direction of the pole piece, the distance between adjacent holes is L1, 0.1mm≤L1≤100mm.

5. The pole piece according to claim 4, wherein: Along the running direction of the pole piece, the spacing between adjacent holes is L1, 0.5mm≤L1≤10mm.

6. The pole piece according to any one of claims 1 to 5, wherein: Along a direction perpendicular to the running direction of the pole piece, the spacing between adjacent holes is L2, 2mm≤L2≤10mm.

7. The pole piece according to any one of claims 1 to 6, wherein: The width of the punching area along the running direction of the pole piece is L3, 0mm<L3≤20mm.

8. The pole piece according to claim 7, wherein: The width of the punched area along the running direction of the pole piece is L3, 1mm≤L3≤10mm.

9. The pole piece according to any one of claims 1 to 8, wherein: The edges of the holes form a molten pool.

10. The pole piece according to any one of claims 1 to 9, wherein: There are multiple holes, all of which are distributed on multiple track lines. The holes on a single track line are arranged in a straight line along the running direction of the pole piece, and multiple track lines are arranged in parallel along a direction perpendicular to the running direction of the pole piece.

11. An electrode assembly, comprising a first electrode piece, a second electrode piece and an isolation membrane, wherein the isolation membrane is used to isolate the first electrode piece from the second electrode piece, and at least one of the first electrode piece and the second electrode piece is the electrode piece according to any one of claims 1 to 10. 12 . A battery cell comprising a packaging film and the electrode assembly according to claim 11 , wherein the packaging film is wrapped around the outside of the electrode assembly.

13. A battery comprising at least one battery cell according to claim 12. 14 . An electrical device comprising the battery cell according to claim 12 or the battery according to claim 13 , wherein the battery cell or the battery is used to store or provide electrical energy.

Images