A coating system and a battery production system

Abstract

The utility model relates to the technical field of lithium ion battery coating, especially to a coating system and battery production system. The coating system is used for coating electrode coating on the surface of current collector; wherein, the current collector has first face and second face which are oppositely arranged, and the coating system coats electrode coating on the first face and the second face in turn; the coating system comprises: coating die head, oven and drying device; the coating die head and the oven are arranged in turn along the conveying direction of the current collector; the drying device is arranged downstream of the oven and is used for drying the first face after being treated by the oven when the coating die head coats the first face; and / or, the drying device is arranged upstream of the coating die head and is used for drying the first face when the coating die head coats the second face. Through the secondary drying or the third drying of the slurry accumulation area in the middle of the current collector by the drying device, the solvent in the electrode slurry is volatilized, compared with the prior art, the situation that the edge of the pole piece is cracked is avoided, and the performance of the battery cell is not affected.

Description

Technical Field

[0001] This utility model relates to the field of lithium-ion battery coating technology, and in particular to a coating system and a battery production system. Background Technology

[0002] In the preparation process of silicon-carbon anodes for semi-solid-state batteries, the electrode coating process directly determines the structural uniformity, mechanical properties, and final electrochemical performance of the electrode. Among these, controlling the drying uniformity of double-sided coating is one of the core technical challenges.

[0003] Silicon-carbon anode coating typically requires sequential coating and drying of the A and B sides of the current collector, such as copper foil. This involves coating and drying the A side first, then flipping it over to coat the B side. However, due to the high activity of silicon-based materials and the unique rheological properties of semi-solid systems, such as high viscosity and sensitivity to solvent evaporation rates, silicon-carbon anode slurries are prone to uneven drying in certain areas during the drying process.

[0004] In existing coating processes, after side A is coated and dried in an oven, a differential drying phenomenon often occurs on the electrode surface: the center is wet while the sides are dry. The central area of ​​the electrode, due to a slightly thicker slurry layer and a longer solvent evaporation path, is prone to retaining residual solvent or moisture. Meanwhile, the edge areas, with thinner slurry layers and more thorough heat exchange with the oven, are drier. This uneven drying of side A directly leads to stability issues in subsequent side B coating. During side B coating, the die pressure and heat from the slurry cause the solvent remaining in the center of side A to evaporate rapidly, resulting in bulging defects in the center of the electrode due to internal gas expansion. This severely affects the flatness of the electrode and the stability of subsequent rolling, slitting, and other processes. Utility Model Content

[0005] (I) The problem to be solved by this utility model is that in the existing double-sided coating process of silicon-carbon anode for semi-solid batteries, there is uneven drying after coating the A side.

[0006] (II) Technical Solution To address the aforementioned technical problems, one embodiment of this utility model provides a coating system for coating an electrode coating onto the surface of a current collector; wherein the current collector has a first surface and a second surface disposed opposite to each other, and the coating system sequentially coats the first surface and the second surface with the electrode coating; The coating system includes: a coating die, an oven, and a drying device; The coating die and the drying oven are arranged sequentially along the conveying direction of the current collector; The drying device is located downstream of the oven and is used to dry the first surface after oven treatment when the first surface is coated by the coating die; and / or, the drying device is located upstream of the coating die and is used to dry the first surface when the second surface is coated by the coating die.

[0007] Furthermore, the drying device includes a fan and a plurality of air outlets communicating with the air outlet end of the fan, the air outlets being spaced apart along the width direction of the collector.

[0008] Furthermore, the air output of the fan is less than or equal to 30m³. 3 / min.

[0009] Furthermore, each of the air outlets is equipped with an adjustment element for adjusting the opening degree of the air outlet.

[0010] Furthermore, the drying device also includes a heating mechanism; the heating mechanism is used to heat the airflow discharged from the outlet of the fan.

[0011] Furthermore, the heating temperature of the heating mechanism is less than or equal to 200°C.

[0012] Furthermore, the heating mechanism employs heat transfer oil heating, infrared heating, or electric heating.

[0013] Furthermore, the drying device includes a housing and control components; The control component is disposed inside the housing, and a first control element and a second control element are disposed on the housing; the first control element is electrically connected to the adjusting element through the control component, and the first control element is used to control the opening degree of the adjusting element; the second control element is electrically connected to the heating mechanism through the control component, and the second control element is used to adjust the heating temperature of the heating mechanism.

[0014] Furthermore, the drying device includes a main pipeline; One end of the main pipeline is connected to the air outlet of the fan, and the other end is sealed; each air outlet is connected to the main pipeline.

[0015] Another embodiment of this utility model provides a lithium battery production system, including the coating system described above.

[0016] The beneficial effects of this utility model are: This utility model provides a coating system for coating an electrode coating onto the surface of a current collector; wherein the current collector has a first surface and a second surface arranged opposite to each other, and the coating system sequentially coats the first surface and the second surface with the electrode coating; the coating system includes: a coating die, an oven, and a drying device; the coating die and the oven are sequentially arranged along the conveying direction of the current collector; the drying device is located downstream of the oven and is used to dry the first surface after oven treatment when the coating die coats the first surface; and / or, the drying device is located upstream of the coating die and is used to dry the first surface when the coating die coats the second surface.

[0017] By using a drying device to perform secondary or tertiary drying on the slurry accumulation area in the current collector, the solvent in the electrode slurry evaporates. Compared with existing technologies, this avoids the occurrence of electrode edge cracking and does not affect the performance of the battery cell. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a coating system provided in one embodiment of the present invention; Figure 2 This is a schematic diagram of the coating system provided in another embodiment of the present invention; Figure 3 This is a schematic diagram of the drying device. Figure 4 This is a schematic diagram of the structure of the drying device and the electrode.

[0020] Icon: 100 - Current collector; 200-Coating Die Head; 300-Oven; 400-Drying device; 410 - Air outlet; 420 - Main pipeline; 430 - Housing; 440 - First control component; 450 - Second control component. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0025] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0028] like Figures 1 to 4As shown, one embodiment of this utility model provides a coating system for coating an electrode coating onto the surface of a current collector 100. The current collector 100 has a first surface and a second surface arranged opposite to each other. The coating process is as follows: first, the first surface of the current collector 100 is coated and dried, and then the second surface of the current collector 100 is coated. The coating system includes a coating die 200, an oven 300, and a drying device 400. The coating die 200 and the drying oven 300 are arranged sequentially along the conveying direction of the current collector 100. The coating die 200 is a slit-type extrusion structure used to uniformly extrude and coat the electrode paste onto the surface of the current collector 100 through the slit. The drying oven 300 is located downstream of the coating die 200 along the conveying direction of the current collector 100. It removes the solvent from the electrode paste by means of hot air circulation or infrared heating, and dries the electrode paste coated on the surface of the current collector 100. During the coating process, the current collector 100 is unwound and conveyed to the coating die 200 through a series of rollers. The first surface of the current collector 100 faces the coating die 200. Electrode paste is coated on the first side of current collector 100. Then current collector 100 enters oven 300, oven 300 dries the electrode paste on the first side of current collector 100, and then it is wound up after passing through a series of rollers. After winding, current collector 100 is unwound again and conveyed to coating die head 200 through a series of rollers. At this time, the second side of current collector 100 faces coating die head 200, and coating die head 200 coats the second side of current collector 100 with electrode paste. Then current collector 100 enters oven 300 again, oven 300 dries the electrode paste on the second side of current collector 100, and then it is wound up after passing through a series of rollers, thus obtaining the electrode sheet. The drying device 400 has several implementations. In one implementation, the drying device 400 is located downstream of the oven 300. After the electrode paste on the first side of the current collector 100 is dried in the oven 300, the drying device 400 performs a second drying on the electrode paste on the first side of the current collector 100. In another implementation, the drying device 400 is located upstream of the coating die 200. After the electrode paste on the first side of the current collector 100 is processed in the oven 300 and then wound up, the drying device 400 performs a second drying on the current collector 100 before the coating die 200 coats the second side of the current collector 100. The electrode paste on the first side of the current collector 100 is dried a second time. In the third embodiment of the drying device 400, the drying device 400 is arranged both downstream of the oven 300 and upstream of the coating die 200. After the electrode paste on the first side of the current collector 100 is processed by the oven 300, the drying device 400 downstream of the oven 300 dries the electrode paste on the first side of the current collector 100 a second time. Then the current collector 100 is wound up. Then the current collector 100 is unwound. Before the coating die 200 coats the second side of the current collector 100 with electrode paste, the drying device 400 upstream of the coating die 200 dries the electrode paste on the first side of the current collector 100 a third time.Optionally, in a third embodiment of the drying device 400, when the coating die 200 coats the electrode slurry on the first side of the current collector 100, the drying device 400 upstream of the coating die 200 does not operate, and when the coating die 200 coats the electrode slurry on the second side of the current collector 100, the drying device 400 downstream of the oven 300 does not operate.

[0029] The coating system provided in this embodiment uses a drying device 400 to perform secondary or tertiary drying on the slurry accumulation area in the current collector 100, causing the solvent in the electrode slurry to evaporate. Compared with the prior art, this avoids the occurrence of cracking at the edge of the electrode sheet and does not affect the performance of the battery cell.

[0030] Optional, such as Figures 1 to 4 As shown, the drying device 400 includes a fan and several air outlets 410. Each air outlet 410 can be a nozzle or an air duct. Each air outlet 410 is connected to the air outlet end of the fan, and the air outlets 410 are spaced apart along the width direction of the collector 100. The airflow discharged from the fan's air outlet blows onto the surface of the collector 100 through the air outlets 410. Because each air outlet 410 is arranged along the width direction of the collector 100, it can effectively cover the surface of the collector 100, thereby accelerating airflow and promoting the evaporation of solvents in the electrode slurry.

[0031] Optionally, the fan's air output volume is less than or equal to 30m³ / h. 3 / min, to avoid damaging the collector 100 while meeting drying requirements. For example, the fan's airflow can be 30 m³ / s. 3 / min, 25 m 3 / min, 20 m 3 / min, 15 m 3 / min, 10m 3 / min, 5 m 3 / min etc.

[0032] Preferably, each air outlet 410 is provided with an adjusting component for adjusting the opening of the air outlet 410. The adjusting component can be an electrically controlled valve, such as a solenoid valve, or it can be a baffle plate provided at the air outlet 410. By providing the adjusting component, the air volume of the drying device 400 can be adjusted, thereby achieving the purpose of uniform drying.

[0033] Optionally, the drying device 400 also includes a heating mechanism, which is located at the air outlet of the fan and is used to heat the airflow discharged from the air outlet of the fan. This allows the drying device 400 to promote the evaporation of solvent in the electrode slurry through baking, thereby improving the drying effect and solving the problem that the electrode coating on the surface of the current collector 100 is "wet in the middle and dry on both sides" after it leaves the oven 300.

[0034] Optionally, the heating temperature of the heating mechanism is less than or equal to 200°C. For example, the heating temperature of the heating mechanism can be 200°C, 180°C, 160°C, 140°C, 120°C, 100°C, 80°C, 60°C, etc. In this embodiment, by adjusting the heating temperature of the heating mechanism, overheating is avoided while meeting the drying requirements, or damage to the current collector 100 is avoided.

[0035] Optionally, in this embodiment, the heating mechanism can employ any one of thermal oil heating, infrared heating, and electric heating. Thermal oil heating involves indirect heat exchange between hot oil and airflow, typically including a heating unit and a heat exchanger. The heat exchanger is located at the air outlet of the fan. The heating unit delivers heated oil to the heat exchanger, where heat exchange is achieved between the oil and the airflow. Infrared heating is a type of radiative heating, utilizing infrared radiation elements to emit infrared rays. Molecules in the airflow absorb the infrared energy and convert it into heat energy, making it suitable for rapid heating and localized heating scenarios, with fast temperature control response. Electric heating generates Joule heat through the flow of current through a resistive element, directly exchanging heat with the airflow.

[0036] Optional, such as Figure 3 As shown, the drying device 400 also includes a housing 430 and a control assembly, with the control assembly located inside the housing 430. The housing 430 is also equipped with a first control element 440 and a second control element 450. The first control element 440 is electrically connected to an adjusting element via the control assembly, allowing the operator to control the opening of the air outlet 410. The second control element 450 is electrically connected to a heating mechanism via the control assembly, allowing the operator to control the heating temperature of the heating mechanism. The first control element 440 and the second control element 450 can be buttons or knobs.

[0037] In this embodiment, the control component mentioned above can be a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0038] Optional, such as Figure 3As shown, the drying device 400 includes a main pipeline 420; one end of the main pipeline 420 is connected to the air outlet of the fan, and the other end is sealed; each air outlet 410 is connected to the main pipeline 420. By setting the main pipeline 420 to connect each air outlet 410, the arrangement of the drying device 400 can be facilitated.

[0039] Optionally, in this embodiment, multiple mounting holes may be provided on the main pipeline 420 for mounting the air outlet 410, thereby enabling the drying device 400 to adapt to various different specifications of the collector 100.

[0040] In other embodiments, the drying device 400 can be slidably mounted on the support of the coating system via a slide rail, thus enhancing the overall integrity of the coating system; when the drying device 400 needs to be inspected or maintained, it can be slid out directly via the slide rail.

[0041] The coating system provided in this embodiment also includes a deviation correction mechanism and a areal density detection mechanism disposed upstream of the coating die 200. The current collector 100 is processed by the areal density detection mechanism and then coated by the coating die 200. Multiple deviation correction mechanisms can be configured; for example, one deviation correction mechanism can be disposed upstream of the areal density detection mechanism, and another between the areal density detection mechanism and the coating die 200. The deviation correction mechanism is used to monitor and correct the positional deviation of the current collector 100 during the transport process in real time, ensuring that the current collector 100 runs stably along a preset reference path, avoiding problems such as uneven coating edges, coating exceeding the range of the current collector 100, or insufficient coating coverage due to deviation. The areal density detection mechanism detects the areal density of the electrode coating after coating in real time, ensuring that it meets preset process standards, and avoiding the impact of areal density fluctuations on the energy density, cycle life, and safety of the lithium battery.

[0042] The coating system provided in this embodiment, after adopting a blowing device, reduced the percentage of dark marks and cracks on the electrode surface from 2.59% to 0.08% through testing.

[0043] Another embodiment of this utility model provides a battery production system, including the coating system described in any of the above embodiments.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A coating system for coating an electrode coating onto the surface of a current collector (100); wherein, The current collector (100) has a first surface and a second surface arranged opposite to each other, and the coating system sequentially coats the first surface and the second surface with an electrode coating. The coating system is characterized in that it comprises: a coating die (200), an oven (300), and a drying device (400). The coating die (200) and the oven (300) are arranged sequentially along the conveying direction of the current collector (100); The drying device (400) is disposed downstream of the oven (300) and is used to dry the first surface after it has been treated in the oven (300) when the first surface is coated by the coating die (200); and / or, the drying device (400) is disposed upstream of the coating die (200) and is used to dry the first surface when the second surface is coated by the coating die (200).

2. The coating system according to claim 1, characterized in that, The drying device (400) includes a fan and a plurality of air outlets (410) connected to the air outlet end of the fan, the air outlets (410) being spaced apart along the width direction of the collector (100).

3. The coating system according to claim 2, characterized in that, The air output of the fan is less than or equal to 30m³. 3 / min.

4. The coating system according to claim 2 or 3, characterized in that, Each of the air outlets (410) is provided with an adjustment element for adjusting the opening of the air outlet (410).

5. The coating system according to claim 4, characterized in that, The drying device (400) further includes a heating mechanism for heating the airflow discharged from the outlet of the fan.

6. The coating system according to claim 5, characterized in that, The heating temperature of the heating mechanism is less than or equal to 200°C.

7. The coating system according to claim 5, characterized in that, The heating mechanism uses heat transfer oil heating, infrared heating, or electric heating.

8. The coating system according to claim 5, characterized in that, The drying device (400) includes a housing (430) and a control assembly; The control component is disposed inside the housing (430), and the housing (430) is provided with a first control element (440) and a second control element (450); the first control element (440) is electrically connected to the adjusting element through the control component, and the first control element (440) is used to control the opening degree of the adjusting element; the second control element (450) is electrically connected to the heating mechanism through the control component, and the second control element (450) is used to adjust the heating temperature of the heating mechanism.

9. The coating system according to claim 2, characterized in that, The drying device (400) includes a main pipeline (420); One end of the main pipeline (420) is connected to the air outlet of the fan, and the other end is sealed; each of the air outlets (410) is connected to the main pipeline (420).

10. A battery production system, characterized in that, Includes the coating system as described in any one of claims 1 to 9.

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