A reflux device for controlling the film thickness of a multi-gap electrode and a control method thereof

Abstract

The present invention belongs to the field of battery technology, and specifically relates to a reflux device for controlling the film thickness of multi-gap electrode sheets, comprising a feed pipe, a coating valve, a reflux valve, a reflux pipe, and a membrane head pipe. The membrane head pipe is connected to the feed pipe to form a main trunk line. The coating valve and the reflux valve are sequentially connected in series to the main trunk line. The reflux pipe is connected to the reflux valve, and the reflux pipe comprises a first pipe and a second pipe, wherein the first pipe and the second pipe are connected in parallel. The reflux device has a simple structure, realizes the production of multi-gap electrode sheets, is simple to operate, operates stably, and has high production efficiency. In addition, a control method for the reflux device is provided to improve its operational stability and efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to a reflux device for controlling the film thickness of a multi-gap electrode and a control method thereof. Background Art

[0002] In the mobile phone battery production process, the coating process uniformly applies slurry to the current collector. With the diaphragm area's return valve closed, the slurry is applied to the current collector through the membrane head. The screw pump creates coating pressure within the membrane head's piping. The gap area's coating valve closes, and the slurry returns to the feed tank via the reflux device. Reflux pressure is then generated within the piping from the coating valve to the reflux diaphragm valve. The reflux device controls the amount of slurry reflux, thereby controlling the reflux pressure and, consequently, the surface weight (called areal density) of the electrode's thick coating area.

[0003] The existing coating process utilizes a single-path reflux mechanism, with the slurry from both gaps returning to the feed tank through the same path. With the new battery cell's centrally positioned tab structure, due to the different blanking lengths between the large and small gaps, the large gap during reflux is larger than the small gap, and the reflux pressure in the large gap is greater than in the small gap. This creates two reflux pressures during coating, resulting in inconsistent head weights for the two film lengths, uncontrollable electrode thickness, and the risk of lithium plating in the finished battery cell, posing a significant safety hazard. This also results in low production yields and lengthy setup times.

[0004] In summary, the relevant technologies have defects and need to be improved urgently. Summary of the Invention

[0005] One of the purposes of the present invention is to address the shortcomings of the existing technology and provide a reflux device for controlling the film thickness of multi-gap electrode sheets. When the electrode sheet is coated with a double-film long double-gap electrode sheet structure product, a dual-path reflux path is developed to control the reflux pressure of the coating large gap and small gap, so that the reflux pressure of the large gap and small gap is kept consistent, so as to adjust the coating pressure of the heads of the two sections of the membrane length to be the same, so that the head surface density and thinning thickness of the two sections of the membrane length remain the same. The device has good anti-fouling effect, low cost, and is easy to promote and use.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A reflux device for controlling the film thickness of a multi-gap electrode comprises a feed pipe, a coating valve, a reflux valve, a reflux pipe and a membrane head pipe. The membrane head pipe is connected to the feed pipe to form a main trunk line. The coating valve and the reflux valve are sequentially connected in series to the main trunk line. The reflux pipe is connected to the reflux valve. The reflux pipe comprises a first pipe and a second pipe. The first pipe and the second pipe are connected in parallel. During operation, when coating the diaphragm area, the screw pump forms a coating pressure in the membrane head pipe cavity. At this time, the reflux valve is closed, the coating valve is opened, and the slurry enters the coating membrane head and is coated on the collector, thereby forming an electrode; when coating the blank areas of large and small gaps, the coating valve is closed, and the slurry reflux adopts the first pipeline and the second pipeline to return the slurry to the buffer tank in a dual-path manner. The dual-path reflux device controls the slurry reflux of large and small gaps; when coating the small gap, the first manual diaphragm valve in the first pipeline is opened, the air-controlled diaphragm valve in the second pipeline is closed, and the slurry returns to the buffer tank through the first pipeline; when coating the large gap, the first manual diaphragm valve in the first pipeline is opened, the air-controlled diaphragm valve in the second pipeline is opened, and the slurry flows out of the first pipeline. The slurry returns to the buffer tank through the first pipeline and the second pipeline; wherein the reflux pressure in the first pipeline and the second pipeline is kept consistent, so that the head weight of each section of the membrane is kept consistent. The reflux device has a simple structure, realizes the production of multi-gap electrodes, is simple to operate, works stably, and has high production efficiency.

[0008] As an improvement of the reflux device for controlling the film thickness of multi-gap electrode sheets of the present invention, the first pipe is used for the main reflux of the main trunk line. During operation, the refluxed slurry is preferably refluxed through the first pipe.

[0009] As an improvement to the reflux device for controlling the film thickness of multi-gap electrode sheets of the present invention, a first manual diaphragm valve is connected in series in the first pipeline, which facilitates controlling the conduction state of the first pipeline.

[0010] As an improvement of the reflux device for controlling the film thickness of multi-gap pole pieces of the present invention, the second pipe is used for auxiliary reflux of the first pipe. During operation, the second pipe is used to assist the first pipe in slurry reflux.

[0011] As an improvement to the reflux device for controlling the film thickness of a multi-gap electrode according to the present invention, a gas-controlled diaphragm valve is connected in series in the second pipeline. This structural design facilitates control of the conduction state of the second pipeline.

[0012] As an improvement to the reflux device for controlling the film thickness of multi-gap electrode sheets of the present invention, a second manual diaphragm valve is further connected in series in the second pipeline. This structural design increases the control mode of the conduction state of the second pipeline and is beneficial to production.

[0013] As an improvement to the reflux device for controlling the film thickness of a multi-gap electrode according to the present invention, a second manual diaphragm valve is connected in series between the reflux valve and the pneumatically controlled diaphragm valve. This structural design ensures that the operation of the second manual diaphragm valve is not affected by the pneumatically controlled diaphragm valve, thereby increasing operational stability.

[0014] As an improvement of the reflux device for controlling the film thickness of multi-gap electrode sheets of the present invention, the device further comprises a coating device, which is connected to the membrane head tube and is used for coating the electrode sheets.

[0015] As an improvement to the reflux device for controlling the film thickness of multi-gap electrode sheets described herein, the coating device includes a coating film head and a coating steel rod. The coating film head is connected to the film head tube, and the coating steel rod is disposed correspondingly to the output end of the coating film head. This structural design facilitates smooth electrode sheet coating.

[0016] As an improvement to the reflux device for controlling the film thickness of multi-gap electrode sheets of the present invention, the coating valve is connected in series between the reflux valve and the coating device. This structural design is conducive to slurry reflux.

[0017] The second purpose of the present invention is to address the deficiencies of the prior art and provide a method for controlling the film thickness of a reflux device for controlling multi-gap pole pieces, so as to improve the stability and efficiency of its operation.

[0018] To achieve the above object, the present invention provides a method for controlling a reflux device for controlling the film thickness of a multi-gap electrode, comprising the following steps:

[0019] In the coating diaphragm area, the screw pump generates coating pressure in the membrane head pipe cavity. At this time, the reflux valve is closed, the coating valve is opened, and the slurry enters the coating membrane head and is coated on the current collector to form a pole piece.

[0020] When coating the blank areas with large and small gaps, the coating valve is closed, and the slurry reflux adopts the first pipe and the second pipe dual-path reflux slurry to return to the buffer tank. The dual-path reflux device controls the slurry reflux of large and small gaps;

[0021] When coating with a small gap, the first manual diaphragm valve in the first pipeline is opened, the air-controlled diaphragm valve in the second pipeline is closed, and the slurry returns to the buffer tank through the first pipeline;

[0022] When coating a large gap, the first manual diaphragm valve in the first pipeline is opened, and the air-controlled diaphragm valve in the second pipeline is opened, and the excess slurry in the first pipeline flows out, and the slurry returns to the buffer tank through the first pipeline and the second pipeline;

[0023] The reflux pressures in the first and second pipes are kept consistent, so that the head weights of the membrane sections are kept consistent. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the pipeline connection in Example 1 of the present invention;

[0026] Figure 2 This is a schematic structural diagram of Example 2 of the present invention;

[0027] Figure 3 This is one of the double reflux areal density tables obtained in Example 4 of the present invention;

[0028] Figure 4 This is the second double reflux surface density table obtained in Example 4 of the present invention;

[0029] Figure 5 This is one of the structural schematic diagrams of the new battery cell electrode structure produced in Example 4 of the present invention;

[0030] Figure 6 This is the second structural diagram of the new battery cell electrode structure produced in Example 4 of the present invention;

[0031] Among them: 1-feeding pipe; 2-coating valve; 3-reflux valve; 4-reflux pipe; 41'-first manual diaphragm valve; 41-first pipeline; 42-second pipeline; 42'-air-controlled diaphragm valve; 42''-second manual diaphragm valve; 5-membrane head pipe; 6-coating device; 61-coating membrane head; 62-coating steel rod. DETAILED DESCRIPTION

[0032] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of the components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect.

[0033] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "horizontal", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0034] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] The present invention will be further described below in conjunction with the accompanying drawings, but this does not limit the present invention.

[0036] Example 1

[0037] like Figure 1 As shown, a reflux device for controlling the film thickness of a multi-gap electrode comprises a feed pipe 1, a coating valve 2, a reflux valve 3, a reflux pipe 4 and a membrane head pipe 5. The membrane head pipe 5 is connected to the feed pipe 1 to form a main line. The coating valve 2 and the reflux valve 3 are connected in series to the main line in sequence. The reflux pipe 4 is connected to the reflux valve 3. The reflux pipe 4 comprises a first pipe 41 and a second pipe 42. The first pipe 41 and the second pipe 42 are connected in parallel. During operation, when coating the diaphragm area, the screw pump forms coating pressure in the cavity of the membrane head tube 5. At this time, the reflux valve 3 is closed, the coating valve 2 is opened, and the slurry enters the coating membrane head 61 and is coated on the collector, thereby forming an electrode; when coating the blank area of ​​large and small gaps, the coating valve 2 is closed, and the slurry reflux adopts the first pipeline 41 and the second pipeline 42 to return the slurry to the buffer tank in a dual-path manner. The dual-path reflux device controls the slurry reflux of large and small gaps; when coating the small gap, the first manual diaphragm valve 41' in the first pipeline 41 is opened, and the air-controlled diaphragm valve in the second pipeline 42 is opened. The valve 42' is closed, and the slurry returns to the buffer tank through the first pipe 41; when coating a large gap, the first manual diaphragm valve 41' in the first pipe 41 is opened, and the air-controlled diaphragm valve 42' in the second pipe 42 is opened, and the excess slurry flows out of the first pipe 41, and the slurry returns to the buffer tank through the first pipe 41 and the second pipe 42; wherein, the reflux pressure in the first pipe 41 and the second pipe 42 is kept consistent, so that the head weight of each section of the film is kept consistent. The reflux device has a simple structure, realizes the production of multi-gap electrodes, is simple to operate, works stably, and has high production efficiency.

[0038] Preferably, the first pipe 41 is used for the main return of the main road. During operation, the slurry to be returned is preferably returned through the first pipe 41.

[0039] Preferably, a first manual diaphragm valve 41 ′ is connected in series in the first pipeline 41 . Connecting the manual diaphragm valve in series in the first pipeline 41 facilitates controlling the conduction state of the first pipeline 41 .

[0040] Preferably, the second pipe 42 is used for auxiliary reflux of the first pipe 41. In operation, the second pipe 42 is used to assist the first pipe 41 in slurry reflux.

[0041] Preferably, a pneumatically controlled diaphragm valve 42 ′ is connected in series in the second pipeline 42 . This structural design is beneficial for controlling the conduction state of the second pipeline 42 .

[0042] The present invention further comprises a coating device 6, which is in communication with the membrane head tube 5. The coating device 6 is used to coat the electrode.

[0043] Preferably, the coating device 6 includes a coating film head 61 and a coating steel rod 62. The coating film head 61 is connected to the film head tube 5, and the coating steel rod 62 is arranged corresponding to the output end of the coating film head 61. This structural design is conducive to the smooth coating of the electrode.

[0044] Preferably, the coating valve 2 is connected in series between the reflux valve 4 and the coating device 6. This structural design is conducive to the slurry reflux.

[0045] The working principle of the present invention is: during operation, when coating the diaphragm area, the screw pump forms a coating pressure in the cavity of the membrane head tube 5, at this time the reflux valve 3 is closed, the coating valve 2 is opened, the slurry enters the coating membrane head 61 and is coated on the current collector, thereby forming a pole piece; when coating the blank area of ​​large and small gaps, the coating valve 2 is closed, and the slurry reflux adopts the first pipe 41 and the second pipe 42 to return the slurry to the buffer tank in a dual-path manner, and the dual-path reflux device controls the slurry reflux of large and small gaps; when coating the small gap, the first manual diaphragm valve 41' in the first pipe 41 is opened, and the second pipe 42 is opened. The air-controlled diaphragm valve 42' is closed, and the slurry returns to the buffer tank through the first pipe 41; when coating a large gap, the first manual diaphragm valve 41' in the first pipe 41 is opened, and the air-controlled diaphragm valve 42' in the second pipe 42 is opened, and the excess slurry flows out of the first pipe 41, and the slurry returns to the buffer tank through the first pipe 41 and the second pipe 42; wherein, the reflux pressure in the first pipe 41 and the second pipe 42 is kept consistent, so that the head weight of each section of the film is kept consistent. The reflux device has a simple structure, realizes the production of multi-gap electrodes, is simple to operate, works stably, and has high production efficiency.

[0046] Example 2

[0047] like Figure 2As shown, the difference from embodiment 1 is that a second manual diaphragm valve 42'' is further connected in series to the second pipeline 42 in this embodiment. This structural design increases the control mode of the conduction state of the second pipeline 42, which is beneficial to production.

[0048] Preferably, the second manual diaphragm valve 42 ″ is connected in series between the reflux valve 3 and the air-controlled diaphragm valve 42 ′. This structural design ensures that the operation of the second manual diaphragm valve 42 ″ is not affected by the air-controlled diaphragm valve 42 ′, thereby increasing the stability of the operation.

[0049] The other structures are the same as those in Example 1 and will not be described again here.

[0050] Example 3

[0051] like Figure 1-2 As shown, a control method for a reflux device for controlling the film thickness of a multi-gap electrode sheet according to embodiment 1 or 2 includes the following steps:

[0052] In the coating membrane area, the screw pump generates coating pressure in the cavity of the membrane head tube 5. At this time, the reflux valve 3 is closed, the coating valve 2 is opened, and the slurry enters the coating membrane head 61 and is coated on the current collector to form a pole piece.

[0053] When coating the blank areas with large and small gaps, the coating valve 2 is closed, and the slurry reflux adopts the first pipe 41 and the second pipe 42 as dual paths to return the slurry to the buffer tank. The dual path reflux device controls the slurry reflux in the large and small gaps.

[0054] When coating a small gap, the first manual diaphragm valve 41' in the first pipe 41 is opened, the air-controlled diaphragm valve 42' in the second pipe 42 is closed, and the slurry returns to the buffer tank through the first pipe 41;

[0055] When coating a large gap, the first manual diaphragm valve 41' in the first pipe 41 is opened, and the air-controlled diaphragm valve 42' in the second pipe 42 is opened, and the excess slurry in the first pipe 41 flows out, and the slurry returns to the buffer tank through the first pipe 41 and the second pipe 42;

[0056] The reflux pressures in the first pipe 41 and the second pipe 42 are kept consistent, so that the head weights of the various film sections are kept consistent.

[0057] Example 4

[0058] like Figure 1-6 As shown, a control method for a reflux device for controlling the film thickness of a multi-gap electrode as in Example 3 includes the following steps:

[0059] Step 1. Turn on the power of the equipment (turn on the power switch and confirm that the rewinding and unwinding are in the center position of the correction. If the correction is not adjusted to manual state and is not centered, the correction function must be set to manual state before using the centering function);

[0060] Step 2, opening inspection: use alcohol to clean the coating machine's film head, steel roller, nip roller, and oven according to the inspection table;

[0061] Step 3, gasket installation: After cleaning, select the appropriate gasket according to the required finish of the product, install it into the membrane head, and start the machine to make 30 minutes of slurry circulation;

[0062] Step 4: Attach the foil and traction belt: Install the foil on the unwinding shaft and connect the traction belt. Align the traction belt on the side of the correction sensor with the edge of the foil. After the traction belt or foil is connected, set it to automatic mode.

[0063] Step 5. Set process parameters: Set the coating parameters according to the process conditions on the control panel;

[0064] Step 6: First piece debugging, dual-circuit reflux debugging: When the weight of the two sections of the diaphragm heads is inconsistent, adjust the reflux pressure at the gap to change the surface density of the coating weight of the head in the long film area, so that the surface density and thinning thickness of the two sections of the head are within the range;

[0065] Step 6.1, open the first pipe 41, close the second pipe 42, apply 3 electrodes according to the document size requirements, weigh the surface density of the front, middle and rear strips, and adjust the surface density of the film length 2 (small gap head) to within the document specifications;

[0066] Step 6.2, open the first pipe 41, close the second pipe 42, apply 3 electrodes according to the file size requirements, weigh the surface density of the front, middle and back of the film length 1 and film length 2, and record the data as follows Figure 3 As shown:

[0067] Step 6.3: Based on the analysis of the above measurement data, the surface density of the head of membrane length 1 (large gap) exceeds the specification and is not within the document specification range. It is necessary to increase the reflux pressure at the gap to change the weight of the head of membrane length 1;

[0068] Step 6.4, open the first pipeline 41, according to the weight of the head of the membrane length 1, adjust the flow rate of the air-controlled diaphragm valve 42' to keep the return pressure of the large gap and the small gap consistent, apply 3 electrodes according to the file size requirements, weigh the surface density of the front, middle and back of the membrane length 1 and the membrane length 2, and record the data as follows Figure 4 As shown;

[0069] Step 6.5: After debugging is completed, the surface density of the two sections of film length meets the specifications of the first plug in the file, the dual-path reflow effect is obvious, and the surface density first piece debugging is completed;

[0070] Step 7, start coating: by debugging the dual-path reflux, adjust the reflux pressure of the two gaps to be consistent, and adjust the head density of film length 1 and film length 2 to be consistent to meet the first piece specification, then coat the film as the formal first piece, take the head, middle and tail of the two film lengths to measure the surface density and the size of the gap head and use the head to thin it. After the first piece is qualified, start the machine for normal coating. Monitor the quality issues such as film appearance, size, surface density, thinning length, misalignment and alignment during the production process;

[0071] Step 8. Shipping and unloading: After coating the film, the buckle needs to be wrapped with plastic wrap and marked with a shipping tag, and then unloaded to the shelf using a lift trolley.

[0072] The foregoing description shows and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. Rather, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the inventive concept described herein by the teachings above or by techniques or knowledge in the relevant art. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be within the scope of the appended claims.

Claims

1. A method for controlling a reflux device for controlling the film thickness of a multi-gap electrode, characterized in that: The reflux device comprises a feed pipe (1), a coating valve (2), a reflux valve (3), a reflux pipe (4) and a membrane head pipe (5); the membrane head pipe (5) is connected to the feed pipe (1) to form a main trunk; the coating valve (2) and the reflux valve (3) are sequentially connected in series to the main trunk; the reflux pipe (4) is connected to the reflux valve (3); the reflux pipe (4) comprises a first pipe (41) and a second pipe (42); the first pipe (41) and the second pipe (42) are connected in parallel; the first pipe (41) is used for the main reflux of the main trunk; a first manual diaphragm valve (41') is connected in series to the first pipe (41); the second pipe (42) is used for the auxiliary reflux of the first pipe (41); and a pneumatic diaphragm valve (42') is connected in series to the second pipe (42); the control method comprises the following steps: In the coating membrane area, the screw pump forms a coating pressure in the cavity of the membrane head tube (5), at which time the reflux valve (3) is closed and the coating valve (2) is opened, and the slurry enters the coating membrane head (61) and is coated on the current collector to form a pole piece; When coating the blank areas of large and small gaps, the coating valve (2) is closed, and the slurry reflux adopts the first pipe (41) and the second pipe (42) to return the slurry to the buffer tank in a dual-path manner, and the dual-path reflux device controls the slurry reflux of large and small gaps; When coating a small gap, the first manual diaphragm valve (41') in the first pipe (41) is opened, the air-controlled diaphragm valve (42') in the second pipe (42) is closed, and the slurry returns to the buffer tank through the first pipe (41); When coating a large gap, the first manual diaphragm valve (41') in the first pipe (41) is opened, and the air-controlled diaphragm valve (42') in the second pipe (42) is opened, so that excess slurry in the first pipe (41) flows out and the slurry returns to the buffer tank through the first pipe (41) and the second pipe (42); The reflux pressure in the first pipe (41) and the second pipe (42) is kept consistent, so that the head weight of each section of the membrane is kept consistent.

2. The method for controlling the reflux device for controlling the film thickness of a multi-gap electrode according to claim 1, wherein: A second manual diaphragm valve (42") is also connected in series in the second pipeline (42) to control the conduction state of the second pipeline (42).

3. The method for controlling the reflux device for controlling the film thickness of a multi-gap electrode according to claim 2, wherein: The second manual diaphragm valve (42") is connected in series between the reflux valve (3) and the air-controlled diaphragm valve (42').

4. The method for controlling a reflux device for controlling the film thickness of a multi-gap electrode according to claim 1, wherein: It also includes a coating device (6), which is connected to the membrane head tube (5).

5. The method for controlling the reflux device for controlling the film thickness of a multi-gap electrode according to claim 4, wherein: The coating device (6) comprises a coating film head (61) and a coating steel rod (62); the coating film head (61) is connected to the film head tube (5); and the coating steel rod (62) is arranged corresponding to the output end of the coating film head (61).

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