Electrode sheet, battery cell, battery, electrical device, and manufacturing method

Abstract

The present application discloses an electrode sheet, a battery cell, a battery, an electrical device, and a manufacturing method. The electrode sheet comprises a composite current collector and a first active material layer. The composite current collector comprises a current collector body and a connecting part which are connected to each other in a first direction, and the first direction is perpendicular to the thickness direction of the current collector body. In the first direction, the connecting part has a slit surface away from the current collector body, and in the thickness direction of the composite current collector, the current collector body has a first surface and a third surface which are opposite to each other, the connecting part has a second surface, and the first surface and the second surface jointly form a first coating area. The first active material layer is arranged on the first coating area. The connecting part comprises a first connecting member and a connecting body which are connected to each other, the connecting body is connected to an end surface of the current collector body in the first direction, and in the first direction, the first connecting member protrudes out of the connecting body and is connected to the first surface or the third surface. The technical solution provided by the present application can effectively improve the reliability of the battery.

Description

Pole piece, battery cell, battery, electric device and manufacturing method Cross-reference to Related Applications

[0001] This application claims priority to Chinese Patent Application No. 202410419419.4, filed on April 9, 2024, entitled “Pole piece, battery cell, battery, electric device and manufacturing method,” 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 pole piece, a battery cell, a battery, an electric device and a manufacturing method. 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 reliability of the battery is a technical problem that needs to be solved in battery technology. SUMMARY

[0005] The present application provides a pole piece, a battery cell, a battery, an electric device and a manufacturing method. The technical solution provided by the present application can effectively improve the reliability of the battery.

[0006] In a first aspect, the present application provides a pole piece, the pole piece comprising a composite current collector and a first active material layer. The composite current collector comprises a current collector body and a connecting portion connected to each other along a first direction, and the first direction is perpendicular to the thickness direction of the current collector body. Along the first direction, the connecting portion has a split surface away from the current collector body. Along the thickness direction of the composite current collector, the current collector body has a first surface and a third surface opposite to each other, and the connecting portion has a second surface. The first surface and the second surface are arranged on the same side and connected to each other, and the first surface and the second surface jointly form a first coating area. The first active material layer is arranged in the first coating area. The material of the connecting portion is a non-metallic material. The connecting portion comprises a first connecting piece and a connecting body connected to each other. The connecting body is connected to the end surface of the current collector body along the first direction. Along the first direction, the connecting body is arranged side by side with the current collector body. The first connecting piece protrudes from the connecting body and is connected to the first surface or the third surface.

[0007] In the above scheme, under the current collection and conduction of the current collector body, the first active material layer is jointly carried by the connecting portion and the current collector body. In the slitting process of the battery manufacturing process, the cutter can act on the connecting portion to form a slitting surface, without cutting the metal material current collector body, thereby fundamentally avoiding the problem of metal particles and burrs generated by slitting, effectively reducing the risk of battery internal short circuit caused by metal particles or burrs piercing the separator, and thus improving the reliability of the battery. At the same time, by providing the protruding first connecting piece, the connection between the connecting portion and the current collector body is stable, so that the first active material layer is stably arranged on the composite current collector, reducing the risk of the first active material layer separating from the composite current collector, and improving the reliability of the battery monomer, thereby improving the reliability of the battery.

[0008] According to some embodiments of the present application, the connecting portion further comprises a second connecting piece, the second connecting piece is connected with the connecting body, the first connecting piece is connected to the first surface, and the second connecting piece protrudes from the connecting body and is connected to the third surface along the first direction.

[0009] In the above scheme, by providing the protruding first connecting piece and the second connecting piece, the connection between the connecting portion and the current collector body is stable, so that the first active material layer is stably arranged on the composite current collector, reducing the risk of the first active material layer separating from the composite current collector, and improving the reliability of the battery monomer, thereby improving the reliability of the battery.

[0010] According to some embodiments of the present application, along the first direction, the first active material layer has a first side surface, and the first side surface and the slitting surface are arranged on the same side. The first side surface is coplanar with the slitting surface, or along the first direction, the slitting surface protrudes from the plane where the first side surface is located.

[0011] In some embodiments, the first side surface and the slitting surface are coplanar, which can improve the amount of the first active material layer on the composite current collector, and is beneficial to improving the volume and mass energy density of the battery. In other embodiments, the slitting surface protrudes beyond the plane where the first side surface is located, which can provide a larger support surface for the first active material layer, reduce the risk of the active material layer separating from the composite current collector, and improve the reliability of the battery monomer, thereby improving the reliability of the battery.

[0012] According to some embodiments of the present application, along the first direction, the first surface comprises a first hollow foil area and a first connecting area connected to each other, the first connecting area is closer to the second surface than the first hollow foil area, and the first connecting area and the second surface jointly form a first coating area.

[0013] In the above scheme, the first hollow foil area is provided to facilitate the output and input of current.

[0014] According to some embodiments of the present application, the pole piece further comprises a second active material layer. Along the thickness direction of the composite current collector, the current collector body has a third surface opposite to the first surface, the connecting part has a fourth surface opposite to the second surface, the third surface and the fourth surface are arranged on the same side and connected to each other, the third surface and the fourth surface jointly form a second coating area, and the second active material layer is arranged in the second coating area.

[0015] In the above scheme, by arranging the second active material layer, the two sides of the composite current collector are respectively provided with active material layers, which is beneficial to the improvement of the battery monomer capacity, so that the battery monomer has a higher volume energy density, and the battery has a higher volume energy density.

[0016] According to some embodiments of the present application, along the thickness direction of the composite current collector, the projections of the first active material layer and the second active material layer coincide with each other.

[0017] In the above scheme, by arranging the projections of the first active material layer and the second active material layer to coincide with each other, no matter which active material layer is used to obtain the reference point for judging the slitting position, the slitting position can be effectively and accurately found, thereby improving the slitting efficiency, reducing the risk of metal particles and burrs caused by the cutting knife cutting into the current collector body, and improving the reliability of the battery monomer and the battery.

[0018] According to some embodiments of the present application, along the first direction, the size of the connecting part is not less than 0.5 mm and not greater than 5 mm.

[0019] In the above scheme, by arranging the size of the connecting part in the first direction to be not less than 0.5 mm, the connecting part can provide a larger support area for the active material layer, reduce the risk of the first active material layer separating from the composite current collector, and reduce the probability of the cutting knife cutting into the current collector body, thereby improving the slitting quality and fundamentally avoiding the problem of metal particles and burrs caused by slitting, effectively reducing the risk of internal short circuit of the battery monomer caused by metal particles or burrs piercing the separator, and thereby improving the reliability of the battery. By arranging the size of the connecting part in the first direction to be not greater than 5 mm, the risk of the connecting part occupying too much space of the current collector body and reducing the conductivity of the composite current collector can be reduced. Therefore, by arranging the size of the connecting part in the first direction to be not less than 0.5 mm and not greater than 5 mm, the support effect on the active material layer, the slitting quality and the conductivity of the composite current collector can be considered.

[0020] According to some embodiments of the present application, the material of the current collector body comprises copper or aluminum.

[0021] According to some embodiments of the present application, the current collector body comprises a metal conductive layer, or the current collector body comprises a metal conductive layer and a polymer layer, and the polymer layer is arranged between the two metal conductive layers along the thickness direction of the composite current collector.

[0022] In the above solution, by arranging the polymer layer, on the one hand, the density of the current collector body can be reduced, thereby improving the mass density of the battery monomer and further improving the mass density of the battery; on the other hand, the material cost of the current collector body can be effectively reduced, thereby reducing the manufacturing cost of the battery; on the other hand, due to the arrangement of the polymer layer, the battery can effectively improve the reliability of the battery when the battery is punctured; on the other hand, when the connecting part is a hot melt material, the polymer layer and the connecting part have good connection effect, so that the current collector body and the connecting part are stably combined and are not easy to break, so that the battery has high reliability.

[0023] According to some embodiments of the present application, the material of the connecting part comprises hot melt adhesive, and the connecting part is connected with the current collector body by hot pressing.

[0024] In the above solution, by arranging the material of the connecting part to comprise hot melt adhesive, the connecting part can form a stable connection relationship with the current collector body under the action of hot pressing.

[0025] According to some embodiments of the present application, the material of the connecting part comprises at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin or acrylic acid copolymer.

[0026] Secondly, the present application also provides a battery monomer, which comprises an electrode assembly, and the electrode assembly comprises a positive electrode sheet and a negative electrode sheet, and at least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet provided in the first aspect.

[0027] Thirdly, the present application also provides a battery, which comprises the battery monomer provided in the second aspect.

[0028] Fourthly, the present application also provides a power utilization device, which comprises the battery monomer provided in the second aspect, and the battery monomer is used to provide electric energy.

[0029] Fifthly, the present application also provides a manufacturing method of an electrode sheet, which comprises the following steps:

[0030] A composite current collector is provided, at least two current collector bodies are arranged at intervals along a first direction and a gap penetrating along a second direction is formed, a connecting part is arranged in the gap, and the adjacent two current collector bodies are connected by the connecting part to form the composite current collector, the first direction is perpendicular to the thickness direction of the current collector body, and the second direction is parallel to the thickness direction of the current collector body.

[0031] Coating the active material on the surface of the current collector body and the surface of the connecting part along the thickness direction of the composite current collector to obtain a current collector tape;

[0032] Corresponding to the connecting part, cutting the current collector tape along the second direction to obtain at least two current collectors.

[0033] In the above scheme, by arranging the connecting part between the two adjacent current collector bodies to form the composite current collector, on the one hand, when the current collector tape is cut, the cutter can fall on the part where the connecting part is located, without cutting the current collector body, thereby fundamentally avoiding the problem of metal particles and burrs generated by cutting, effectively reducing the risk of metal particles or burrs piercing the separator film to cause internal short circuit of the battery cell, thereby making the battery reliable; on the other hand, the active material can be coated on the current collector body and the connecting part with low cost and density, which is supported by the current collector body and the connecting part, can reduce the material cost of the current collector, reduce the cost of the battery cell, thereby reducing the cost of the battery, and can effectively reduce the mass of the battery, so that the mass density of the battery cell is high, thereby making the mass density of the battery high.

[0034] According to some embodiments of the present application, the material of the connecting part includes hot melt adhesive. The composite current collector comprises:

[0035] The hot melt adhesive is located between the two adjacent current collector bodies and overlaps the surfaces of the two adjacent current collector bodies along the thickness direction of the composite current collector. Hot pressing the hot melt adhesive makes the hot melt adhesive melt and enter the gap to form the connecting part.

[0036] In the above scheme, by setting the material of the connecting part to include hot melt adhesive, the connecting part can be efficiently formed between the two adjacent current collector bodies through a simple hot pressing process, thereby making the manufacturing efficiency of the composite current collector high.

[0037] According to some embodiments of the present application, the composite current collector comprises:

[0038] Along the thickness direction of the composite current collector, the two opposite sides of the two adjacent current collector bodies are respectively provided with hot melt adhesive.

[0039] In the above scheme, by arranging the hot melt adhesive on the two opposite sides of the two adjacent current collector bodies, the hot melt adhesive can uniformly enter the gap between the two adjacent current collector bodies from the two opposite sides of the two adjacent current collector bodies when melting, on the one hand, making the structural relationship between the two adjacent current collector bodies and the connecting part stable, on the other hand, making the part of the connecting part formed after the hot melt adhesive melts and adheres to the surface of the current collector body uniform in thickness, thereby making the active material layer stably arranged on the surface of the current collector body and the connecting part.

[0040] According to some embodiments of the present application, a composite current collector is provided, comprising:

[0041] The hot melt adhesive has a center line parallel to the second direction, and the distance between the center lines of the two hot melt adhesives located on the two sides of the two current collector bodies opposite to each other in the first direction is not greater than 0.5 mm.

[0042] In the above scheme, by offsetting the center lines of the two hot melt adhesives located on the two sides of the current collector body by a distance not greater than 0.5 mm, the hot melt adhesive can melt and enter the gap between the two adjacent current collector bodies from both sides of the two current collector bodies opposite to each other, so that the composite current collector has high surface flatness, and the active material can be coated on the surface of the composite current collector.

[0043] According to some embodiments of the present application, the material of the connecting part includes at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin or acrylic acid acetate copolymer.

[0044] According to some embodiments of the present application, the current collector body includes a metal conductive layer, or the current collector body includes a metal conductive layer and a polymer layer, and the polymer layer is sandwiched between the two metal conductive layers in the thickness direction of the composite current collector.

[0045] In the above scheme, by providing the polymer layer, on the one hand, the density of the current collector body can be reduced, thereby improving the mass density of the battery monomer and the mass density of the battery; on the other hand, the material cost of the current collector body can be effectively reduced, thereby reducing the manufacturing cost of the battery; on the other hand, due to the provision of the polymer layer, the battery can have a circuit breaking efficiency when it is punctured, thereby effectively improving the reliability of the battery; on the other hand, when the connecting part is a hot melt material, the polymer layer has good connection effect with the connecting part, so that the current collector body and the connecting part are stably combined and are not easy to break, thereby improving the reliability of the battery.

[0046] The above description is only a summary of the technical solutions of the embodiments of the present application, in order to more clearly understand the technical means of the present application, the embodiments can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following will specifically describe the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0048] FIG1 is a schematic diagram of a vehicle in some embodiments of the present application;

[0049] FIG2 is an exploded perspective view of a battery provided in some embodiments of the present application;

[0050] FIG3 is an exploded perspective view of a battery cell provided in some embodiments of the present application;

[0051] FIG4 is a schematic diagram of a pole piece in some embodiments of the present application;

[0052] FIG5 is a schematic diagram of a composite current collector in some embodiments of the present application;

[0053] FIG6 is a schematic diagram of pole pieces in other embodiments of the present application;

[0054] FIG7 is a flowchart of a method for manufacturing a pole piece in some embodiments of the present application;

[0055] FIG8 is a schematic diagram of the manufacturing process of a composite current collector in some embodiments of the present application;

[0056] FIG9 is a schematic diagram of two current collector bodies and tapes in some embodiments of the present application;

[0057] FIG10 is a schematic diagram of the manufacturing process of composite current collectors in other embodiments of the present application;

[0058] FIG11 is a schematic diagram of two current collector bodies and two tapes in other embodiments of the present application;

[0059] FIG12 is a schematic diagram of a composite current collector in some embodiments of the present application;

[0060] FIG13 is a schematic diagram of a pole piece strip in some embodiments of the present application;

[0061] FIG14 is a schematic diagram of a pole piece strip after slitting in some embodiments of the present application;

[0062] FIG15 is a schematic diagram of a current collector body and tape in other embodiments of the present application;

[0063] FIG16 is a schematic diagram of a current collector body and tape in other embodiments of the present application;

[0064] FIG17 is a schematic diagram of a current collector body and a connecting portion in other embodiments of the present application;

[0065] FIG18 is a schematic diagram of a pole piece strip in some other embodiments of the present application;

[0066] FIG19 is a schematic diagram of the electrode strip after slitting in other embodiments of the present application.

[0067] Icon: 400 - electrode plate; 40 - composite current collector; 41 - current collector body; 410 - first surface; 4100 - first empty foil area; 4101 - first connection area; 411 - third surface; 412 - metal conductive layer; 413 - polymer layer; 42 - connection part; 420 - slitting surface; 421 - second surface; 422 - fourth surface; 423 - first connecting piece; 424 - connecting body; 425 - second connecting piece; 43 - first coating area; 50 - first active material layer; 51 - first side surface; 60 - second active material layer; 70 - adhesive tape; 71 - hot roller; 72 - running roller; 80 - electrode plate tape; y - thickness direction of the composite current collector; x - first direction; z - third direction; 10 - battery cell; 11 - electrode assembly; 111 - tab; 12 - case; 120 - case body; 121 - end cover; 13 - electrode terminal; 14 - adapter; 100 - battery; 30 - box body; 31 - upper box body; 32 - lower box body; 1000 - vehicle; 200 - controller; 300 - motor. DETAILED DESCRIPTION

[0068] 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 below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0069] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by one of ordinary skill in the art to which this application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0070] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0071] In the description of the application, it should be explained that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" 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 application can be understood according to the specific circumstances.

[0072] The term "and / or" in the present application is only to describe the association relationship of 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 that the front and rear associated objects have an "or" relationship.

[0073] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, and the overall thickness, length, width and other dimensions of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0074] "Multiple" appearing in the present application means two or more (including two).

[0075] In the present application, the battery cell can include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium-sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, etc. The present application embodiments are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The present application embodiments are also not limited thereto.

[0076] The battery referred to in the embodiments of the present application means a single physical module including one or more battery cells to provide higher voltage and capacity. The battery generally includes a box for packaging one or more battery cells. The box can avoid the influence of liquid or other foreign matters on the charging or discharging of the battery cell.

[0077] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode tab and the negative electrode tab to work. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer serves as a positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer serves as a negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a winding type structure or a stacking type structure, and the embodiments of the present application are not limited thereto.

[0078] The development of battery technology needs to consider various design factors, such as battery life, energy density, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the reliability of the battery also needs to be considered. In the manufacturing process of the battery, the size of the battery cell is produced according to the needs, and the electrode tab material belt is slitting to obtain multiple electrode tabs with sizes meeting the needs. However, the current collector is generally made of metal material, such as aluminum or copper. The burrs and metal particles generated by the metal current collector during the electrode tab slitting process may pierce the separator, causing the positive and negative electrodes of the battery cell to be short-circuited, resulting in high voltage breakdown and even thermal runaway risk, affecting the reliability of the battery.

[0079] In view of this, in order to improve the problem of low battery reliability caused by burrs generated during the slitting of the electrode tab, some embodiments of the present application provide an electrode tab, which includes a composite current collector and a first active material layer. The composite current collector includes a current collector body and a connecting portion connected to each other along a first direction, the first direction being perpendicular to the thickness direction of the current collector body. Along the first direction, the connecting portion has a slitting surface away from the current collector body. Along the thickness direction of the composite current collector, the current collector body has a first surface, and the connecting portion has a second surface. The first surface and the second surface are disposed on the same side and connected to each other, and the first surface and the second surface together form a first coating area. The first active material layer is arranged in the first coating area.

[0080] In the above scheme, under the current collection and conduction effect of the current collector body, the first active material layer is jointly borne by the connecting portion and the current collector body, in the slitting process of the battery manufacturing process, the cutter can act on the connecting portion to form a slitting surface, and the current collector body of the metal material is not cut, so that the problem of metal particles and burrs generated by slitting can be fundamentally avoided, thereby effectively reducing the risk of internal short circuit of the battery cell caused by metal particles or burrs piercing the isolation film, and further improving the reliability of the battery.

[0081] The technical solutions described in the embodiments of the present application are suitable for battery cells, batteries and electric devices using batteries.

[0082] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, for example, a game machine, an electric car toy, an electric ship toy and an electric plane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer, etc. The embodiments of the present application do not specially limit the above electric devices.

[0083] The following embodiments are described for convenience of illustration, taking the electric device as a vehicle as an example.

[0084] Please refer to FIG. 1, which is a schematic diagram of a vehicle 1000 in some embodiments of the present application. The vehicle 1000 can be a fuel car, a gas car or a new energy car, and the new energy car can be a pure electric car, a hybrid car or a range extended car, etc. The vehicle 1000 is internally provided with a battery 100, which can be arranged at the bottom, head or 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 the 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, for the working power demand of the vehicle 1000 during starting, navigation and driving.

[0085] In some embodiments of the present application, the battery 100 can not only be used as the operating power supply of the vehicle 1000, but also be used as the driving power supply of the vehicle 1000, instead of or partially instead of fuel or natural gas to provide driving power for the vehicle 1000.

[0086] Please refer to FIG. 2, which is a perspective exploded view of the battery 100 according to some embodiments of the present application. The battery 100 includes a box 30 and a battery cell 10, which is accommodated in the box 30. The box 30 is configured to provide a space for accommodating the battery cell 10, and can have various structures. In some embodiments, the box 30 can include an upper box 31 and a lower box 32, which are coupled to each other to define a space for accommodating the battery cell 10. The lower box 32 can be a hollow structure with one open end, and the upper box 31 can be a plate structure, which is coupled to the open end of the lower box 32 to define the space for accommodating the battery cell 10 together with the lower box 32. Alternatively, the upper box 31 and the lower box 32 can both be hollow structures with one open end, and the open end of the upper box 31 is coupled to the open end of the lower box 32. Of course, the box 30 formed by the upper box 31 and the lower box 32 can have various shapes, such as a cylinder, a cuboid, etc.

[0087] In the battery 100, the battery cell 10 can be a plurality of battery cells 10, which can be connected in series, in parallel, or in a mixed manner. The mixed manner means that the plurality of battery cells 10 are connected in series and in parallel. The plurality of battery cells 10 can be directly connected in series, in parallel, or in a mixed manner, and then accommodated in the box 30. Alternatively, the plurality of battery cells 10 can be first connected in series, in parallel, or in a mixed manner to form a battery module, and then a plurality of battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box 30. The battery 100 can further include other structures, for example, the battery 100 can further include a busbar component for electrically connecting the plurality of battery cells 10.

[0088] Each battery cell 10 can be a secondary battery cell or a primary battery cell, and can be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited thereto. The battery cell 10 can have a cylindrical shape, a flat shape, a cuboid shape, or other shapes.

[0089] Please refer to FIG. 3, which is a perspective exploded view of the battery cell 10 according to some embodiments of the present application. The battery cell 10 includes an electrode assembly 11 and a case 12. The case 12 includes a case body 120 and a terminal cap 121. The case body 120 has an opening, and the electrode assembly 11 is disposed in the case body 120. The terminal cap 121 is coupled to the case body 120 to close the opening, so that the electrode assembly 11 is located in a closed space. In some embodiments, the terminal cap 121 can be provided with a liquid injection hole, through which electrolyte can be injected into the case. In some embodiments, the terminal cap 121 can be riveted, welded, adhered, or threadedly coupled to the case body 120.

[0090] In some embodiments, the shell 12 is determined according to the shape of the one or more electrode assemblies 11 combined (i.e. in some embodiments of the present application, the number of electrode assemblies in a battery cell can be one or more), for example, the shell 12 can be a hollow cuboid or a hollow cube or a hollow cylinder. In some embodiments of the present application, the shell 12 can be made of a metal material, for example, aluminum or aluminum alloy, etc. The shell 12 can also be made of plastic. In some embodiments, the shell 12 is provided with electrode terminals 13, which are connected with the tabs 111 of the electrode assemblies 11 to realize the output and input of electric energy. In some embodiments of the present application, the positions of the electrode terminals 13 are not limited, for example, the electrode terminals 13 with opposite polarities are arranged on the same wall of the shell to connect the tabs 111 with the respective corresponding polarities, for example, the electrode terminals 13 with opposite polarities are arranged on the end cover 121; for another example, the electrode terminals 13 with opposite polarities are arranged on different walls of the shell to connect the tabs 111 with the respective corresponding polarities, for example, the electrode terminals 13 with one polarity are arranged on the end cover 121, and the electrode terminals 13 with the other polarity are arranged on the bottom wall of the shell 120. In some embodiments, the electrode terminals 13 are connected with the tabs 111 through adapters 14.

[0091] The electrode assembly 11 is composed of a pole piece and a separator film, the pole piece including a positive pole piece and a negative pole piece with opposite polarities, and the separator film being arranged between the positive pole piece and the negative pole piece. Exemplarily, the positive pole piece includes a positive current collector and a positive active material layer, the positive active material layer being coated on the surface of the positive current collector, the positive current collector without the positive active material layer being protruded from the positive current collector with the positive active material layer, the positive current collector without the positive active material layer serving as a positive tab, and the positive pole piece being connected with a corresponding electrode terminal. In some embodiments, the material of the positive current collector can include aluminum or other metals. The negative pole piece includes a negative current collector and a negative active material layer, the negative active material layer being coated on the surface of the negative current collector, the negative current collector without the negative active material layer being protruded from the negative current collector with the negative active material layer, the negative current collector without the negative active material layer serving as a negative tab, and the negative tab being connected with a corresponding electrode terminal. In some embodiments, the material of the negative current collector can include copper or other metals.

[0092] In some embodiments of the present application, a pole piece is provided, which can be a positive pole piece or a negative pole piece. Please refer to FIG. 4, which is a schematic view of a pole piece in some embodiments of the present application.

[0093] The pole piece 400 includes a composite current collector 40 and a first active material layer 50. The composite current collector 40 includes a current collector body 41 and a connecting portion 42 connected to each other along a first direction x perpendicular to a thickness direction of the current collector body 41. Along the first direction x, the connecting portion 42 has a split surface 420 facing away from the current collector body 41, along a thickness direction y of the composite current collector, the current collector body 41 has a first surface 410, the connecting portion 42 has a second surface 421, the first surface 410 and the second surface 421 are disposed on the same side and connected to each other, and the first surface 410 and the second surface 421 together form a first coating area 43. The first active material layer 50 is disposed on the first coating area 43.

[0094] The composite current collector 40 includes the current collector body 41 and the connecting portion 42. In some embodiments, the current collector body 41 is a main component of the composite current collector 40, and the current collector body 41 functions to achieve current collection and conduction and to support the first active material layer 50. In some embodiments, the current collector body 41 can be a metal foil. For example, when the pole piece 400 is a positive pole piece, the current collector body 41 can be made of aluminum or other metal materials, and when the pole piece 400 is a negative pole piece, the current collector body 41 can be made of copper or other metal materials. In other embodiments, the current collector body 41 can have a multi-layer structure. For example, when the pole piece 400 is a positive pole piece, the current collector body 41 includes a multi-layer structure of aluminum, a polymer layer 413, and aluminum. When the pole piece 400 is a negative pole piece, the current collector body 41 includes a multi-layer structure of copper, a polymer layer 413, and copper.

[0095] In some embodiments, the connecting portion 42 is a non-metal material, and the connecting portion 42 is connected to the current collector body 41. The connecting portion 42 functions to support the first active material layer 50 together with the current collector body 41. In some embodiments, the surfaces on the same side of the current collector body 41 and the connecting portion 42 along the thickness direction y of the composite current collector support the active material layer together. For example, the active material layer is disposed on one side of the composite current collector 40, and for another example, the active material layer is disposed on both sides of the composite current collector 40.

[0096] Exemplarily, along the thickness direction y of the composite current collector, the current collector body 41 has a first surface 410, the connecting part 42 has a second surface 421, the first surface 410 and the second surface 421 are disposed on the same side and connected to each other, the first surface 410 and the second surface 421 together form the first coating area 43, along the thickness direction y of the composite current collector, the current collector body 41 has a third surface 411, the third surface 411 and the first surface 410 are opposite to each other, the connecting part 42 has a fourth surface 422, the fourth surface 422 and the second surface 421 are opposite to each other, the third surface 411 and the fourth surface 422 are disposed on the same side and connected to each other, the third surface 411 and the fourth surface 422 together form the second coating area, the active material is coated on the first coating area 43 and dried to form the first active material layer 50, and the active material is coated on the second coating area and dried to form the second active material layer 60.

[0097] In some embodiments, the connecting part 42 can have a certain electrical conductivity, so that the connecting part 42 has the functions of converging and conducting current.

[0098] In some embodiments, the connecting part 42 is connected to the current collector body 41 by adhesion, hot melting, clamping or the like.

[0099] The "along the first direction x, the connecting part 42 has a split surface 420 away from the current collector body 41" can be understood as, when the split current collector strip 80 is split, the split position falls on the connecting part 42, so that the side surface of the connecting part 42 away from the current collector body 41 is the split surface 420. The split surface 420 can be a surface generated by splitting in the splitting process, for example, the composite current collector strip includes two current collector bodies 41 and a connecting part 42 connecting the two current collector bodies 41, the splitting knife directly falls on the connecting part 42, which is divided into two, forming two connecting parts 42, one of which is connected to one of the current collector bodies 41 to form one composite current collector 40, and the connecting part 42 of the composite current collector 40 is away from the current collector body. The surface is the split surface 420, and the other connecting part 42 is connected to the other current collector to form another composite current collector 40, and the connecting part 42 of the composite current collector 40 is away from the current collector body. The surface is the split surface 420.

[0100] In some embodiments, the connecting portion 42 can be connected to the current collector body 41 by means of hot melting, for example, when manufacturing the composite current collector 40, at least two current collector bodies 41 are arranged side by side and spaced apart, the connecting portion 42 capable of hot melting is arranged between the two adjacent current collector bodies 41 to connect the two adjacent current collector bodies 41, the current collector body 41 and the connecting portion 42 are run by the action of the running roller 72 (see FIG. 8), and the two adjacent current collector bodies 41 are connected by the hot pressing of the hot roller 71 (see FIG. 8) to form a composite current collector tape.

[0101] Subsequently, the composite current collector tape enters the coating process to coat the active material, and forms an active material layer on the surface of the composite current collector 40 to form a pole piece tape 80, and then the pole piece tape 80 enters the slitting station, and the slitting cutter head is slitted along the connecting portion 42 between the two adjacent current collector bodies 41 to form at least two pole pieces 400.

[0102] In some embodiments, the material of the connecting portion 42 can include at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin, or acrylic acid acetate copolymer.

[0103] In some embodiments, the material of the connecting portion 42 can include a polymer with electrical conductivity, such as polyaniline, polycarbazole, etc.

[0104] In some embodiments, the second surface 421 of the connecting portion 42 can be a concave-convex surface, which is arranged to increase the area of the first active material layer 50 carried, thereby effectively improving the connection stability between the connecting portion 42 and the first active material layer 50.

[0105] In the above scheme, under the current collection and conduction effect of the current collector body 41, the connecting portion 42 and the current collector body 41 are arranged to jointly carry the first active material layer 50, in the slitting process of the battery manufacturing process, the cutter can act on the connecting portion 42 to form a slitting surface 420, and the metal material current collector body 41 is not cut, so as to fundamentally avoid the problem of metal particles and burrs generated by slitting, thereby effectively reducing the risk of internal short circuit of the battery cell caused by metal particles or burrs piercing the isolation film, and thereby improving the reliability of the battery.

[0106] In some embodiments, the connection portion 42 can be made of a low-cost material, such as a polymer, which can include at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin, or acrylic acid acetate copolymer, thereby reducing the material cost of the pole piece 400, the cost of the battery cell, and the cost of the battery. In some embodiments, the connection portion 42 can be made of a low-density material, such as a polymer, which can include at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin, or acrylic acid acetate copolymer, thereby effectively reducing the mass of the battery, so that the mass density of the battery cell is high, and the mass density of the battery is high.

[0107] According to some embodiments of the present application, along the thickness direction y of the composite current collector, the current collector body 41 has a third surface 411 opposite the first surface 410, and the connection portion 42 includes a first connecting piece 423 (see FIG. 5) and a connecting body 424 (see FIG. 5) connected to each other, the connecting body 424 is connected to the end surface of the current collector body 41 along the first direction x, and along the first direction x, the connecting body 424 is arranged side by side with the current collector body 41, and the first connecting piece 423 protrudes from the connecting body 424 and is connected to the first surface 410 or the third surface 411.

[0108] Along the thickness direction y of the composite current collector, the current collector body 41 has a first surface 410 and a third surface 411 opposite each other, and along the thickness direction y of the composite current collector, the connection portion 42 includes a first connecting piece 423 and a connecting body 424 connected to each other. The first connection portion 42 is arranged corresponding to the first surface 410, and the first connecting piece 423 is connected to the first surface 410. Alternatively, the first connection portion 42 is arranged corresponding to the third surface 411, and the first connecting piece 423 is connected to the third surface 411.

[0109] The connecting body 424 is located on the side of the current collector body 41 along the first direction x, and the connecting body 424 is connected to the end surface of the current collector body 41 along the first direction x.

[0110] In some embodiments, along the thickness direction y of the composite current collector, the first connecting piece 423 and the orthographic projection portion of the current collector body 41 overlap.

[0111] Exemplarily, when manufacturing the composite current collector 40, at least two current collector bodies 41 are arranged side by side and spaced apart, the heat-meltable connecting portion 42 is arranged between the two adjacent current collector bodies 41, and the number of the connecting portion 42 can be one, and one connecting portion 42 can be located on one side of the current collector body 41 and lap the first surface 410 or the third surface 411 of the current collector body 41. The current collector body 41 and the connecting portion 42 are conveyed by the action of the conveying roller 72, and the connecting portion 42 located on the first surface 410 or the third surface 411 is heat-melted by the hot pressing of the hot roller 71 to connect the two adjacent current collector bodies 41, and the part of the connecting portion 42 which changes in shape due to heat-melting fills the gap between the two current collector bodies 41 and the part laps the surface of the current collector body 41. In the subsequent slitting process, the part of the connecting portion 42 located in the gap is slitted into the connecting body 424, and the part lapping the surface of the current collector body 41 is slitted into the first connecting piece 423.

[0112] In some embodiments, the hot roller 71 can correspond to one conveying roller 72, and the current collector body 41 and the connecting portion 42 can be rolled on the conveying roller 72 by the hot roller 71.

[0113] According to some embodiments of the present application, please refer to FIG. 5, which is a schematic view of the composite current collector 40 in some embodiments of the present application.

[0114] The connecting portion 42 further comprises a second connecting piece 425 connected with the connecting body 424.

[0115] In the first direction x, the first connecting piece 423 protrudes from the connecting body 424 and is connected to the first surface 410, and the second connecting piece 425 protrudes from the connecting body 424 and is connected to the third surface 411.

[0116] In the thickness direction y of the composite current collector, the current collector body 41 has the first surface 410 and the third surface 411 opposite to each other; in the thickness direction y of the composite current collector, the connecting portion 42 comprises the first connecting piece 423, the connecting body 424 and the second connecting piece 425 connected with each other, the first connecting portion 42 is arranged corresponding to the first surface 410, the first connecting piece 423 is connected to the first surface 410, the second connecting piece 425 is arranged corresponding to the third surface 411, the second connecting piece 425 is connected to the third surface 411, the connecting body 424 is located on the side of the current collector body 41 in the first direction x, and the connecting body 424 is connected with the end surface of the current collector body 41 in the first direction x.

[0117] In some embodiments, in the thickness direction y of the composite current collector, the first connecting piece 423, the second connecting piece 425 and the orthographic projection part of the current collector body 41 overlap.

[0118] Exemplarily, when manufacturing the composite current collector 40, the at least two current collector bodies 41 are arranged side by side and spaced apart, the heat-fusible connecting portions 42 are arranged between the adjacent two current collector bodies 41, and the number of the connecting portions 42 is two, the two connecting portions 42 are respectively located on the two sides of the current collector body 41 and respectively overlap the surface of the current collector body 41; the current collector body 41 and the connecting portion 42 are conveyed by the action of the conveying roller 72, and the two connecting portions 42 on the two sides are heat-fused to connect the adjacent two current collector bodies 41 by the hot pressing of the heat roller 71, and the portions of the two connecting portions 42 that change in form due to heat-fusion fill the gap between the two current collector bodies 41 and overlap the surface of the current collector body 41. In the subsequent slitting process, the portion of the connecting portion 42 in the gap is slit into the connecting body 424, and the portion overlapping the surface of the current collector body 41 is slit into the first connecting piece 423 and the second connecting piece 425.

[0119] In some embodiments, the heat roller 71 can correspond to one conveying roller 72, and the current collector body 41 and the connecting portion 42 can be rolled by the heat roller 71 on the conveying roller 72.

[0120] In the above scheme, by arranging the protruding first connecting piece 423 and the second connecting piece 425, the connection relationship between the connecting portion 42 and the current collector body 41 can be stable, so that the first active material layer 50 is stably arranged on the composite current collector 40, the risk of the first active material layer 50 being separated from the composite current collector 40 is reduced, the reliability of the battery cell is high, and the reliability of the battery is high.

[0121] In some embodiments, the connecting portion 42 comprises the first connecting piece 423 and the connecting body 424 connected to each other, and the first connecting piece 423 is connected to the first surface 410. In other embodiments, the connecting portion 42 comprises the second connecting piece 425 and the connecting body 424 connected to each other, and the second connecting piece 425 is connected to the third surface 411. In other embodiments, the connecting portion 42 comprises the connecting body 424.

[0122] According to some embodiments of the present application, along the first direction x, the first active material layer 50 has a first side surface 51, and the first side surface 51 and the slitting surface 420 are arranged on the same side. The first side surface 51 is coplanar with the slitting surface 420, or along the first direction x, the slitting surface 420 protrudes from the plane where the first side surface 51 is located.

[0123] The first side surface 51 is a side surface of the first active material layer 50 in the first direction x, and the first side surface 51 is arranged on the same side as the cutting surface 420. In some embodiments, referring to FIG4 , the first side surface 51 and the cutting surface 420 are coplanar. When the first side surface 51 and the cutting surface 420 are coplanar, it can be understood that when the electrode strip 80 is cut, the cutting head cuts the electrode strip 80 along the thickness direction y of the composite current collector, and the cutting portion corresponds to the connecting portion 42. During the cutting, the first active material layer 50 and the connecting portion 42 are acted upon to simultaneously form the first side surface 51 and the cutting surface 420. In other embodiments, along the first direction x, the cutting surface 420 protrudes from the plane where the first side surface 51 is located, that is, the first active material layer 50 does not completely cover the surface of the connecting portion 42, and there is an area where the first active material layer 50 is not provided, that is, during the cutting, the active material layer is not acted upon.

[0124] In the above scheme, in some embodiments, the first side surface 51 and the cutting surface 420 are arranged coplanarly, which can increase the amount of the first active material layer 50 on the composite current collector 40, thereby improving the battery volume and mass energy density. In other embodiments, the cutting surface 420 extends beyond the plane of the first side surface 51, which can enable the connection portion 42 to provide a larger support surface for the first active material layer 50, reducing the risk of the active material layer detaching from the composite current collector 40, thereby improving the reliability of the battery cell and the battery reliability.

[0125] According to some embodiments of the present application, referring to FIG. 4 , along a first direction x, a first surface 410 includes a first empty foil area 4100 and a first connection area 4101 connected to each other. The first connection area 4101 is closer to the second surface 421 relative to the first empty foil area 4100. The first connection area 4101 and the second surface 421 together form a first coating area 43.

[0126] The first empty foil area 4100 is the area of ​​the first surface 410 not coated with active material, and the first connection area 4101 is the area of ​​the first surface 410 coated with active material. Along the first direction x, the first empty foil is located in the area of ​​the first connection area 4101 away from the second surface 421.

[0127] In some embodiments, the first empty foil area 4100 can be die-cut to form the tabs through a die-cutting process, or the first empty foil area 4100 can be connected to the tabs through welding, riveting, or the like.

[0128] In the above solution, the first empty foil area 4100 is provided to facilitate the output and input of current.

[0129] According to some embodiments of the present application, referring to FIG. 4, the pole piece 400 further comprises a second active material layer 60. Along the thickness direction y of the composite current collector, the current collector body 41 has a third surface 411 opposite to the first surface 410, the connecting portion 42 has a fourth surface 422 opposite to the second surface 421, the third surface 411 and the fourth surface 422 are located on the same side and connected to each other, and the third surface 411 and the fourth surface 422 jointly form a second coating area, and the second active material layer 60 is arranged in the second coating area.

[0130] The second active material layer 60 is an active structure arranged on the surface of the composite current collector 40. In some embodiments, along the thickness direction y of the composite current collector, the second active material layer 60 is arranged opposite to the first active material layer 50, and the two are respectively located on the opposite sides of the composite current collector 40.

[0131] Part of the second active material layer 60 is carried by the third surface 411 of the current collector body 41, and another part of the second active material layer 60 is carried by the fourth surface 422 of the connecting portion 42.

[0132] In some embodiments, the fourth surface 422 of the connecting portion 42 can be a concave-convex surface. By arranging the concave-convex surface, the area carrying the second active material layer 60 is increased, thereby effectively improving the connection stability between the connecting portion 42 and the second active material layer 60.

[0133] In the above scheme, by arranging the second active material layer 60, the two sides of the composite current collector 40 are respectively provided with an active material layer, which is beneficial to the improvement of the battery monomer capacity, so that the battery monomer has a higher volumetric energy density, and the battery has a higher volumetric energy density.

[0134] According to some embodiments of the present application, along the thickness direction y of the composite current collector, the projections of the first active material layer 50 and the second active material layer 60 coincide with each other.

[0135] In some embodiments, taking the end of the current collector body 41 away from the connecting portion 42 as the empty foil end, the distance between the first active material layer 50 and the empty foil end can be equal to the distance between the second active material layer 60 and the empty foil end.

[0136] In some embodiments, in the pole piece material strip 80, the active material can cover the connecting portion 42 between the two current collector bodies 41, and the first active material layer 50 and the second active material layer 60 on the surface can be used to judge the slitting position when slitting, so that the area of the slitting action is the area where the connecting portion 42 is located.

[0137] In the above scheme, by setting the projections of the first active material layer 50 and the second active material layer 60 to coincide with each other, on the one hand, no matter whether the first active material layer 50 or the second active material layer 60 is used to obtain the reference point for determining the slitting position, the slitting position can be effectively and accurately found in the process of slitting the pole piece 400, thereby improving the slitting efficiency, reducing the risk of the cutting knife cutting into the current collector body 41 to generate metal particles and burrs, and improving the reliability of the battery cell and the battery.

[0138] According to some embodiments of the present application, please refer to FIG. 4, along the first direction x, the size of the connecting part 42 is not less than 0.5 mm and not greater than 5 mm.

[0139] In FIG. 4, the size of the connecting part 42 in the first direction x is marked as A, which can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, …, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, or any value between any two adjacent values.

[0140] In the above scheme, by setting the size of the connecting part 42 in the first direction x to be not less than 0.5 mm, the connecting part 42 can provide a larger support area for the active material layer, reduce the risk of the first active material layer 50 separating from the composite current collector 40, and reduce the probability of the cutting knife cutting into the current collector body 41, thereby improving the slitting quality, fundamentally avoiding the problem of metal particles and burrs generated by slitting, effectively reducing the risk of metal particles or burrs piercing the isolation film to cause internal short circuit of the battery cell, and thereby improving the reliability of the battery; by setting the size of the connecting part 42 in the first direction x to be not greater than 5 mm, the risk of the connecting part 42 occupying too much space of the current collector body 41, thereby reducing the conductivity of the composite current collector 40, can be reduced; therefore, by setting the size of the connecting part 42 in the first direction x to be not less than 0.5 mm and not greater than 5 mm, the support effect on the active material layer, the slitting quality, and the conductivity of the composite current collector 40 can be considered.

[0141] According to some embodiments of the present application, the material of the current collector body 41 includes copper or aluminum.

[0142] In some embodiments, the current collector body 41 can be a copper foil or an aluminum foil. In other embodiments, the current collector body 41 can be other metal foil or a multi-layer structure of metal foil plus polymer layer 413.

[0143] According to some other embodiments of the present application, please refer to FIG. 6, which is a schematic diagram of the pole piece 400 in some other embodiments of the present application.

[0144] The current collector body 41 comprises a metal conductive layer 412, or the current collector body 41 comprises a metal conductive layer 412 and a polymer layer 413, and the polymer layer 413 is sandwiched between two metal conductive layers 412 along the thickness direction y of the composite current collector.

[0145] In some embodiments, the current collector body 41 of the pole piece 400 can be a multi-layer structure, for example, a multi-layer structure of a metal conductive layer 412, a polymer layer 413 and a metal conductive layer 412. The metal conductive layer 412 can be a metal foil, for example, an aluminum foil or a copper foil. In some embodiments, part of the connecting part 42 can be connected with the polymer layer 413, and the remaining part can be connected with the metal conductive layer 412. The active material can be coated on the connecting part 42 and the metal conductive layer 412, for example, the first active material layer 50 can be coated on the surface of the connecting part 42 and the surface of the metal conductive layer 412, and the second active material layer 60 can be coated on the surface of the connecting part 42 and the surface of the other metal conductive layer 412.

[0146] In the above scheme, by setting the polymer layer 413, on the one hand, the density of the current collector body 41 can be reduced, thereby improving the mass density of the battery monomer and further improving the mass density of the battery; on the other hand, the material cost of the current collector body 41 can be effectively reduced, thereby reducing the manufacturing cost of the battery; on the other hand, due to the setting of the polymer layer 413, the battery can effectively improve the reliability when the battery is punctured; on the other hand, when the connecting part 42 is a hot melt material, the polymer layer 413 and the connecting part 42 have good connection effect, so that the current collector body 41 and the connecting part 42 are stably combined and are not easy to break, so that the battery has high reliability.

[0147] According to some embodiments of the present application, the material of the connecting part 42 comprises hot melt adhesive, and the connecting part 42 is connected with the current collector body 41 by hot pressing.

[0148] In some embodiments, when the composite current collector 40 is manufactured, the raw material forming the connecting part 42 can be hot melt adhesive, and the hot melt adhesive in the form of adhesive tape 70 is arranged between two current collector bodies 41, and the adhesive tape 70 is melted by hot pressing, so as to connect the two current collector bodies 41.

[0149] In the above scheme, by setting the material of the connecting part 42 to comprise hot melt adhesive, the connecting part 42 can form a stable connection relationship with the current collector body 41 under the action of hot pressing.

[0150] In other embodiments, the material of the connecting part 42 can comprise a polymer plus an adhesive layer, the polymer is the body of the connecting part 42, and the polymer is adhered to the current collector body 41 through the adhesive layer.

[0151] According to some embodiments of the present application, the material of the connecting portion 42 comprises at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin, or acrylic acid acetate copolymer.

[0152] Some embodiments of the present application also provide a battery cell, as shown in FIG. 3, the battery cell 10 comprises an electrode assembly 11, the electrode assembly 11 comprises a positive electrode sheet and a negative electrode sheet, at least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet 400 provided above.

[0153] In some embodiments, the positive electrode sheet and the negative electrode sheet can be the electrode sheet 400 provided above, that is, when the positive electrode sheet material belt is slit, the slitting position is the connecting portion 42, not the positive current collector body of metal material, and when the negative electrode sheet material belt is slit, the slitting position is the connecting portion 42, not the negative current collector body of metal material.

[0154] In some embodiments, the positive electrode sheet can be the electrode sheet 400 provided above. In other embodiments, the negative electrode sheet can be the electrode sheet 400 provided above.

[0155] The battery cell 10 further comprises a shell 12. The shell 12 comprises a shell body 120 and an end cover 121, the shell body 120 has an opening, the electrode assembly 11 is arranged in the interior of the shell body, and the end cover 121 is connected with the shell body 120 to close the opening, so that the electrode assembly 11 is located in a closed space. In some embodiments, the end cover 121 can be provided with a liquid injection hole, and electrolyte can be injected into the shell through the liquid injection hole. In some embodiments, the end cover can be riveted, welded, bonded, or threadedly connected to the shell.

[0156] In the above scheme, the electrode sheet 400 in the battery cell 10, by setting the connecting portion 42 to jointly bear the active material layer with the current collector body 41, on the one hand, in the slitting process of the battery manufacturing process, the cutter can act on the connecting portion 42 to form the slitting surface 420, without cutting the current collector body 41 of metal material, so as to fundamentally avoid the problem of metal particles and burrs generated by slitting, thereby effectively reducing the risk of internal short circuit of the battery cell caused by metal particles or burrs piercing the separator, and thus making the battery reliable. On the other hand, the connecting portion 42 with lower cost can be used to reduce the material cost of the electrode sheet 400, thereby reducing the cost of the battery cell and the cost of the battery. In addition, the connecting portion 42 with smaller density can effectively reduce the mass of the battery, so as to make the mass density of the battery cell high, and thus make the mass density of the battery high.

[0157] Some embodiments of the present application also provide a battery, as shown in FIG. 2, the battery comprises the battery cell provided above.

[0158] The battery 100 comprises a box 30 and battery cells 10 accommodated in the box 30. The box 30 is configured to provide an accommodation space for the battery cells 10, and the box 30 can have various structures. In some embodiments, the box 30 can comprise an upper box 31 and a lower box 32, the upper box 31 and the lower box 32 are overlapped with each other, and the upper box 31 and the lower box 32 jointly define an accommodation space for accommodating the battery cells 10. The lower box 32 can be a hollow structure with one end open, and the upper box 31 can be a plate structure, the upper box 31 is overlapped with the open side of the lower box 32 to jointly define the accommodation space with the lower box 32; or the upper box 31 and the lower box 32 can both be hollow structures with one side open, and the open side of the upper box 31 is overlapped with the open side of the lower box 32. Of course, the box 30 formed by the upper box 31 and the lower box 32 can have various shapes, such as a cylinder, a cuboid, etc.

[0159] In the battery 100, the battery cells 10 can be multiple, and the multiple battery cells 10 can be connected in series, in parallel or in a mixed manner. The mixed manner means that the multiple battery cells 10 are connected in series and in parallel. The multiple battery cells 10 can be directly connected in series, in parallel or in a mixed manner, and then the multiple battery cells 10 are accommodated in the box 30 as a whole; of course, the battery 100 can also be that the multiple battery cells 10 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 and are accommodated in the box 30. The battery 100 can further comprise other structures, for example, the battery 100 can further comprise a current combing component for realizing the electrical connection between the multiple battery cells 10.

[0160] According to some embodiments of the present application, a power consuming device is also provided, the power consuming device comprises the battery cell provided above, and the battery cell is configured to provide electric energy.

[0161] In some embodiments, the power consuming device can be a vehicle, which 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, etc. The vehicle is internally provided with the battery cell, which can be arranged at the bottom, the head or the tail of the vehicle. The battery cell can be used for power supply of the vehicle.

[0162] According to some embodiments of the present application, a manufacturing method of the pole piece 400 is also provided, please refer to FIG. 7, which is a flow chart of the manufacturing method of the pole piece according to some embodiments of the present application.

[0163] The manufacturing method of the pole piece comprises the following steps:

[0164] S1, providing a composite current collector 40, at least two current collector bodies 41 are arranged in a first direction x with a gap formed in a second direction, a connecting part 42 is arranged in the gap, the two current collector bodies 41 are connected by the connecting part 42 to form the composite current collector 40, the first direction x is perpendicular to the thickness direction of the current collector body 41, and the second direction is parallel to the thickness direction of the current collector body 41;

[0165] S2, coating an active material on the surface of the current collector body 41 and the surface of the connecting part 42 in the thickness direction y of the composite current collector to obtain a pole piece tape 80;

[0166] S3, cutting the pole piece tape 80 in the second direction corresponding to the connecting part 42 to obtain at least two pole pieces 400.

[0167] The second direction can be parallel to the thickness direction y of the composite current collector. In step S1, the current collector body 41 and the connecting part 42 are provided. The connecting part 42 can be a hot melt adhesive, which is in the form of an adhesive tape, hereinafter referred to as adhesive tape 70. The current collector body 41 and the adhesive tape 70 are in the form of a tape. The two current collector bodies 41 are arranged side by side by the tape running roller 72, and the tape running direction can be the third direction z, and the third direction z, the second direction and the first direction x are perpendicular to each other. The two current collector bodies 41 are arranged in the first direction x with a gap formed in the second direction. In some embodiments, please refer to FIG. 8 and FIG. 9, FIG. 8 is a schematic diagram of the manufacturing process of the composite current collector 40 in some embodiments of the present application, and FIG. 9 is a schematic diagram of two current collector bodies 41 and adhesive tapes 70 in some embodiments of the present application. The adhesive tape 70 is arranged on the side (for example, the upper side) of the current collector body 41, the adhesive tape 70 is running, and is arranged on the surface of the two current collector bodies 41 and closes the gap. In another embodiment, please refer to FIG. 10 and FIG. 11, FIG. 10 is a schematic diagram of the manufacturing process of the composite current collector 40 in another embodiment of the present application, and FIG. 11 is a schematic diagram of two current collector bodies 41 and two adhesive tapes 70 in another embodiment of the present application. The adhesive tapes 70 are arranged on the opposite sides of the current collector body 41, for example, the upper side and the lower side of the current collector body 41, respectively, the two adhesive tapes 70 are running, and are arranged on the opposite surfaces of the two current collector bodies 41 and jointly close the gap.

[0168] Please refer to FIG. 12, FIG. 12 is a schematic diagram of the composite current collector 40 in some embodiments of the present application. The hot pressing of the hot roller 71 makes the adhesive tape 70 hot melt in the gap and connects the two current collector bodies 41, and the adhesive tape 70 forms the connecting part 42 after cooling, thereby forming a composite current collector tape, and then entering the coating process, that is, performing step S2.

[0169] In step S2, please refer to FIG. 13, which is a schematic diagram of the electrode tab material strip 80 in some embodiments of the present application. The active material is coated on the surface of the current collector body 41 and the surface of the connecting part 42 to form an active material layer, and the electrode tab material strip 80 is obtained. In step S2, the active material layer can be coated on both sides of the current collector body 41 and the connecting part 42, respectively, to obtain the first active material layer 50 and the second active material layer 60, respectively.

[0170] In step S3, please refer to FIG. 14, which is a schematic diagram of the electrode tab material strip 80 after being cut in some embodiments of the present application. The electrode tab material strip 80 obtained in step S2 is cut, and the cutting position corresponds to the connecting part 42, so that the cutter cuts the electrode tab material strip 80 along the connecting part 42 in the second direction to cut the electrode tab material strip 80 into two electrode tabs 400.

[0171] In the above scheme, by arranging the connecting part 42 between the two adjacent current collector bodies 41 to form the composite current collector 40, on the one hand, when the electrode tab material strip 80 is cut, the cutter can be positioned on the part where the connecting part 42 is located, and the current collector body 41 is not cut, thereby fundamentally avoiding the problem of metal particles and burrs generated by cutting, effectively reducing the risk of metal particles or burrs piercing the separator film to cause internal short circuit of the battery cell, and thereby improving the reliability of the battery; on the other hand, the active material can be coated on the current collector body 41 and the connecting part 42 with lower cost and density, which is supported by the current collector body 41 and the connecting part 42, can reduce the material cost of the electrode tab 400, reduce the cost of the battery cell, thereby reducing the cost of the battery, and effectively reducing the mass of the battery, so that the mass density of the battery cell is high, thereby improving the mass density of the battery.

[0172] According to some embodiments of the present application, the material of the connecting part 42 includes hot melt adhesive. In step S1, the composite current collector 40 includes:

[0173] The hot melt adhesive is located between the two adjacent current collector bodies 41 and overlaps the surfaces of the two adjacent current collector bodies 41 in the thickness direction y of the composite current collector, and the hot melt adhesive is hot-pressed to melt and enter the gap to form the connecting part 42.

[0174] For example, please refer to FIG. 8. In some embodiments, the hot melt adhesive is arranged on the current collector body 41 in the form of an adhesive tape 70. The hot melt adhesive is arranged on one side of the current collector body 41, and the hot melt adhesive is arranged on the surfaces of the two current collector bodies 41 and closes the gap. Alternatively, two hot melt adhesives are arranged on the opposite sides of the current collector body 41, respectively, for example, the hot melt adhesives are arranged on the upper side and the lower side of the current collector body 41, respectively, and the two hot melt adhesives are arranged on the opposite surfaces of the two current collector bodies 41 and jointly close the gap.

[0175] The hot melt adhesive is hot-pressed, and the hot-pressing temperature can be adjusted according to the specific material of the hot melt adhesive. For example, the hot-pressing temperature can be between 80 degrees Celsius and 250 degrees Celsius. During the process of hot melt adhesive and current collector body 41, hot-pressing can be performed by hot roller 71. The effect of hot-pressing can include reducing the height of the hot melt adhesive beyond the surface of the current collector body 41, avoiding rolling bulging; allowing the hot melt adhesive to enter the gap between the two current collector bodies 41 for filling; and by compressing the hot melt adhesive, the thickness of the active material coated on the surface of the hot melt adhesive can be increased, which is beneficial to improve the energy density of the battery.

[0176] In some embodiments, when the hot melt adhesive is provided on only one side of the current collector body 41, the thickness of the hot melt adhesive before hot-pressing is not greater than the thickness of the current collector body 41.

[0177] In the above scheme, by setting the material of the connecting portion 42 to include hot melt adhesive, the connecting portion 42 can be efficiently formed between the two adjacent current collector bodies 41 by a simple hot-pressing process, thereby making the manufacturing efficiency of the composite current collector 40 high.

[0178] According to some embodiments of the present application, referring to FIG. 10, in step S1, the composite current collector 40 is provided, including:

[0179] The two sides of the adjacent two current collector bodies 41 opposite to each other are respectively provided with hot melt adhesive along the thickness direction y of the composite current collector.

[0180] Exemplarily, referring to FIGS. 8-12. In some embodiments, the hot melt adhesive is provided in the state of adhesive tape 70 on the current collector body 41. Two hot melt adhesives are respectively provided on the two sides of the current collector body 41 opposite to each other, for example, hot melt adhesives are respectively provided on the upper side and the lower side of the current collector body 41. The two hot melt adhesives are provided on the surfaces of the two current collector bodies 41 opposite to each other and jointly seal the gap. The hot melt adhesive is hot-pressed, and the hot-pressing temperature can be adjusted according to the specific material of the hot melt adhesive. For example, the hot-pressing temperature can be between 80 degrees Celsius and 250 degrees Celsius. During the process of hot melt adhesive and current collector body 41, hot-pressing can be performed by hot roller 71.

[0181] In some embodiments, when the hot melt adhesive is provided on the two sides of the current collector body 41, the sum of the thicknesses of the two hot melt adhesives before hot-pressing is not greater than the thickness of the current collector body 41.

[0182] In the above scheme, by arranging the hot melt adhesive on the two opposite sides of the adjacent two current collector bodies 41, the hot melt adhesive can uniformly enter the gap between the adjacent two current collector bodies 41 when melted, on the one hand, the structural relationship between the adjacent two current collector bodies 41 and the connecting portion 42 is stable, and on the other hand, the thickness of the part of the connecting portion 42 adhered to the surface of the current collector body 41 after the hot melt adhesive is melted is uniform, so that the active material layer is stably arranged on the surface of the current collector body 41 and the connecting portion 42.

[0183] According to some embodiments of the present application, in step S1, the composite current collector 40 is provided, comprising:

[0184] The hot melt adhesive has a center line parallel to the second direction, and the distance between the center lines of the two hot melt adhesives on the two opposite sides of the adjacent two current collector bodies 41 in the first direction x is not greater than 0.5 mm.

[0185] In some embodiments, the hot melt adhesive has a center line parallel to the second direction, which divides the hot melt adhesive into two areas of equal area along the first direction x. Please refer to FIG. 11, in which the center lines of the two hot melt adhesives are denoted by reference numerals B and C.

[0186] In some embodiments, the hot melt adhesive on the upper side of the current collector body 41 is the first hot melt adhesive, and the center line is denoted by reference numeral B, and the hot melt adhesive on the lower side of the current collector body 41 is the second hot melt adhesive, and the center line is denoted by reference numeral C. Along the first direction x, the distance between the center line B of the first hot melt adhesive and the center line C of the second hot melt adhesive can be 0, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm or any value between adjacent two values.

[0187] In some embodiments, in order to achieve good connection stability between the adjacent two current collector bodies 41 and the hot melt adhesive, the center line of the hot melt adhesive can be arranged corresponding to the gap between the adjacent two current collector bodies 41.

[0188] In some embodiments, by arranging the distance between the center lines of the two hot melt adhesives on the two opposite sides of the adjacent two current collector bodies 41 in the first direction x to be not greater than 0.5 mm, the alignment between the hot melt adhesives on the two sides is high, so that the hot melt adhesives on the two sides can stably connect the current collector bodies 41.

[0189] In the above scheme, by offsetting the center lines of the two hot melt adhesives on both sides of the current collector body 41 by a distance not greater than 0.5 mm, the hot melt adhesive can uniformly enter the gap between the two adjacent current collector bodies 41 from both sides of the two adjacent current collector bodies 41 when melted, so that the composite current collector 40 has high surface flatness, and the active material is beneficial to be coated on the surface of the composite current collector 40.

[0190] According to some embodiments of the present application, the material of the connecting portion 42 includes at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin, or acrylic acid acetate copolymer.

[0191] In some embodiments, the connecting portion 42 has a material that can include at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin, or acrylic acid acetate copolymer, so that in step S1, the connecting portion 42 is formed between the two adjacent current collector bodies 41 by hot pressing.

[0192] According to some embodiments of the present application, the current collector body 41 includes a metal conductive layer 412, or the current collector body 41 includes a metal conductive layer 412 and a polymer layer 413, and the polymer layer 413 is sandwiched between the two metal conductive layers 412 along the thickness direction y of the composite current collector.

[0193] In some embodiments, referring to FIGS. 8-14, the current collector body 41 can be a metal conductive layer 412.

[0194] In other embodiments, please refer to FIG. 8 and FIG. 15, or please refer to FIG. 10, FIG. 16-FIG. 19, FIG. 15 is a schematic diagram of the current collector body 41 and the adhesive tape 70 in some other embodiments of the present application, FIG. 16 is a schematic diagram of the current collector body 41 and the adhesive tape 70 in some other embodiments of the present application, FIG. 17 is a schematic diagram of the current collector body 41 and the connecting portion 42 in some other embodiments of the present application, FIG. 18 is a schematic diagram of the pole piece material tape 80 in some other embodiments of the present application, and FIG. 19 is a schematic diagram of the pole piece material tape 80 after being cut in some other embodiments of the present application.

[0195] The current collector body 41 can be a multilayer structure of a metal conductive layer 412 and a polymer layer 413, for example, the polymer layer 413 is sandwiched between the two metal conductive layers 412 along the thickness direction y of the composite current collector.

[0196] Exemplarily, in step S1, the current collector body 41 of the multi-layer structure and the connecting portion 42 are provided, the connecting portion 42 can be a hot melt adhesive, and the hot melt adhesive is in the state of the adhesive tape 70, hereinafter referred to as the adhesive tape 70. The current collector body 41 and the adhesive tape 70 are in the state of a material tape. The two current collector bodies 41 are side by side by the tape running roller 72, and the tape running direction can be the third direction z, and the third direction z, the second direction and the first direction x are perpendicular to each other. The two current collector bodies 41 are arranged along the first direction x and form a gap along the second direction. In some embodiments, please refer to FIG. 8 and FIG. 15. The adhesive tape 70 is arranged on the side (for example, the upper side) of the current collector body 41, the adhesive tape 70 is running, and is arranged on the surface of the two current collector bodies 41 and closes the gap. In some other embodiments, please refer to FIG. 10 and FIG. 16, the adhesive tape 70 is arranged on the two opposite sides of the current collector body 41 respectively, for example, the upper side and the lower side of the current collector body 41 respectively, the two adhesive tapes 70 are running, and are arranged on the opposite surfaces of the two current collector bodies 41 and jointly close the gap.

[0197] Please refer to FIG. 17, the hot pressing of the hot roller 71 makes the adhesive tape 70 hot melt in the gap and connects the two current collector bodies 41, the adhesive tape 70 after hot melting can connect the polymer layer 413 and the metal conductive layer 412, and after cooling, the connecting portion 42 is formed, the composite current collector material tape is formed, and then enters the coating process, that is, step S2 is performed.

[0198] In step S2, please refer to FIG. 18, the active material is coated on the surface of the current collector body 41 and the surface of the connecting portion 42 to form an active material layer, and the pole piece material tape 80 is obtained. In step S2, the active material layer can be coated on the two sides of the current collector body 41 and the connecting portion 42 respectively to obtain the first active material layer 50 and the second active material layer 60 respectively.

[0199] In step S3, please refer to FIG. 19, the pole piece material tape 80 obtained from step S2 is cut, and the cutting position corresponds to the connecting portion 42, so that the cutting knife cuts the pole piece material tape 80 into two pole pieces 400 along the connecting portion 42 in the second direction.

[0200] In the above scheme, by arranging the polymer layer 413, on the one hand, the density of the current collector body 41 can be reduced, thereby improving the mass density of the battery monomer and further improving the mass density of the battery; on the other hand, the material cost of the current collector body 41 can be effectively reduced, thereby reducing the manufacturing cost of the battery; on the other hand, due to the arrangement of the polymer layer 413, the battery can be effectively improved in reliability when the battery is punctured; on the other hand, when the connecting portion 42 is a hot melt material, the polymer layer 413 and the connecting portion 42 have good connection effect, so that the combination between the current collector body 41 and the connecting portion 42 is stable and not easy to break, so that the battery has high reliability.

[0201] According to some embodiments of the present application, referring to FIGS. 7-19, a manufacturing method of the pole piece 400 is provided, the manufacturing method of the pole piece 400 comprises the following steps:

[0202] S1, providing a composite current collector 40, at least two current collector bodies 41 are arranged in a first direction x and a gap is formed in a second direction, a connecting part 42 is arranged in the gap, the two adjacent current collector bodies 41 are connected by the connecting part 42 to form the composite current collector 40, the first direction x is perpendicular to the thickness direction of the current collector body 41, and the second direction is parallel to the thickness direction of the current collector body 41;

[0203] S2, coating the active material on the surface of the current collector body 41 and the surface of the connecting part 42 in the thickness direction y of the composite current collector to obtain a pole piece tape 80;

[0204] S3, cutting the pole piece tape 80 in the second direction corresponding to the connecting part 42 to obtain at least two pole pieces 400.

[0205] In step S1, the current collector body 41 can be a metal conductive layer 412, or a multilayer structure of the metal conductive layer 412 plus a polymer layer 413, such as a multilayer structure of the metal conductive layer 412 plus the polymer layer 413 plus the metal conductive layer 412. The connecting part 42 can be a hot melt adhesive, which is arranged (e.g. bonded) on the same side or opposite sides of the two adjacent current collectors in the form of an adhesive tape 70.

[0206] Exemplarily, two current collector bodies 41 are arranged side by side in the first direction x, and are respectively fed by a feeding roller 72 in a third direction z, and the feeding direction is parallel to the third direction. The two current collector bodies 41 are arranged in the first direction x and a gap is formed in the second direction, and the size of the gap in the first direction x can be not less than 1 mm and not more than 10 mm (e.g. 1 mm, 2 mm, 3 mm, 4 mm…9 mm, 10 mm or any value between adjacent two values). In some embodiments, the size of the two current collector bodies 41 in the first direction x can be equal or not equal.

[0207] The adhesive tape 70 is arranged on one side of the current collector body 41, or arranged on the upper side and the lower side of the current collector body 41 respectively, and the alignment error of the adhesive tapes 70 on the two sides is not more than 0.5 mm. The adhesive tape 70 is fed and closed with the surface of the current collector body 41 and the gap. The hot pressing of the hot roller 71 makes the adhesive tape 70 hot melt in the gap and connects the two current collector bodies 41, and forms the connecting part 42 after cooling to form a composite current collector tape. The hot pressing temperature can be between 80 degrees Celsius and 250 degrees Celsius, which can be determined according to the specific material of the actual adhesive tape 70.

[0208] In step S2, the active material is coated on the surface of the current collector body 41 and the surface of the connecting part 42 to form an active material layer, obtaining the electrode tab material strip 80. In step S2, the active material layer can be coated on both sides of the current collector body 41 and the connecting part 42 respectively, to obtain the first active material layer 50 and the second active material layer 60 respectively. In some embodiments, the composite current collector material strip coated with the active material can be cooled and die-cut.

[0209] In step S3, the electrode tab material strip 80 obtained in step S2 is cut, and when cutting, the cutter is positioned at the area where the adhesive tape 70 is bonded, that is, the area where the connecting part 42 is located, so that the electrode tab material strip 80 is cut into two electrode tabs 400. Since the cutter does not contact the metal conductive layer 412 of the current collector body 41, no metal particles and burrs are generated during cutting.

[0210] In the above scheme, by arranging the connecting part 42 between the two adjacent current collector bodies 41 to form the composite current collector 40, on the one hand, when cutting the electrode tab material strip 80, the cutter can be positioned at the area where the connecting part 42 is located, without cutting the current collector body 41, so that the problem of metal particles and burrs generated during cutting can be fundamentally avoided, effectively reducing the risk of metal particles or burrs piercing the separator film to cause internal short circuit of the battery cell, thereby making the battery reliable; on the other hand, the active material can be coated on the current collector body 41 and the connecting part 42 with lower cost and density, which is supported by the current collector body 41 and the connecting part 42, can reduce the material cost of the electrode tab 400, reduce the cost of the battery cell, thereby reducing the cost of the battery, and can effectively reduce the mass of the battery, so that the mass density of the battery cell is high, thereby making the mass density of the battery high.

[0211] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A pole piece, wherein: include: A composite current collector, the composite current collector comprising a current collector body and a connecting portion interconnected along a first direction, the first direction being perpendicular to a thickness direction of the current collector body, the connecting portion having a sectional surface facing away from the current collector body along the first direction, the current collector body having a first surface and a third surface opposing each other along the thickness direction of the composite current collector, the connecting portion having a second surface, the first surface and the second surface being disposed on the same side and interconnected, the first surface and the second surface jointly forming a first coating region; a first active material layer, the first active material layer being disposed in the first coating area; In which, the connecting part is made of non-metallic material, and the connecting part includes a first connecting member and a connecting body that are connected to each other. The connecting body is connected to the end face of the current collector body along the first direction. Along the first direction, the connecting body and the current collector body are arranged side by side, and the first connecting member protrudes from the connecting body and is connected to the first surface or the third surface.

2. The pole piece according to claim 1, wherein: The connecting portion further includes a second connecting member connected to the connecting body. The first connecting member is connected to the first surface. Along the first direction, the second connecting member protrudes from the connecting body and is connected to the third surface.

3. The pole piece according to claim 1 or 2, wherein: Along the first direction, the first active material layer has a first side surface, and the first side surface and the cutting surface are arranged on the same side; The first side surface is coplanar with the cutting surface, or along the first direction, the cutting surface protrudes from the plane where the first side surface is located.

4. The pole piece according to any one of claims 1 to 3, wherein: Along the first direction, the first surface includes a first hollow foil area and a first connecting area connected to each other. The first connecting area is closer to the second surface than the first hollow foil area. The first connecting area and the second surface together form the first coating area.

5. The pole piece according to claim 4, wherein: The pole piece further includes a second active material layer; Along the thickness direction of the composite current collector, the current collector body has a third surface, the third surface and the first surface are opposite to each other, the connecting portion has a fourth surface, the fourth surface and the second surface are opposite to each other, the third surface and the fourth surface are arranged on the same side and are connected to each other, the third surface and the fourth surface together form a second coating area, and the second active material layer is arranged in the second coating area.

6. The pole piece according to claim 5, wherein: Along the thickness direction of the composite current collector, projections of the first active material layer and the second active material layer overlap with each other.

7. The pole piece according to any one of claims 1 to 6, wherein: Along the first direction, a size of the connecting portion is not less than 0.5 mm and not more than 5 mm.

8. The pole piece according to any one of claims 1 to 7, wherein: The material of the current collector body includes copper or aluminum.

9. The pole piece according to any one of claims 1 to 8, wherein: The current collector body includes a metal conductive layer, or the current collector body includes a metal conductive layer and a polymer layer, and along the thickness direction of the composite current collector, the polymer layer is sandwiched between two metal conductive layers.

10. The pole piece according to any one of claims 1 to 9, wherein: The connecting portion is made of hot melt adhesive, and the connecting portion is connected to the current collector body by hot pressing.

11. The pole piece according to claim 10, wherein: The material of the connecting portion includes at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin or acetic acid acrylic acid copolymer.

12. A battery cell, wherein: The invention comprises an electrode assembly, wherein the electrode assembly comprises a positive electrode sheet and a negative electrode sheet, and at least one of the positive electrode sheet and the negative electrode sheet is the electrode sheet according to any one of claims 1 to 11.

13. A battery, wherein: The battery cell according to claim 12 is included.

14. An electrical device, wherein: The battery cell according to claim 12 is used to provide electrical energy.

15. A method for manufacturing a pole piece, wherein: The following steps are involved: Providing a composite current collector, wherein at least two current collector bodies are spaced apart along a first direction to form a gap extending through the gap along a second direction, wherein a connecting portion is provided in the gap, and adjacent two current collector bodies are connected by the connecting portion to form the composite current collector, wherein the first direction is perpendicular to the thickness direction of the current collector bodies, and the second direction is parallel to the thickness direction of the current collector bodies; along the thickness direction of the composite current collector, coating the active material on the surface of the current collector body and the surface of the connecting portion to obtain a pole sheet strip; Corresponding to the connecting portion, the pole piece strip is cut along the second direction to obtain at least two pole pieces.

16. The method for manufacturing a pole piece according to claim 15, wherein: The material of the connecting portion includes hot melt adhesive; The method of providing a composite current collector comprises: The hot melt adhesive is located between two adjacent current collector bodies and overlaps the surfaces of the two adjacent current collector bodies along the thickness direction of the composite current collector. The hot melt adhesive is hot pressed so that the hot melt adhesive melts and enters the gap to form the connecting portion.

17. The method for manufacturing a pole piece according to claim 16, wherein: The method of providing a composite current collector comprises: Along the thickness direction of the composite current collector, the hot melt adhesive is respectively provided on two opposite sides of two adjacent current collector bodies.

18. The method for manufacturing a pole piece according to claim 17, wherein: The method of providing a composite current collector comprises: The hot melt adhesive has a center line parallel to the second direction, and the distance between the center lines of the two hot melt adhesives located on opposite sides of the two adjacent current collector bodies in the first direction is no more than 0.5 mm.

19. The method for manufacturing a pole piece according to any one of claims 16 to 18, wherein: The material of the connecting portion includes at least one of polyurethane hot melt adhesive, copolyester hot melt adhesive, vinyl acetate copolymer, copolyamide, polyolefin or acetic acid acrylic acid copolymer.

20. The method for manufacturing a pole piece according to any one of claims 15 to 19, wherein: The current collector body includes a metal conductive layer, or the current collector body includes a metal conductive layer and a polymer layer, and along the thickness direction of the composite current collector, the polymer layer is sandwiched between two metal conductive layers.

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