Drying equipment and precision molding process for lithium battery cell production

Abstract

This invention discloses a drying device and its precision forming process for lithium battery cell production, belonging to the field of lithium battery technology. It includes a housing, several air intake baffles disposed within the housing, and a hot air drying assembly. The air intake baffles are stacked vertically, with a hollow inner layer forming an air distribution cavity. The outer wall of the air intake baffles is concave inward to form an arc-shaped cavity. The arc-shaped cavities of adjacent air intake baffles are fitted together to form a cell drying channel capable of accommodating cylindrical battery cells. The hot air outlet of the hot air drying assembly communicates with the air distribution cavity of each air intake baffle. Several air holes are formed on the inner wall of the arc-shaped cavity, and the cell drying channel communicates with the corresponding air distribution cavity through these air holes. This invention improves the uniformity of drying moisture on the battery cell surface, increases drying efficiency, ensures the performance of battery cell production, and thus improves the stability, safety, and service life of the battery cell.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a drying device for lithium battery cell production and its precision molding process. Background Technology

[0002] Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as the positive / negative electrode materials and a non-aqueous electrolyte solution. A lithium-ion battery mainly consists of a cell and a protection board. The protection board primarily comprises a protection chip, MOSFETs, resistors, capacitors, and a PCB board. The cell, essentially the heart of the lithium-ion battery, mainly consists of positive electrode materials, negative electrode materials, electrolyte, separator, and casing. Due to their high energy density and environmental friendliness, lithium-ion batteries are widely used in electric vehicles, energy storage systems, digital devices, and military products.

[0003] Electrolyte filling is a crucial step in the production of cylindrical battery cells. Before filling, the cells typically need to be dried to remove surface moisture. Otherwise, residual moisture after encapsulation can cause corrosion and short circuits, affecting battery performance and safety. Therefore, drying before electrolyte filling improves the uniformity of internal materials, enhances battery performance and cycle life, reduces the probability of thermal runaway, and improves battery stability and safety.

[0004] Existing methods for drying battery cells before electrolyte injection often involve stacking the cells in a material tray and then placing them in a drying oven. Due to the stacking of the cells and their contact with the material tray, the drying speed and effect of the contact area and the exposed surface of the cells are significantly different. Furthermore, the drying time is often increased to ensure the removal of moisture, which leads to uneven drying of the surface moisture of the cells and low drying efficiency. Summary of the Invention

[0005] To improve the uniformity of moisture drying on the surface of battery cells, increase drying efficiency, ensure the performance of battery cell manufacturing, and enhance the stability, safety, and lifespan of the cells, this invention improves a drying apparatus and its precision forming process for lithium battery cell production.

[0006] The technical solution adopted by this invention to solve its technical problem is: a drying device for lithium battery cell production, including a housing, a plurality of air inlet baffles disposed in the housing, and a hot air drying assembly. The plurality of air inlet baffles are stacked vertically. The inner layer of each air inlet baffle is hollow and forms an air distribution cavity. The outer wall of each air inlet baffle is concave inward to form an arc-shaped cavity. The arc-shaped cavities of two adjacent air inlet baffles are adapted to each other and form a cell drying channel that can accommodate cylindrical cells. The hot air outlet of the hot air drying assembly is connected to the air distribution cavity of each air inlet baffle. The inner wall of each arc-shaped cavity is provided with a plurality of air holes. The cell drying channel is connected to the corresponding air distribution cavity through the air holes.

[0007] Furthermore, the diameter of the cell drying channel is larger than the diameter of the cell. Two overhead support members are provided on the inner wall of the arc-shaped cavity located at the bottom of the cell drying channel. The overhead support members are symmetrically arranged on both sides of the bottom of the cell. The cell is connected to the arc-shaped cavity through the overhead support members. When the cell is located in the cell drying channel, the cell and the cell drying channel are coaxial, and a drying air film is left between the outer wall of the cell and the inner wall of the cell drying channel.

[0008] Furthermore, when several battery cells are placed in the battery cell drying channel for drying, an overhead ball is provided between two adjacent battery cells. The overhead ball is hollow inside and has several perforations on its surface.

[0009] Furthermore, each of the cell drying channels is provided with a sealing element on both sides. The sealing element is located between two adjacent air intake baffles. The sealing element consists of two sealing gaskets, which are pressed together and fixedly connected to the outer wall of the adjacent air intake baffle.

[0010] Furthermore, the overhead support includes a core rod, several sleeves, and several support blocks. A first slot is opened in the inner wall of the arc-shaped cavity located at the bottom of the cell drying channel. The support block is located in the first slot and is fixedly connected to the inner walls on both sides of the first slot. The core rod passes through each support block and is fixedly connected to the support block. The sleeve is located between two adjacent support blocks and is sleeved on the outside of the core rod.

[0011] Furthermore, a rubber roller is provided on the inner wall of the arc-shaped cavity located at the top of the cell drying channel. The inner wall of the arc-shaped cavity has a second slot for installing the rubber roller. The rubber roller is rotatably connected in the second slot and abuts against the outer wall of the cell.

[0012] Furthermore, a lifting and stacking mechanism is provided between the air intake baffle and the housing. The lifting and stacking mechanism includes a lifting cylinder and several guide rods. The lifting cylinder is fixed to the top wall of the housing. The piston rod of the lifting cylinder passes through the housing and is fixedly connected to the top wall of the top air intake baffle. The guide rods are vertically fixed inside the housing. Each air intake baffle has a guide tube fixed to its outer wall near the guide rod. The guide tube is slidably sleeved outside the guide rod. The bottom air intake baffle is fixed inside the housing. Except for the bottom air intake baffle, the guide tubes on the other two adjacent air intake baffles are connected by a lifting rope.

[0013] Furthermore, a cell deflection mechanism is provided inside the housing. The cell deflection mechanism includes a synchronizing rod, a sliding cylinder, and several driving slide rods. Each driving slide rod passes through a corresponding air intake baffle and is slidably connected to the air intake baffle. The sliding direction between the driving slide rod and the air intake baffle is perpendicular to the axial direction of the cell drying channel. The outer circumferential surface of the rubber roller located inside the air intake baffle has incomplete teeth. The bottom of the driving slide rod near the rubber roller has a strip portion that meshes with the incomplete teeth. One end of each driving slide rod passes through the air intake baffle and is slidably connected to the synchronizing rod. The sliding direction of the driving slide rod and the synchronizing rod is the same as the lifting direction of the air intake baffle. The sliding cylinder is fixed to the outer wall of the housing. The piston rod of the sliding cylinder passes through the housing and is fixedly connected to the synchronizing rod. The sleeve is rotatably connected to the core rod.

[0014] Furthermore, support columns are provided at both ends of the side of the box body near the feed inlet. The box body is pivotally connected to the support columns. The rotation axis of the support columns and the box body is horizontally arranged. A lifting mechanism is provided on the bottom surface of the box body away from the support columns. The lifting mechanism includes a drive cylinder, a first connecting rod, a second connecting rod, a first connecting seat, and a second connecting seat. One end of the first connecting rod is hinged to the bottom surface of the box body, and the other end is hinged to the second connecting rod. The end of the second connecting rod away from the first connecting rod is hinged to the second connecting seat. The cylinder body of the drive cylinder is hinged to the first connecting seat, and the piston rod of the drive cylinder is hinged to the middle of the second connecting rod.

[0015] This invention also discloses a precision forming process for lithium battery cells.

[0016] A technical solution for a precision forming process of lithium battery cells, employing any of the aforementioned drying devices for lithium battery cell production, includes the following steps:

[0017] S1: Winding: The positive and negative electrode tabs are welded to different electrode sheets to obtain positive and negative electrode sheets. After being arranged in the order of positive electrode sheet-separator-negative electrode sheet-separator, they are wound to form a cylindrical battery cell substrate.

[0018] S2: Housing: The cell substrate is installed into the cell shell, and the cell shell is grooved to make the cell shell partially concave, ensuring the stability between the cell substrate and the cell shell;

[0019] S3: Drying: The battery cells after casing are dried using drying equipment, including the following steps:

[0020] a. The lifting mechanism is activated, tilting the feed inlet of the box upwards, and then the battery cells are loaded into the battery cell drying channel. Under the action of their own weight, the battery cells slide into the bottom of the battery cell drying channel and are stacked in sequence, and an overhead ball is placed between two adjacent battery cells in the same battery cell drying channel.

[0021] b. The lifting and stacking mechanism is activated, driving the air intake baffles to descend, so that the air intake baffles are stacked together and the rubber rollers come into contact with the battery cells;

[0022] c. The hot air drying assembly introduces hot air into the air distribution chamber of each air intake baffle. The hot air flows into the cell drying channel through the air holes to dry the cell and remove its surface moisture.

[0023] d. During the hot air drying process of the battery cell, the battery cell deflection mechanism is activated, which can drive the circumferential position of the battery cell in the battery cell drying channel to deflect at a certain angle.

[0024] e. After the hot air drying is completed, the lifting and stacking mechanism drives the air intake baffle to move upward, so that the rubber roller is separated from the battery cell. Then the lifting mechanism is activated, so that the feed port of the box tilts downward, completing the unloading of the battery cell.

[0025] S4: Electrolyte injection: Injecting electrolyte into the dried battery cell;

[0026] S5: Packaging: After soldering the caps to the positive and negative electrode tabs, the cells are sealed using a sealing machine to complete the cell assembly.

[0027] The beneficial effects of this invention are:

[0028] (1) When drying the cells, the drying device for lithium battery cell production places the cells in the cell drying channel. Several cells are stacked axially in the cell drying channel. The hot air from the hot air drying component enters the air inlet baffle. The air distribution chamber has a uniform distribution effect on the hot air. The hot air then enters each cell drying channel through the air hole, which can perform a more uniform and efficient drying operation on the periphery of several cells in each cell drying channel.

[0029] (2) The bottom side of the battery cell can be dried evenly and effectively through the overhead support, and the battery cell and the battery cell drying channel are kept in a coaxial state to ensure that the thickness of the hot air layer on the side of the battery cell is uniform, thereby further improving the drying uniformity of the battery cell surface and improving the drying efficiency.

[0030] (3) The setting of the sealing element can reduce the mutual disturbance between the hot air in each cell drying channel, ensure that the hot air can effectively circulate in each cell drying channel, and ensure that the hot air volume in each cell drying channel is balanced, thus ensuring the drying effect.

[0031] (4) The overhead ball prevents the end faces of two axially adjacent cells from touching each other, and the hot air in the cell drying channel can effectively dry the end faces of the cells through the perforations of the overhead ball.

[0032] (5) The output end of the cell deflection mechanism is connected to the rubber roller to drive the rubber roller to rotate. This can simultaneously drive all the cells in the box to deflect circumferentially, change the contact position between the rubber roller, the sleeve and the cell, prevent poor drying at the local contact surface, further improve drying efficiency and uniformity, effectively remove residual moisture on the cell surface, and thus ensure the production and preparation performance of the cell, improve the stability, safety and service life of the cell. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention.

[0034] Figure 2 This is a schematic diagram illustrating the internal structure of the box in an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram illustrating the structure of the hot air intake assembly in an embodiment of the present invention.

[0036] Figure 4 This is a partial structural diagram illustrating the intake baffle in an embodiment of the present invention.

[0037] Figure 5 This is a schematic diagram of the intake baffle in an embodiment of the present invention.

[0038] Figure 6 This is a partial structural schematic diagram of the battery cell drying channel in an embodiment of the present invention.

[0039] Figure 7 This is a schematic diagram of the structure of the battery cell stacking method according to an embodiment of the present invention.

[0040] Figure 8 This is a partial structural schematic diagram of the rubber roller in an embodiment of the present invention.

[0041] Figure 9 This is a partial structural schematic diagram illustrating the cell deflection mechanism in an embodiment of the present invention.

[0042] Figure 10 This is a schematic diagram of the lifting mechanism according to an embodiment of the present invention.

[0043] In the diagram: 1. Housing; 11. Exhaust chamber; 12. Exhaust pipe; 2. Intake baffle; 201. First intake baffle; 202. Second intake baffle; 203. Third intake baffle; 204. Fourth intake baffle; 21. Air distribution chamber; 22. Arc-shaped cavity; 221. Air hole; 222. First slot; 223. Second slot; 23. Cell drying channel; 24. Sealing element; 25. Overhead support element; 251. Core rod; 252. Sleeve; 26. Overhead ball; 27. Rubber roller ; 271. Incomplete toothed section; 3. Hot air drying assembly; 31. Main intake pipe; 32. Branch intake pipe; 4. Lifting and stacking mechanism; 41. Lifting cylinder; 42. Guide rod; 43. Guide tube; 44. Lifting rope; 5. Battery cell deflection mechanism; 51. Sliding cylinder; 52. Synchronizing rod; 53. Drive slide rod; 54. Ruler section; 6. Lifting mechanism; 61. Drive cylinder; 62. First connecting rod; 63. Second connecting rod; 64. First connecting seat; 65. Second connecting seat; 66. Support column. Detailed Implementation

[0044] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0045] This invention discloses a drying device for lithium battery cell production and its precision molding process.

[0046] Reference Figures 1 to 5 The drying device for lithium battery cell production includes a housing 1, a hot air drying assembly 3 installed inside the housing 1, and several layers of air intake baffles 2. The several layers of air intake baffles 2 can be stacked to form a drying chamber. In this embodiment, four layers of air intake baffles 2 are provided. For ease of description, the four layers of air intake baffles 2 are designated as the first air intake baffle 201, the second air intake baffle 202, the third air intake baffle 203, and the fourth air intake baffle 204 from bottom to top. In actual manufacturing and use, the number of air intake baffles can be adjusted according to requirements and is not limited to the four layers of air intake baffles 2 shown in this embodiment. The interior of each air intake baffle 2 is hollow to form an air distribution cavity 21. The outer wall of the air intake baffle 2 is concave inward to form several parallel arc-shaped cavities 22, such as the upper arc-shaped cavity 22 and the lower arc-shaped cavity 22. The arc-shaped cavities 22 of two adjacent air intake baffles 2 are adapted to each other and form a cell drying channel 23 that can accommodate cylindrical cells. Since the bottom surface of the first air intake baffle 201 and the top surface of the fourth air intake baffle 204 cannot be used to arrange battery cells, the bottom surface of the first air intake baffle 201 and the top surface of the fourth air intake baffle 204 are not provided with arc-shaped cavities 22 in order to reduce manufacturing difficulty and cost.

[0047] The cell drying channel 23 is cylindrical, with a diameter larger than that of the cell. The hot air outlet of the hot air drying assembly 3 is connected to the air distribution chamber 21 of each air inlet baffle 2. The inner wall of the arc-shaped cavity 22 is provided with several air holes 221, which are evenly distributed along the axial direction of the cell drying channel 23. The cell drying channel 23 is connected to the corresponding air distribution chamber 21 through the air holes 221. During the production and preparation of cylindrical cells, when drying the cells, the cells are placed in the cell drying channel 23, and several cells are stacked axially in the cell drying channel 23. The hot air from the hot air drying assembly 3 enters the air inlet baffle 2. The air distribution chamber 21 in the air inlet baffle 2 evenly distributes the hot air. The hot air then enters each cell drying channel 23 through the air holes 221, which can perform a relatively uniform and efficient drying operation on the circumference of several cells in each cell drying channel 23.

[0048] Reference Figure 3 , Figure 4 and Figure 6 To ensure uniform and effective drying even on the bottom edge of the battery cell, two overhead support members 25 are installed on the inner wall of the arc-shaped cavity 22 located at the bottom of the battery cell drying channel 23. These overhead support members 25 are symmetrically arranged on both sides of the bottom of the battery cell, and the battery cell is connected to the arc-shaped cavity 22 through the overhead support members 25. When the battery cell is located within the battery cell drying channel 23, it is coaxial with the channel, and a drying air film is left between the outer wall of the battery cell and the inner wall of the drying channel 23. The overhead support members 25 ensure that the battery cell and the drying channel 23 remain coaxial, thereby guaranteeing a uniform thickness of the hot air layer around the battery cell. This not only ensures effective drying of the bottom edge of the battery cell but also effectively improves the uniformity of drying on the battery cell surface, thus increasing drying efficiency.

[0049] Reference Figure 3 , Figure 4 and Figure 6 The overhead support frame includes a core rod 251, several sleeves 252, and several support blocks. A first slot 222 is formed on the inner wall of the arc-shaped cavity 22 located at the bottom of the cell drying channel 23. The support blocks are located within the first slot 222 and welded to the inner walls on both sides of the first slot 222. The support blocks are evenly distributed along the axial direction of the cell drying channel 23, providing support and fixation for the core rod 251, reducing the possibility of bending under stress. The core rod 251 passes through each support block and is fixedly connected to it. The sleeves 252 are made of stainless steel and are located between adjacent support blocks, rotatably fitted over the core rod 251. The sleeves 252 are rotatably connected to the core rod 251 to reduce friction between the cell and the overhead support frame, facilitating subsequent circumferential deflection of the cell. In some embodiments, the overhead support 25 can be connected to a rotary drive component, such as a motor, which drives the sleeves 252 to rotate, facilitating circumferential deflection of the cell.

[0050] Reference Figure 7 To ensure uniform and efficient drying of both ends of the battery cells, when several battery cells are placed in the battery cell drying channel 23, a plastic suspended ball 26 is installed between adjacent battery cells within the same drying channel 23. This suspended ball 26 is hollow inside and has several perforations on its surface. The suspended ball 26 prevents the axially adjacent battery cell ends from touching each other, allowing the hot air in the battery cell drying channel 23 to effectively dry the battery cell ends through the perforations in the suspended ball 26.

[0051] Reference Figure 6 In order to reduce the mutual disturbance between the hot air in each cell drying channel 23 and ensure that the hot air can effectively circulate in each cell drying channel 23, thereby ensuring the drying effect, a sealing element 24 is provided on both sides of the cell drying channel 23. The sealing element 24 is located between two adjacent air inlet baffles 2, and the sealing element 24 is composed of two sealing gaskets. During drying, the two sealing gaskets are pressed together, and each sealing length is bonded and fixed to the adjacent air inlet baffle 2.

[0052] Reference Figure 3 , Figure 4 and Figure 6 A rubber roller 27 is installed on the inner wall of the arc-shaped cavity 22 located at the top of the battery cell drying channel 23. The inner wall of the arc-shaped cavity 22 has a second groove 223 for the rubber roller 27 to be installed. The rubber roller 27 is rotatably connected to the second groove 223 and abuts against the outer wall of the battery cell. The rubber roller 27 is made of rubber to prevent damage to the battery cell from compression and to increase the friction between the rubber roller 27 and the battery cell, facilitating the deflection of the battery cell by the rubber roller 27. A battery cell deflection mechanism 5 is also installed inside the housing 1. The output end of the battery cell deflection mechanism 5 is connected to the rubber roller 27 to drive the rubber roller 27 to rotate, thereby causing each battery cell to deflect circumferentially, changing the contact position between the rubber roller 27, the sleeve 252, and the battery cell. This prevents poor drying at local contact surfaces and further improves drying efficiency and uniformity. In some embodiments, the overhead support 25 can be connected to a rotary drive component, such as a motor, and rotate synchronously with the rubber roller 27 to ensure the deflection driving effect on the battery cell.

[0053] Reference Figure 2The effective function of the cell deflection mechanism 5 requires the rubber roller 27 to contact the cell to ensure its driving friction. Therefore, to facilitate the drying and loading of the cell, a lifting and stacking mechanism 4 is provided between the air intake baffle 2 and the box 1. The lifting and stacking mechanism 4 includes a lifting cylinder 41 and several guide rods 42. The lifting cylinder 41 is bolted to the top wall of the box 1. The piston rod of the lifting cylinder 41 passes through the box 1 and is fixedly connected to the top wall of the fourth air intake baffle 204. The guide rods 42 are vertically welded inside the box 1. Each air intake baffle 2 has a guide tube 43 welded to the outer wall near the guide rod 42. The guide tube 43 is slidably sleeved outside the guide rod 42. The first air intake baffle 201 is bolted to the bottom surface inside the box 1. Except for the first air intake baffle 201, the guide tubes 43 on the other two adjacent air intake baffles 2 are connected by a lifting rope 44. Furthermore, when the lifting cylinder 41 moves the fourth air intake baffle 204 upward, the lifting rope 44 between the guide tubes 43 can sequentially lift the third air intake baffle 203 and the second air intake baffle 202, causing each air intake baffle 2 to disengage from each other, facilitating the loading of the battery cell. When the air intake baffles 2 disengage from each other, the distance between two adjacent air intake baffles 2 is 5mm-10mm.

[0054] In some embodiments, cylinders can be installed between each air intake baffle 2. The first air intake baffle 201 is connected to the first mounting cylinder, the second air intake baffle 202 is connected to the second mounting cylinder, the third air intake baffle 203 is connected to the third mounting cylinder, and the fourth air intake baffle 204 is connected to the fourth mounting cylinder. The spacing between adjacent air intake baffles 2 can be adjusted by using the first mounting cylinder, the second mounting cylinder, the third mounting cylinder, and the fourth mounting cylinder. This not only facilitates the loading of battery cells but also better adapts to the drying operations of battery cells of different sizes.

[0055] Reference Figure 2 , Figure 8 and Figure 9The cell deflection mechanism 5 includes a synchronizing rod 52, a sliding cylinder 51, and several driving slide rods 53. In this embodiment, three driving slide rods 53 are provided, corresponding to each air intake baffle 2. Each driving slide rod 53 passes through the corresponding air intake baffle 2 and is slidably connected to the air intake baffle 2. The sliding direction between the driving slide rod 53 and the air intake baffle 2 is perpendicular to the axial direction of the cell drying channel 23. The outer peripheral surface of the rubber roller 27 located inside the air intake baffle 2 is provided with an incomplete toothed portion 271. The bottom of the driving slide rod 53 near the rubber roller 27 forms a strip portion 54 that meshes with the incomplete toothed portion 271. One end of each driving slide rod 53 passes through the air intake baffle 2 and is slidably connected to the synchronizing rod 52. The sliding direction of the driving slide rod 53 and the synchronizing rod 52 is the same as the lifting direction of the air intake baffle 2. The sliding cylinder 51 is fixed to the outer wall of the housing 1. The piston rod of the sliding cylinder 51 passes through the housing 1 and is fixedly connected to the synchronizing rod 52. The sliding cylinder 51, via the synchronizing rod 52, can simultaneously drive each drive slide rod 53 to slide within the air intake baffle 2. This, in turn, through the meshing action of the ruler section 54 and the incomplete gear section 271, drives the rubber roller 27 to rotate, thereby driving the battery cell to deflect. The battery cell deflection angle ranges from 1° to 30°. One end of the drive slide rod 53 is slidably connected to the synchronizing rod 52, ensuring that when the lifting and stacking mechanism 4 moves the air intake baffle 2 up and down, the drive slide rod 53 moves synchronously with the corresponding air intake baffle 2, preventing motion interference. Furthermore, since the rubber roller 27 is made of rubber, to ensure the meshing effect of the incomplete gear, a thin metal plate is bonded and covered to the surface of the incomplete gear section 271. The incomplete gear section 271 meshes with the ruler section 54 through the thin metal plate.

[0056] Reference Figure 3 The hot air intake assembly includes a main intake pipe 31 and several intake branch pipes 32. The main intake pipe 31 is a corrugated telescopic pipe to adapt to the lifting and stacking mechanism 4. Each intake branch pipe 32 corresponds to an intake baffle 2. One end of the intake branch pipe 32 is connected to the main intake pipe 31, and the other end branches out into several air outlets that are connected to the inner cavity of the intake baffle 2 to ensure sufficient and balanced hot air intake in the air distribution chamber 21. An exhaust chamber 11 is provided at the rear of the housing 1. Each cell drying channel 23 is connected to the exhaust chamber 11. An exhaust pipe 12 connected to the exhaust chamber 11 is provided at the top of the housing 1.

[0057] Reference Figure 10Support columns 66 are provided at both ends of the side of the housing 1 near the feed inlet. The housing 1 is pivotally connected to the support columns 66. The support columns 66 are horizontally aligned with the rotation axis of the housing 1. A lifting mechanism 6 is provided on the bottom surface of the housing 1 away from the support columns 66. The lifting mechanism 6 includes a drive cylinder 61, a first connecting rod 62, a second connecting rod 63, a first connecting seat 64, and a second connecting seat 65. One end of the first connecting rod 62 is hinged to the bottom surface of the housing 1, and the other end is hinged to the second connecting rod 63. The end of the second connecting rod 63 away from the first connecting rod 62 is hinged to the second connecting seat 65. The cylinder body of the drive cylinder 61 is hinged to the first connecting seat 64, and the piston rod of the drive cylinder 61 is hinged to the middle of the second connecting rod 63. The lifting mechanism 6 can control the feeding tendency of the housing 1 to improve the convenience of drying, loading, and unloading of the battery cells.

[0058] This invention also discloses a precision forming process for lithium battery cells.

[0059] The precision molding process for lithium battery cells, using any of the aforementioned drying devices for lithium battery cell production, includes the following steps:

[0060] S1: Winding: The positive and negative electrode tabs are welded to different electrode sheets to obtain positive and negative electrode sheets. After being arranged in the order of positive electrode sheet-separator-negative electrode sheet-separator, they are wound to form a cylindrical battery cell substrate.

[0061] S2: Housing: The cell substrate is installed into the cell shell, and the cell shell is grooved to make the cell shell partially concave, ensuring the stability between the cell substrate and the cell shell;

[0062] S3: Drying: The battery cells after casing are dried using drying equipment, including the following steps:

[0063] a. The lifting mechanism 6 is activated, causing the feed inlet of the box 1 to tilt upwards, and then the battery cells are loaded into the battery cell drying channel 23. The battery cells slide into the bottom of the battery cell drying channel 23 under their own weight and are stacked in sequence, and an overhead ball 26 is placed between two adjacent battery cells in the same battery cell drying channel 23.

[0064] b. The lifting and stacking mechanism 4 is activated, driving the air intake baffle 2 to descend, so that each air intake baffle 2 is stacked and the rubber roller 27 comes into contact with the battery cell.

[0065] c. The hot air drying assembly 3 introduces hot air into the air distribution chamber 21 of each air intake baffle 2. The hot air flows into the cell drying channel 23 through the air hole 221 to dry the cell and remove surface moisture.

[0066] d. During the hot air drying process of the battery cell, the battery cell deflection mechanism 5 is activated, which can drive the circumferential position of the battery cell in the battery cell drying channel 23 to deflect at a certain angle.

[0067] e. After the hot air drying is completed, the lifting and stacking mechanism 4 drives the air intake baffle 2 to move upward, so that the rubber roller 27 is separated from the battery cell. Then the lifting mechanism 6 is started, so that the feed port of the box 1 is tilted downward to complete the unloading of the battery cell.

[0068] S4: Electrolyte injection: Injecting electrolyte into the dried battery cell;

[0069] S5: Packaging: After soldering the caps to the positive and negative electrode tabs, the cells are sealed using a sealing machine to complete the cell assembly.

[0070] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A drying apparatus for lithium battery cell production, characterized in that: The device includes a housing (1), several air inlet baffles (2) disposed within the housing (1), and a hot air drying assembly (3). The several air inlet baffles (2) are stacked vertically. The inner layer of each air inlet baffle (2) is hollow and forms an air distribution cavity (21). The outer wall of each air inlet baffle (2) is recessed inward to form an arc-shaped cavity (22). The arc-shaped cavities (22) of two adjacent air inlet baffles (2) are adapted to each other and form a cell drying channel (23) that can accommodate cylindrical cells. The hot air outlet of the hot air drying assembly (3) is connected to the air distribution cavity (21) of each air inlet baffle (2). The inner wall of each arc-shaped cavity (22) is provided with several air holes (221). The cell drying channel (23) is connected to the corresponding air distribution cavity (21) through the air holes (221). A rubber roller (27) is provided on the inner wall of the arc-shaped cavity (22) located at the top of the cell drying channel (23). A second slot (223) for installing the rubber roller (27) is opened on the inner wall of the arc-shaped cavity (22). The rubber roller (27) is rotatably connected in the second slot (223). The rubber roller (27) abuts against the outer wall of the cell. A lifting and stacking mechanism (4) is provided between the air intake baffle (2) and the box (1). The lifting and stacking mechanism (4) includes a lifting cylinder (41) and several guide rods (42). The lifting cylinder (41) is fixed to the top wall of the box (1). The piston rod of the lifting cylinder (41) passes through the box (1) and is fixedly connected to the top wall of the top air intake baffle (2). The guide rods (42) are vertically fixed inside the box (1). Each air intake baffle (2) has a guide tube (43) fixed to the outer wall near the guide rod (42). The guide tube (43) is slidably sleeved outside the guide rod (42). The air intake baffle (2) located at the bottom is fixed inside the box (1). Except for the bottom air intake baffle (2), the guide tubes (43) on the other two adjacent air intake baffles (2) are connected by a lifting rope (44). The housing (1) is equipped with a cell deflection mechanism (5). The output end of the cell deflection mechanism (5) is connected to the rubber roller (27) to drive the rubber roller (27) to rotate, thereby driving each cell to deflect circumferentially.

2. The drying apparatus for lithium battery cell production according to claim 1, characterized in that: The diameter of the cell drying channel (23) is larger than the diameter of the cell. Two overhead support members (25) are provided on the inner wall of the arc-shaped cavity (22) located at the bottom of the cell drying channel (23). The overhead support members (25) are symmetrically arranged on both sides of the bottom of the cell. The cell is connected to the arc-shaped cavity (22) through the overhead support members (25). When the cell is located in the cell drying channel (23), the cell and the cell drying channel (23) are coaxial. A drying air film is left between the outer wall of the cell and the inner wall of the cell drying channel (23).

3. The drying apparatus for lithium battery cell production according to claim 2, characterized in that: When several battery cells are placed in the battery cell drying channel (23) for drying, an overhead ball (26) is provided between two adjacent battery cells. The overhead ball (26) is hollow inside and has several perforations on its surface.

4. The drying apparatus for lithium battery cell production according to claim 2, characterized in that: Each of the battery cell drying channels (23) is provided with a sealing element (24) on both sides. The sealing element (24) is located between two adjacent air intake baffles (2). The sealing element (24) is composed of two sealing gaskets. The two sealing gaskets are pressed together and the sealing gaskets are fixedly connected to the outer wall of the adjacent air intake baffle (2).

5. A drying apparatus for lithium battery cell production according to any one of claims 2-4, characterized in that: The overhead support (25) includes a core rod (251), several sleeves (252) and several support blocks. The inner wall of the arc-shaped cavity (22) located at the bottom of the cell drying channel (23) is provided with a first slot (222). The support blocks are located in the first slot (222) and are fixedly connected to the inner walls on both sides of the first slot (222). The core rod (251) passes through each support block and is fixedly connected to the support block. The sleeves (252) are located between two adjacent support blocks and are sleeved on the outside of the core rod (251).

6. A drying apparatus for lithium battery cell production according to claim 5, characterized in that: The cell deflection mechanism (5) includes a synchronizing rod (52), a sliding cylinder (51), and several driving slide rods (53). Each driving slide rod (53) passes through a corresponding air intake baffle (2) and is slidably connected to the air intake baffle (2). The sliding direction between the driving slide rod (53) and the air intake baffle (2) is perpendicular to the axial direction of the cell drying channel (23). The rubber roller (27) has an incomplete toothed portion (271) on its outer peripheral surface inside the air intake baffle (2). The driving slide rod (53) is close to the bottom of the rubber roller (27). The part has a strip (54) that meshes with the incomplete toothed part (271). One end of each of the drive slide rods (53) passes through the air intake baffle (2) and is slidably connected to the synchronizing rod (52). The sliding direction of the drive slide rod (53) and the synchronizing rod (52) is the same as the lifting direction of the air intake baffle (2). The sliding cylinder (51) is fixed to the outer wall of the housing (1). The piston rod of the sliding cylinder (51) passes through the housing (1) and is fixedly connected to the synchronizing rod (52). The sleeve (252) is rotatably connected to the core rod (251).

7. A drying apparatus for lithium battery cell production according to claim 6, characterized in that: Support columns (66) are provided at both ends of the side of the box (1) near the feed inlet of the box (1). The box (1) is pivotally connected to the support columns (66). The rotation axis of the support columns (66) and the box (1) is set horizontally. A lifting mechanism (6) is provided on the bottom surface of the box (1) away from the support columns (66). The lifting mechanism (6) includes a drive cylinder (61), a first connecting rod (62), a second connecting rod (63), a first connecting seat (64), and a second connecting seat (65). One end of the first connecting rod (62) is hinged to the bottom surface of the box (1), and the other end is hinged to the second connecting rod (63). The end of the second connecting rod (63) away from the first connecting rod (62) is hinged to the second connecting seat (65). The cylinder body of the drive cylinder (61) is hinged to the first connecting seat (64), and the piston rod of the drive cylinder (61) is hinged to the middle of the second connecting rod (63).

8. A precision forming process for lithium battery cells, which employs the drying apparatus for lithium battery cell production as described in claim 7, characterized in that: Includes the following steps: S1: Winding: The positive and negative electrode tabs are welded to different electrode sheets to obtain positive and negative electrode sheets. After being arranged in the order of positive electrode sheet-separator-negative electrode sheet-separator, they are wound to form a cylindrical battery cell substrate. S2: Housing: The cell substrate is installed into the cell shell, and the cell shell is grooved to make the cell shell partially concave, ensuring the stability between the cell substrate and the cell shell; S3: Drying: The battery cells after casing are dried using a drying device, including the following steps: a. The lifting mechanism (6) is started, causing the feed inlet of the box (1) to tilt upward, and then the battery cells are loaded into the battery cell drying channel (23); the battery cells slide into the bottom of the battery cell drying channel (23) under their own weight and are stacked in sequence, and an overhead ball (26) is placed between two adjacent battery cells in the same battery cell drying channel (23); b. The lifting and stacking mechanism (4) is activated, driving the air intake baffle (2) to descend, so that each air intake baffle (2) is stacked together, and the rubber roller (27) comes into contact with the battery cell. c. The hot air drying assembly (3) introduces hot air into the air distribution chamber (21) of each air inlet baffle (2), and the hot air flows into the cell drying channel (23) through the air hole (221) to dry the cell and remove its surface moisture. d. During the hot air drying process of the battery cell, the battery cell deflection mechanism (5) is activated, which can drive the circumferential position of the battery cell in the battery cell drying channel (23) to deflect at a certain angle. e. After the hot air drying is completed, the lifting and stacking mechanism (4) drives the air intake baffle (2) to move upward, so that the rubber roller (27) is separated from the battery cell. Then the lifting mechanism (6) is started, so that the feed port of the box (1) is tilted downward to complete the unloading of the battery cell. S4: Electrolyte injection: Injecting electrolyte into the dried battery cell; S5: Packaging: After soldering the caps to the positive and negative electrode tabs, the cells are sealed using a sealing machine to complete the cell assembly.

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