Battery cell vacuum tunnel baking oven

Abstract

The present application relates to the technical field of battery cell baking equipment, in particular to a battery cell vacuum tunnel baking furnace, which comprises a main control cabinet, the front and rear ends of the main control cabinet are provided with sealing doors for opening and closing, a vacuum chamber, a power mechanism and a heating mechanism are arranged in the main control cabinet, a conveying belt for carrying battery cells is arranged in the vacuum chamber along the working direction, the power mechanism comprises an external motor and a dynamic sealing axial magnetic fluid, the external motor is arranged outside the vacuum chamber, the dynamic sealing axial magnetic fluid is connected between the output shaft of the external motor and the transmission shaft of the conveying belt and penetrates through the side wall of the vacuum chamber; a heating plate is installed in the conveying belt, the heating plate is attached to the inner surface of the conveying belt and is used for directly transferring heat to the bottom of the battery cell through the conveying belt, and the heating mechanism is used for heating the heating plate. The present application has the effects of improving the baking sealing performance and the heating uniformity.

Description

Technical Field

[0001] This invention relates to the technical field of battery cell baking equipment, and in particular to a battery cell vacuum tunnel baking oven. Background Technology

[0002] Vacuum baking of battery cells is a key process in the production of various battery cells, such as lithium-ion batteries and sodium-ion batteries. It requires heating in a vacuum environment to remove residual moisture inside the battery cell. The uniformity of baking and the stability of the vacuum directly determine the electrochemical performance, cycle life and safety of the battery cell.

[0003] In existing technologies, battery cell vacuum baking equipment requires a conveying mechanism that penetrates the vacuum chamber and is equipped with a corresponding heating unit to achieve continuous conveying and baking of battery cells. However, in practical applications, the following defects are common: 1. The power source of the conveying mechanism in traditional vacuum baking equipment is usually located outside the vacuum chamber. The drive shaft needs to penetrate the vacuum chamber wall to connect with the internal conveying components. Traditional dynamic seals mostly use mechanical seals or ordinary oil seals. These seals rely on the squeezing contact between the sealing element and the drive shaft to achieve sealing. During the continuous rotation of the drive shaft, friction and wear are easily generated, resulting in poor sealing reliability, easy vacuum leakage, and reduced drying efficiency. 2. Traditional vacuum baking equipment mainly uses non-contact radiant heating, where heat is transferred to the surface of the battery cell through radiation. This method suffers from long heat transfer paths, high energy loss, and poor heating uniformity. It is also difficult to accurately control the heating degree of different parts of the battery cell, which can easily lead to incomplete drying or local overheating damage. Furthermore, it has low heat utilization efficiency and high energy consumption, making it difficult to guarantee the drying quality of the battery cell. Therefore, how to design a vacuum tunnel baking oven for battery cells that can improve drying efficiency, reduce energy consumption, and improve the sealing of the vacuum chamber to ensure a stable baking vacuum environment is a technical problem that enterprise technicians urgently need to solve. Summary of the Invention

[0004] To address the shortcomings of the prior art, this application provides a vacuum tunnel baking oven for battery cells.

[0005] The above-mentioned inventive objective of this application is achieved through the following technical solutions: A vacuum tunnel baking oven for battery cells includes a main control chassis. The main control chassis has sealing doors for opening and closing at both the front and rear ends. The main control chassis contains a vacuum chamber, a power mechanism, and a heating mechanism. A conveyor belt for carrying battery cells is arranged inside the vacuum chamber along the working direction. The power mechanism includes an external motor and a dynamic sealing axial magnetohydrodynamic fluid. The external motor is located outside the vacuum chamber. The dynamic sealing axial magnetohydrodynamic fluid is connected between the output shaft of the external motor and the drive shaft of the conveyor belt and is installed through the side wall of the vacuum chamber. A heating plate is installed inside the conveyor belt. The heating plate is attached to the inner surface of the conveyor belt and is used to directly transfer heat to the bottom of the battery cell through the conveyor belt. The heating mechanism is used to heat the heating plate.

[0006] Preferably, the heating plate has several circulating liquid bath channels inside, the heating mechanism is a liquid bath heater, and the liquid bath heater passes through the outside of the conveyor belt through a pipe and is connected between the external heat transfer liquid supply equipment and the several circulating liquid bath channels.

[0007] Preferably, the heating mechanism is an electric heater, which is disposed inside the heating plate and generates heat by energizing the heating plate.

[0008] Preferably, the vacuum chamber is provided with a support frame, and the support frame is provided with multiple layers of frame space along its height direction. The conveyor belt and the power mechanism are provided with multiple sets of the multiple layers of frame space.

[0009] Preferably, a vacuum pump is installed inside the main control chassis, and the vacuum pump is connected to a vacuum pipeline. The vacuum pump passes through the vacuum pipeline through the vacuum chamber to extract air and water molecules that have overflowed from the battery cell from the vacuum chamber.

[0010] Preferably, the main control chassis is equipped with an audio-visual module, which is used to automatically trigger an alarm to prompt material unloading after baking is completed.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes a dynamic sealing axial magnetofluid that penetrates the sidewall of a vacuum chamber between the output shaft of an external motor and the drive shaft of a conveyor belt. Compared to traditional mechanical seals, the magnetofluid forms a liquid sealing film within the shaft gap under the influence of a magnetic field, resulting in friction-free wear and a stable dynamic sealing effect. This fundamentally eliminates vacuum leakage and ensures a stable vacuum environment for baking. The heating plate adheres to the inner surface of the conveyor belt to form a contact-type bottom heating, directly transferring heat to the bottom of the battery cell. This significantly reduces heat loss, improves heating uniformity, and prevents incomplete drying or localized overheating of the battery cell. Furthermore, the multi-layered layout of the vacuum chamber, combined with multiple conveyor belts, increases production capacity. The vacuum pump continuously removes air from the chamber and moisture from the battery cell. After baking, an audible and visual alarm automatically alerts the user to unload the battery cell. Overall, this achieves efficient, stable, and low-consumption continuous vacuum baking of the battery cell. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a structure in one embodiment of this application; Figure 2 This is a schematic diagram of the structure after removing the feeding sealing door in one embodiment of this application; Figure 3This is a schematic diagram of the structure after removing the main control chassis in one embodiment of this application; Figure 4 This is a partial structural schematic diagram of the conveyor belt in one embodiment of this application; Figure 5 yes Figure 4 A magnified view of part A in the middle; Figure 6 This is a schematic diagram of the structure after removing the vacuum chamber in one embodiment of this application.

[0013] Reference numerals in the attached diagram: 1. Main control chassis; 2. Loading sealing door; 3. Unloading sealing door; 4. Vacuum chamber; 5. Power mechanism; 51. External motor; 52. Dynamic seal axial magnetohydrodynamic fluid; 53. Drive shaft; 6. Heating mechanism; 61. Heating plate; 62. Liquid bath heater; 63. Circulating liquid bath channel; 7. Vacuum pump; 8. Vacuum pipeline; 9. Conveyor belt; 10. Support frame. Detailed Implementation

[0014] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0015] It should be noted that the terms "first," "second," etc., used in this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this disclosure.

[0016] Furthermore, the term "and / or" in this article 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, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0017] The following is a reference appendix. Figure 1 To be continued Figure 6 This application describes a vacuum tunnel baking oven for battery cells.

[0018] Reference Figures 1 to 6The battery cell vacuum tunnel baking oven includes a main control box 1, which serves as the installation and protection carrier for the equipment. Both ends of the main control box 1 are equipped with openable and closable sealing doors. The front end is a feeding sealing door 2, and the rear end is a discharging sealing door 3. The sealing doors can be pneumatically automatic or manually opened and closed. A silicone sealing gasket (not shown in the figure) is provided between the door and the main control box 1 and the vacuum chamber 4 to ensure the sealing reliability in the closed state. The main control chassis 1 integrates a vacuum chamber 4, a power mechanism 5, a heating mechanism 6, a vacuum system, and a control system. The vacuum chamber 4 is a sealed working space for vacuum baking of the battery cells. Inside the vacuum chamber 4, a conveyor belt 9 is installed along the working direction of the battery cells to carry them. The battery cells can be placed directly or on a tray on the conveyor belt 9, and are continuously conveyed and baked along with the conveyor belt 9. Specifically, a support frame 10 is fixedly installed inside the vacuum chamber 4. The support frame 10 is arranged in multiple layers along the height direction, and a conveyor belt 9 is installed in each layer of the frame space to form a multi-layer parallel conveying structure. This allows for the dense placement of multiple layers, columns, and rows of battery cells, greatly improving the space utilization of the equipment and the baking capacity per unit time. It is worth mentioning that the conveyor belt 9 is a flat belt with high temperature resistance and good thermal conductivity. The belt is tensioned on the drive roller and the driven roller. The rotation of the drive roller drives the conveyor belt 9 to run smoothly. The running direction of the conveyor belt 9 is consistent with the working direction of the battery cells from loading to unloading.

[0019] The power mechanism 5 includes an external motor 51 and a dynamic seal axial magnetic fluid 52. The external motor 51 is fixedly installed on the outer wall of the vacuum chamber 4, without occupying the internal space of the vacuum chamber 4. At the same time, it avoids the motor components being exposed to the high temperature environment of the vacuum, thus improving the stability of the equipment operation. The side wall of the vacuum chamber 4 has a shaft hole for the drive shaft 53 of the conveyor belt 9 to pass through. The drive shaft 53 needs to pass from the outside of the vacuum chamber 4 into the inside to connect to the drive roller of the conveyor belt 9. An annular through-shaft gap is formed between the outer diameter of the drive shaft 53 and the inner wall of the shaft hole. The dynamic seal axial magnetic fluid 52 is sealed and installed at the shaft hole position. One end of it is connected to the output shaft of the external motor 51, and the other end passes through the through-shaft gap and is fixedly connected to the drive shaft 53 of the conveyor belt 9 inside the vacuum chamber 4. It should be noted that the dynamic seal axial magnetic fluid 52 is internally equipped with a permanent magnet and a pole shoe structure, which can form a stable magnetic field at the shaft gap. Under the action of the magnetic field, the magnetic fluid is attracted and filled in the shaft gap between the drive shaft 53 and the pole shoe, forming a continuous and complete liquid sealing film. This sealing film has no solid friction and no mechanical wear. During the dynamic process of continuous rotation of the drive shaft 53, it always maintains a complete seal of the shaft gap, structurally preventing leakage of the vacuum chamber 4 through the shaft gap, and ensuring that the vacuum degree inside the vacuum chamber 4 is maintained stably. The permanent magnet and pole shoe matching structure used in the dynamic seal axial magnetic fluid 52 is common knowledge in the field and will not be described in detail here.

[0020] A heating plate 61 is fitted inside the conveyor belt 9. In this embodiment, the heating plate 61 is a flat heat-conducting plate, and its upper and lower surfaces are tightly fitted to the inner surface of the conveyor belt 9. The heating mechanism 6 provides a heat source for the heating plate 61 and adopts a contact bottom heating method. The heat of the heating plate 61 is directly and evenly transferred to the bottom of the battery cell through the conveyor belt 9, which can significantly shorten the heat transfer path, reduce heat loss, and ensure that all parts of the battery cell are heated evenly. In one embodiment, the heating plate 61 has several circulating liquid bath channels 63 inside. The heating mechanism 6 adopts a liquid bath heater 62, which is usually composed of a liquid storage tank, a circulating pump, a temperature control component, etc. It is a conventional and mature structure in the field. During operation, the liquid bath heater 62 heats the heat transfer liquid to the set temperature. The circulating pump drives the heat transfer liquid to circulate continuously in the circulating liquid bath channel 63 through the heat insulation pipeline. The heat is evenly transferred to the heating plate 61 through heat conduction. It has high temperature stability and is suitable for battery cells with strict requirements for baking uniformity.

[0021] In another embodiment, the heating mechanism 6 uses an electric heater (not shown in the figure), such as an electric heating tube or an electric heating film, which are conventional electric heating elements in the art. By embedding the electric heater inside the heating plate 61, heat is directly generated based on the current heating effect after power is applied, which quickly and evenly heats the heating plate 61. The heating speed is fast and the temperature control is precise, which is suitable for the rapid baking requirements of the battery cells.

[0022] In addition, a vacuum pump 7 is installed inside the main control box 1. The air inlet of the vacuum pump 7 is connected to a vacuum pipe 8, which extends into the vacuum chamber 4. During operation, the vacuum pump 7 is started and continuously draws air from the vacuum chamber 4 through the vacuum pipe 8, as well as water molecules that overflow from the battery cell during the baking process. This allows the vacuum chamber 4 to quickly reach and maintain the set vacuum level, lowers the boiling point of the water inside the battery cell, accelerates the vaporization and overflow of water, and improves the drying efficiency.

[0023] In addition, an audio-visual module (not shown in the figure) is installed on the outside of the main control chassis 1. The audio-visual module is electrically connected to the control system. The control system presets process parameters such as baking time, temperature, and vacuum degree. When the battery cell is baked, the control system immediately triggers the audio-visual module to prompt the operator to load and unload the battery cell in time through flashing lights and sound, so as to avoid over-baking or failure to process the battery cell in time, thereby improving the continuity of operation and production efficiency. Typically, the audio-visual module consists of a warning light and a buzzer. The warning light emits light or flashes when powered on to provide visual prompts, and the buzzer vibrates when powered on to produce sound to provide auditory prompts. The two work together to form an audio-visual linkage prompt. Its composition and working principle are common knowledge to those skilled in the art and will not be described in detail here.

[0024] The implementation principle of the battery cell vacuum tunnel baking oven in this application embodiment is as follows: The equipment uses the main control box 1 as the control core, and a sealed baking space is formed through the vacuum chamber 4. The external motor 51 transmits power through the dynamic seal axial magnetic fluid 52. The magnetic fluid forms a stable liquid sealing film in the shaft gap, which eliminates friction and wear and ensures that the vacuum chamber 4 is sealed and leak-proof throughout the process. Multiple sets of power mechanisms 5 drive the multi-layer conveyor belts 9 to operate smoothly, realizing continuous conveying of the battery cells. The heating plate 61 is in close contact with the inner surface of the conveyor belt 9 to form a contact bottom heating. Liquid bath heating or electric heating can be selected according to process requirements. The heat is directly and efficiently transferred to the bottom of the battery cell through the conveyor belt 9, which significantly improves the heating uniformity and heat utilization rate and avoids uneven heating of the battery cell. The vacuum pump 7 continuously extracts the air and water molecules released from the battery cell in the vacuum chamber 4, which lowers the boiling point of water in the vacuum environment and accelerates the rapid removal of water from the battery cell. After baking, the sound and light module is triggered to prompt the unloading. The entire process realizes continuous, efficient and well-sealed vacuum baking operation of the battery cells.

[0025] It should be noted that this invention is adaptable to both manual and automated loading / unloading modes. Automated loading / unloading can be equipped with a conventional loading / unloading robot (not shown in the figure), which is uniformly controlled by the main control box 1. Automatic material feeding is completed at the loading sealing door 2, and automatic material retrieval is completed at the unloading sealing door 3, realizing fully automated operation. The loading / unloading robot is a conventional setting in this field, and the relevant structure and control method are all mature components that can be purchased on the market, so they will not be described in detail here. Manual loading / unloading involves directly opening the front and rear sealing doors manually and placing or removing the battery cells row by row along the multi-layer conveyor belt 9. The operation is simple and convenient. The two modes can be flexibly switched according to the scale of the production line, and the equipment has stronger adaptability. The conveyor belt 9 adopts a layered pitch feeding method, which works in conjunction with the loading and unloading operations. During loading, a person or a loading / unloading robot places a row of battery cells or trays at the outermost edge of each layer of conveyor belt 9 along the transverse direction, and so on, completing the loading of the outermost row of all layers in sequence. After the outermost row of all layers is filled, the power mechanism 5 drives the conveyor belt 9 to move one pitch along the working direction, so that a row of empty space is exposed at the outermost edge of each layer of conveyor belt 9, preparing for the placement of the next row of battery cells or trays. The above steps are repeated until all layers are filled with battery cells or trays along the working direction, and the loading is completed. The unloading process is the same as the loading principle, using a row-by-row picking and pitch feeding method, which will not be described in detail here.

[0026] The specific embodiments described above do not constitute a limitation on the scope of protection of this application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A vacuum tunnel baking oven for battery cells, characterized in that, include: The main control chassis (1) is provided with sealing doors for opening and closing at both the front and rear ends. The main control chassis (1) is provided with a vacuum chamber (4), a power mechanism (5) and a heating mechanism (6) inside. The vacuum chamber (4) is provided with a conveyor belt (9) for carrying the battery cells along the working direction inside. The power mechanism (5) includes an external motor (51) and a dynamic sealing axial magnetic fluid (52). The external motor (51) is located outside the vacuum chamber (4). The dynamic sealing axial magnetic fluid (52) is connected between the output shaft of the external motor (51) and the drive shaft (53) of the conveyor belt (9) and is installed through the side wall of the vacuum chamber (4). A heating plate (61) is installed inside the conveyor belt (9). The heating plate (61) is attached to the inner surface of the conveyor belt (9) and is used to directly transfer heat to the bottom of the battery cell through the conveyor belt (9). The heating mechanism (6) is used to heat the heating plate (61).

2. The battery cell vacuum tunnel baking oven as described in claim 1, characterized in that, The heating plate (61) has several circulating liquid bath channels (63) inside. The heating mechanism (6) adopts a liquid bath heater (62). The liquid bath heater (62) passes through the outside of the conveyor belt (9) through a pipeline and is connected between the external heat transfer liquid supply equipment and several circulating liquid bath channels (63).

3. The cell vacuum tunnel baking oven as described in claim 1, characterized in that, The heating mechanism (6) uses an electric heater, which is located inside the heating plate (61). The electric heater generates heat by energizing the heating plate (61).

4. The cell vacuum tunnel baking oven as described in claim 1, characterized in that, The vacuum chamber (4) is provided with a support frame (10), and the support frame (10) is provided with multiple layers of frame space along its height direction. The conveyor belt (9) and the power mechanism (5) are provided with multiple sets of the multiple layers of frame space.

5. The cell vacuum tunnel baking oven as described in claim 1, characterized in that, The main control chassis (1) is equipped with a vacuum pump (7), which is connected to a vacuum pipeline (8). The vacuum pump (7) passes through the vacuum chamber (4) via the vacuum pipeline (8) to extract air and water molecules overflowing from the battery cell in the vacuum chamber (4).

6. The cell vacuum tunnel baking oven as described in claim 1, characterized in that, The main control chassis (1) is equipped with an audio-visual module. After baking is completed, the audio-visual module is used to automatically trigger an alarm to prompt the material to be unloaded.

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