Battery monomer, composite pole piece preparation device and method, battery device and energy storage device

Abstract

The present application belongs to the field of battery technology and provides a battery cell, a composite electrode preparation device and method, a battery device, and an energy storage device, including an electrode assembly, wherein the electrode assembly includes a positive electrode and a negative electrode, wherein the positive electrode and / or the negative electrode is a composite electrode, and the composite electrode includes a electrode body and a diaphragm, wherein the electrode body is connected to a pole tab, and the diaphragm is bonded to a side surface of the electrode body and avoids the pole tab; an adhesive layer is provided between the diaphragm and the electrode body, and the adhesive layer is made of a polymer material; the electrode body includes a first side and a second side, wherein the first side extends in a first direction and the second side extends in a second direction, and the adhesive layer is applied to the electrode body along the first direction, and the adhesive layer has a discontinuous structure and a hollow area. The purpose is to minimize the occurrence of wrinkling, damage, warping of the diaphragm, and misalignment with the electrode, thereby reducing the risk of lithium plating and short circuit.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery cell, a composite electrode preparation device and method, a battery device, and an energy storage device. Background Art

[0002] Battery devices are being used more and more widely. They can be used in new energy vehicles or other electrical equipment. Battery devices include battery cells, which include electrode assemblies. The electrode assemblies are prepared by alternating stacking and winding of negative electrode sheets, diaphragms, positive electrode sheets, and diaphragms. Due to factors such as process fluctuations, the diaphragms are prone to wrinkling, breakage, and warping. Wrinkling and warping of the diaphragms hinder the movement of lithium ions, and lithium deposition is likely to occur at the wrinkled and warped locations. At the same time, the electrode sheets and diaphragms are prone to relative slippage, resulting in dislocation. The relative slippage, dislocation, and damage to the diaphragm result in a greater risk of short circuit between the positive and negative electrode sheets. Summary of the Invention

[0003] In view of the above problems, the present application provides a battery cell, a composite electrode preparation device and method, a battery device and an energy storage device, aiming to prevent the diaphragm from wrinkling, breakage, warping and misalignment with the electrode as much as possible, thereby reducing the risk of lithium plating and short circuit.

[0004] In the first aspect, the present application provides a battery cell, including an electrode assembly, the electrode assembly including a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and / or the negative electrode sheet is a composite electrode sheet, the composite electrode sheet includes a electrode sheet body and a diaphragm, the electrode sheet body is connected to a pole ear, the diaphragm is bonded to one side surface of the electrode sheet body and avoids the pole ear; an adhesive layer is provided between the diaphragm and the electrode sheet body, the material of the adhesive layer is a polymer material, the electrode sheet body includes a first side edge and a second side edge, the extension direction of the first side edge is a first direction, and the extension direction of the second side edge is a second direction, the adhesive layer is coated on the electrode sheet body along the first direction, and the adhesive layer has a discontinuous structure and has a hollow area. In the battery cell of this embodiment, the separator and the electrode body of the electrode assembly are of an integrated structure, that is, the separator is adhered to the surface of one side of the electrode body, and the separator and the electrode body are not misaligned, so that the electrode body (e.g., the positive electrode body) to which the separator is adhered is reliably isolated from the adjacent electrode body (e.g., the negative electrode body), reducing the risk of short circuits between the electrode bodies. In addition, the separator is attached to the electrode body, thus reducing the risk of wrinkling, damage, or warping of the separator itself during winding, and also reducing the risk of lithium deposition at the corresponding position of the electrode body. The material of the adhesive layer is a polymer material. The adhesive layer has viscosity, so it can firmly adhere the electrode body and the separator to form a whole, avoiding relative displacement. The polymer material has high chemical stability. The electrode body includes a first side and a second side. The first side extends in a first direction, and the second side extends in a second direction. The adhesive layer is applied to the electrode body along the first direction. This ensures uniform distribution and facilitates bonding with the separator. The bonding layer is discontinuous and features hollow areas. These hollow areas can be soaked with electrolyte to enhance ion conduction. Furthermore, the hollow areas provide space for expansion of the electrode body.

[0005] In one embodiment of the first aspect, the adhesive layer is in a grid, stripe, or lattice shape. When the adhesive layer is dispersed between the two in a grid, stripe, or lattice shape, it is preferably evenly distributed to reduce the risk of uneven metal ion embedding and deintercalation caused by uneven distribution of the adhesive layer.

[0006] In one embodiment of the first aspect, the adhesive layer is located at a circumferential edge of the pole piece body. The distribution of the adhesive layer can meet the connection strength requirements between the pole piece body and the diaphragm, and a large area in the center of the pole piece body is not provided with the adhesive layer and can be filled with electrolyte, i.e., soaked with electrolyte.

[0007] In one embodiment of the first aspect, the distribution area of ​​the adhesive layer is larger than one quarter of the area of ​​the pole piece body. The distribution area is set to be larger than one quarter of the area of ​​the pole piece body, which also ensures the firmness of the connection.

[0008] In one embodiment of the first aspect, the adhesive layer includes one or more of polyvinylidene fluoride, styrene-butadiene rubber, sodium carboxymethyl cellulose, polyacrylic acid, and polyacrylonitrile. These materials do not hinder ion migration, or the degree of hindrance is minimal, and thus fully meet usage requirements without worsening lithium deposition.

[0009] In an embodiment of the first aspect, the material of the diaphragm includes one or more of polypropylene, polyethylene, styrene-butadiene rubber, polyacrylate, and polyvinylidene fluoride. Firstly, these materials are insulating materials that can well isolate the pole pieces from each other and achieve insulation.

[0010] In a second aspect, the present application further provides a composite electrode sheet preparation device for preparing the composite electrode sheet included in the battery cell provided in any one of the above embodiments, comprising:

[0011] a first rotating roller, the first rotating roller being used to pass the strip-shaped substrate forming the diaphragm, wherein the movement speed of the strip-shaped substrate wound around the first rotating roller is equal to the linear speed of the first rotating roller;

[0012] a second roller, disposed downstream of the first roller, for simultaneously winding around the strip of sheet for preparing the electrode body and the strip of substrate wound from the first roller, so as to adhere the strip of sheet and the strip of substrate to form a composite body, wherein the moving speed of the composite body is equal to the linear speed of the second roller, and the linear speed of the second roller is greater than the linear speed of the first roller;

[0013] a spraying device, disposed upstream of the second rotating roller, for spraying an adhesive layer onto the surface of the strip-shaped sheet for laminating the strip-shaped substrate; and

[0014] The cutting device, located downstream of the second roller, is used to cut the composite body to form the composite electrode sheet. The continuous rotation of the first and second rollers allows for uninterrupted lamination of the strip substrate and the strip sheet. Prior to lamination, the speed difference between the two rollers is used to stretch the strip substrate to adjust various parameters of the diaphragm, achieving automated and efficient adjustment. The adhesive layer of the spray device achieves a secure connection, ultimately forming a composite electrode sheet that meets the requirements.

[0015] In one embodiment of the second aspect, the linear speed of the first roller is V1, and the linear speed of the second roller is V2, such that 3 < V2 / V1 < 15. When the speeds of the first and second rollers meet this condition, the strip substrate can be stretched and adjusted within a desired range, thereby better ensuring that the separator meets usage requirements.

[0016] In an embodiment of the second aspect, 5<V2 / V1<10, which can achieve a better stretching effect.

[0017] In one embodiment of the second aspect, the composite electrode sheet preparation apparatus further includes a take-up roller for taking up the composite material unwound from the second rotating roller. This provides a composite material storage structure capable of accommodating a large number of strip-shaped sheets and strip-shaped substrate composite materials, thereby facilitating storage for subsequent cutting and use, and enabling continuous production and storage of composite materials while occupying a limited space.

[0018] In an embodiment of the second aspect, the composite electrode preparation device further includes:

[0019] an extrusion device disposed upstream of the first roller, for extruding the melt; and

[0020] Multiple stretching rollers, positioned upstream of the first roller, are configured to sequentially pass over the melt and longitudinally stretch it to produce the strip-shaped substrate. This provides a method for generating and producing the strip-shaped substrate. The extrusion-stretching process allows for rapid formation of the strip-shaped substrate, enabling continuous production and significantly improving efficiency.

[0021] In an embodiment of the second aspect, the extrusion device comprises:

[0022] An extruder, wherein the extruder has a discharge die head, the discharge die head is used to extrude the melt, and the distance between the discharge die head and the adjacent first stretching roller is adjustable; and

[0023] The feeding mechanism is used to feed the extruder. It melts the raw materials at high temperatures and extrudes them to form a melt. The feeding mechanism continuously feeds the raw materials, enabling continuous automated production and improving production efficiency. The distance between the discharge die and the third roller is adjustable, thereby adjusting the thickness of the melt and, ultimately, the thickness of the diaphragm.

[0024] In one embodiment of the second aspect, the composite electrode sheet preparation apparatus further includes a cooling device, which is disposed on one side of the stretching roller and is used to cool the melt to accelerate its temperature drop, accelerate the cooling and forming of the melt, and quickly form a strip-shaped substrate.

[0025] In a third aspect, the present application further provides a method for preparing a composite electrode sheet, which is used to prepare the composite electrode sheet included in the battery cell provided in any one of the above embodiments, and comprises:

[0026] preparing the diaphragm raw material into a colloidal melt;

[0027] The melt is passed through a plurality of stretching rollers for stretching and cooling to form a tape-shaped substrate;

[0028] The strip-shaped substrate wound from the plurality of stretching rollers is stretched and laminated with the strip-shaped sheet through the adhesive layer to form a composite body, wherein the strip-shaped sheet is used to form the pole piece body;

[0029] The composite body is cut to form composite electrode pieces. Composite electrode pieces can be produced quickly, and during the preparation process, stretching and cooling the melt and stretching the strip substrate can effectively adjust various parameters of the diaphragm, including material characteristic parameters such as porosity, thickness, and air permeability, ensuring the molding quality of the diaphragm and meeting usage requirements.

[0030] In one embodiment of the third aspect, preparing the separator raw material into a colloidal melt includes: conveying the raw material to an extruder, and extruding the melt through the extruder. In this embodiment, melting and extruding the raw material through the extruder is not only rapid but also enables continuous production, preparing the raw material into a melt structure capable of forming a separator.

[0031] In one embodiment of the third aspect, the step of stretching the strip-shaped substrate wound off from the plurality of stretching rollers and laminating and bonding the strip-shaped substrate with the strip-shaped sheet through the adhesive layer to form a composite body comprises:

[0032] An adhesive layer is sprayed onto the surface of the strip. The strip and the strip substrate, which has exited the stretching roller, are bonded together at the composite roller via the adhesive layer and simultaneously exit the composite roller to form the composite. The adhesive layer significantly enhances the connection between the strip and the substrate, ensuring a good integration between the resulting diaphragm and the electrode body.

[0033] In one embodiment of the third aspect, the linear velocity of the substrate strip as it exits the stretching roller is V1, and the linear velocity of the composite on the composite roller is V2, where V2 is greater than V1. Thus, the substrate strip is stretched between the stretching roller and the composite roller, thereby adjusting various parameters of the subsequent separator.

[0034] In one embodiment of the third aspect, 3<V2 / V1<15. This embodiment also provides a specific relationship between V2 and V1, that is, V2 is 3 to 15 times V1. Under this speed ratio, effective stretching of the strip substrate can be achieved.

[0035] In an embodiment of the third aspect, 5<V2 / V1<10. Within this range, a better stretching effect can be achieved.

[0036] In one embodiment of the third aspect, the extruder includes a discharge die, and the gap between the discharge die and the first stretching roller is adjustable. This embodiment provides for an adjustable gap between the discharge die and the stretching roller, which improves operability and facilitates adjusting the melt winding thickness according to the required membrane thickness and stretching requirements.

[0037] In a fourth aspect, the present application further provides a battery device comprising the battery cell provided in any one of the above embodiments, thereby improving the reliability of the battery device.

[0038] In a fifth aspect, the present application further provides an energy storage device, comprising the battery device provided in the above embodiment, wherein the battery device is used to store or provide electrical energy, and the reliability of the energy storage device is also improved.

[0039] In a sixth aspect, the present application further provides an electrical device, comprising the battery device provided in the above embodiment or the energy storage device provided in the above embodiment.

[0040] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0042] In the attached figure:

[0043] Figure 1 A schematic structural diagram of a vehicle according to some embodiments of the present application;

[0044] Figure 2 A schematic structural diagram of a battery device provided in some embodiments of the present application;

[0045] Figure 3 A schematic diagram of the structure of a composite electrode preparation device provided in some embodiments of the present application;

[0046] Figure 4 A schematic diagram of the structure of a composite electrode provided in some embodiments of the present application;

[0047] Figure 5A schematic structural diagram of a pole piece body provided with an adhesive layer having a continuous planar structure according to some embodiments of the present application;

[0048] Figure 6 A schematic structural diagram of a pole piece body provided with a lattice-shaped adhesive layer according to some embodiments of the present application;

[0049] Figure 7 A schematic structural diagram of a pole piece body provided with a striped adhesive layer according to some embodiments of the present application;

[0050] Figure 8 A schematic structural diagram of a pole piece body provided with a grid-shaped adhesive layer in some embodiments of the present application.

[0051] The accompanying drawings in the specific implementation manner are as follows:

[0052] 1000, vehicle;

[0053] 100, battery device; 200, controller; 300, motor;

[0054] 10. Battery cell; 11. Composite electrode; 111. Electrode body; 112. Diaphragm; 14. First roller; 15. Second roller; 16. Strip substrate; 17. Strip sheet; 18. Spraying device; 19. Unwinding roller; 20. Winding roller; 21. Third roller; 22. Fourth roller; 23. Melt; 24. Extrusion device; 241. Extruder; 242. Discharge die; 243. Feeding mechanism; 25. Composite body; 26. Electrode tab; 27. Material tank; 2. Stretching roller; 3. Adhesive layer. DETAILED DESCRIPTION

[0055] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0057] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0058] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0059] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0060] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0061] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0062] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0063] Currently, market developments indicate that battery applications are becoming increasingly widespread. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. As battery applications continue to expand, market demand is also growing.

[0064] The battery device may include a plurality of battery cells, each of which includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator.

[0065] The positive electrode sheet, negative electrode sheet and separator can be in a wound form or a stacked form. When the winding form is adopted, the separator and the electrode sheet are not in a fixed state. Due to factors such as process fluctuations during winding, the separator is prone to wrinkling, warping, and damage. Wrinkling and warping of the separator will increase the resistance to lithium ion migration at that position or increase the path, and lithium deposition will occur at the corresponding position of the negative electrode sheet. When the separator is damaged or the separator slips and dislocates, there will be a greater risk of short circuit between the positive and negative electrode sheets. Especially for new batteries, such as metal batteries, for metal batteries, active metals will grow along the edges of the electrode sheets. In this case, the misalignment of the separator is particularly likely to cause a short circuit between the positive and negative electrodes, resulting in a decrease in the performance of the battery cell.

[0066] Based on the above considerations, an embodiment of the present application provides a battery cell 10, which aims to reduce the phenomenon of wrinkling, breakage, warping of the diaphragm and misalignment with the electrode, and reduce the risk of lithium plating and short circuit.

[0067] The present application also provides a battery device 100 , comprising the above-mentioned battery cell 10 .

[0068] The embodiment of the present application further provides an electrical device having the above-mentioned battery device 100 , that is, an electrical device using the battery device 100 as a power source.

[0069] The embodiment of the present application also provides an energy storage device or energy storage system using the battery device 100 as an energy storage element, which can increase the safety of the electrical device and the energy storage system.

[0070] The battery apparatus 100 (Battery Apparatus) mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly (Battery Cell Assembly) may include multiple battery cells, which are connected in series, parallel, or hybrid via a busbar. Hybrid refers to a combination of series and parallel connections.

[0071] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are housed in the case.

[0072] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0073] As an example, the battery cell assembly may also be housed in the box by directly fixing the plurality of battery cells to the box.

[0074] As an example, the housing may include a first housing and a second housing. The first housing and the second housing engage to form an enclosed space within the housing to accommodate the battery cell assembly. The enclosed space may be sealed or unsealed. The first housing may be a top cover or a bottom plate.

[0075] As an example, the box may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame to form a closed space inside the box to accommodate the battery cell assembly.

[0076] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0077] In some embodiments, a battery cell includes an electrode assembly. In some cases, the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. The electrode assembly primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive active material layer protrudes from the positive electrode collector coated with the positive active material layer, and the positive electrode collector not coated with the positive active material layer serves as the positive electrode tab. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative active material layer protrudes from the negative electrode collector coated with the negative active material layer, and the negative electrode collector not coated with the negative active material layer serves as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, among others. To ensure high current flow without melting, multiple positive tabs are stacked together, and multiple negative tabs are stacked together. The separator can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0078] The technical solutions described in the embodiments of the present application are applicable to various electrical devices using battery devices, wherein the electrical devices may be vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys and electric tools, etc. Vehicles may be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0079] The battery device 100 disclosed in the embodiment of the present application can be used in, but is not limited to, electrical devices such as vehicles, ships, or aircraft. The electrical devices can use a power supply system equipped with the battery device 100 disclosed in the present application.

[0080] For the convenience of description, the following embodiments are described by taking the electric device provided in the embodiments of the present application as a vehicle as an example.

[0081] Please refer to Figure 1 , Figure 1 A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device is provided inside the vehicle 1000, and the battery device may be provided at the bottom, head or tail of the vehicle 1000. The battery device may be used to power the vehicle 1000, for example, the battery device may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, and the controller 200 is used to control the battery device to power the motor 300, for example, for starting, navigating and operating power requirements of the vehicle 1000 during driving.

[0082] In some embodiments of the present application, the battery device 100 can serve not only as an operating power source for the vehicle 1000 , but also as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

[0083] See also Figure 2 、 Figure 4-Figure 8A battery cell 10 provided in an embodiment of the present application includes an electrode assembly, the electrode assembly includes a positive electrode sheet and a negative electrode sheet, the positive electrode sheet and / or the negative electrode sheet is a composite electrode sheet 11, the composite electrode sheet 11 includes a electrode sheet body 111 and a diaphragm 112, the electrode sheet body 111 is connected to a pole ear 26, the diaphragm 112 is bonded to one side surface of the electrode sheet body 111 and avoids the pole ear 26 of the electrode sheet body 111; an adhesive layer 3 is provided between the diaphragm 12 and the electrode sheet body 111, the material of the adhesive layer 3 is a polymer material, the electrode sheet body 111 includes a first side edge and a second side edge, the extension direction of the first side edge is a first direction, and the extension direction of the second side edge is a second direction, the adhesive layer 3 is coated on the electrode sheet body 111 along the first direction, and the adhesive layer 3 has a discontinuous structure and has a hollow area.

[0084] Specifically, see Figure 4 This embodiment provides a composite electrode 11, which includes a electrode body 111 in addition to a diaphragm 112. The diaphragm 112 and the electrode body 111 form an integrated structure. Specifically, the composite electrode 11 can be a positive electrode and / or a negative electrode.

[0085] The composite electrode 11 is specifically configured such that a diaphragm 112 is bonded to one side of the electrode body 111, so that the diaphragm 112 and the electrode body 111 are integrally formed. The diaphragm 112 is not bonded to the tab 26 of the electrode body 111, allowing the tab 26 to be welded to the adapter. A gap may be formed between the diaphragm 112 and the electrode body 111 to allow for the entry of electrolyte.

[0086] In the battery cell 10 of this embodiment, the diaphragm 112 and the pole piece body 111 of the electrode assembly are of an integrated structure, that is, the diaphragm 112 is adhered to the surface of one side of the pole piece body 111, and the diaphragm 112 and the pole piece body 111 will not be misaligned, so that the pole piece body 111 (for example, the positive pole piece body) adhered with the diaphragm 112 and the adjacent pole piece body 111 (for example, the negative pole piece body) maintain a reliable isolation state, reducing the risk of short circuit between the pole piece bodies 111, and the diaphragm 112 is attached to the pole piece body 111, so that the risk of wrinkling, damage, and warping of the diaphragm 112 itself during winding is reduced, and the risk of lithium deposition at the corresponding position of the pole piece body 111 is also reduced.

[0087] An adhesive layer 3 is provided between the diaphragm 112 and the pole piece body 111 , and the material of the adhesive layer 3 is a polymer material.

[0088] The diaphragm 112 is connected to the pole piece body 111 via an adhesive layer 3 , and the adhesive layer 3 does not react with the electrolyte to ensure effective bonding between the diaphragm 112 and the pole piece body 111 .

[0089] Specifically, adhesive layer 3 is disposed between diaphragm 112 and electrode body 111, increasing the connection strength between them and enhancing the stability and robustness of the integrated structure. This integrated structure also reduces the risk of fracture of electrode body 111 and increases its strength. Furthermore, adhesive layer 3 is chemically stable, does not react with the electrolyte, and does not participate in ion deintercalation reactions, thus meeting usage requirements.

[0090] The adhesive layer 3 has adhesiveness, so it can firmly bond the electrode body 111 and the diaphragm 112 to form the two into one, thus avoiding the relative displacement phenomenon. The polymer material has high chemical stability.

[0091] In some embodiments, the chemical stability of the adhesive layer 3 needs to be compatible with the operating conditions and environment of the corresponding battery cell 10. For example, when the normal operating temperature of the battery cell 10 is below 80°C, the adhesive layer 3 does not decompose at temperatures below 80°C, nor does it react with the electrolyte, separator 112, active material, etc., thereby adapting to the normal operating temperature of the electrode assembly and maintaining continuous adhesion.

[0092] For another example, when the output voltage of the battery cell 10 is 2-4.2 V, the adhesive layer 3 needs to not decompose within this voltage range and not react with the electrolyte, the separator 112 , the active material, etc.

[0093] The pole piece body 111 includes a first side and a second side. The first side extends in a first direction, and the second side extends in a second direction. The adhesive layer 3 is applied to the pole piece body 111 along the first direction.

[0094] Specifically, the pole piece body 111 is generally rectangular in the unfolded state, specifically a long rectangle, so generally the pole piece body 111 includes a first side and a second side. The first side can be the longer side of the pole piece body 111, and the second side can be the shorter side of the pole piece body 111. This embodiment provides that the adhesive layer 3 extends and distributes along the first direction, that is, the direction of the first side, so that the distribution can be uniform and reasonable, which is conducive to mutual adhesion with the diaphragm 112.

[0095] The adhesive layer 3 has a discontinuous structure and has a hollow area.

[0096] Specifically, the discontinuous structure means that the distribution is not continuous in a planar manner, but has an intermittent distribution form, so the area where the adhesive layer 3 is not distributed is a hollow area.

[0097] like Figure 6 、 Figure 7 and Figure 8The adhesive layer 3 has a discontinuous structure and a hollow area. The adhesive layer 3 has a discontinuous structure. Its material can be a material that is conducive to electrolyte infiltration and ion permeability, or a material with slightly poor electrolyte infiltration performance and low ion permeability. It is provided in the local area between the electrode body 111 and the diaphragm 112 and has a grid, stripe, or lattice shape.

[0098] Specifically, this embodiment provides that the adhesive layer 3 is disposed in a local area between the electrode body 111 and the diaphragm 112, that is, it does not fill the entire space between the two. The space between the two, excluding the adhesive layer 3, does not affect the infiltration of the electrolyte and the conduction of ions. In other words, the hollow area can be infiltrated with electrolyte to enhance ion conduction. In addition, due to the presence of the hollow area, the hollow area can also provide space to accommodate the expansion of the electrode body 111.

[0099] In the above embodiment, the hollow area between the diaphragm 112 and the electrode body 111, where no adhesive layer 3 is provided, forms a gap for accommodating the electrolyte, thereby minimizing the effect of the adhesive layer 3 on the electrolyte infiltration effect. In addition, the gap can be used to provide space for the electrode body 111 to expand.

[0100] In some cases, the adhesive layer 3 may also be distributed in the form of a continuous planar structure.

[0101] Therefore, the structure of the adhesive layer 3 can be various, such as Figure 5 , can be a whole surface structure that extends continuously in a two-dimensional plane, such as Figure 6-Figure 8 , or it can be a discontinuous structure with a hollow area.

[0102] In some embodiments, as Figure 6-Figure 8 When the adhesive layer 3 is a discontinuous structure, the adhesive layer 3 may be in a grid shape, a stripe shape or a dot matrix shape.

[0103] The discontinuous structure includes a dot matrix structure, a stripe structure, a grid structure, and may also include a stripe or dotted line structure bonded only to the edge of the electrode body 111. When the material of the adhesive layer 3 is not conducive to the penetration of metal ions, a discontinuous structure is preferred to avoid affecting the charge and discharge performance of the battery cell 10; when the material of the adhesive layer 3 is conducive to the penetration of metal ions, a continuous full-surface structure may be selected, but is not limited to it. Similarly, when the material of the adhesive layer 3 is not conducive to the infiltration of the electrolyte, a discontinuous structure is preferred to avoid affecting the charge and discharge performance of the battery cell 10; when the material of the adhesive layer 3 is conducive to the infiltration of the electrolyte, a continuous full-surface structure may be selected, but is not limited to it.

[0104] Specifically, when the adhesive layer 3 is dispersed between the two in the form of a grid, stripes or lattice, it is preferably evenly distributed to reduce the risk of uneven deintercalation and embedding of metal ions caused by the uneven distribution of the adhesive layer. Of course, the total area and setting position of the adhesive layer 3 shall be based on the connection strength requirements between the electrode body 111 and the diaphragm 112.

[0105] In some embodiments, the adhesive layer 3 is located at the circumferential edge of the pole piece body 111 .

[0106] Specifically, when the adhesive layer 3 is in a dot matrix shape, it can be dispersed near the edge of the pole piece body 111 and distributed in sequence along the extension direction of the edge, or when it is in a stripe shape, it can also be arranged along the position close to the edge. The striped adhesive layer 3 can be set to a state parallel to the edge of the pole piece body 111.

[0107] The distribution position of the adhesive layer 3 provided in this embodiment can meet the connection strength requirements between the electrode body 111 and the diaphragm 112, and the large area in the center of the electrode body 111 is not provided with the adhesive layer 3, which can be filled with electrolyte, that is, soaked with electrolyte. It is more suitable for situations where the material of the adhesive layer 3 is not conducive to electrolyte infiltration or the penetration of metal ions.

[0108] In some embodiments, the distribution area of ​​the adhesive layer 3 is greater than one quarter of the area of ​​the pole piece body 111 .

[0109] Specifically, when the adhesive layer 3 is a discontinuous structure, the distribution area of ​​the adhesive layer 3 is set to be larger than one quarter of the area of ​​the electrode body 111 , which also ensures the firmness of the connection.

[0110] When the adhesive layer 3 is a continuous planar structure, in order to ensure effective bonding between the diaphragm 112 and the pole piece body 111 , the adhesive layer 3 must also occupy more than a quarter of the area of ​​the pole piece body 111 .

[0111] like Figure 5 When the adhesive layer 3 is a continuous planar structure, its area is larger than one-quarter of the area of ​​the electrode body 111. When the adhesive layer 3 provided in this embodiment is a continuous planar structure, the material of the adhesive layer 3 is selected to facilitate metal ion permeation and electrolyte infiltration. Its area is larger than one-quarter of the area of ​​the electrode body 111. While ensuring the normal charge and discharge performance of the battery cell 10, the bonding strength can be greatly increased, forming a solid whole between the diaphragm 112 and the electrode body 111, further enhancing the integrity and preventing warping, wrinkling, or even misalignment of the diaphragm 112 with the electrode body 111.

[0112] In some embodiments, the material of the adhesive layer 3 includes one or more of polyvinylidene fluoride, styrene-butadiene rubber, sodium carboxymethyl cellulose, polyacrylic acid, and polyacrylonitrile.

[0113] The above materials have good corrosion resistance, oxidation resistance, wear resistance, flexibility, high expansion strength and impact resistance, and excellent heat resistance and insulation effect. In addition, the ion permeability is high and will not deteriorate lithium deposition.

[0114] Due to the above advantages, the effective connection between the diaphragm 112 and the pole piece body 111 can be effectively ensured during long-term use, and the heat-resistant effect and insulation are enhanced, which also increases the safety of the battery cell 10 during use.

[0115] In some embodiments, the material of the diaphragm 112 includes one or more of polypropylene, polyethylene, styrene-butadiene rubber, polyacrylate, and polyvinylidene fluoride. The diaphragm 112 is made of the above materials because these materials are insulating materials that can effectively isolate and insulate the pole pieces 111 from each other.

[0116] In some embodiments, the composite electrode 11 can be selected as a negative electrode. Since lithium plating usually occurs in the negative electrode, it is necessary to increase the space of the negative electrode to accommodate lithium ions. Therefore, the size of the negative electrode is usually designed to be larger, that is, the area of ​​the negative electrode is larger than the area of ​​the positive electrode. Therefore, in this embodiment, the separator 112 is bonded to the electrode body 111 of the negative electrode, which can effectively cover the electrode body 111 of the negative electrode, so as to isolate the positive and negative electrodes as much as possible, thereby reducing the risk of short circuit between the negative and positive electrodes.

[0117] In some embodiments, the positive and negative electrodes can be simultaneously selected as composite electrodes 11. This is equivalent to having both electrodes of opposite polarity covered with the diaphragm 112, which acts as a double layer of insurance, further strengthening the isolation between the positive and negative electrodes and greatly reducing the risk of short circuits.

[0118] The electrode body 111 includes a current collector and an active material on its surface. When the composite electrode 11 is a negative electrode, the current collector of the electrode body 111 is made of the material required for a negative electrode, specifically copper foil, and the active material is a negative electrode active material. When the composite electrode 11 is a positive electrode, the current collector of the electrode body 111 is made of the material required for a positive electrode, specifically aluminum foil, and the active material is a positive electrode active material. The same applies to the second electrode.

[0119] This application also provides a specific embodiment of a composite electrode preparation device, such as Figure 3 , used to prepare the composite pole piece 11 included in the battery cell 10 provided in any of the above embodiments, including a first rotating roller 14, a second rotating roller 15, a spraying device 18, and a cutting device.

[0120] The first roller 14 is used to pass the strip-shaped substrate 16 forming the diaphragm 112 . The moving speed of the strip-shaped substrate 16 wound around the first roller 14 is equal to the linear speed of the first roller 14 .

[0121] The second roller 15 is disposed downstream of the first roller 14 and is used to simultaneously pass over the strip-shaped sheet 17 used to prepare the electrode body 111 and the strip-shaped substrate 16 wound off the first roller 14, so as to adhere the strip-shaped sheet 17 and the strip-shaped substrate 16 to form a composite body 25. The movement speed of the composite body 25 is equal to the linear speed of the second roller 15, and the linear speed of the second roller 15 is greater than the linear speed of the first roller 14.

[0122] The spraying device 18 is provided upstream of the second rotating roller 15 and is used to spray the adhesive layer 3 onto the surface of the strip-shaped sheet 17 for bonding to the strip-shaped substrate 16;

[0123] The cutting device is disposed downstream of the second rotating roller 15 and is used for cutting the composite body 25 of the strip-shaped substrate 16 and the strip-shaped sheet 17 to form a composite pole piece 11 .

[0124] Specifically, the first roller 14 and the second roller 15 are cylindrical or substantially cylindrical roller structures, located at different positions and arranged parallel to each other. Driven by a power mechanism, such as a servo motor, the first roller 14 and the second roller 15 can rotate about their respective axes. The drive mechanism can control the start and stop of the first roller 14 and the second roller 15, as well as the speed of the movement.

[0125] Strip substrate 16 refers to the strip-like structure used to form diaphragm 112. It is the substrate forming diaphragm 112. Strip substrate 16 is wound around first roller 14 and moves as first roller 14 rotates. It should be noted that the speed of strip substrate 16 wound around first roller 14 is equal to the speed of first roller 14, that is, the two move synchronously and do not move relative to each other. The arrangement of first roller 14 and strip substrate 16 around allows strip substrate 16 to move continuously, allowing it to be applied uninterruptedly to the surface of strip sheet 17 for adhesion, thereby improving production efficiency.

[0126] The strip sheet 17 refers to a substrate for forming the electrode body 111 . After the strip sheet 17 and the strip substrate 16 are bonded together, they can be cut by a cutting device to obtain a composite electrode 11 .

[0127] The second roller 15 is used to simultaneously pass the strip-shaped substrate 16 and the strip-shaped sheet 17 around the second roller 15 to bond them together. Specifically, the strip-shaped substrate 16 and the strip-shaped sheet 17 pass around the second roller 15 simultaneously, i.e., they pass around in a stacked manner to bond them together. When the strip-shaped substrate 16 is unwound from the first roller 14, it passes around the second roller 15 simultaneously with the strip-shaped sheet 17.

[0128] Before being attached to the strip-shaped sheet 17, the strip-shaped substrate 16 needs to be subjected to appropriate stress stretching. This allows the porosity, thickness, air permeability, and other material properties of the strip-shaped substrate 16 to be adjusted after forming the diaphragm 112. Specifically, the speed of the strip-shaped substrate 16 wound on the first roller 14 is equal to the linear speed of the first roller 14. When the strip-shaped substrate 16 and the strip-shaped sheet 17 are wound together on the second roller 15, the speeds of the strip-shaped substrate 16 and the strip-shaped sheet 17 are equal to the linear speed of the second roller 15. In other words, the strip-shaped substrate 16 and the strip-shaped sheet 17 wound on the second roller 15 move synchronously with the second roller 15. Since the linear speed of the second roller 15 is greater than the linear speed of the first roller 14, the strip-shaped substrate 16 is stretched, thereby adjusting the porosity, thickness, air permeability, and other properties of the diaphragm 112 after forming. Specifically, the stretching force can be adjusted according to the parameter setting requirements, which can be achieved by adjusting the speed difference between the second roller 15 and the first roller 14 .

[0129] In order to strengthen the adhesion between the strip substrate 16 and the strip sheet 17, this embodiment further provides a spraying device 18. The spraying device 18 is used to spray the adhesive layer 3 onto the surface of the strip sheet 17. Specifically, the spraying is performed before the strip sheet 17 is wound around the second roller 15, that is, before it is attached to the strip substrate 16. This can effectively strengthen the adhesion. The spraying amount and spraying frequency of the spraying device 18 can also be adjusted and set.

[0130] When the strip substrate 16 and the strip sheet 17 pass through the second roller 15, they are bonded together to form a composite body 25, which can be stored in the form of a roll. When the composite electrode 11 is made, it is wound out and cut. It can be cut according to the size of the composite electrode 11 to form a single composite electrode 11, and the electrode ear 26 is cut out at the same time during the cutting process.

[0131] The effect of this embodiment is that the strip substrate 16 and the strip sheet 17 can be continuously compounded by the continuous rotation of the first roller 14 and the second roller 15. Before bonding, the strip substrate 16 is stretched by the speed difference of the two rollers to adjust the various parameters of the diaphragm 112, thereby realizing automatic adjustment with high efficiency, and a firm connection is achieved with the help of the adhesive layer 3 of the spraying device 18, and finally a composite electrode 11 that meets the requirements is formed by cutting by the cutting device.

[0132] In some embodiments, the linear velocity of the first rotating roller 14 is V1, the linear velocity of the second rotating roller 15 is V2, and 3<V2 / V1<15.

[0133] This embodiment provides a linear velocity relationship between the first roller 14 and the second roller 15, i.e., 3<V2 / V1<15. When the speeds of the first roller 14 and the second roller 15 meet this condition, the strip substrate 16 can be stretched and adjusted within the required range, so that the diaphragm 112 can better meet the use requirements.

[0134] Furthermore, 5<V2 / V1<10, and better stretching effect can be achieved within this ratio range.

[0135] In some embodiments, as Figure 3 The composite electrode preparation device also includes a reel 19 , and the strip sheet 17 is wound on the reel 19 and passes around the second roller 15 after being unwound.

[0136] Specifically, before the strip sheet 17 is wound around the second rotating roller 15 together with the strip substrate 16, in order to achieve continuous production and save the space occupied by the strip sheet 17, the strip sheet 17 is wound on the unwinding roller 19, and the unwinding roller 19 rotates to unwind the strip sheet 17, thereby realizing continuous automated production, and the unwinding speed can also be determined by controlling the rotation speed of the unwinding roller 19.

[0137] In some embodiments, as Figure 3 The composite electrode preparation device further includes a winding roller 20 , which is used to wind up the composite body 25 wound off from the second rotating roller 15 .

[0138] Specifically, the composite body 25 formed after the strip sheet 17 and the strip substrate 16 are bonded together by the second rotating roller 15 will continue to move, that is, continue to move to the winding roller 20, so that the composite body 25 is stored. When it is necessary to form a composite electrode 11, the winding roller 20 is unwound in reverse, so that the composite body 25 is cut by the cutting device, cut into a suitable size and the pole ear 26 is cut out to form a composite electrode 11.

[0139] The effect of this embodiment is that it provides a storage structure for the complex 25, which can accommodate more strip sheets 17 and strip substrate 16 complexes 25, thereby facilitating storage for subsequent cutting and use, and also realizing continuous production and storage of the complex 25 on the basis of occupying limited space.

[0140] In some embodiments, as Figure 3 The composite electrode preparation device also includes an extrusion device 24 and a plurality of stretching rollers 2 arranged upstream of the first roller 14.

[0141] The extrusion device 24 extrude a melt 23 for forming a strip-shaped substrate 16 ; the plurality of stretching rollers 2 are used to sequentially pass through the melt 23 and longitudinally stretch the melt 23 to obtain the strip-shaped substrate 16 .

[0142] Specifically, two stretching rollers 2 can be selected, namely the third roller 21 and the fourth roller 22. The third roller 21 is used to bypass the melt 23; the fourth roller 22 is used to bypass the melt 23 wound out from the third roller 21, and a strip-shaped substrate 16 is formed when it is wound out of the fourth roller 22. The wound strip-shaped substrate 16 bypasses the first roller 14.

[0143] Specifically, the melt 23 is in a semi-molten, gel-like structure before forming the strip-shaped substrate 16. It is extruded from the extruder 24 and has a relatively high temperature and good plasticity, so it needs to be stretched and shaped to form the strip-shaped substrate 16. This embodiment provides a stretching roller 2 to wrap around the melt 23, and stretches it as the stretching roller 2 rotates. Specifically, after being extruded from the extruder 24, the melt 23 can first pass around the third roller 21, then around the fourth roller 22, and form the strip-shaped substrate 16 when it passes through the fourth roller 22. This process is called the cast sheet stage, in which the melt 23 is subjected to high-multiple stretching and rapid cooling by the third and fourth rollers 21, 22 to obtain a polyolefin cast sheet with high orientation and low crystallinity. Cooling and crystallization occur under the stress field of high-speed drawing to obtain the strip-shaped substrate 16 with a lamellar structure. After passing through the fourth roller 22, the strip-shaped substrate 16 is passed around the first roller 14 for subsequent operations.

[0144] The effect of this embodiment is that it provides a form of generating and producing a strip-shaped substrate 16. The strip-shaped substrate 16 can be quickly formed through extrusion and stretching processing, thereby achieving continuous production and greatly improving efficiency.

[0145] In some embodiments, as Figure 3 The extrusion device 24 includes an extruder 241 and a feeding mechanism 243.

[0146] The extruder 241 has a discharge die 242 for extruding the melt 23 . The distance between the discharge die 242 and the first adjacent stretching roller 2 is adjustable. The feeding mechanism 243 is used to feed material into the extruder 241 .

[0147] Specifically, the feeding mechanism 243 is connected to the extruder 241 and has a feeding port that can be connected to the feed tank 27, so that the material is fed into the extruder 241 through the feeding mechanism 243. The material is the raw material used to form the diaphragm 112, and can be particles of polypropylene, polyethylene, styrene-butadiene rubber, polyacrylate, polyvinylidene fluoride, etc. The feeding mechanism 243 can melt the raw material particles at a high temperature, and then extrude them through the extruder 241, specifically through the discharge die 242 of the extruder 241 to form a melt 23. The melt 23 then passes through multiple stretching rollers 2, specifically the third roller 21 and the fourth roller 22, and then passes through the first roller 14. The distance between the discharge die 242 and the first stretching roller 2, that is, the third roller 21, is adjustable, so that the thickness of the melt 23 can be adjusted when it is extruded, that is, the thickness of the melt 23 around the third roller 21.

[0148] This embodiment achieves the effect of melting and extruding the raw materials at high temperature to form a melt 23. The feed mechanism 243 continuously feeds the raw materials, which, in conjunction with the extruder 241, enables continuous automated production, improving production efficiency. The distance between the discharge die 242 and the third roller 21 is adjustable, thereby adjusting the thickness of the melt 23 and, ultimately, the thickness of the diaphragm 112.

[0149] In some embodiments, the composite electrode preparation device further includes a cooling device, which is disposed on one side of the stretching roller 2 and is used to cool the melt 23 .

[0150] Specifically, when the melt 23 is on the stretching roller 2, in addition to being stretched, the melt 23 is also cooled so that the strip-shaped substrate 16 can be formed. Therefore, a cooling device is also provided on one side of the stretching roller 2. The cooling device can specifically be an air-cooling device, which can blow cold air toward the melt 23 on the stretching roller 2 to accelerate its cooling, accelerate the cooling and molding of the melt 23, and quickly form the strip-shaped substrate 16.

[0151] The present application also provides a specific embodiment of a composite pole piece preparation method, which is used to prepare the composite pole piece 11 included in the battery cell 10 provided in any of the above embodiments, comprising:

[0152] The raw material of the diaphragm 112 is prepared into a colloidal melt 23;

[0153] The melt 23 is passed through a plurality of stretching rollers 2 for stretching and cooling to form a strip-shaped substrate 16;

[0154] The strip-shaped substrate 16 wound from the plurality of stretching rollers 2 is stretched and laminated with the strip-shaped sheet 17 via the adhesive layer 3 to form a composite body 25, wherein the strip-shaped sheet 17 is used to form the pole piece body 111;

[0155] The composite body 25 is cut to form composite pole pieces 11 .

[0156] Specifically, the raw materials for forming the diaphragm 112 can be particles of polypropylene, polyethylene, styrene-butadiene rubber, polyacrylate, polyvinylidene fluoride, etc. The raw materials are melted and extruded to form a melt 23. At this time, the melt 23 is a plastic soft structure with a high temperature. First, the melt 23 needs to be stretched for the first time, that is, stretched by multiple stretching rollers 2. The stretching operation is performed by passing the melt 23 around the multiple stretching rollers 2 in sequence, and the melt 23 is cooled during this process to finally form a strip-shaped substrate 16. The strip-shaped substrate 16 is used to form the diaphragm 112. The strip-shaped substrate 16 then needs to be stretched for the second time and then can be bonded to the strip-shaped sheet 17. Specifically, the strip-shaped substrate 16 that comes out of the stretching roller 2 is stretched for the second time and finally bonded to the strip-shaped sheet 17 to form a composite 25. After the composite 25 is cut, a composite pole piece 11 can be formed.

[0157] This embodiment provides a specific method for preparing a composite electrode 11, which can quickly produce a composite electrode 11. During the preparation process, the melt 23 is stretched and cooled, and the strip substrate 16 is stretched, etc., which can effectively adjust various parameters of the diaphragm 112, including material characteristic parameters such as porosity, thickness, and permeability, thereby ensuring the molding quality of the diaphragm 112 and meeting the use requirements.

[0158] It should be noted that the stretching roller 2 may be the third roller 21 and the fourth roller 22 in the above device embodiment, and the number of stretching rollers 2 may be set as needed.

[0159] In some embodiments, preparing the raw material of the diaphragm 112 into a gel-like melt 23 includes: conveying the raw material to an extruder 241 , and extruding the melt 23 through the extruder 241 .

[0160] Specifically, the raw materials can be stored, and when used for production, the raw materials can be transported to the material tank 27, which is connected to the feeding mechanism 243 of the extrusion device 24. The raw materials are fed through the feeding mechanism 243 and melted at high temperature, and then the melt 23 is extruded from the extruder 241.

[0161] In this embodiment, the raw material is melted and extruded by the extrusion device 24 , which is not only fast but also realizes continuous production, and the raw material is prepared into a melt 23 structure that can form the diaphragm 112 .

[0162] In some embodiments, the strip-shaped substrate 16 wound off from multiple stretching rollers 2 is stretched and laminated and bonded with the strip-shaped sheet 17 through an adhesive layer 3 to form a composite body 25, including: spraying the adhesive layer 3 onto the surface of the strip-shaped sheet 17, and the strip-shaped sheet 17 and the strip-shaped substrate 16 wound off the stretching rollers 2 are bonded at the composite roller through the adhesive layer 3 and are synchronously wound off the composite roller to form a composite body 25.

[0163] Specifically, before the strip-shaped sheet 17 is bonded to the strip-shaped substrate 16, an adhesive layer 3 is sprayed on the side intended for bonding with the strip-shaped substrate 16. After the strip-shaped substrate 16 is unwound from the stretching roller 2, it is simultaneously wound onto a composite roller with the strip-shaped sheet 17, with the adhesive layer 3 positioned between the strip-shaped sheet 17 and the strip-shaped substrate 16, bonding the two together. After unwound from the stretching roller 2, the strip-shaped substrate 16 can also be passed over the aforementioned first roller 14 before being bonded to the strip-shaped sheet 17. The first roller 14 and the stretching roller 2 have the same linear speed. The composite roller can be the aforementioned second roller 15.

[0164] The effect of this embodiment is that the bonding layer 3 greatly improves the connectivity between the strip sheet 17 and the strip substrate 16 , thereby maintaining a good integrity between the finally formed diaphragm 112 and the pole piece body 111 .

[0165] In some embodiments, an implementation method for stretching the strip substrate 16 is provided, wherein the linear velocity of the strip substrate 16 when it wraps around the stretching roller 2 is V1, and the linear velocity of the composite 25 moving on the composite roller is V2, where V2 is greater than V1, so as to stretch the strip substrate 16 before composite.

[0166] Specifically, the speed of the strip substrate 16 when it wraps around the stretching roller 2 is V1, that is, the speed at which the strip substrate 16 and the stretching roller 2 move synchronously is V1, that is, the linear speed of the stretching roller 2 is V1, and the speed at which the composite roller drives the composite body 25 to move synchronously is V2, that is, the linear speed of the composite roller is V2, and V2 is greater than V1. In this way, the strip substrate 16 between the stretching roller 2 and the composite roller is stretched, thereby adjusting the various parameters of the later diaphragm 112.

[0167] The effect of this embodiment is that this stretching method also realizes the stretching operation during winding, and completes the stretching process of the strip substrate 16 without stopping the machine. It is not only fast, but also the stretching force of each section of the strip substrate 16 in the length direction is balanced and uniform, so that the consistency of each diaphragm 112 after subsequent cutting is better.

[0168] This embodiment also provides a specific relationship between V2 and V1, that is, V2 is 3 to 15 times of V1, that is, 3 < V2 / V1 < 15. Under this speed ratio, the strip-shaped substrate 16 can be effectively stretched.

[0169] Furthermore, 5<V2 / V1<10, which can achieve better stretching effect.

[0170] It should be noted that the composite roller may be the second roller 15 in the above device embodiment.

[0171] In some embodiments, the extruder 241 has a discharge die 242, and the gap between the discharge die 242 and the first stretching roller 2 is adjustable. The discharge die 242 is used to extrude the melt 23, and when extruded, it will be wound around the first stretching roller 2. Therefore, the gap between the discharge die 242 and the first stretching roller 2 determines the winding thickness of the melt 23 to a certain extent, and also determines the degree of stretching required later and the thickness of the diaphragm 112 finally formed. Therefore, the present embodiment sets the spacing between the discharge die 242 and the stretching roller 2 to be adjustable, which has better operability and is very convenient to adjust the winding thickness of the melt 23 according to the thickness requirements of the diaphragm 112 and the stretching requirements.

[0172] The present application also provides a battery device 100 , comprising the battery cell 10 provided in any of the above embodiments.

[0173] Since the battery device 100 includes the battery cell 10 , the reliability of the battery device 100 is improved.

[0174] The present application also provides an energy storage device, including the above-mentioned battery device 100, and the battery device 100 is used to store or provide electrical energy.

[0175] The energy storage device of this embodiment includes one or more battery clusters to increase the device's voltage and capacity. A battery cluster can include multiple battery devices 100 connected in series via a busbar to increase the device's voltage. When the energy storage device includes multiple battery clusters, the battery clusters are connected in parallel to increase the device's capacity.

[0176] Energy storage devices can be used in energy storage power stations, wind power systems, solar power systems, mobile power systems, or temporary power supply systems. They can store electrical energy as needed and deliver it when appropriate. For example, they can store energy during low-demand periods and provide it to users or devices during peak demand periods.

[0177] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0178] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters housed in the cabinet.

[0179] In some embodiments, the energy storage device may include modules such as a thermal management module, a main control module, a master control module, a power distribution module, and a fire protection module.

[0180] As an example, the thermal management module may include a liquid cooling unit that provides cooling liquid for regulating the temperature of the battery cells 10 to each battery device 100 through pipelines.

[0181] For example, the master control module can serve as the battery management unit (BMU) of a battery cluster, monitoring and managing the battery cluster. The master control module can monitor information such as the battery cluster's current, voltage, power, and temperature. For example, it can control the battery cluster's charge and discharge current and voltage. The master control module includes modules such as the slave battery management unit (SBMU) and a fusion switch.

[0182] As an example, the master control module can serve as a battery management unit of an energy storage device, used to monitor and manage the energy storage device. The master control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device. For example, the charge and discharge current, voltage, etc. of the energy storage device can be controlled. As an example, the master control module includes an insulation monitoring module IMM (IMM), a master battery management unit MBMU (MBMU), an Ethernet ETH (ETH), and a fiber optic conversion module.

[0183] As an example, the fire protection module includes a control panel, detectors, alarm devices, etc., which are used to detect, alarm or extinguish fires in the energy storage system.

[0184] As an example, the power distribution module can be used to distribute power to modules in the energy storage device that require power.

[0185] This embodiment may also provide an energy storage system, including a power conversion device and the above-mentioned energy storage device, wherein the power conversion device is used to electrically connect the power generation device and the energy storage device.

[0186] The energy storage system provided in the embodiments of the present application can be any power system that requires an energy storage device.

[0187] The energy storage system may include one or more energy storage devices and a power converter system (PCS). The power converter system is used to connect between the power generation equipment and the energy storage device. The power generation equipment is used to generate electrical energy, and the electrical energy generated by the power generation equipment can be stored in the energy storage device through the power converter. As an example, the power generation equipment can specifically be solar panels, hydropower generation equipment, thermal power generation equipment, wind power generation equipment, etc. The specific type of power generation equipment is not limited in this application.

[0188] This embodiment further provides an electrical device, which may include the aforementioned battery device 100 or the aforementioned energy storage device, and may also include the aforementioned energy storage system.

[0189] The present application may also provide a charging network, including a charging pile and the above-mentioned energy storage device and / or the above-mentioned energy storage system, wherein the energy storage device is used to provide electrical energy to the charging pile.

[0190] The charging station is electrically connected to the battery device 100 in the energy storage device via a cable. The battery device 100 can provide its stored energy to the charging station. The charging station has one or more connectors for connecting to an electrical device (such as a vehicle 1000) to replenish energy.

[0191] The energy storage device can be located inside the charging pile (such as an integrated storage and charging machine) or outside the charging pile.

[0192] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A composite electrode preparation device, characterized in that: The composite pole piece is used to prepare a battery cell, wherein the composite pole piece includes a pole piece body and a diaphragm. The composite pole piece preparation device includes: a first rotating roller, the first rotating roller being used to pass the strip-shaped substrate forming the diaphragm, wherein the movement speed of the strip-shaped substrate wound around the first rotating roller is equal to the linear speed of the first rotating roller; an extrusion device disposed upstream of the first roller, for extruding the melt; a plurality of stretching rollers disposed upstream of the first roller, for sequentially passing over the melt and longitudinally stretching the melt to obtain the strip-shaped substrate; A second roller is disposed downstream of the first roller and is used to simultaneously pass around the strip of sheet used to prepare the electrode body and the strip of substrate wound from the first roller, so that the strip of sheet and the strip of substrate are bonded to form a composite body. The movement speed of the composite body is equal to the linear speed of the second roller, and the linear speed of the second roller is greater than the linear speed of the first roller. The linear speed of the first roller is V1, and the linear speed of the second roller is V2, then 3<V2 / V1<15; a spraying device, disposed upstream of the second rotating roller, for spraying an adhesive layer onto the surface of the strip-shaped sheet for laminating the strip-shaped substrate; and The cutting device is arranged downstream of the second rotating roller and is used for cutting the composite body to form the composite electrode piece.

2. The composite electrode preparation device according to claim 1, characterized in that: 5<V2 / V1<10.

3. The composite electrode preparation device according to claim 1, characterized in that: The composite electrode preparation device further includes a winding roller, which is used to wind up the composite body wound off from the second rotating roller.

4. The composite electrode preparation device according to claim 1, characterized in that: The extrusion device comprises: An extruder, wherein the extruder has a discharge die head, the discharge die head is used to extrude the melt, and the distance between the discharge die head and the adjacent first stretching roller is adjustable; and The feeding mechanism is used for feeding materials into the extruder.

5. The composite electrode preparation device according to claim 1, characterized in that: The composite electrode preparation device further includes a cooling device, which is arranged on one side of the stretching roller and is used to cool the melt.

6. A method for preparing a composite electrode, characterized in that: The composite pole piece is prepared by the composite pole piece preparation device according to any one of claims 1 to 5, comprising: preparing the diaphragm raw material into a colloidal melt; The melt is passed through a plurality of stretching rollers for stretching and cooling to form a tape-shaped substrate; The strip-shaped substrate wound from the plurality of stretching rollers is stretched and laminated with the strip-shaped sheet through the adhesive layer to form a composite body, wherein the strip-shaped sheet is used to form the pole piece body; The composite body is cut to form composite pole pieces.

7. The method for preparing a composite electrode according to claim 6, wherein: The step of preparing the membrane raw material into a colloidal melt comprises: conveying the raw material to an extruder, and extruding the melt through the extruder.

8. The method for preparing a composite electrode according to claim 6, wherein: The step of stretching the strip-shaped substrate wound from the plurality of stretching rollers and laminating and bonding the strip-shaped substrate with the strip-shaped sheet through the adhesive layer to form a composite body comprises: An adhesive layer is sprayed on the surface of the strip sheet, and the strip sheet and the strip substrate wound off the stretching roller are attached to each other at a composite roller through the adhesive layer and are simultaneously wound off the composite roller to form the composite body.

9. The method for preparing a composite electrode according to claim 8, wherein: The linear velocity of the strip substrate when it winds off the stretching roller is V1, and the linear velocity of the composite body moving on the composite roller is V2, and V2 is greater than V1.

10. The method for preparing a composite electrode according to claim 9, wherein: 3<V2 / V1<15.

11. The method for preparing a composite electrode according to claim 10, wherein: 5<V2 / V1<10.

12. The method for preparing a composite electrode according to claim 7, wherein: The extruder has a discharge die head, and the gap between the discharge die head and the first stretching roller is adjustable.

13. A battery device, characterized in that: A battery cell comprising a composite pole piece prepared by the composite pole piece preparation device according to any one of claims 1 to 5 or the composite pole piece preparation method according to any one of claims 6 to 12.

14. An energy storage device, characterized in that: The battery device according to claim 13 is used to store or provide electrical energy.

15. An electrical device, characterized in that: Comprising the battery device according to claim 13 or the energy storage device according to claim 14.

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