Pole piece production device and battery production system

Abstract

The utility model provides a pole piece production device and a battery production system, and solves the problem of how to improve the compaction density of a pole piece in the prior art. The pole piece production device comprises a rolling mechanism; the rolling mechanism comprises a first roller and a second roller which are oppositely arranged and is used for rolling the pole piece; and at least one of the first roller and the second roller is a vibrating roller.

Description

Technical Field

[0001] This application relates to the technical field of battery electrode sheet processing, and particularly to an electrode sheet production device and a battery production system. Background Art

[0002] During the production process of battery electrode sheets, the high compaction density of the electrode sheet is one of the important improvement paths for enhancing the energy density of battery monomers. The existing cold rolling equipment can achieve a limited compaction density, and how to improve the compaction density of the electrode sheet has become a problem to be solved. Summary of the Utility Model

[0003] The main technical problem to be solved by this application is to provide an electrode sheet production device and a battery production system to solve the problem of how to improve the compaction density of the electrode sheet in the prior art.

[0004] To solve the above technical problem, the first technical solution provided by this application is: to provide an electrode sheet production device, including a rolling mechanism; the rolling mechanism includes a first roll and a second roll arranged oppositely, for rolling the electrode sheet; wherein, at least one of the first roll and the second roll is a vibrating roll.

[0005] In this embodiment, at least one of the rolls in the rolling mechanism is set as a vibrating roll. The vibrating roll can release the stress in the electrode sheet during the rolling process of the electrode sheet, making the contact between the internal materials of the electrode sheet closer, thereby improving the compaction density.

[0006] In some embodiments, the radii of the first roll and the second roll are 700 - 800 mm.

[0007] In this embodiment, the radii of the rolls are selected to be 700 - 800 mm. During the rolling process of the electrode sheet, it is beneficial to increase the contact area between the electrode sheet and the rolls, can distribute the pressure more effectively, reduce the pressure per unit area, and thus reduce the risk of damage to the electrode sheet caused by excessive compression.

[0008] In some embodiments, along the vertical direction, the first roll is located above the second roll, and only the first roll is a vibrating roll.

[0009] In this embodiment, the vibrating roll is arranged above the electrode sheet, and the gravity is used to help the electrode sheet better fit the second roll, thereby improving the compaction effect. At the same time, it also helps to reduce the lateral offset of the electrode sheet when passing through the vibrating roll.

[0010] In some embodiments, the pole piece production device further includes a traction mechanism, a driving mechanism, and a control circuit; the traction mechanism is used to traction the pole piece so that the pole piece is transmitted within the gap between the first roll and the second roll; the driving mechanism is connected to the rolling mechanism and is used to drive the first roll to rotate while vibrating in the vertical direction; the control circuit is electrically connected to the traction mechanism and the driving mechanism respectively; wherein, the control circuit is used to control the tape running speed of the pole piece to be 50-110 m / min through the traction mechanism, and control the vibration frequency of the first roll to be 500 Hz-3400 Hz through the driving mechanism.

[0011] In this embodiment, the tape running speed of the pole piece is 50-110 m / min, which enables the pole piece to have an appropriate moving speed, facilitating the preparation of the pole piece and the control of the production rhythm. Secondly, the vibration frequency of the first roll is selected to be 500 Hz-3400 Hz, which is convenient for eliminating the stress in the pole piece, thereby reducing the risk of local stress concentration and reducing the springback of the thickness of the pole piece, contributing to improving the compaction density of the pole piece.

[0012] In some embodiments, the control circuit is further used to control the tape running speed of the pole piece and the vibration frequency of the first roll to satisfy: the tape running speed of the pole piece is 50-70 m / min, and the vibration frequency of the first roll is 500 Hz-2000 Hz; or the tape running speed of the pole piece is 70-90 m / min, and the vibration frequency of the first roll is 700 Hz-2800 Hz; or the tape running speed of the pole piece is 90-110 m / min, and the vibration frequency of the first roll is 840 Hz-3400 Hz.

[0013] In this embodiment, the tape running speed of the pole piece is associated with the vibration frequency of the first roll to prevent resonance, ensuring the stability during the pole piece rolling process and the quality of the pole piece.

[0014] In some embodiments, the control circuit is further used to control the vibration amplitude of the first roll to be 10-20 μm through the driving mechanism.

[0015] In this embodiment, by controlling the vibration amplitude of the first roll to be 10-20 μm, relatively obvious vibration marks can be generated on the surface of the pole piece, increasing the surface area of the pole piece, thereby improving the infiltration efficiency.

[0016] In some embodiments, the first roll includes a roll body and a plurality of eccentric rotors; the plurality of eccentric rotors are arranged inside the roll body.

[0017] In this embodiment, a plurality of eccentric rotors are arranged inside the first roll to utilize the centrifugal force generated by the rotation of the eccentric rotors to make the first roll vibrate periodically, so that vibration marks can be generated on the surface of the pole piece during the rolling process of the pole piece.

[0018] In some embodiments, the rolling mechanism is a cold rolling mechanism.

[0019] In this embodiment, the rolling mechanism is a cold pressing rolling mechanism. Since the operating conditions are relatively mild, the thickness, density, and surface quality of the electrode sheet are easier to control, and the consistency between different batches of products is better. Secondly, in this embodiment, vibration and cold pressing are integrated into the rolling mechanism, which has a simple structure and is beneficial to simplifying the processing flow of the electrode sheet. In addition, the rebound rate of the electrode sheet after conventional cold pressing rolling can also be reduced, thereby improving the thickness consistency of the cold-pressed electrode sheet after rebound.

[0020] In some embodiments, the electrode sheet production device further includes a coating mechanism and a drying mechanism; the coating mechanism is used to coat the current collector to obtain the electrode sheet; the drying mechanism is arranged upstream of the rolling mechanism and is used to dry the electrode sheet.

[0021] In this embodiment, the electrode sheet is cold-pressed after drying, so that during the rolling process of the electrode sheet, the material properties are more stable and more compatible with subsequent processes.

[0022] To solve the above technical problems, the second technical solution provided by this application is: to provide a battery production system, including the above-mentioned electrode sheet production device and a battery assembly device; the battery assembly device is used to assemble the electrode sheets prepared by the electrode sheet production device into battery monomers.

[0023] In this embodiment, the battery production system includes the above-mentioned electrode sheet production device. Therefore, the battery production system has the same technical effects as the above-mentioned electrode sheet production device.

[0024] To solve the above technical problems, the third technical solution provided by this application is: to provide a battery monomer, which includes a housing and battery electrode sheets. The battery electrode sheets include current collectors and active layers; the active layers are arranged on at least one surface of the current collectors; wherein, the surface of the active layer far from the current collector has a plurality of depressions arranged at intervals, and the inner wall surface of the depressions is an arc-shaped curved surface.

[0025] In this embodiment, the surface of the battery electrode sheet of the battery monomer is designed with a plurality of depressions arranged at intervals, which can increase the surface area of the battery electrode sheet, thereby improving the infiltration efficiency.

[0026] In some embodiments, the surface of the active layer far from the current collector is wavy, and the wavy shape has a plurality of wave peaks and a plurality of wave valleys arranged alternately; the wave valleys are depressions.

[0027] In this embodiment, the surface of the battery electrode sheet is wavy, which can increase the surface area of the battery electrode sheet, thereby improving the infiltration efficiency and heat dissipation efficiency; secondly, the wavy surface can compensate for the slight fluctuations in the thickness of the battery electrode sheet by adjusting the heights of the wave peaks and wave valleys, thereby improving the overall thickness consistency of the battery electrode sheet.

[0028] In some embodiments, the distance between two adjacent wave crests is 0.5 to 2 mm.

[0029] In this embodiment, the distance between two adjacent wave crests is 0.5 to 2 mm to select appropriate heights of the wave crests and wave troughs, so that the pole piece has appropriate surface texture. While increasing the surface area of the battery pole piece, it is beneficial to improve the overall thickness consistency of the battery pole piece.

[0030] In some embodiments, along the thickness direction of the active layer, the distance from the highest point of the wave crest to the lowest point of the wave trough is 10 to 20 μm.

[0031] In this embodiment, the distance from the highest point of the wave crest to the lowest point of the wave trough is 10 to 20 μm, so that the battery pole piece has appropriate surface texture. While increasing the surface area of the battery pole piece, it is beneficial to improve the overall thickness consistency of the battery pole piece.

[0032] In some embodiments, the number of active layers is two, namely a first active layer disposed on one surface of the current collector and a second active layer disposed on the other surface of the current collector. The wave shape of the surface of the first active layer far from the current collector is a mirror image of the wave shape of the surface of the second active layer far from the current collector.

[0033] In this embodiment, the surfaces on the opposite sides of the pole piece are wave shapes that are mirror images of each other, which can increase the surface area of the battery pole piece as much as possible. At the same time, it is convenient to adjust the overall thickness consistency of the battery pole piece.

[0034] To solve the above technical problems, the fourth technical solution provided by this application is: to provide a battery device. The battery device includes the above-mentioned battery cell.

[0035] In this embodiment, the battery device includes the above-mentioned battery cell, so the battery device has the same technical effects as the above-mentioned battery cell.

[0036] To solve the above technical problems, the fifth technical solution provided by this application is: to provide an electrical equipment. The electrical equipment includes the above-mentioned battery device.

[0037] In this embodiment, the electrical equipment includes the above-mentioned battery device, so the electrical equipment has the same technical effects as the above-mentioned battery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without any creative work, other drawings can also be obtained based on these drawings.

[0039] Figure 1 is a schematic structural diagram of an embodiment of an electrical device provided by the present application;

[0040] Figure 2 is a three-dimensional structural diagram of an embodiment of a battery device provided by the present application;

[0041] Figure 3 is an exploded structural diagram of an embodiment of a battery cell provided by an embodiment of the present application;

[0042] Figure 4 is a schematic structural diagram of an embodiment of a battery electrode provided by an embodiment of the present application;

[0043] Figure 5 is a schematic structural diagram of an embodiment of a battery production system provided by an embodiment of the present application;

[0044] Figure 6 is a schematic structural diagram of a pole piece production device in a first vibration mode and a pole piece provided by an embodiment of the present application;

[0045] Figure 7 is a schematic connection structural diagram of a rolling mechanism, a driving mechanism and a control circuit in a battery production system provided by an embodiment of the present application;

[0046] Figure 8 is Figure 6 an enlarged structural diagram at K in;

[0047] Figure 9 is a schematic structural diagram of a pole piece production device in a second vibration mode and a pole piece provided by an embodiment of the present application;

[0048] Figure 10 is a schematic structural diagram of a pole piece production device in a third vibration mode and a pole piece provided by an embodiment of the present application.

[0049] Explanation of the reference numerals in the drawings:

[0050] 100. Battery production system; 1. Electrode sheet production device; 10. Rolling mechanism; 10A. First roll; 11. Roll body; 12. Eccentric rotor; 10B. Second roll; 20. Traction mechanism; 30. Driving mechanism; 40. Control circuit; 50. Coating mechanism; 60. Drying mechanism; 2. Electrode sheet; 3. Battery assembly device; 4. Battery device; 410. Battery cell; 41. Connecting member; 42. Cover plate; 43. Terminal post; 44. Safety valve; 45. Electrode assembly; 46. Housing; 421. Box body; 421A. First part; 421B. Second part; 47. Battery electrode sheet; 471. Current collector; 472. Active layer; 4720. Depression; 472A. First active layer; 472B. Second active layer; 5. Electrical appliance; A. Vibration amplitude; λ. Spacing. Detailed implementation manners

[0051] The following will, with reference to the accompanying drawings of the specification, elaborate on the solutions of the embodiments of the present application in detail.

[0052] In the following description, specific details such as specific system structures, interfaces, and technologies are presented for the purpose of illustration rather than limitation, so as to understand the present application thoroughly.

[0053] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0054] The terms "first", "second", and "third" in the present application are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0055] As used herein, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of the present application. The phrase may not necessarily refer to the same embodiment at various positions in the specification, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0056] In the production process of battery electrodes, the high compaction density of electrodes is one of the important improvement paths for enhancing the energy density of battery cells. The existing cold rolling process has reached its limit in different material systems such as graphite, lithium iron phosphate, and ternary materials, and the breakage rate of electrodes remains high during the extreme cold rolling process.

[0057] In the related art, generally, after the roller rolls the electrode, the vibratory roller is used to vibrate the rolled electrode. This method has a complex process flow and limited production efficiency.

[0058] To solve the problem of how to improve the compaction density of electrodes in the prior art, the present application provides an electrode production device, including a rolling mechanism; the rolling mechanism includes a first roller and a second roller arranged oppositely, which are used to roll the electrode; wherein, at least one of the first roller and the second roller is a vibratory roller. In this embodiment, at least one roller in the rolling mechanism is set as a vibratory roller. The vibratory roller can release the stress in the electrode during the rolling process of the electrode, making the contact between the internal materials of the electrode closer, thereby improving the compaction density.

[0059] See Figure 1 , an embodiment of the present application provides an electrical device, and the electrical device includes a battery device 4.

[0060] The electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, and an electric tool, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc. The spacecraft includes an airplane, a rocket, a space shuttle, and a spaceship, etc. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, and an electric airplane 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, a hammer drill, an impact electric drill, a concrete vibrator, and a planer, etc. For the convenience of description, the following embodiments take the electrical device as a vehicle as an example for illustration.

[0061] In some embodiments, the electrical device further includes an electrical appliance component 5. The battery device 4 is electrically connected to the electrical appliance component 5. The battery device 4 is used to supply electrical energy to the electrical device so that the electrical appliance component 5 can operate.

[0062] The electrical appliance component 5 can be an element or device that can use electricity; the electrical appliance component 5 can be a controller and electronic components, etc. The controller can be a Central Processing Unit (CPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0063] In some examples, the electrical device can be a vehicle, and the electrical appliance component 5 can be a vehicle lamp (such as a headlamp, a taillight, etc.), a display screen, an instrument panel, a control system (such as a controller), etc. The vehicle can also include a vehicle frame, and both the battery device 4 and the electrical appliance component 5 are mounted on the vehicle body.

[0064] See Figure 2 , the embodiment of the present application also provides a battery device 4, and the battery device 4 includes battery cells 410.

[0065] The battery device 4 may further include a battery box 421. The battery box 421 has a chamber, and one or more battery cells 410 are accommodated in the chamber. The battery box 421 can play a role in protecting the battery cells 410 and also facilitates concentrating multiple battery cells 410 together. The shape of the battery box 421 can be specifically set according to needs. For example, the shape of the battery box 421 can be cylindrical, rectangular, etc.

[0066] Among them, the box 421 can adopt various structures. In some embodiments, the box 421 can include a first part 421A and a second part 421B. The first part 421A and the second part 421B are covered with each other, and the first part 421A and the second part 421B jointly define an accommodation space for accommodating the battery cells 410. The second part 421B can be a hollow structure with one end open, and the first part 421A can be a plate-like structure. The first part 421A covers the open side of the second part 421B so that the first part 421A and the second part 421B jointly define the accommodation space; the first part 421A and the second part 421B can also both be hollow structures with one side open, and the open side of the first part 421A covers the open side of the second part 421B.

[0067] Such as Figure 3 and Figure 4As shown in the figure, an embodiment of the present application further provides a battery cell 410. The battery cell 410 includes a housing 46 and battery electrodes 47; the battery electrodes 47 include a current collector 471 and an active layer 472; the active layer 472 is disposed on at least one surface of the current collector 471; wherein, the surface of the active layer 472 away from the current collector 471 has a plurality of recesses 4720 arranged at intervals, and the inner wall surface of the recesses 4720 is an arc-shaped curved surface.

[0068] The battery cell 410 can be a secondary battery, which refers to a battery cell 410 that can be activated by charging after discharging to continue to be used. The battery cell 410 can include, but is not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0069] The housing 46 has a communicating cavity and an installation opening. The housing 46 is a hollow structure, and the material of the housing 46 can be metal or plastic; for example, the material of the housing 46 can be copper, iron, aluminum, steel, aluminum alloy, etc. The outer wall surface of the housing 46 is a ring-shaped structure. The outer wall surface of the housing 46 encloses to form a communicating cavity. The cross-section of the housing 46 can be in the shape of a rectangle, triangle, rhombus, etc. The housing 46 is filled with an electrolyte, such as an electrolyte solution.

[0070] The battery cell 410 can include an electrode assembly 45 and a cover plate 42. The cover plate 42 is connected to the housing 46 and covers the installation opening.

[0071] The number of the electrode assemblies 45 can be one or more; the electrode assemblies 45 are installed in the cavity of the housing 46. During the charge and discharge process of the battery cell 410, active ions (such as lithium ions) are embedded and extracted back and forth between the anode electrode and the cathode electrode. The separator can play a role in preventing the anode electrode from short-circuiting with the cathode electrode to a certain extent, and at the same time can allow active ions to pass through.

[0072] The battery cell 410 can further include a safety valve 44 (which can also be called a pressure relief valve), two pole columns 43, and two connection members 41 (which can also be called current collecting members). The safety valve 44 can be disposed on the cover plate 42, for example, the safety valve 44 is fixed on the cover plate 42, and the safety valve 44 is used to actuate to discharge the internal electrolyte when the internal pressure or temperature of the battery cell 410 reaches a threshold value to reduce the internal pressure or temperature of the battery cell 410. For example, the safety valve 44 can be a temperature-sensitive valve, a pressure-sensitive valve, etc. The two pole columns 43 can be disposed on the cover plate 42. The two pole columns 43 are respectively a positive pole column 43 and a negative pole column 43, and one pole column 43 is correspondingly connected to one connection member 41. The connection member 41 is located between the cover plate 42 and the electrode assembly 45 and is used to electrically connect the electrode assembly 45 and the pole column 43.

[0073] The battery electrode 47 is the region where electrochemical reactions occur in the battery cell 410, and it is divided into a positive electrode and a negative electrode. During the charge and discharge process, lithium ions (or other ions) move between the positive electrode and the negative electrode, generating an electric current.

[0074] The current collector 471 is divided into a positive current collector and a negative current collector.

[0075] In some examples, aluminum foil is usually used as the positive current collector. Aluminum foil has good electrical conductivity and corrosion resistance, and can effectively collect and transmit electrons.

[0076] In some examples, copper foil is usually used as the negative current collector. Copper foil has better electrical conductivity and is suitable for use in the negative electrode.

[0077] The active layer 472 is divided into a positive active layer and a negative active layer.

[0078] The positive active layer includes lithium iron phosphate (LFP), ternary materials (such as NCM, NCA), lithium cobalt oxide (LCO), etc. These materials can intercalate and deintercalate lithium ions, thus realizing the charge and discharge process.

[0079] The negative active layer includes graphite, silicon-based materials, lithium titanate (LTO), etc.

[0080] When the battery electrode 47 is the positive electrode, the current collector 471 is the positive current collector, and the active layer 472 is the positive active layer; when the battery electrode 47 is the negative electrode, the current collector 471 is the negative current collector, and the active layer 472 is the negative active layer.

[0081] The battery electrode 47 may also include a binder, which is used to adhere the active material particles in the active layer 472 to the current collector 471 to ensure that they do not fall off during the charge and discharge process. Commonly used binders include polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (CMC), etc.

[0082] The battery electrode 47 may also include a conductive agent, which is used to improve the electrical conductivity of the active layer 472 and reduce the internal resistance. Commonly used conductive agents include carbon black (Super P), carbon nanotubes (CNT), graphene, etc.

[0083] The active layer 472 can be disposed on one surface of the current collector 471, or can also be disposed on two surfaces on opposite sides of the active layer 472. In this embodiment, the example of double-sided coating of the active layer 472 on the current collector 471 is mainly used for illustration.

[0084] Due to the first rolling mill 10A (see Figure 6 ), and the second rolling mill 10B (see Figure 6)(All are cylindrical. During the vibration of the roller, the contact surface between the active layer 472 and the surface of the roller body 11 of the roller forms a concave 4720 with an arc-shaped surface.)

[0085] In this embodiment, the surface of the battery electrode sheet 47 is designed with a plurality of recesses 4720 with arc-shaped surfaces arranged at intervals, which can increase the surface area of the battery electrode sheet 47, thereby improving the wetting efficiency. Moreover, the recess 4720 with an arc-shaped surface can be directly formed by rolling through the rolling mechanism 10 of the electrode sheet production device 1 of the present application, with a simple process and high production efficiency.)

[0086] In some embodiments, the surface of the active layer 472 away from the current collector 471 is wavy, with a plurality of alternately arranged wave peaks and a plurality of wave valleys; the wave valleys are the recesses 4720.)

[0087] The wave peak refers to the highest point on a periodic fluctuation or surface. The wave valley refers to the lowest point on a periodic fluctuation or surface.)

[0088] In this embodiment, the surface of the battery electrode sheet 47 is wavy, which can increase the surface area of the battery electrode sheet 47, thereby improving the wetting efficiency and heat dissipation efficiency; secondly, the wavy surface can adjust the small fluctuations in the thickness of the battery electrode sheet 47 by adjusting the heights of the wave peaks and wave valleys, thereby improving the overall average thickness consistency of the battery electrode sheet 47.)

[0089] In some embodiments, the distance λ between two adjacent wave peaks is 0.5 - 2 mm.)

[0090] In this embodiment, the distance λ between two adjacent wave peaks is 0.5 - 2 mm to select appropriate heights of the wave peaks and wave valleys, so that the electrode sheet 2 has appropriate surface patterns, which is beneficial to improving the overall average thickness consistency of the battery electrode sheet 47 while increasing the surface area of the battery electrode sheet 47.)

[0091] In some embodiments, along the thickness direction of the active layer 472, the distance from the highest point of the wave peak to the lowest point of the wave valley is 10 - 20 μm. That is, the vibration amplitude A is 10 - 20 μm.)

[0092] In this embodiment, the distance from the highest point of the wave peak to the lowest point of the wave valley is 10 - 20 μm, so that the battery electrode sheet 47 has appropriate surface patterns, which is beneficial to improving the overall thickness consistency of the battery electrode sheet 47 while increasing the surface area of the battery electrode sheet 47.)

[0093] In some embodiments, the number of active layers 472 is two, namely a first active layer 472A disposed on one surface of the current collector 471 and a second active layer 472B disposed on the other surface of the current collector 471. The wave shape on the surface of the first active layer 472A away from the current collector 471 is a mirror image of the wave shape on the surface of the second active layer 472B away from the current collector 471.

[0094] A mirror image refers to the symmetric mapping of an object or a figure with respect to a certain plane (mirror surface).

[0095] In this embodiment, the surfaces on the opposite sides of the electrode tab 2 are wave-shaped and are mirror images of each other, which can increase the surface area of the battery electrode tab 47 as much as possible. At the same time, it is convenient to adjust the overall thickness consistency of the battery electrode tab 47.

[0096] As Figure 5 shown, the present application also provides a battery production system 100, including an electrode tab production device 1 and a battery assembly device 3; the battery assembly device 3 is used to assemble the electrode tabs 2 prepared by the electrode tab production device 1 into battery cells 410.

[0097] The battery production system 100 is used to prepare battery cells 410.

[0098] In some embodiments, the battery assembly device 3 may further include structures such as an electrode tab cutting mechanism (not shown in the figure), a winding mechanism (not shown in the figure), a case loading mechanism (not shown in the figure), a liquid injection mechanism (not shown in the figure), etc.

[0099] The electrode tab cutting mechanism performs different cutting and slitting processes on the to-be-processed electrode tab to form the battery electrode tab 47 for manufacturing the battery cell 410. The to-be-processed electrode tab may be the electrode tab 2 produced by the electrode tab production device 1.

[0100] In some examples, the electrode tab cutting mechanism cuts the continuously produced long strip-shaped electrode tab 2 according to a predetermined size to obtain a battery electrode tab 47 with a length and width meeting the design requirements of the battery cell 410. The cut electrode tab 2 will enter the winding or stacking process to form the electrode assembly 45.

[0101] For cylindrical or soft-pack battery cells 410, the winding mechanism is responsible for sequentially laminating and winding the anode electrode tab, the separator, and the cathode electrode tab into a tight cylinder or bag-like structure to form the electrode assembly 45. For square battery cells, stacking may be used instead of winding.

[0102] The case loading mechanism loads the wound or stacked electrode assembly 45 into a pre-prepared case 46, fixes the position, and seals it to prevent the external environment from affecting the performance of the battery cell 410.

[0103] The liquid injection mechanism injects an appropriate amount of electrolyte into the interior of the housing 46. The electrolyte acts as an ion transport medium in the battery cell 410, enabling ions to move between the positive and negative electrodes, thereby realizing the charge and discharge process.

[0104] As Figure 5 and Figure 6 shown, an electrode sheet production apparatus 1 is further provided in an embodiment of the present application. The electrode sheet production apparatus 1 includes a rolling mechanism 10; the rolling mechanism 10 includes a first roll 10A and a second roll 10B which are oppositely arranged and are used for rolling the electrode sheet 2; wherein, at least one of the first roll 10A and the second roll 10B is a vibrating roll.

[0105] The rolling mechanism 10 is used for calendering the electrode sheet 2. During the process of rolling the electrode sheet 2, the electrode sheet 2 is located at the gap between the first roll 10A and the second roll 10B. Calendering refers to applying mechanical pressure to a material through a pair or more pairs of rotating rolls to cause plastic deformation of the material, thereby changing its thickness, density, and surface characteristics. During the manufacturing process of the battery cell 410, calendering is used to further compact the electrode sheet 2 after coating and drying to improve its performance.

[0106] Each roll includes a roll body 11. The roll body 11 is the main structure of the roll, and the surface of this main structure is usually a cylindrical surface. The roll body 11 is installed on a rotating shaft (not shown in the figure), and transmission devices such as gears, chains, or belts can be connected to both ends of the rotating shaft so that the roll body 11 can be driven to rotate by an external motor.

[0107] A vibrating roll is a mechanical structure that compacts materials by generating periodic vibrations. The vibrating roll uses vibration energy to rearrange the particles in the material to be compacted, eliminating air gaps, thereby improving the density of the material. The vibrating roll can both rotate and vibrate, and can vibrate while rotating.

[0108] In some examples, one of the first roll 10A and the second roll 10B is a vibrating roll. Using one vibrating roll to improve the compaction density of the electrode sheet 2 can simplify the structure and control of the rolling mechanism 10.

[0109] In other examples, both the first roll 10A and the second roll 10B are vibrating rolls. The two vibrating rolls can produce a synergistic effect to further improve the compaction effect of the electrode sheet 2, that is, increase the upper limit of the compaction density of the electrode sheet 2. For example, when both the first roll 10A and the second roll 10B are vibrating rolls, the vibration directions of the first roll 10A and the second roll 10B are opposite.

[0110] The sizes of the first roller 10A and the second roller 10B can be the same or different. For example, one of the two larger rollers can provide a larger contact area, while the smaller roller can be used for quick response or finer control. For another example, the surface of one of the two rollers is smooth and the surface of the other roller is textured, so that the sizes of the two rollers are different.

[0111] In some examples, the first roller 10A and the second roller 10B have the same size (i.e., the same radius), and the surfaces of both the first roller 10A and the second roller 10B are smooth.

[0112] In this embodiment, at least one roller in the rolling mechanism 10 is set as a vibrating roller. The vibrating roller can release the stress in the pole piece 2 during the process of rolling the pole piece 2, making the contact between the internal materials of the pole piece 2 closer, so as to improve the compaction density.

[0113] In some embodiments, the radii of the first roller 10A and the second roller 10B are 700 - 800 mm.

[0114] The radii of the first roller 10A and the second roller 10B can take values such as 700 mm, 720 mm, 740 mm, 760 mm, 780 mm or 800 mm.

[0115] In some examples, the radii of both the first roller 10A and the second roller 10B are 750 mm.

[0116] In this embodiment, since the vibrating roller rotates and vibrates during the process of the rolling mechanism 10 rolling the pole piece 2, compared with the roller that only rotates without vibrating, under the same pressure, the pressure of the vibrating roller on the pole piece 2 in the embodiment of the present application will increase. Selecting the radius of the roller to be 700 - 800 mm is beneficial to increasing the contact area between the pole piece 2 and the roller, can distribute the pressure more effectively, reduce the pressure per unit area, and thus reduce the risk of damage to the pole piece 2 caused by excessive compression.

[0117] In some embodiments, along the vertical direction, the first roller 10A is located above the second roller 10B, and only the first roller 10A is a vibrating roller.

[0118] The vertical direction can be the direction of gravity. Setting the vibrating roller above the pole piece 2 is convenient for the operator to observe the vibration lines on the surface of the pole piece 2 (see Figure 8 )

[0119] In other embodiments, along the vertical direction, the first roller 10A can be located below the second roller 10B, and only the first roller 10A is a vibrating roller.

[0120] In this embodiment, the vibrating roller is arranged above the electrode sheet 2, and the gravity is utilized to help the electrode sheet 2 better adhere to the second rolling roller 10B, thereby improving the compaction effect. Meanwhile, it also helps to reduce the lateral offset of the electrode sheet 2 when passing through the vibrating roller.

[0121] In some other embodiments, the first rolling roller 10A and the second rolling roller 10B can be arranged along the horizontal direction, and the horizontal direction is perpendicular to the gravity direction, that is, the first rolling roller 10A and the second rolling roller 10B are arranged left and right. In other embodiments, the first rolling roller 10A and the second rolling roller 10B can also be arranged along other directions.

[0122] As Figure 5 and Figure 7 shown, in some embodiments, the electrode sheet production device 1 further includes a traction mechanism 20, a driving mechanism 30 and a control circuit 40; the traction mechanism 20 is used to traction the electrode sheet 2 so that the electrode sheet 2 is transmitted in the gap between the first rolling roller 10A and the second rolling roller 10B; the driving mechanism 30 is connected to the rolling mechanism 10 and is used to drive the first rolling roller 10A to rotate and vibrate along the vertical direction at the same time; the control circuit 40 is electrically connected to the traction mechanism 20 and the driving mechanism 30 respectively; wherein, the control circuit 40 is used to control the running speed of the electrode sheet 2 to be 50-110 m / min through the traction mechanism 20, and control the vibration frequency of the first rolling roller 10A to be 500 Hz-3400 Hz through the driving mechanism 30.

[0123] The traction mechanism 20 provides a stable traction force and running speed for the electrode sheet 2 to ensure uniform tension of the electrode sheet 2 during transmission and prevent wrinkles or breaks.

[0124] The traction mechanism 20 may further include traction rollers. The traction rollers may be components that directly contact the electrode sheet 2 and drive the electrode sheet 2 to move. The traction rollers can be used in pairs and are composed of two or more upper and lower rollers. The electrode sheet 2 is pulled forward by the friction between these rollers. There may be multiple traction mechanisms 20.

[0125] The traction rollers can be rubber-coated to increase the friction with the electrode sheet 2 and prevent slipping. The traction rollers can also be metal rollers with special textures or coatings, which are suitable for electrode sheets 2 of specific types of materials.

[0126] The traction mechanism 20 may further include a driving motor, and the driving motor provides power for the traction rollers. It can be a servo motor or a stepping motor, which can provide precise speed and position control to ensure that the electrode sheet 2 moves at a predetermined speed and along a predetermined path.

[0127] The traction mechanism 20 may further include a guiding device, and the guiding device is used to ensure that the electrode sheet 2 advances along the correct path and reduce offset or winding. The guiding device can be a fixed guide rail, guide wheel or an adjustable guiding plate.

[0128] The driving mechanism 30 is connected to the rolling mechanism 10, and can provide power for the first roll 10A and the second roll 10B to rotate and perform rolling treatment on the pole piece 2.

[0129] The driving mechanism 30 may include a driving motor (not shown in the figure). The driving motor provides power for the rolls. The driving motor can be an AC motor, a DC motor, a servo motor or a stepper motor. The driving motors for the traction roll and the rolls are different to facilitate the precise control of the rotational speeds of the traction roll and the rolls.

[0130] The driving mechanism 30 may also include a reducer (not shown in the figure). The reducer converts the high-speed rotation of the driving motor into a low-speed and high-torque output suitable for the rolls. The selection of the reducer needs to be optimized according to the required speed ratio and torque requirements. The reducer can be a gear reducer, a worm and worm gear reducer or a planetary gear reducer, etc.

[0131] The driving mechanism 30 may also include a coupling (not shown in the figure). The coupling connects the driving motor and the reducer, or connects the reducer and the rotating shaft (i.e., the roll shaft) that drives the rolls to rotate, transmits torque and compensates for the small alignment error between the two shafts. The coupling can be a rigid coupling, an elastic coupling or a universal joint coupling, etc.

[0132] The driving mechanism 30 may also include a transmission system (not shown in the figure). The transmission system can be a belt drive, and the power of the driving motor is transmitted to the roll shaft through a belt. The transmission system can be a chain drive, and the power of the driving motor is transmitted to the roll shaft through a chain. The transmission system can be a gear drive, and the power of the driving motor is directly transmitted to the roll shaft through gears. The transmission system is selected according to actual requirements.

[0133] The control circuit 40 is connected to the traction mechanism 20 and the driving mechanism 30, and coordinates their operations. The control circuit 40 consists of two parts: hardware and software. The hardware includes various sensors, controllers, actuators, etc., and the software includes control algorithms and user interfaces.

[0134] The sensor can be at least one of a speed sensor, a tension sensor, a position sensor and a temperature sensor. The speed sensor monitors the speeds of the traction mechanism 20 and the driving mechanism 30 in real time to ensure their synchronous operation. The tension sensor monitors the tension of the pole piece 2 during transmission to prevent damage or deformation of the pole piece 2 caused by being too tight or too loose. The position sensor monitors the position of the pole piece 2 to ensure that it maintains the correct path during transmission and rolling. The temperature sensor monitors the temperatures of the driving motor, the reducer and other key components to prevent overheating damage.

[0135] The controller includes a PLC (Programmable Logic Controller), a motion controller, and a variable frequency drive (VFD), etc. As the core control unit, the PLC is responsible for receiving signals from sensors and sending instructions to actuators according to preset control logic to regulate the operation of the traction mechanism 20 and the drive mechanism 30. The motion controller is specifically used to control the motion of the drive motor and can achieve precise speed, position, and torque control. The variable frequency controller is used to adjust the speed of the drive motor to ensure that the speeds of the traction mechanism 20 and the drive mechanism 30 can be flexibly adjusted according to production requirements.

[0136] Control algorithms can include PID control (Proportional-Integral-Derivative Control), fuzzy control, or adaptive control, etc. PID control achieves precise control of speed, tension, and position through the adjustment of three parameters: proportional, integral, and derivative. Fuzzy control is a control method based on fuzzy logic and can achieve good control effects under uncertain and complex environments. Adaptive control automatically adjusts control parameters according to the dynamic changes of the system to ensure the best control effect.

[0137] The user interface includes a touch screen, providing an interface for operators to interact with the control system, facilitating the setting and monitoring of production processes.

[0138] In some examples, the control circuit 40 can receive information from sensors, such as parameters like the thickness, speed, and tension of the pole piece 2, and adjust the actions of the traction mechanism 20 and the drive mechanism 30 according to this information to ensure that the produced pole piece 2 meets the predetermined specifications and quality standards. In addition, the control circuit 40 may also include a safety protection mechanism, such as automatically stopping the operation of the equipment when an abnormal situation is detected.

[0139] The running speed of the pole piece 2 refers to the speed at which the traction mechanism 20 drives the pole piece 2 to move.

[0140] The vibration frequency of the rolling mill roll refers to the number of periodic vibrations that occur during the operation of the roll.

[0141] In this embodiment, the running speed of the pole piece 2 is 50 - 110 m / min, which enables the pole piece 2 to have an appropriate moving speed, facilitating the preparation of the pole piece 2 and the control of the production rhythm. Secondly, the vibration frequency of the first rolling mill roll 10A is selected to be 500 Hz - 3400 Hz, which is convenient for eliminating the stress in the pole piece 2, thereby reducing the risk of local stress concentration and reducing the springback of the thickness of the pole piece 2, contributing to improving the compaction density of the pole piece 2.

[0142] In some embodiments, the control circuit 40 is also used to control the tape speed of the pole piece 2 and the vibration frequency of the first roller 10A to satisfy: the tape speed of the pole piece 2 is 50~70m / min, and the vibration frequency of the first roller 10A is 500Hz~2000Hz; or the tape speed of the pole piece 2 is 70~90m / min, and the vibration frequency of the first roller 10A is 700Hz~2800Hz; or the tape speed of the pole piece 2 is 90~110m / min, and the vibration frequency of the first roller 10A is 840Hz~3400Hz.

[0143] The conveying speed of the pole piece 2 and the vibration frequency of the first roller 10A will affect the size of the vibration pattern (ie, texture) on the surface of the pole piece 2. Appropriate vibration pattern is selected according to actual needs.

[0144] In this embodiment, the tape running speed of the pole piece 2 is associated with the vibration frequency of the first roller 10A to prevent resonance, thereby ensuring the stability of the pole piece 2 during rolling and the quality of the pole piece 2 .

[0145] In some embodiments, the control circuit 40 is further used to control the vibration amplitude A of the first roller 10A to be 10-20 um through the driving mechanism 30.

[0146] The vibration amplitude A of the first roller 10A can be 10um, 12um, 14um, 16um, 18um, 20um, etc.

[0147] The vibration amplitude A of the vibration roller is related to the amplitude of the vibration pattern generated on the surface of the pole piece 2. The vibration amplitude A of the vibration roller is 10-20 um, which means that the distance from the highest point of the wave crest to the lowest point of the wave trough in the vibration pattern is 10-20 um.

[0148] In this embodiment, the vibration amplitude A of the first roller 10A is controlled to be 10-20 um to generate obvious vibration lines on the surface of the pole piece 2, thereby increasing the surface area of ​​the pole piece 2 and improving the wetting efficiency.

[0149] In some embodiments, the first rolling roller 10A includes a roller body 11 and a plurality of eccentric rotors 12 ; the plurality of eccentric rotors 12 are disposed in the roller body 11 .

[0150] A cavity or channel specifically for accommodating a plurality of eccentric rotors 12 is provided in the roller body 11 of the first roller 10A to ensure that the eccentric rotors 12 can rotate freely and will not interfere with each other during operation.

[0151] The core of each eccentric rotor 12 is an eccentric mass block, that is, a mass block whose center of mass is not on the axis of rotation. When the eccentric rotor 12 rotates, due to mass imbalance, a centrifugal force will be generated, thus causing vibration. That is, when the eccentric rotor 12 rotates, the centrifugal force generated by the eccentric mass block will exert a periodic force on the roller body 11, causing the roller body 11 to vibrate.

[0152] The eccentric rotors 12 are installed on independent rotating shafts, and these rotating shafts are supported by bearings and fixed on the inner wall of the roller body 11. That is, the eccentric rotors 12 and the roller body 11 are installed on different rotating shafts. The position or angle of the eccentric rotors 12 is adjusted through a manual or automatic system to change the vibration amplitude A and the vibration frequency. The centrifugal forces of multiple eccentric rotors 12 will be superimposed on each other to form a complex vibration mode. By reasonably designing the number, position and rotational speed of the eccentric rotors 12, the vibration frequency and the vibration amplitude A can be regulated to meet different rolling requirements.

[0153] In some examples, there are four eccentric rotors 12. The four eccentric rotors 12 are arranged at equal intervals circumferentially along the axis of rotation of the roller body 11. In the direction of gravity, the eccentric directions of two relatively arranged eccentric rotors 12 are set in the same direction (see Figure 6 ); or, in the direction of gravity, the eccentric directions of two relatively arranged eccentric rotors 12 are set in opposite directions (see Figure 9 ); or, in the direction of gravity, the eccentric directions of two relatively arranged eccentric rotors 12 in one group are sequentially inclined clockwise, and the eccentric directions of two relatively arranged eccentric rotors 12 in the other group are sequentially inclined counterclockwise (see Figure 10 ).

[0154] The eccentric direction of the eccentric rotor 12 refers to the deviation direction of the eccentric mass block relative to the axis of rotation, and this direction determines the direction of the centrifugal force generated when the eccentric rotor 12 rotates.

[0155] In the direction of gravity, when the eccentric directions of two relatively arranged eccentric rotors 12 are set in the same direction, the vibration amplitude A of the vibrating roller is larger; in the direction of gravity, when the eccentric directions of two relatively arranged eccentric rotors 12 are set in opposite directions, due to the cancellation of the opposite centrifugal forces, the vibration amplitude A of the vibrating roller is smaller. That is, by adjusting the eccentric directions of two relatively arranged eccentric rotors 12 in the direction of gravity, that is, adjusting the cancellation and gain of the centrifugal force, the modulation of the vibration energy can be realized.

[0156] In this embodiment, a plurality of eccentric rotors 12 are arranged in the first rolling roller 10A to utilize the centrifugal force generated by the rotation of the eccentric rotors 12 to cause the first rolling roller 10A to vibrate periodically, so that vibration lines can be generated on the surface of the pole piece 2 during the process of rolling the pole piece 2.

[0157] In some embodiments, the rolling mechanism 10 is a cold rolling mechanism 10.

[0158] In this embodiment, the rolling mechanism 10 is a cold rolling mechanism. Since the operating conditions are relatively mild, the thickness, density, and surface quality of the electrode sheet 2 are easier to control, and the consistency between different batches of products is better. Secondly, in this embodiment, vibration and cold pressing are integrated into the rolling mechanism 10, which has a simple structure and is beneficial to simplifying the processing flow of the electrode sheet 2. In addition, it can also reduce the rebound rate of the electrode sheet 2 after conventional cold rolling, thereby improving the thickness consistency of the cold-pressed electrode sheet 2 after rebound.

[0159] In some embodiments, the electrode sheet production device 1 further includes a coating mechanism 50 and a drying mechanism 60; the coating mechanism 50 is used to coat the current collector 471 to obtain the electrode sheet 2; the drying mechanism 60 is arranged upstream of the rolling mechanism 10 and is used to dry the electrode sheet 2.

[0160] The coating mechanism 50 can be a doctor blade coater, which uses a scraper with a fixed width to control the coating thickness. By adjusting the gap between the scraper and the current collector 471, the thickness of the coating can be precisely controlled. The coating mechanism 50 can also be a slot die coater, which uses a slot nozzle to uniformly coat the slurry onto the current collector 471. This coating method can achieve higher precision and better thickness consistency. The coating mechanism 50 can also be a rotary coater, which is suitable for continuous production and evenly distributes the slurry on the surface of the current collector 471 through a rotating drum.

[0161] The drying mechanism 60 quickly evaporates the solvent in the electrode sheet 2 through heating and ventilation, ensuring the drying of the coating and improving the adhesion.

[0162] The coating mechanism 50 and the drying structure work together, which can not only improve the production efficiency, but also improve the quality and consistency of the electrode sheet 2.

[0163] In this embodiment, the electrode sheet 2 is cold-pressed after drying, so that during the rolling process of the electrode sheet 2, the material properties are more stable and more compatible with subsequent processes.

[0164] The above are only the implementation manners of the present application, and do not limit the patent protection scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A pole piece production device, characterized in that: include: The rolling mechanism comprises a first rolling roller and a second rolling roller arranged opposite to each other and used for rolling the pole piece; Wherein, at least one of the first roller and the second roller is a vibrating roller; The rolling mechanism is a cold rolling mechanism.

2. The electrode production device according to claim 1, characterized in that: The radius of the first roller and the second roller is 700-800 mm.

3. The pole piece production device according to claim 1, characterized in that: In the vertical direction, the first roller is located above the second roller, and only the first roller is a vibrating roller.

4. The pole piece production device according to claim 3, characterized in that: The pole piece production device also includes: A traction mechanism, used for traction of the pole piece, so that the pole piece is transferred in the gap between the first roller and the second roller; A driving mechanism, connected to the rolling mechanism, for driving the first roller to rotate and vibrate along the vertical direction at the same time; A control circuit, electrically connected to the traction mechanism and the driving mechanism respectively; Wherein, the control circuit is used to control the tape running speed of the pole piece to be 50-110 m / min through the traction mechanism, and to control the vibration frequency of the first roller to be 500 Hz-3400 Hz through the driving mechanism.

5. The pole piece production device according to claim 4, characterized in that: The control circuit is also used to control the tape travel speed of the pole piece and the vibration frequency of the first roller to satisfy: The pole piece has a running speed of 50-70 m / min, and the first roller has a vibration frequency of 500 Hz-2000 Hz; or The pole piece has a running speed of 70-90 m / min, and the first roller has a vibration frequency of 700 Hz-2800 Hz; or The pole piece has a conveying speed of 90-110 m / min, and the first roller has a vibration frequency of 840 Hz-3400 Hz.

6. The pole piece production device according to claim 4, characterized in that: The control circuit is also used to control the vibration amplitude of the first roller to be 10-20 um through the driving mechanism.

7. The pole piece production device according to any one of claims 2 to 6, characterized in that: The first roller comprises: Roller body; A plurality of eccentric rotors are arranged in the roller body.

8. The pole piece production device according to any one of claims 1 to 6, characterized in that: The pole piece production device also includes: A coating mechanism, used for coating the current collector to obtain the pole piece; The drying mechanism is arranged upstream of the rolling mechanism and is used for drying the pole piece.

9. A battery production system, characterized in that: include: The pole piece production device according to any one of claims 1 to 8; A battery assembly device is used to assemble the pole pieces prepared by the pole piece production device into battery cells.

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