Electrode sheet manufacturing system, electrode sheet manufacturing method, and secondary battery

Abstract

The application provides a pole piece manufacturing system, a pole piece manufacturing method and a secondary battery. The pole piece manufacturing system comprises a piece manufacturing mechanism, a vibration mechanism and a rolling mechanism. The piece manufacturing mechanism is configured to form a pre-drying pole piece. The vibration mechanism is arranged downstream of the piece manufacturing mechanism. The vibration mechanism is configured to perform vibration treatment on the pre-drying pole piece. The rolling mechanism is arranged downstream of the vibration mechanism. The rolling mechanism is configured to perform rolling on the pre-drying pole piece after the vibration treatment. The application effectively improves the packing density of the particles in the pre-drying pole piece through the vibration treatment on the pre-drying pole piece, thereby effectively improving the ultimate compaction density of the pole piece.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to an electrode manufacturing system, an electrode manufacturing method, and a secondary battery. Background Technology

[0002] Batteries, as a new generation of energy storage and conversion devices, are widely used in portable electronic devices, electric vehicles and other fields. Among them, batteries with high volumetric energy density are highly favored by customers.

[0003] The compaction density of the electrode significantly affects the volumetric energy density of the battery. However, the current process steps to improve the compaction density of the electrode are usually quite complex and have limited improvement effects. They may even damage the active material particles of the electrode, resulting in poor battery performance. Summary of the Invention

[0004] In view of this, the main technical problem to be solved in this application is how to effectively improve the compaction density of the electrode sheet.

[0005] To address the aforementioned technical problems, a first aspect of this application provides an electrode manufacturing system. The electrode manufacturing system includes a sheet-forming mechanism, a vibration mechanism, and a rolling mechanism. The sheet-forming mechanism is configured to form a pre-dried electrode. The vibration mechanism is located downstream of the sheet-forming mechanism and is configured to vibrate the pre-dried electrode. The rolling mechanism is located downstream of the vibration mechanism and is configured to roll the vibrated pre-dried electrode to form an electrode.

[0006] In the technical solution of this application embodiment, by setting a sheet-making mechanism, a pre-dried electrode sheet can be obtained, that is, the pre-dried electrode sheet contains no solvent or only a very small amount of solvent residue, which helps to reduce the obstruction to vibration energy transmission during subsequent vibration treatment, thereby effectively improving the energy transmission efficiency of the vibration mechanism for the powder on the pre-dried electrode sheet. Simultaneously, by vibrating the pre-dried electrode sheet, relative displacement occurs between the powder particles, thus breaking the arching phenomenon between particles, allowing for rearrangement and filling between particles, thereby effectively reducing the porosity between particles and improving the compaction density of the electrode sheet. Furthermore, vibrating the pre-dried electrode sheet, compared to vibrating a pre-dried electrode sheet containing solvent, helps to reduce solvent evaporation during vibration, thereby reducing corrosion or contamination to the vibration mechanism. Further, placing the roller pressing mechanism downstream of the vibration mechanism can further compact the vibrated pre-dried electrode sheet, making the contact between the active material layer and the current collector in each region of the pre-dried electrode sheet closer and more uniform, thereby improving the consistency and compaction density of the electrode sheet.

[0007] In some embodiments, the electrode fabrication mechanism includes a coating assembly and a drying assembly; the coating assembly is configured to coat a slurry onto a current collector; and the drying assembly is configured to dry the slurry coated onto the current collector to form a pre-fabricated dried electrode.

[0008] In the embodiments of this application, by setting a coating component, the slurry can be uniformly coated onto the current collector, which is beneficial to improving the thickness uniformity of the coating on the current collector surface. By setting a drying component, the slurry coated on the current collector can be effectively dried, allowing the solvent present in the slurry to evaporate quickly, thereby reducing the resistance of the solvent to the transmission of vibration energy during subsequent vibration processing, improving the energy transmission efficiency of the vibration mechanism to the powder on the pre-dried electrode sheet, and thus improving the compaction density of the electrode sheet.

[0009] In some embodiments, the electrode fabrication mechanism includes a film-forming assembly configured to form a self-supporting electrode film, which is a pre-formed dried electrode sheet; the electrode manufacturing system further includes a composite assembly located downstream of the vibration mechanism and upstream of the rolling mechanism, the composite assembly being configured to composite the self-supporting electrode film with a current collector.

[0010] In the embodiments of this application, by setting up a film-forming assembly, a self-supporting electrode film can be obtained without the use of solvents, eliminating steps such as slurry coating and drying, making the production process simpler and more efficient, and also helping to reduce production costs. Simultaneously, the absence of solvents also helps to reduce the resistance of solvents to vibration energy transfer during subsequent vibration processing, thereby improving the energy transfer efficiency of the vibration mechanism to the powder particles. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film is closer, which helps to increase the compaction density of the electrode sheet.

[0011] In some embodiments, the film-forming mechanism includes a film-forming component and a composite component. The film-forming component is configured to form a self-supporting electrode film, which is a pre-formed dried electrode sheet. The composite component is configured to composite the self-supporting electrode film with a current collector.

[0012] In the embodiments of this application, by setting up a film-forming assembly, a self-supporting electrode film can be obtained without the use of solvents, eliminating steps such as slurry coating and drying, making the production process simpler and more efficient, and also helping to reduce production costs. Simultaneously, the absence of solvents also helps to reduce the resistance of solvents to vibration energy transfer during subsequent vibration treatment, thereby improving the energy transfer efficiency of the vibration mechanism to the powder particles. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film is closer, which helps to improve the compaction density of the electrode sheet. Moreover, by combining the self-supporting electrode film with the current collector before vibration treatment, the problem of powder shedding or even breakage of the self-supporting electrode film due to excessive vibration energy can be reduced.

[0013] In some embodiments, the vibration mechanism includes a vibrating plate and a vibration generator; the vibration generator is configured to drive the vibrating plate to vibrate; a main surface of the vibrating plate is configured to hold a pre-formed dried electrode.

[0014] In the embodiments of this application, by setting a vibration mechanism including a vibration plate and a vibration generator, after the pre-dried electrode sheet is made by the sheet-making mechanism, the pre-dried electrode sheet can be placed on the vibration plate. When the vibration generator is running, it can drive the vibration plate and the pre-dried electrode sheet placed on the vibration plate to vibrate, so that the powder particles on the pre-dried electrode sheet will undergo relative displacement, destroy the arching phenomenon between particles, and allow the particles to rearrange and fill, thereby effectively reducing the porosity between particles and improving the compaction density of the electrode sheet.

[0015] In some embodiments, the main surface is configured to adsorb pre-dried electrodes.

[0016] In the embodiments of this application, by setting the main surface to be able to adsorb the pre-dried electrode, the pre-dried electrode and the main surface of the vibrating plate are in full contact, which is beneficial to improving the energy transfer efficiency of the vibration generator to the pre-dried electrode, thereby improving the compaction density of the electrode.

[0017] In some embodiments, the main surface is provided with adsorption holes; the vibrating plate is also provided with air extraction holes, the adsorption holes and the air extraction holes are connected, and the air extraction holes are configured to connect to an air extraction device.

[0018] In the embodiments of this application, the air is extracted through the air extraction hole by the air extraction device, and a certain negative pressure can be generated in the adsorption hole, so that the adsorption hole can generate a certain adsorption force on the pre-dried electrode. The pre-dried electrode can make full contact with the main surface of the vibration plate, which is beneficial to improving the energy transfer efficiency of the vibration generator to the pre-dried electrode, thereby improving the compaction density of the electrode.

[0019] In some embodiments, the number density of adsorption pores per unit area on the main surface is 53ea / m. 2 ~5318ea / m 2 ; and / or, the pore size of the adsorption pores is 0.4 mm to 2 mm.

[0020] In the embodiments of this application, by setting the number density of adsorption pores per unit area on the main surface and the pore diameter of the adsorption pores within the above-mentioned range, a suitable negative pressure is generated at the interface between the adsorption pores and the pre-made dried electrode, so that the adsorption pores can generate a suitable adsorption force on the pre-made dried electrode. On the one hand, this is conducive to the full contact between the pre-made dried electrode and the main surface of the vibrating plate, and on the other hand, it can also alleviate the problem of the pre-made dried electrode being affected by excessive adsorption force or being damaged.

[0021] In some embodiments, the vibration mechanism includes multiple vibration plates; the multiple vibration plates are arranged sequentially at intervals along the conveying direction of the pre-dried electrode sheet; the adsorption holes of two adjacent vibration plates are staggered.

[0022] In the embodiments of this application, by arranging multiple vibrating plates in the conveying direction of the pre-dried electrode sheet, the pre-dried electrode sheet can be subjected to multiple and continuous vibrations during the conveying process. This is beneficial for the powder particles on the pre-dried electrode sheet to be fully vibrated, thereby further reducing the porosity between particles and improving the compaction density of the electrode sheet. Simultaneously, the adsorption holes of adjacent vibrating plates are staggered, allowing different areas of the pre-dried electrode sheet to be adsorbed during the conveying process. This improves the consistency of vibration processing and effectively alleviates the problem of damage to the pre-dried electrode sheet caused by continuous adsorption of the same area.

[0023] In some embodiments, the vibrating plate is configured to generate a magnetic field to cause the pre-dried electrode to adhere to the main surface.

[0024] In the embodiments of this application, a magnetic field is generated to adsorb the pre-dried electrode. Since the magnetic field can be distributed more evenly on the pre-dried electrode, a more stable and reliable adsorption force can be generated, thereby helping to reduce damage to the surface of the pre-dried electrode. In addition, the vibrating plate structure based on magnetic field adsorption is relatively simple, eliminating the need for other mechanical parts and vacuum equipment, which helps to reduce the manufacturing cost and complexity of the equipment.

[0025] In some embodiments, the vibrating plate is configured such that the width of the vibrating plate is greater than the width of the pre-formed dried electrode sheet.

[0026] In the embodiments of this application, the width of the vibrating plate is set to be greater than the width of the pre-dried electrode. The larger width of the vibrating plate can provide a wider contact area, allowing the entire surface of the pre-dried electrode to fully contact the main surface of the vibrating plate. This enables the adsorption force and vibration energy to be evenly distributed in various areas of the pre-dried electrode, which helps to reduce the possibility of uneven force caused by deviation during the conveying process, thereby improving the stability and consistency of the pre-dried electrode during the vibration treatment process.

[0027] In some embodiments, the length of the vibrating plate is 0.1m to 0.5m.

[0028] In the embodiments of this application, by setting the length of the vibrating plate within the above-mentioned range, the pre-dried electrode sheet can obtain a suitable vibration treatment time during the conveying process while meeting the preparation efficiency, which is beneficial to improving the compaction density of the electrode sheet.

[0029] In some embodiments, the vibration generator is an ultrasonic transducer.

[0030] In the embodiments of this application, the ultrasonic transducer can convert electrical energy into mechanical energy to generate vibration, and can select appropriate vibration frequency and amplitude according to the material characteristics, size and specific manufacturing process requirements of the pre-dried electrode sheet, so that the vibration effect on the pre-dried electrode sheet is more effective, thereby helping to improve the compaction density of the electrode sheet.

[0031] A second aspect of this application provides a method for manufacturing an electrode sheet, comprising: obtaining a pre-dried electrode sheet; subjecting the pre-dried electrode sheet to vibration treatment; and rolling the vibration-treated pre-dried electrode sheet to obtain an electrode sheet.

[0032] In the technical solution of this application embodiment, by obtaining a pre-dried electrode sheet, i.e., a pre-dried electrode sheet containing no solvent or only a very small amount of solvent residue, it is beneficial to reduce the obstruction to vibration energy transmission during subsequent vibration treatment, thereby effectively improving energy transmission efficiency. Simultaneously, by vibrating the pre-dried electrode sheet, relative displacement occurs between the powder particles, thus breaking the arching phenomenon between particles and allowing for rearrangement and filling, thereby effectively reducing the porosity between particles and improving the compaction density of the electrode sheet. Furthermore, vibrating the pre-dried electrode sheet also helps reduce solvent evaporation during vibration, thereby reducing corrosion or contamination. Further, rolling the vibrated pre-dried electrode sheet further compacts it, making the contact between the active material layer and the current collector in each region of the pre-dried electrode sheet closer and more uniform, thereby improving the consistency and compaction density of the electrode sheet.

[0033] In some embodiments, the step of obtaining a pre-dried electrode includes: preparing a slurry, the slurry comprising an active material; coating the slurry onto the surface of a current collector to obtain a wet film; and drying the wet film to obtain a pre-dried electrode.

[0034] In the embodiments of this application, the method of preparing slurry and coating facilitates the attachment of active materials to the current collector. By drying the wet film, the slurry coated on the current collector can be effectively dried, allowing the solvent in the slurry to evaporate quickly. This reduces the resistance of the solvent to the transmission of vibration energy during subsequent vibration treatment, thereby improving the energy transmission efficiency of the vibration treatment process.

[0035] In some embodiments, the step of obtaining a pre-dried electrode includes: obtaining a mixed powder, the mixed powder including an active material; calendering the mixed powder into a film to obtain a self-supporting electrode film, the self-supporting electrode film being a pre-dried electrode; and after the step of vibrating the pre-dried electrode, further comprising: combining the pre-dried electrode with a current collector.

[0036] In the embodiments of this application, a self-supporting electrode film is obtained without the use of solvents, eliminating steps such as slurry coating and drying, making the production process simpler and more efficient, and also helping to reduce production costs. Simultaneously, the absence of solvents also helps to reduce the resistance of solvents to vibration energy transfer during subsequent vibration treatment, thereby improving the energy transfer efficiency of the vibration treatment process. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film is closer, which helps to increase the compaction density of the electrode sheet.

[0037] In some embodiments, the step of obtaining a pre-dried electrode sheet includes: obtaining a mixed powder, the mixed powder including an active material; calendering the mixed powder into a film to obtain a self-supporting electrode film; and combining the self-supporting electrode film with a current collector to obtain a pre-dried electrode sheet.

[0038] In the embodiments of this application, the self-supporting electrode film is obtained without the use of solvents, eliminating steps such as slurry coating and drying, making the production process simpler and more efficient, and also helping to reduce production costs. Simultaneously, the absence of solvents also helps to reduce the resistance of solvents to vibration energy transfer during subsequent vibration treatment, thereby improving the energy transfer efficiency of the vibration treatment process. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film is closer, which helps to increase the compaction density of the electrode sheet. Moreover, combining the self-supporting electrode film with the current collector before vibration treatment can reduce the problem of powder shedding or even breakage of the self-supporting electrode film due to excessive vibration energy.

[0039] In some embodiments, the step of vibrating the pre-dried electrode sheet includes: vibrating the pre-dried electrode sheet using a vibration mechanism; wherein the vibration mechanism includes a plurality of vibration generators, which are arranged sequentially at intervals along the conveying direction of the pre-dried electrode sheet; along the conveying direction of the pre-dried electrode sheet, the vibration frequencies of the plurality of vibration generators are the same, or the vibration frequencies of the plurality of vibration generators decrease sequentially; and / or, along the conveying direction of the pre-dried electrode sheet, the amplitudes of the plurality of vibration generators decrease sequentially.

[0040] In the embodiments of this application, multiple vibration generators are sequentially and spaced apart along the conveying direction of the pre-dried electrode sheet. This allows the pre-dried electrode sheet to undergo multiple and continuous vibrations during the conveying process, which is beneficial for the powder particles on the pre-dried electrode sheet to be fully vibrated, thereby further reducing the porosity between particles and improving the compaction density of the electrode sheet. Simultaneously, by setting the vibration frequency or amplitude to decrease along the conveying direction, the particles on the pre-dried electrode sheet receive sufficient vibration energy at the beginning of the vibration treatment, which helps to break up particle agglomerations, allowing the particles to migrate more easily into the pores. In subsequent vibration treatments, a relatively smaller vibration frequency or amplitude is used, which helps the particles gradually move into the pores through small displacements. This also helps to reduce the problem of particles creating new pores or damaging the particle skeleton structure due to excessive vibration energy.

[0041] In some embodiments, the vibration frequency of the vibration generator is 20 kHz to 500 kHz; and / or the ratio of the vibration generator amplitude to the volume average particle size Dv90 of the active material is 0.1 to 0.3.

[0042] In the embodiments of this application, by setting the vibration frequency of the vibration generator within the aforementioned range, the vibration generator can generate ultrasonic waves. Ultrasonic waves have strong penetrating power, capable of reaching deep into various regions within the pre-dried electrode sheet. This allows the powder particles in the pre-dried electrode sheet to undergo sufficient vibration, resulting in rearrangement and filling, which is beneficial for further improving the compaction density of the electrode sheet. By controlling the ratio of the vibration generator's amplitude to the volume average particle size Dv90 of the active material within a specific range, the vibration intensity can be adjusted according to the particle size of the active material. This ensures that active materials of different particle sizes receive appropriate vibration, preventing insufficient vibration intensity from failing to achieve the desired processing effect, and also preventing excessive vibration intensity from causing material structure damage or detachment, thereby effectively improving the quality and compaction density of the electrode sheet.

[0043] In some embodiments, the vibration mechanism further includes a vibrating plate; the step of using the vibration mechanism to vibrate the pre-dried electrode sheet includes: adsorbing the pre-dried electrode sheet onto the vibrating plate; wherein the adsorption force of the vibrating plate on the pre-dried electrode sheet per unit area is 10 N / mm². 2 ~40N / mm 2 The vibration generator is driven to make the vibrating plate vibrate.

[0044] In the embodiments of this application, by adsorbing the pre-dried electrode onto the vibrating plate, the pre-dried electrode and the vibrating plate are in full contact, which is beneficial to improving the energy transfer efficiency of the vibration generator to the pre-dried electrode. By controlling the adsorption force per unit area to the above-mentioned range, on the one hand, it is beneficial to ensure full contact between the pre-dried electrode and the vibrating plate, and on the other hand, it can reduce the problem of the pre-dried electrode being affected by excessive adsorption force or damaged.

[0045] A third aspect of this application provides a secondary battery comprising an electrode manufactured by the electrode manufacturing method provided in the second aspect. The secondary battery provided by the embodiments of this application, due to including the electrode manufactured by the electrode manufacturing method provided in the second aspect, has at least the same advantages as the electrode manufactured by the electrode manufacturing method provided in the second aspect.

[0046] In some embodiments, the active material of the electrode includes lithium cobalt oxide, and the limiting compaction density of the electrode is 4.30 g / cm³. 3 ~4.35g / cm 3 Alternatively, the active material of the electrode may include lithium nickel cobalt manganese oxide, and the limiting compaction density of the electrode is 3.61 g / cm³. 3 ~3.75g / cm 3 Alternatively, the active material of the electrode may include lithium iron phosphate, and the limiting compaction density of the electrode is 2.51 g / cm³. 3 ~2.6g / cm 3 Alternatively, the active material of the electrode may include graphite, and the limiting compaction density of the electrode may be 1.8 g / cm³. 3 ~1.88g / cm 3 Alternatively, the active material of the electrode may include silicon-carbon composite materials, and the limiting compaction density of the electrode is 1.85 g / cm³. 3 ~1.93g / cm 3 .

[0047] In the embodiments of this application, since the pre-dried electrode is subjected to specific vibration treatment during the manufacturing process, the porosity between particles on the electrode is smaller and the packing density is greater, thereby giving the electrode a higher ultimate compaction density. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the first embodiment of the electrode manufacturing system provided in this application;

[0050] Figure 2 This is a schematic diagram of a second embodiment of the electrode manufacturing system provided in this application.

[0051] Figure 3 This is a schematic diagram of a third embodiment of the electrode manufacturing system provided in this application.

[0052] Figure 4 This is a top view of the plurality of vibration plates provided in the embodiments of this application;

[0053] Figure 5 This is a side view of a plurality of vibration plates provided in an embodiment of this application;

[0054] Figure 6 This is a top view of the main surface of multiple vibrating plates provided in the embodiments of this application when pre-dried electrodes are mounted on them;

[0055] Figure 7 This is an exploded structural diagram of the secondary battery provided in an embodiment of this application;

[0056] Figure 8 This is an exploded view of the battery pack provided in an embodiment of this application;

[0057] Figure 9 This is a schematic diagram of the structure of the electrical equipment provided in the embodiments of this application.

[0058] Explanation of key figure labels:

[0059] Electrical equipment 1000; Battery pack 100; Controller 200; Motor 300; Housing 10; First part 11; Second part 12; Secondary battery 20; Cover 21; Electrode terminal 21a; Housing 22; Cell structure 23; Tab 23a; Current collector 24; Pre-dried electrode 25; Electrode 26; Self-supporting electrode film 27; Electrode manufacturing system 30; Electrode making mechanism 31; Vibration mechanism 32; Vibration plate 321; Vibration generator 322; Main surface 323; Adsorption hole 324; Air extraction hole 325; Rolling mechanism 33; Coating assembly 34; Drying assembly 35; Film forming assembly 36; Composite assembly 37; Conveying direction X; Width of vibration plate W1; Length of vibration plate L1; Width of pre-dried electrode W2. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0061] The terms "first," "second," and "third" in this application are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indications also change accordingly. Furthermore, the terms "comprising" and "having," 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 may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices.

[0062] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0063] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0064] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0065] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0066] During battery manufacturing, the compaction density of the electrodes has a significant impact on battery performance, and discovering the optimal compaction density is crucial for battery design. Generally, within the material's allowable compaction range, a higher electrode compaction density allows for a higher battery capacity; therefore, compaction density is considered one of the reference indicators for battery energy density. However, current processes for improving electrode compaction density are typically complex, with limited improvement effects, and may even damage the active material particles in the electrodes, leading to compromised battery performance. For example, technicians in related fields can improve the compaction density of electrodes by adjusting the particle distribution during material synthesis and calcination, i.e., optimizing the particle size distribution, so that small particles at the electrode layer fill the pores between large particles. However, this method is complex, has a low manufacturing yield, and is costly. Some technicians use graphene-like conductive agents to act as lubricants. During cold pressing, the particles slide into the pores with the assistance of graphene, thus improving the compaction density of the electrodes. However, the effect of improving the compaction density of the electrodes is limited. Other technicians use multiple cold pressing or increase the rolling pressure. Although this can improve the compaction density of the electrodes to a certain extent, it also brings about the problem of particle breakage inside the electrodes.

[0067] In summary, to solve the above problems, please refer to... Figures 1-3 , Figure 1This is a schematic diagram of the first embodiment of the electrode manufacturing system provided in this application. Figure 2 This is a schematic diagram of a second embodiment of the electrode manufacturing system provided in this application. Figure 3 This is a schematic diagram of a third embodiment of the electrode manufacturing system provided in this application. In a first aspect, this application provides an electrode manufacturing system 30, which includes a sheet-making mechanism 31, a vibration mechanism 32, and a rolling mechanism 33. The sheet-making mechanism 31 is configured to form a pre-dried electrode 25. The vibration mechanism 32 is located downstream of the sheet-making mechanism 31 and is configured to vibrate the pre-dried electrode 25. The rolling mechanism 33 is located downstream of the vibration mechanism 32 and is configured to roll the vibrated pre-dried electrode 25 to form an electrode 26.

[0068] The pre-dried electrode 25 is a pre-made electrode that has not been solvent-added or has undergone drying treatment during the preparation process. When the pre-dried electrode 25 is a pre-made electrode that has been solvent-added and dried during the preparation process, the solvent content of the pre-dried electrode 25 is 100ppm to 2000ppm; the pre-dried electrode 25 needs to be rolled before it can be formed into electrode 26.

[0069] The vibration mechanism 32 is located downstream of the sheet-making mechanism 31, meaning that the material passes through the sheet-making mechanism 31 first and then the vibration mechanism 32 during the conveying process. Similarly, the rolling mechanism 33 is located downstream of the vibration mechanism 32, meaning that the material passes through the vibration mechanism 32 first and then the rolling mechanism 33 during the conveying process. The vibration mechanism 32 can be integrated online between the sheet-making mechanism 31 and the rolling mechanism 33, meaning that the pre-dried electrode 25 can be automatically moved into the vibration mechanism 32 for vibration treatment after leaving the sheet-making mechanism 31, following the conveyor belt. Alternatively, the vibration mechanism 32 can be set offline, meaning that the pre-dried electrode 25 needs to be removed from the conveyor belt by external force after leaving the sheet-making mechanism 31 and moved into the vibration mechanism 32 for vibration treatment.

[0070] Vibration treatment can be ultrasonic vibration treatment, electromagnetically driven vibration treatment, piezoelectric vibration treatment, mechanical vibration treatment, fluid vibration treatment, etc. Rolling can be performed on the pre-dried electrode 25 at room temperature or under heating conditions. The rolling can be performed once or multiple times.

[0071] In the technical solution of this application embodiment, by setting the sheet-making mechanism 31, a pre-dried electrode sheet 25 can be obtained. This pre-dried electrode sheet 25 contains no solvent or only a very small amount of solvent residue, which helps reduce the obstruction to vibration energy transmission during subsequent vibration processing, thereby effectively improving the energy transmission efficiency of the vibration mechanism 32 for the powder on the pre-dried electrode sheet 25. Simultaneously, by vibrating the pre-dried electrode sheet 25, relative displacement occurs between the powder particles, thus breaking the arching phenomenon between particles and allowing for rearrangement and filling between particles. This effectively reduces the porosity between particles and helps improve the compaction density of the electrode sheet 26. Furthermore, vibrating the pre-dried electrode sheet 25, compared to vibrating a pre-dried electrode sheet containing solvent, also helps reduce solvent evaporation during vibration, thereby reducing corrosion or contamination of the vibration mechanism 32. Furthermore, by placing the roller pressing mechanism 33 downstream of the vibration mechanism 32, the pre-dried electrode 25 after vibration treatment can be further compacted, making the contact between the active material layer in each region of the pre-dried electrode 25 and the current collector 24 more compact and uniform, thereby improving the consistency and compaction density of the electrode 26.

[0072] In some embodiments, please refer to Figure 1 The electrode preparation mechanism 31 includes a coating assembly 34 and a drying assembly 35; the coating assembly 34 is configured to coat the slurry onto the current collector 24; the drying assembly 35 is configured to dry the slurry coated on the current collector 24 to form a pre-dried electrode 25.

[0073] The slurry is a viscous substance made up of a mixture of various components during the preparation process. It mainly includes active materials, conductive agents, binders and solvents mixed in a certain mass ratio. By configuring it into the form of a slurry, it helps to uniformly disperse the active materials and conductive agents in the whole system, prevent them from agglomerating, and thus ensure the consistency and stability of the electrode 26.

[0074] The current collector 24 is a structure or component that collects current. It not only carries the active material but also collects electrons generated by the electrochemical reaction and conducts them to the external circuit, thus realizing the conversion of chemical energy into electrical energy. Currently, the thickness of current collectors commonly used in battery cell production, such as the positive electrode aluminum foil, can be 10μm to 20μm, and the negative electrode copper foil, can be 6μm to 8μm. The aluminum foil is mainly rolled aluminum foil, and the copper foil is mainly electrolytic copper foil.

[0075] The coating assembly 34 can coat the slurry onto one surface of the current collector 24 or onto both surfaces of the current collector 24.

[0076] In the embodiments of this application, by providing the coating component 34, the slurry can be uniformly coated onto the current collector 24, which is beneficial to improving the thickness uniformity of the coating on the surface of the current collector 24. By providing the drying component 35, the slurry coated on the current collector 24 can be effectively dried, allowing the solvent present in the slurry to evaporate quickly, thereby reducing the resistance of the solvent to the transmission of vibration energy during subsequent vibration processing, improving the energy transmission efficiency of the vibration mechanism 32 to the powder on the pre-dried electrode 25, and thus improving the compaction density of the electrode 26.

[0077] In some embodiments, please refer to Figure 2 The electrode fabrication mechanism 31 includes a film forming component 36, which is configured to form a self-supporting electrode film 27, which is a pre-dried electrode 25. The electrode manufacturing system 30 also includes a composite component 37, which is located downstream of the vibration mechanism 32 and upstream of the rolling mechanism 33. The composite component 37 is configured to composite the self-supporting electrode film 27 with the current collector 24.

[0078] The self-supporting electrode film 27 is a film-like structure prepared using a dry process. It does not rely on solvents or current collectors for support and is directly made from powder materials such as active materials, conductive agents, and binders through a specific process. It possesses certain mechanical strength and flexibility, can exist independently, and can serve as a component of an electrode. For example, the self-supporting electrode film 27 can be formed by thoroughly mixing powders such as active materials, conductive agents, and binders, followed by fiberization treatment, and then using mechanical pressure to compress and bond the powder particles together, ultimately forming a continuous film-like structure.

[0079] The composite component 37 can composite the self-supporting electrode film 27 with one surface of the current collector 24, or it can composite the self-supporting electrode film 27 with both surfaces of the current collector 24.

[0080] In the embodiments of this application, by setting the film-forming component 36, the self-supporting electrode film 27 can be obtained without the use of solvents, eliminating steps such as slurry coating and drying, making the production process simpler and more efficient, and also helping to reduce production costs. Simultaneously, without the use of solvents, it is also beneficial to reduce the resistance of solvents to vibration energy transmission during subsequent vibration processing, thereby improving the energy transmission efficiency of the vibration mechanism 32 to the powder particles. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film 27 is closer, which helps to increase the compaction density of the electrode sheet 26.

[0081] In some embodiments, please refer to Figure 3The film-forming mechanism 31 includes a film-forming component 36 and a composite component 37. The film-forming component 36 is configured to form a self-supporting electrode film 27, which is a pre-formed dried electrode 25. The composite component 37 is configured to composite the self-supporting electrode film 27 with a current collector 24.

[0082] In the embodiments of this application, by setting the film-forming component 36, the self-supporting electrode film 27 can be obtained without the use of solvents, eliminating steps such as slurry coating and drying, making the production process simpler and more efficient, and also helping to reduce production costs. Simultaneously, without the use of solvents, it is also beneficial to reduce the resistance of solvents to vibration energy transmission during subsequent vibration treatment, thereby improving the energy transmission efficiency of the vibration mechanism 32 to the powder particles. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film 27 is closer, which helps to improve the compaction density of the electrode sheet 26. Moreover, by combining the self-supporting electrode film 27 with the current collector 24 before vibration treatment, the problem of powder shedding or even breakage of the self-supporting electrode film 27 due to excessive vibration energy can be reduced.

[0083] In some embodiments, please refer to Figures 1-4 The vibration mechanism 32 includes a vibration plate 321 and a vibration generator 322; the vibration generator 322 is configured to drive the vibration plate 321 to vibrate; a main surface 323 of the vibration plate 321 is configured to place a pre-made dried electrode 25.

[0084] In the embodiments of this application, by setting the vibration mechanism 32 including the vibration plate 321 and the vibration generator 322, after the pre-dried electrode 25 is made by the sheet-making mechanism 31, the pre-dried electrode 25 can be placed on the vibration plate 321. When the vibration generator 322 runs, it can drive the vibration plate 321 and the pre-dried electrode 25 placed on the vibration plate 321 to vibrate, so that the powder particles on the pre-dried electrode 25 will undergo relative displacement, destroy the arching phenomenon between particles, and allow the particles to rearrange and fill, thereby effectively reducing the porosity between particles and improving the compaction density of the electrode 26.

[0085] In some embodiments, the vibrating plate 321 is a planar plate, and the vibration generator 322 is located on the side of the vibrating plate 321 away from the main surface 323 and connected to the vibrating plate 321. By setting the vibrating plate 321 as a planar plate structure and reasonably setting the position of the vibration generator 322, the vibration transmission is more stable and uniform, which can reduce the mechanical damage that may be caused to the pre-dried electrode 25 and protect the integrity and performance of the electrode 26 from being affected.

[0086] In some embodiments, the main surface 323 is configured to adsorb the pre-dried electrode 25.

[0087] In the embodiments of this application, by setting the main surface 323 to be able to adsorb the pre-dried electrode 25, the pre-dried electrode 25 is in full contact with the main surface 323 of the vibration plate 321, which is beneficial to improve the energy transfer efficiency of the vibration generator 322 to the pre-dried electrode 25, thereby improving the compaction density of the electrode 26.

[0088] In some embodiments, the main surface 323 is planar. A planar structure of the main surface 323 helps to reduce damage to the pre-dried electrode 25 during the adsorption process.

[0089] In some embodiments, please refer to Figure 4 and Figure 5 The main surface 323 is provided with an adsorption hole 324; the vibrating plate 321 is also provided with an air extraction hole 325, the adsorption hole 324 is connected to the air extraction hole 325, and the air extraction hole 325 is configured to connect to an air extraction device.

[0090] In the embodiments of this application, the air is extracted through the air extraction hole 325 by the air extraction device, and a certain negative pressure can be generated in the adsorption hole 324, so that the adsorption hole 324 can generate a certain adsorption force on the pre-dried electrode 25. The pre-dried electrode 25 can make full contact with the main surface 323 of the vibration plate 321, which is beneficial to improving the energy transfer efficiency of the vibration generator 322 to the pre-dried electrode 25, thereby improving the compaction density of the electrode 26.

[0091] Optionally, the pumping device can be a vacuum pump, a gas compressor, an adsorption pump, etc.

[0092] In some embodiments, the number density of adsorption pores 324 per unit area on the main surface 323 is 53ea / m. 2 ~5318ea / m 2 ; and / or, the pore size of the adsorption pore 324 is 0.4 mm to 2 mm.

[0093] The number density of adsorption pores 324 per unit area on the main surface 323 refers to the number density per unit area of ​​1m². 2 The total number of adsorption pores 324 set on the main surface is used to measure the density of the distribution of adsorption pores 324 on the main surface 323.

[0094] In the embodiments of this application, by setting the number density of adsorption holes 324 per unit area on the main surface 323 and the pore size of adsorption holes 324 within the above-mentioned range, a suitable negative pressure is generated at the interface between the adsorption holes 324 and the pre-made dried electrode 25, so that the adsorption holes 324 can generate a suitable adsorption force on the pre-made dried electrode 25. On the one hand, this is conducive to the full contact between the pre-made dried electrode 25 and the main surface 323 of the vibrating plate 321, and on the other hand, it can also alleviate the problem of the pre-made dried electrode 25 being affected by excessive adsorption force or being damaged.

[0095] For example, the number density of adsorption pores 324 per unit area on the main surface 323 can be 53ea / m. 2 150ea / m 2 555ea / m 2 1500ea / m 2 3455ea / m 2 5318ea / m 2 etc., or a range consisting of any two of the above values, for example, 53ea / m 2 ~150ea / m 2 150ea / m 2 ~3455ea / m 2 3455ea / m 2 ~5318ea / m 2 The pore size of the adsorption pores 324 can be 0.4 mm, 0.5 mm, 0.8 mm, 1.4 mm, 1.9 mm, 2 mm, etc., or a range of any two of the above values, such as 0.4 mm to 0.5 mm, 0.5 mm to 1.9 mm, 1.9 mm to 2 mm, etc. For example, the adsorption pores 324 are arranged in an array on the main surface 323, that is, the adsorption pores 324 are arranged on the main surface 323 according to a certain pattern and order; optionally, adjacent adsorption pores 324 maintain an equal distance, and this arrangement can make the adsorption effect of the pre-dried electrode 25 in various areas of the main surface 323 basically consistent.

[0096] In some embodiments, please refer to Figure 4 The vibration mechanism 32 includes multiple vibration plates 321; along the conveying direction X of the pre-dried electrode 25, the multiple vibration plates 321 are arranged in sequence at intervals; the adsorption holes 324 of two adjacent vibration plates 321 are staggered.

[0097] The adsorption holes 324 of two adjacent vibrating plates 321 are staggered, that is, after the adsorption hole 324 of one vibrating plate 321 is translated along the conveying direction X, it does not completely overlap with the adsorption hole 324 of the other vibrating plate 321.

[0098] In the embodiments of this application, by setting multiple vibrating plates 321 along the conveying direction X of the pre-dried electrode 25, the pre-dried electrode 25 can be subjected to multiple and continuous vibrations during the conveying process. This is beneficial for the powder particles on the pre-dried electrode 25 to be fully vibrated, thereby further reducing the porosity between particles and improving the compaction density of the electrode 26. At the same time, the adsorption holes 324 of two adjacent vibrating plates 321 are staggered, so that different areas of the pre-dried electrode 25 can be adsorbed during the conveying process. This is beneficial for improving the consistency of vibration processing and effectively alleviating the problem of damage to the pre-dried electrode 25 due to continuous adsorption of the same area of ​​the pre-dried electrode 25.

[0099] Optionally, the conveying speed of the pre-dried electrode 25 along the conveying direction X is 20 m / s to 30 m / s. Setting the conveying speed to the above range is beneficial to improving the preparation efficiency of the electrode 26.

[0100] In some embodiments, the vibrating plate 321 includes at least one vibration direction. By providing at least one vibration direction, the powder particles on the pre-dried electrode 25 can be displaced in multiple directions, which facilitates particle rearrangement and filling, thereby improving the compaction density of the electrode 26. Exemplarily, the vibration direction is perpendicular to the plane of the main surface 323; exemplarily, the vibrating plate 321 simultaneously includes a first vibration direction and a second vibration direction, the first vibration direction being perpendicular to the plane of the main surface 323, and the second vibration direction being parallel to the plane of the main surface 323. Optionally, the vibrating plate 321 may further include a third vibration direction, which includes any direction that is neither perpendicular nor parallel to the plane of the main surface 323.

[0101] In some embodiments, the vibrating plate 321 is configured to generate a magnetic field to cause the main surface 323 to adsorb the pre-dried electrode 25.

[0102] In the embodiments of this application, a magnetic field is generated to adsorb the pre-dried electrode 25. Since the magnetic field can be distributed more evenly on the pre-dried electrode 25, a more stable and reliable adsorption force can be generated, which helps to reduce damage to the surface of the pre-dried electrode 25. In addition, the structure of the vibrating plate 321 based on magnetic field adsorption is relatively simple, which can eliminate the need for other mechanical parts and vacuum equipment, thus reducing the manufacturing cost and complexity of the equipment.

[0103] In some embodiments, please refer to Figure 6 The vibrating plate 321 is configured such that the width W1 of the vibrating plate 321 is greater than the width W2 of the pre-dried electrode 25.

[0104] In the embodiments of this application, the main surface 323 of the vibrating plate 321 includes two sides extending along the conveying direction X, and the distance between these two sides is the width W1 of the vibrating plate 321. Similarly, the surface of the pre-dried electrode 25 includes two sides extending along the conveying direction X, and the distance between these two sides is the width W2 of the pre-dried electrode 25. The width W1 of the vibrating plate 321 is set to be greater than the width W2 of the pre-dried electrode 25. The larger width W1 of the vibrating plate 321 can provide a wider contact area, allowing the entire surface of the pre-dried electrode 25 to fully contact the main surface 323 of the vibrating plate 321. This allows the adsorption force and vibration energy to be evenly distributed in various areas of the pre-dried electrode 25, which helps to reduce the possibility of uneven force caused by deviation during the conveying process, thereby improving the stability and consistency of the pre-dried electrode 25 during the vibration processing.

[0105] Optionally, the ratio of the width W2 of the pre-dried electrode 25 to the width W1 of the vibrating plate 321 is (0.83 to 0.95):1. For example, the ratio of the width W2 of the pre-dried electrode 25 to the width W1 of the vibrating plate 321 can be 0.83:1, 0.85:1, 0.89:1, 0.9:1, 0.93:1, 0.95:1, etc., or a range consisting of any two of the above values, such as (0.83 to 0.85):1, (0.85 to 0.93):1, (0.93 to 0.95):1, etc.

[0106] In some embodiments, the length L1 of the vibrating plate 321 is 0.1m to 0.5m.

[0107] In the embodiments of this application, the main surface 323 of the vibrating plate 321 includes two sides extending perpendicular to the conveying direction X. The distance between these two sides is the length L1 of the vibrating plate 321. By setting the length L1 of the vibrating plate 321 within the above range, the pre-dried electrode 25 can obtain a suitable vibration treatment time during the conveying process while meeting the preparation efficiency, which is beneficial to improving the compaction density of the electrode 26.

[0108] For example, the length L1 of the vibrating plate 321 can be 0.1m, 0.15m, 0.2m, 0.28m, 0.45m, 0.5m, etc., or a range of any two of the above values, such as 0.1m~0.15m, 0.15m~0.45m, 0.45m~0.5m, etc.

[0109] In some embodiments, the vibration generator 322 is an ultrasonic transducer.

[0110] In the embodiments of this application, the ultrasonic transducer can convert electrical energy into mechanical energy (i.e., ultrasonic waves) to generate vibration, and can select appropriate vibration frequency and amplitude according to the material characteristics, size and specific manufacturing process requirements of the pre-dried electrode 25, so that the vibration effect on the pre-dried electrode 25 is more effective, thereby helping to improve the compaction density of the electrode 26.

[0111] Optionally, the vibration generator 322 may also include a vibration motor, an electromagnetic vibrator, a hydraulic vibrator, etc.

[0112] Optionally, the vibration generator 322 is connected to the vibrating plate 321 via an amplitude adjusting rod. The amplitude adjusting rod can work with the vibration generator 322 to change the amplitude transmitted by the vibration generator 322 while transmitting mechanical energy, and drive the connected vibrating plate 321 to vibrate with a certain amplitude, which helps to improve the transmission efficiency of vibration energy.

[0113] A second aspect of this application provides a method for manufacturing an electrode sheet, comprising: obtaining a pre-dried electrode sheet 25; subjecting the pre-dried electrode sheet 25 to vibration treatment; and rolling the vibration-treated pre-dried electrode sheet 25 to obtain an electrode sheet 26. It should be noted that the electrode sheet manufacturing system 30 described in the above embodiments can be used to implement this method to manufacture the electrode sheet 26. The electrode sheet manufacturing method provided in this embodiment can be used to manufacture both positive and negative electrode sheets.

[0114] In the technical solution of this application embodiment, by obtaining a pre-dried electrode 25, i.e., the pre-dried electrode 25 contains no solvent or only a very small amount of solvent residue, it is beneficial to reduce the obstruction to vibration energy transmission during subsequent vibration treatment, thereby effectively improving energy transmission efficiency. Simultaneously, by vibrating the pre-dried electrode 25, relative displacement occurs between the powder particles on the pre-dried electrode 25, thus breaking the arching phenomenon between particles, allowing for rearrangement and filling between particles, thereby effectively reducing the porosity between particles and improving the compaction density of the electrode 26. Furthermore, vibrating the pre-dried electrode 25 also helps reduce solvent evaporation during vibration, thereby reducing corrosion or contamination. Further, rolling the vibrated pre-dried electrode 25 further compacts it, making the contact between the active material layer and the current collector 24 in each region of the pre-dried electrode 25 closer and more uniform, thereby improving the consistency and compaction density of the electrode 26.

[0115] In some embodiments, the step of obtaining the pre-dried electrode 25 includes: preparing a slurry, the slurry comprising an active material; coating the slurry onto the surface of the current collector 24 to obtain a wet film 28; and drying the wet film 28 to obtain the pre-dried electrode 25.

[0116] Active materials are generally divided into positive electrode active materials and negative electrode active materials. For example, positive electrode active materials include lithium nickel oxide, lithium manganese oxide, lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, etc., while negative electrode materials generally include amorphous carbon materials, graphitized carbon materials, silicon-based materials, nitrides, novel alloys, etc.

[0117] In the embodiments of this application, the method of preparing slurry and coating facilitates the attachment of active materials to the current collector 24. By drying the wet film 28, the slurry coated on the current collector 24 can be effectively dried, allowing the solvent in the slurry to evaporate quickly. This reduces the resistance of the solvent to the transmission of vibration energy during subsequent vibration treatment, thereby improving the energy transmission efficiency of the vibration treatment process.

[0118] In some embodiments, the step of obtaining the pre-dried electrode 25 includes: obtaining a mixed powder, the mixed powder including an active material; calendering the mixed powder into a film to obtain a self-supporting electrode film 27, the self-supporting electrode film 27 being the pre-dried electrode 25; after the step of vibrating the pre-dried electrode 25, the step further includes: combining the pre-dried electrode 25 with a current collector 24.

[0119] In the embodiments of this application, the self-supporting electrode film 27 is obtained without the use of solvents, which eliminates steps such as slurry coating and drying, making the production process simpler and more efficient, and also helps to reduce production costs. Simultaneously, the absence of solvents also helps to reduce the resistance of solvents to vibration energy transfer during subsequent vibration treatment, thereby improving the energy transfer efficiency of the vibration treatment process. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film 27 is closer, which helps to increase the compaction density of the electrode sheet 26.

[0120] In some embodiments, the step of obtaining the pre-dried electrode 25 includes: obtaining a mixed powder, the mixed powder including an active material; calendering the mixed powder into a film to obtain a self-supporting electrode film 27; and combining the self-supporting electrode film 27 with a current collector 24 to obtain the pre-dried electrode 25.

[0121] In the embodiments of this application, the self-supporting electrode film 27 is obtained without the use of solvents, which eliminates steps such as slurry coating and drying, making the production process simpler and more efficient, and also helps to reduce production costs. Simultaneously, the absence of solvents also helps to reduce the resistance of solvents to vibration energy transfer during subsequent vibration treatment, thereby improving the energy transfer efficiency of the vibration treatment process. Furthermore, since there are no voids left after solvent evaporation, the contact between particles on the self-supporting electrode film 27 is closer, which helps to increase the compaction density of the electrode sheet 26. Moreover, by combining the self-supporting electrode film 27 with the current collector 24 before vibration treatment, the problem of powder shedding or even breakage of the self-supporting electrode film 27 due to excessive vibration energy can be reduced.

[0122] In some embodiments, the step of vibrating the pre-dried electrode 25 includes: vibrating the pre-dried electrode using a vibration mechanism 32; wherein the vibration mechanism includes a plurality of vibration generators 322, which are arranged sequentially at intervals along the conveying direction X of the pre-dried electrode 25; along the conveying direction X of the pre-dried electrode 25, the vibration frequencies of the plurality of vibration generators 322 are the same, or the vibration frequencies of the plurality of vibration generators 322 decrease sequentially; and / or, along the conveying direction X of the pre-dried electrode 25, the amplitudes of the plurality of vibration generators 322 decrease sequentially.

[0123] In the embodiments of this application, multiple vibration generators 322 are sequentially and spaced along the conveying direction X of the pre-dried electrode 25, so that the pre-dried electrode 25 is subjected to multiple and continuous vibrations during the conveying process. This is beneficial for the powder particles on the pre-dried electrode 25 to be fully vibrated, thereby further reducing the porosity between particles and improving the compaction density of the electrode 26. At the same time, by setting the vibration frequency or amplitude to decrease along the conveying direction X, the particles on the pre-dried electrode 25 can obtain sufficient vibration energy at the beginning of the vibration treatment, which is beneficial for breaking up particle agglomeration, so that the particles can migrate more easily into the pores. In subsequent vibration treatments, a relatively small vibration frequency or amplitude is used, which is beneficial for the particles to gradually move into the pores through small displacements. It is also beneficial for reducing the problem of particles generating new pores or damaging the particle skeleton structure due to excessive vibration energy.

[0124] In some embodiments, the vibration frequency of the vibration generator 322 is 20kHz to 500kHz; and / or the ratio of the amplitude of the vibration generator 322 to the volume average particle size Dv90 of the active material is 0.1 to 0.3.

[0125] The volume average particle size Dv90 is common knowledge in the field and has a common meaning in the field. It can be measured by methods and instruments in the field.

[0126] In the embodiments of this application, by setting the vibration frequency of the vibration generator 322 within the aforementioned range, the vibration generator can generate ultrasonic waves. Ultrasonic waves have strong penetrating power, allowing them to penetrate deep into various areas within the pre-dried electrode 25. This causes the powder particles in the pre-dried electrode 25 to undergo sufficient vibration, resulting in rearrangement and filling, which is beneficial for further improving the compaction density of the electrode 26. By controlling the ratio of the vibration amplitude of the vibration generator 322 to the volume average particle size Dv90 of the active material within a specific range, the vibration intensity can be adjusted according to the particle size of the active material. This ensures that active materials of different particle sizes receive appropriate vibration, preventing insufficient vibration intensity from failing to achieve the desired treatment effect, and also preventing excessive vibration intensity from causing material structure damage or detachment. This effectively improves the quality and compaction density of the electrode 26.

[0127] For example, the vibration frequency of the vibration generator 322 can be 20kHz, 50kHz, 100kHz, 220kHz, 420kHz, 500kHz, etc., or a range consisting of any two of the above values, such as 20kHz~50kHz, 50kHz~420kHz, 420kHz~500kHz, etc. The ratio of the vibration amplitude of the vibration generator 322 to the volume average particle size Dv90 of the active material can be 0.1, 0.15, 0.18, 0.2, 0.25, 0.3, etc., or a range consisting of any two of the above values, such as 0.1~0.15, 0.15~0.25, 0.25~0.3, etc.

[0128] In some embodiments, along the conveying direction X of the pre-dried electrode 25, the amplitudes of the plurality of vibration generators 322 decrease sequentially according to 0.05 times the volume average particle size Dv90 of the active material.

[0129] In the embodiments of this application, by using successively decreasing amplitudes, it is beneficial for particles to gradually move into the pores through small displacements, and it is also beneficial to reduce the problem of particles generating new pores or damaging the particle skeleton structure due to excessive vibration energy.

[0130] In some embodiments, the vibration mechanism 32 further includes a vibration plate 321; the step of using the vibration mechanism 32 to vibrate the pre-dried electrode 25 includes: adsorbing the pre-dried electrode 25 onto the vibration plate 321; wherein the adsorption force of the vibration plate 321 on the pre-dried electrode 25 per unit area is 10 N / mm. 2 ~40N / mm 2 The vibration generator 322 is driven to cause the vibrating plate 321 to vibrate.

[0131] In the embodiments of this application, by adsorbing the pre-dried electrode 25 onto the vibrating plate 321, the pre-dried electrode 25 and the vibrating plate 321 are in full contact, which is beneficial to improving the energy transfer efficiency of the vibration generator 322 to the pre-dried electrode 25. By controlling the adsorption force per unit area to the above-mentioned range, on the one hand, it is beneficial to ensure full contact between the pre-dried electrode 25 and the vibrating plate 321, and on the other hand, it can also reduce the problem of the pre-dried electrode 25 being affected by excessive adsorption force or damaged.

[0132] For example, the adsorption force of the vibrating plate 321 on the pre-dried electrode 25 per unit area can be 10 N / mm². 2 15N / mm 2 20N / mm 2 22N / mm 2 36N / mm 2 40N / mm 2 etc., or a range consisting of any two of the above values, for example, 10 N / mm 2 ~15N / mm 2 15N / mm 2 ~36N / mm 2 36N / mm 2 ~40N / mm 2 wait.

[0133] A third aspect of this application provides a secondary battery 20, including an electrode 26 manufactured by the electrode manufacturing method provided in the second aspect. The secondary battery 20 provided in the embodiments of this application, due to including the electrode 26 manufactured by the electrode manufacturing method provided in the second aspect, has at least the same advantages as the electrode 26 manufactured by the electrode manufacturing method provided in the second aspect.

[0134] In some embodiments, the active material of electrode 26 includes lithium cobalt oxide, and the limiting compaction density of electrode 26 is 4.30 g / cm³. 3 ~4.35g / cm 3 Alternatively, the active material of electrode 26 may include lithium nickel cobalt manganese oxide, and the limiting compaction density of electrode 26 is 3.61 g / cm³. 3 ~3.75g / cm 3 Alternatively, the active material of electrode 26 may include lithium iron phosphate, and the limiting compaction density of electrode 26 is 2.51 g / cm³. 3 ~2.6g / cm 3 Alternatively, the active material of electrode 26 may include graphite, and the limiting compaction density of electrode 26 is 1.8 g / cm³. 3 ~1.88g / cm 3 Alternatively, the active material of electrode 26 may include silicon-carbon composite material, and the ultimate compaction density of electrode 26 is 1.85 g / cm³.3 ~1.93g / cm 3 .

[0135] In the embodiments of this application, since the pre-dried electrode 25 is subjected to specific vibration treatment during the manufacturing process of the electrode 26, the porosity between particles on the electrode 26 is smaller and the packing density is greater, thereby giving the electrode 26 a higher ultimate compaction density.

[0136] For example, the active material of electrode 26 includes lithium cobalt oxide, and the ultimate compaction density of electrode 26 can be 4.30 g / cm³. 3 4.31 g / cm 3 4.32 g / cm 3 4.34 g / cm 3 4.35g / cm 3 etc., or a range consisting of any two of the above values, for example, 4.30 g / cm³. 3 ~4.32g / cm 3 4.32 g / cm 3 ~4.34g / cm 3 4.34 g / cm 3 ~4.35g / cm 3 The active materials of electrode 26 include lithium nickel cobalt manganese oxide (LiNiO2 ... 0.8 Co 0.1 Mn 0.1 O2), the ultimate compaction density of electrode 26 can be 3.61 g / cm³. 3 3.64 g / cm 3 3.68g / cm 3 3.7g / cm 3 3.72g / cm 3 3.75g / cm 3 etc., or a range consisting of any two of the above values, for example, 3.61 g / cm³. 3 ~3.68g / cm 3 3.68g / cm 3 ~3.72g / cm 3 3.72g / cm 3 ~3.75g / cm 3 The active material of electrode 26 includes lithium iron phosphate, and the ultimate compaction density of electrode 26 can be 2.51 g / cm³. 3 2.52g / cm 3 2.54 g / cm 3 2.56 g / cm 3 2.58g / cm 3 2.6g / cm 3etc., or a range consisting of any two of the above values, for example, 2.51 g / cm³. 3 ~2.54g / cm 3 2.54 g / cm 3 ~2.56g / cm 3 2.58g / cm 3 ~2.6g / cm 3 The active material of electrode 26 includes graphite, and the ultimate compaction density of electrode 26 can be 1.8 g / cm³. 3 1.82g / cm 3 1.84 g / cm 3 1.85g / cm 3 1.86 g / cm 3 1.88g / cm 3 etc., or a range consisting of any two of the above values, for example, 1.8 g / cm³. 3 ~1.84g / cm 3 1.84 g / cm 3 ~1.86g / cm 3 1.86 g / cm 3 ~1.88g / cm 3 The active material of electrode 26 may include silicon-carbon composite material, and the ultimate compaction density of electrode 26 may be 1.85 g / cm³. 3 1.87 g / cm 3 1.89 g / cm 3 1.9g / cm 3 1.91g / cm 3 1.93g / cm 3 etc., or a range consisting of any two of the above values, for example, 1.85 g / cm³. 3 ~1.89g / cm 3 1.89 g / cm 3 ~1.91g / cm 3 1.91g / cm 3 ~1.93g / cm 3 wait.

[0137] In addition, the secondary battery 20, battery pack 100 and electrical device 1000 of this application will be described below with appropriate reference to the accompanying drawings.

[0138] In this embodiment, the secondary battery 20 is the smallest unit constituting the battery pack 100. The secondary battery 20 also includes an electrolyte and a separator. The separator is disposed between the positive and negative electrode plates, primarily serving to prevent short circuits between the positive and negative electrodes, while also allowing ions to pass through. During battery charging and discharging, active ions Li... +The electrolyte moves back and forth between the positive and negative electrode plates, inserting and de-inserting, while acting as a conductor of ions between them.

[0139] The positive electrode includes a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector, the positive electrode film layer including a positive electrode active material composition.

[0140] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0141] In some embodiments, the positive current collector may be a metal foil or a composite current collector. For example, aluminum foil may be used as the metal foil. The composite current collector may include a polymer substrate and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0142] In some embodiments, the positive electrode film layer may optionally include a binder. As an example, the binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins.

[0143] In some embodiments, the positive electrode film may optionally include a conductive agent. As an example, the conductive agent may include at least one selected from superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0144] In some embodiments, the positive electrode sheet can be prepared by dispersing the above-mentioned components for preparing the positive electrode sheet, such as positive active material, conductive agent, binder and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry; coating the positive electrode slurry onto the positive electrode current collector, and then obtaining the positive electrode sheet after drying, cold pressing and other processes.

[0145] The negative electrode sheet includes a negative current collector and a negative electrode film layer disposed on at least one surface of the negative current collector, the negative electrode film layer including a negative electrode active material.

[0146] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0147] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. The composite current collector may include a polymer material substrate and a metal layer formed on at least one surface of the polymer material substrate. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).

[0148] In some embodiments, the negative electrode film layer may optionally include a binder. The binder may be selected from at least one of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).

[0149] In some embodiments, the negative electrode film may optionally include a conductive agent. The conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0150] In some embodiments, the negative electrode film may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)).

[0151] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as the negative electrode active material, conductive agent, binder and any other components, in a solvent (e.g., deionized water) to form a negative electrode slurry; coating the negative electrode slurry onto the negative electrode current collector, and then obtaining the negative electrode sheet after drying, cold pressing and other processes.

[0152] The electrolyte acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific restrictions on the type of electrolyte; it can be selected according to requirements.

[0153] In some embodiments, the electrolyte includes an electrolyte salt and a solvent.

[0154] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0155] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.

[0156] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain battery performance, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.

[0157] In some embodiments, the secondary battery 20 includes a separator. This application does not impose any particular limitation on the type of separator; any known porous separator with good chemical and mechanical stability can be selected.

[0158] In some embodiments, the diaphragm material can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The diaphragm can be a single-layer film or a multi-layer composite film, without particular limitation. When the diaphragm is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation.

[0159] In some implementations, the positive electrode, negative electrode, and separator can be fabricated into a cell structure using a winding or stacking process.

[0160] In some implementations, such as Figure 7 As shown, the secondary battery 20 may include a casing 22. This outer packaging can be used to encapsulate the aforementioned cell structure 23 and electrolyte. The outer packaging includes a cover 21, the casing 22, and other functional components.

[0161] The cover 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the secondary battery 20 from the external environment. The shape of the cover 21 can be adapted to the shape of the housing 22 to fit it. Optionally, the cover 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the cover 21 is not easily deformed under pressure or impact, giving the secondary battery 20 higher structural strength and improved stability. Functional components such as electrode terminals 21a can be provided on the cover 21. The electrode terminals 21a can be used to electrically connect to the cell structure 23 for outputting or inputting electrical energy into the secondary battery 20. In some embodiments, the cover 21 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the secondary battery 20 reaches a threshold. The material of the cover 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element (not shown) may be provided on the inner side of the cover 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the cover 21 to reduce the risk of short circuits. For example, the insulating element may be made of plastic, rubber, etc.

[0162] The housing body 22a is a component used to cooperate with the cover 21 to form the internal environment of the secondary battery 20. This internal environment can accommodate the cell structure 23, electrolyte, and other components. The housing body 22a and the cover 21 can be independent components. An opening can be provided on the housing body 22a, and the cover 21 can be used to close the opening to form the internal environment of the secondary battery 20. Alternatively, the cover 21 and the housing body 22a can be integrated. Specifically, the cover 21 and the housing body 22a can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing body 22a, the cover 21 closes the housing body 22a. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the cell structure 23. The material of the housing 22 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special limitations on this.

[0163] The casing 22 may contain one or more cell structures 23. The portions of the positive and negative electrodes that do not contain active material each constitute a tab 23a. The positive and negative tabs may be located together at one end of the main body or at opposite ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs 23a connect to the electrode terminals to form a current loop.

[0164] Please refer to Figure 8The battery pack 100 includes a housing 10 and a secondary battery 20, with the secondary battery 20 housed within the housing 10. The housing 10 provides a space for the secondary battery 20 and can have various structures. In some embodiments, the housing 10 may include a first portion 11 and a second portion 12, which overlap each other, collectively defining a space for accommodating the secondary battery 20. The second portion 12 may be a hollow structure with one open end, and the first portion 11 may be a plate-like structure, covering the open side of the second portion 12 so that the first portion 11 and the second portion 12 together define the space. Alternatively, both the first portion 11 and the second portion 12 may be hollow structures with one open side, with the open side of the first portion 11 covering the open side of the second portion 12. Of course, the housing 10 formed by the first portion 11 and the second portion 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0165] In the battery pack 100, there can be multiple secondary batteries 20, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that some of the secondary batteries 20 are connected in series while others are in parallel. Multiple secondary batteries 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple secondary batteries 20 is housed within the housing 10. Alternatively, the battery pack 100 can also consist of multiple secondary batteries 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. The battery pack 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple secondary batteries 20.

[0166] The battery pack 100 in this embodiment includes a secondary battery 20. In other embodiments, the battery pack 100 may further include any one or more of lithium-sulfur batteries, sodium-ion batteries, and magnesium-ion batteries, but is not limited thereto. The secondary battery 20 may be cylindrical, flat, cuboid, or other shapes.

[0167] In some embodiments, the battery pack 100 can be assembled into a battery module, and the number of batteries contained in the battery module can be one or more, the specific number of which can be selected by those skilled in the art according to the application and capacity of the battery module.

[0168] In addition, this application also provides an electrical device 1000, which includes at least one of the secondary battery 20 and / or battery pack 100 provided in this application. The secondary battery 20 or battery pack 100 can be used as a power source for the electrical device 1000 or as an energy storage unit for the electrical device 1000. The electrical device 1000 may include mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but is not limited thereto.

[0169] like Figure 9 As shown, the electrical device 1000 is a vehicle such as a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. A partial structural diagram of one embodiment of the electrical device is provided. A battery pack 100 is internally disposed in the electrical device 1000, and the battery pack 100 can be located at the bottom, head, or tail of the electrical device 1000. The battery pack 100 can be used to power the electrical device 1000; for example, the battery pack 100 can serve as the operating power source for the electrical device 1000. The electrical device 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery pack 100 to supply power to the motor 300, for example, to meet the power requirements of the electrical device 1000 during startup, navigation, and operation.

[0170] In some embodiments of this application, the battery pack 100 can not only serve as the operating power source for the electrical equipment 1000, but also as the driving power source for the electrical equipment 1000, replacing or partially replacing fuel oil or natural gas to provide driving power for the electrical equipment 1000.

[0171] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0172] Example 1

[0173] Preparation of pre-dried electrode sheets

[0174] Lithium cobalt oxide (CNT), a conductive agent (SP+CNT), polyvinylidene fluoride (PVDF), and N-methylpyrrolidone (NMP) were mixed thoroughly at a mass ratio of 97:1.6:1.4:50 to obtain a cathode slurry. The cathode slurry was then coated onto both surfaces of an aluminum foil current collector to form a wet film. After drying, a pre-fabricated dry electrode sheet with a width of 0.8 μm was obtained.

[0175] Vibration treatment of pre-dried electrode sheets

[0176] First, a vibration mechanism is used to vibrate the pre-dried electrode sheet. This mechanism includes two vibrating plates, each connected to a vibration generator. The two plates are spaced 0.5m apart along the conveying direction of the pre-dried electrode sheet. Both plates are 0.9m wide and 1m long. Along the conveying direction, the first vibration generator has a frequency and amplitude of 50kHz and 0.2·Dv90, while the second vibration generator has a frequency and amplitude of 20kHz and 0.15·Dv90. The main surface of the vibrating plates has adsorption pores with a pore size of 1mm and a number density of pores per unit area of ​​636ea / m². 2 By using a vacuum device to draw air into the adsorption pores to a negative pressure, the adsorption force of the vibrating plate on the pre-dried electrode sheet per unit area is made to be 25 N / mm². 2 After vibrating the pre-dried electrode sheet, it is then rolled and cut to obtain the electrode sheet.

[0177] The main experimental parameters of Examples 2-9 and Comparative Examples 1-7 differ from those of Example 1 as shown in Table 1. The difference between Example 4 and Example 1 lies in the preparation process of the pre-dried electrode. The preparation process of the pre-dried electrode in Example 4 is as follows: Artificial graphite (negative electrode active material), carbon black (conductive agent), carboxymethyl cellulose (CMC) (binder), and water (solvent) are thoroughly stirred at a mass ratio of 95:2:3:100 to obtain a uniform negative electrode slurry. The negative electrode slurry is then coated onto both surfaces of the copper foil (negative electrode current collector) to obtain a wet film. After drying the wet film, a pre-dried electrode with a width of 0.8 μm is obtained.

[0178] The difference between Example 5 and Example 4 is that silicon-carbon composite material is used as the active material.

[0179] The difference between Example 9 and Example 1 lies in the different preparation process of the pre-dried electrode. The preparation process of the pre-dried electrode in Example 9 is as follows: the positive electrode active material LiCoO2, the conductive agent (including conductive carbon SP and conductive carbon nanotubes CNT, wherein the mass ratio of SP to CNT is 10:7) and the binder polytetrafluoroethylene (PTFE) are weighed according to the mass ratio of 96:1.7:2.3. LiCoO2 and a conductive agent were added to a double planetary mixer and mixed for 2 minutes at 20°C and a stirring speed of 50 rpm. Then, the mixture was mixed for 5 minutes at 50°C, a stirring speed of 50 rpm, and a dispersing disc speed of 2000 rpm. Following this, the mixture was cooled for 5 minutes at 20°C and a stirring speed of 50 rpm. PTFE was then added to the double planetary mixer and mixed for 2 minutes at 20°C and a stirring speed of 50 rpm. This was followed by mixing for 5 minutes at 30°C, a stirring speed of 50 rpm, and a dispersing disc speed of 2000 rpm. Next, the mixture was mixed for 10 minutes at 80°C, a stirring speed of 50 rpm, and a dispersing disc speed of 3500 rpm. Finally, the mixture was cooled for 5 minutes at 20°C and a stirring speed of 50 rpm to obtain a mixed powder. The mixed powder was then subjected to a three-roll mill heating process with progressively decreasing temperature until a target areal density of 300 mg / 1540.25 mm was achieved. 2 The self-supporting electrode film is a pre-formed dried electrode sheet. The roller surface temperature is 100℃, the linear speed ratio of the three rollers is 3:5:12, and the gap between each roller is adjusted according to the target surface density (range ≤100μm).

[0180] The difference between Comparative Example 4 and Example 4 is that the pre-dried electrode sheet is not subjected to vibration treatment.

[0181] The difference between Comparative Example 5 and Example 4 is that silicon-carbon composite material is used as the active material and the pre-dried electrode is not subjected to vibration treatment.

[0182] The difference between Comparative Example 6 and Example 1 is that the positive electrode slurry is coated on both surfaces of the positive electrode current collector aluminum foil, and after obtaining a wet film, the wet film is not dried.

[0183] The difference between Comparative Example 7 and Example 9 is that the pre-dried electrode sheet is not subjected to vibration treatment.

[0184] The experimental parameters and process steps not recorded in Examples 2-9 and Comparative Examples 1-7 in Table 1 are consistent with those in Example 1 and will not be repeated here.

[0185] The specific testing methods for the relevant parameters in the above embodiments and comparative examples are as follows:

[0186] 1. Ultimate compaction density test

[0187] Weigh the electrode to obtain its areal density M0 (after deducting the weight of the base copper foil or aluminum foil). Apply a series of gradually increasing pressures to the electrode and record the corresponding thickness changes until the electrode thickness decays and stabilizes at a certain value THK0 (after deducting the thickness of the base copper foil or aluminum foil). Then, the ultimate compaction density of the electrode = M0 / THK0.

[0188] 2. Adsorption force test

[0189] A pressure sensor is installed on the surface of the vibrating plate. When the vibrating plate adsorbs the pre-dried electrode, the pressure sensor can measure the pressure on the pre-dried electrode in real time, that is, the magnitude of the adsorption force of the vibrating plate on the pre-dried electrode.

[0190] 3. Volume average particle size Dv90 test

[0191] Equipment Model: Malvern 2000 (MasterSizer 2000) laser particle size analyzer; Reference Standard Procedure: GB / T19077-2016 / ISO 13320:2009; Specific Test Procedure: Take an appropriate amount of the sample to be tested (the sample concentration should be 8%-12% opacity), add 20ml of deionized water, and sonicate for 5 minutes (53KHz / 120W) to ensure complete dispersion of the sample. Then, measure the sample according to the GB / T19077-2016 / ISO 13320:2009 standard.

[0192]

[0193] Based on Table 1 above, a brief analysis is as follows:

[0194] Comparative Examples 1-9 and 1-7 show that vibration treatment of pre-dried electrodes is beneficial to increasing the packing density of particles inside the pre-dried electrodes, thereby effectively increasing the ultimate compaction density of the electrodes. Comparative Examples 1-5 and 1-5 show that vibration treatment of pre-dried electrodes with different chemical systems can all improve the ultimate compaction density of the electrodes. Comparative Examples 1 and 6 show that increasing the vibration frequency and amplitude of the vibrating plate is beneficial to improving the ultimate compaction density of the electrodes within a certain range. Comparative Examples 1 and 7-8 show that increasing the adsorption force of the vibrating plate on the pre-dried electrodes is beneficial to improving the ultimate compaction density of the electrodes within a certain range. Comparative Examples 9 and 7 show that vibration treatment of pre-dried electrodes prepared by dry process is also beneficial to improving the ultimate compaction density of the electrodes.

[0195] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. An electrode manufacturing system, characterized in that, include: The electrode preparation mechanism is configured to form pre-dried electrode sheets; A vibration mechanism is located downstream of the sheet-making mechanism, and the vibration mechanism is configured to vibrate the pre-dried electrode sheet. A rolling mechanism is located downstream of the vibration mechanism and is configured to roll the pre-dried electrode sheet after vibration treatment to form an electrode sheet.

2. The electrode manufacturing system according to claim 1, characterized in that, The electrode preparation mechanism includes a coating component and a drying component; the coating component is configured to coat a slurry onto a current collector; the drying component is configured to dry the slurry coated onto the current collector to form the pre-made dried electrode.

3. The electrode manufacturing system according to claim 1, characterized in that, The electrode fabrication mechanism includes a film-forming component configured to form a self-supporting electrode film, which is the pre-dried electrode sheet. The electrode manufacturing system further includes a composite component located downstream of the vibration mechanism and upstream of the rolling mechanism, configured to composite the self-supporting electrode film with a current collector.

4. The electrode manufacturing system according to claim 1, characterized in that, The film-forming mechanism includes a film-forming component and a composite component. The film-forming component is configured to form a self-supporting electrode film, which is the pre-formed dried electrode sheet. The composite component is configured to composite the self-supporting electrode film with a current collector.

5. The electrode manufacturing system according to any one of claims 1 to 4, characterized in that, The vibration mechanism includes a vibrating plate and a vibration generator; the vibration generator is configured to drive the vibrating plate to vibrate. One main surface of the vibrating plate is configured to hold the pre-dried electrode.

6. The electrode manufacturing system according to claim 5, characterized in that, The main surface is configured to adsorb the pre-dried electrode.

7. The electrode manufacturing system according to claim 5 or 6, characterized in that, The main surface is provided with adsorption holes; the vibrating plate is also provided with air extraction holes, the adsorption holes are connected to the air extraction holes, and the air extraction holes are configured to connect to an air extraction device.

8. The electrode manufacturing system according to claim 7, characterized in that, The number density of the adsorption pores per unit area on the main surface is 53ea / m. 2 ~5318ea / m 2 ; and / or, the pore size of the adsorption pore is 0.4 mm to 2 mm.

9. The electrode manufacturing system according to any one of claims 5 to 8, characterized in that, The vibration mechanism includes multiple vibration plates; the multiple vibration plates are arranged sequentially at intervals along the conveying direction of the pre-dried electrode sheet; the adsorption holes of two adjacent vibration plates are staggered.

10. The electrode manufacturing system according to claim 5 or 6, characterized in that, The vibrating plate is configured to generate a magnetic field to cause the pre-dried electrode to adhere to the main surface.

11. The electrode manufacturing system according to any one of claims 5 to 10, characterized in that, The vibrating plate is configured such that its width is greater than the width of the pre-dried electrode sheet.

12. The electrode manufacturing system according to any one of claims 5 to 11, characterized in that, The length of the vibrating plate is 0.1m to 0.5m.

13. The electrode manufacturing system according to any one of claims 5 to 12, characterized in that, The vibration generator is an ultrasonic transducer.

14. A method for manufacturing an electrode sheet, characterized in that, include: Obtain pre-dried electrode sheets; The pre-dried electrode sheet is subjected to vibration treatment; The pre-dried electrode sheet after vibration treatment is rolled to obtain the electrode sheet.

15. The electrode manufacturing method according to claim 14, characterized in that, The steps for obtaining the pre-dried electrode sheet include: Prepare a slurry, the slurry comprising an active material; The slurry is coated onto the surface of the current collector to obtain a wet film; The wet film is dried to obtain the pre-made dried electrode.

16. The electrode manufacturing method according to claim 14, characterized in that, The steps for obtaining the pre-dried electrode sheet include: Obtain a mixed powder, wherein the mixed powder includes an active material; The mixed powder is calendered into a film to obtain a self-supporting electrode film, wherein the self-supporting electrode film is the pre-prepared dried electrode sheet; Following the step of vibrating the pre-dried electrode sheet, the method further includes: The pre-dried electrode is combined with the current collector.

17. The electrode manufacturing method according to claim 14, characterized in that, The steps for obtaining the pre-dried electrode sheet include: Obtain a mixed powder, wherein the mixed powder includes an active material; The mixed powder is calendered into a film to obtain a self-supporting electrode film; The self-supporting electrode film is combined with a current collector to obtain the pre-dried electrode sheet.

18. The method for manufacturing an electrode according to any one of claims 15 to 17, characterized in that, The step of vibrating the pre-dried electrode sheet includes: The pre-formed dried electrode sheet is subjected to vibration treatment using a vibration mechanism; wherein, the vibration mechanism includes multiple vibration generators, which are arranged sequentially at intervals along the conveying direction of the pre-formed dried electrode sheet; along the conveying direction of the pre-formed dried electrode sheet, the vibration frequencies of the multiple vibration generators are the same, or the vibration frequencies of the multiple vibration generators decrease sequentially; and / or, Along the conveying direction of the pre-dried electrode, the amplitude of the plurality of vibration generators decreases sequentially.

19. The electrode manufacturing method according to claim 18, characterized in that, The vibration frequency of the vibration generator is 20kHz to 500kHz; and / or the ratio of the amplitude of the vibration generator to the volume average particle size Dv90 of the active material is 0.1 to 0.

3.

20. The electrode manufacturing method according to claim 18 or 19, characterized in that, The vibration mechanism further includes a vibration plate; the step of using the vibration mechanism to vibrate the pre-dried electrode sheet includes: The pre-prepared dried electrode sheet is adsorbed onto the vibrating plate; wherein the adsorption force of the vibrating plate on the pre-prepared dried electrode sheet per unit area is 10 N / mm². 2 ~40N / mm 2 ; The vibration generator is driven to cause the vibrating plate to vibrate.

21. A secondary battery, characterized in that, This includes electrodes manufactured using the electrode manufacturing method described in any one of claims 12 to 20 above.

22. The secondary battery according to claim 21, characterized in that, The active material of the electrode includes lithium cobalt oxide, and the limiting compaction density of the electrode is 4.30 g / cm³. 3 ~4.35g / cm 3 Alternatively, the active material of the electrode may include lithium nickel cobalt manganese oxide, and the limiting compaction density of the electrode may be 3.61 g / cm³. 3 ~3.75g / cm 3 Alternatively, the active material of the electrode may include lithium iron phosphate, and the limiting compaction density of the electrode may be 2.51 g / cm³. 3 ~2.6g / cm 3 Alternatively, the active material of the electrode may include graphite, and the limiting compaction density of the electrode may be 1.8 g / cm³. 3 ~1.88g / cm 3 Alternatively, the active material of the electrode may include a silicon-carbon composite material, and the limiting compaction density of the electrode may be 1.85 g / cm³. 3 ~1.93g / cm 3 .

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