Constant pressure feeding device for lithium battery pole piece coating

Abstract

The utility model relates to a kind of lithium battery pole piece coating constant-pressure feed device, it is applicable to slit coating equipment, it includes flow control valve, flow control valve includes valve body, and inlet and outlet are opened in valve body, two bulkheads are provided in valve body, and the internal space of valve body is divided into first cavity, second cavity and third cavity by two bulkheads, and adjusting assembly is provided in third cavity, and the side of two bulkheads is located in the same side and is provided with communication hole;Adjusting assembly includes valve core, plunger and piston rod, valve core and plunger are all with the clearance cooperation of the inner wall of third cavity, valve core is located in the side close to communication hole, plunger is located in the other side away from communication hole, the cavity between valve core and plunger keeps closed state, one end of piston rod is connected with plunger, and the other end is from the side of valve body away from valve core and goes out.The present application can be adapted to the working condition of different screw rod pump feed, ensure the stability of slurry supply pressure, improve coating precision.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing equipment technology, specifically to a constant pressure feeding device for coating lithium battery electrode sheets. Background Technology

[0002] The production process of lithium batteries requires the coating of electrode slurry onto the electrodes. This process demands high precision, as the performance, safety, and consistency of lithium batteries are closely related to the quality of the electrode coating. Inconsistent coating thickness at different locations on the electrode can result in excessively low or high battery capacity. Inconsistent parameters before and after coating can lead to significant differences in capacity and cycle life. Uneven coating thickness can also cause micro-short circuits within the battery, and in severe cases, even lead to battery fires and explosions. The quality of electrode coating is also closely related to the stability of the slurry supply pressure; variations in slurry pressure can cause inconsistent coating thickness.

[0003] In the lithium battery electrode coating process, screw pumps are typically used for feeding. However, both large and small screw pumps have certain drawbacks. For example, when using a single large screw pump, fluctuations in the slurry can cause changes in slurry pressure, leading to unstable feeding and inconsistent longitudinal coating thickness. While using multiple smaller screw pumps can ensure accuracy, it results in a complex, bulky, and costly coating system. Utility Model Content

[0004] One of the main objectives of this invention is to overcome at least one of the above-mentioned defects and to provide a constant pressure feeding device for coating lithium battery electrodes, which can be adapted to different screw pump feeding conditions, ensure the stability of slurry supply pressure, and improve coating accuracy.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a constant pressure feeding device for lithium battery electrode coating, applicable to slot coating equipment. The slot coating equipment includes a storage tank, a feeding pipe, a conveying pump, and a coating die arranged according to the material flow direction. The constant pressure feeding device includes a flow control valve, which includes a valve body with an inlet and an outlet. Two partitions are installed inside the valve body, dividing its internal space into a first cavity, a second cavity, and a third cavity. An adjustment component is installed in the third cavity. The first cavity is connected to the feed inlet, and the second cavity is connected to the discharge outlet. The two partitions are provided with connecting holes on the same side, through which the first cavity, the second cavity, and the third cavity are connected to each other. The regulating assembly includes a valve core, a plunger, and a piston rod. Both the valve core and the plunger are in clearance fit with the inner wall of the third cavity. The valve core is located on the side close to the connecting hole, and the plunger is located on the other side away from the connecting hole. The cavity between the valve core and the plunger remains closed. One end of the piston rod is connected to the plunger, and the other end protrudes from the side of the valve body away from the valve core.

[0006] According to one embodiment of the present invention, the inlet and outlet are located on the left and right sides of the valve body, respectively, and the two partitions are vertically arranged inside the valve body.

[0007] According to one embodiment of the present invention, the connecting hole on the partition is located near the lower end of the valve body.

[0008] According to one embodiment of the present invention, the adjusting component is disposed at the upper end of the valve body.

[0009] According to one embodiment of the present invention, the adjusting assembly includes a sealing and fixing device, which is disposed on the outer side of the upper end of the valve body, the piston rod is disposed parallel to the partition plate, and the other end of the piston rod passes through the sealing and fixing device.

[0010] According to one embodiment of the present invention, a baffle is provided in the cavity between the valve core and the plunger. The baffle is used to limit the downward limit position of the plunger, and the baffle is fixedly connected to the two partitions.

[0011] According to one embodiment of the present invention, the cavity between the valve core and the plunger remains closed, and the internal air pressure is constant.

[0012] According to one embodiment of the present invention, a pressure sensor is provided in the cavity between the valve core and the plunger.

[0013] According to one embodiment of the present invention, it includes a controller and a drive unit, wherein the power shaft of the drive unit is connected to the piston rod, and the output control terminal of the controller is electrically connected to the drive unit.

[0014] According to one embodiment of the present invention, the signal output terminal of the pressure sensor is connected to the input terminal of the controller.

[0015] Compared with the prior art, the advantages and beneficial effects of the lithium battery electrode coating constant pressure feeding device of this utility model patent application are as follows: The constant-pressure feeding device of this application can adaptively adjust the slurry supply pressure during the electrode coating process, enabling the slurry to be uniformly coated on the electrode, thereby ensuring the consistency and uniformity of the coating thickness and improving the performance and operational stability of the lithium battery. Furthermore, the constant-pressure feeding device of this application can be used in new electrode coating equipment as well as for retrofitting existing coating equipment, with low retrofitting costs. Attached Figure Description

[0016] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a schematic diagram of a constant pressure feeding device for coating lithium battery electrode sheets according to an embodiment of the present invention, wherein the valve core does not block the connecting hole; Figure 2 This is a schematic diagram of a constant pressure feeding device for coating lithium battery electrode sheets according to an embodiment of the present invention, wherein the valve core portion blocks the connecting hole; Figure 3 This is a schematic diagram of a constant-pressure feeding device for coating lithium battery electrode sheets according to another embodiment of the present invention.

[0017] The annotations in the attached figures are explained as follows: 1. Valve body; 11. First cavity; 12. Second cavity; 13. Third cavity; 14. Cavity between valve core and plunger; 2. Adjustment assembly; 21. Valve core; 22. Plunger; 23. Piston rod; 24. Sealing and fixing device; 25. Baffle. 31. Barometric pressure sensor; 32. Controller; 33. Drive unit; 41. Feed inlet, 42. Discharge outlet, 43. Return outlet 5. Partition plate; 51. Connecting hole. Detailed Implementation

[0018] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0020] like Figure 1 and Figure 2 As shown, this embodiment describes a constant-pressure feeding device for lithium battery electrode coating, suitable for slot coating equipment. The slot coating equipment includes a storage tank, a feeding pipe, a conveying pump, and a coating die arranged according to the material flow direction. The constant-pressure feeding device includes a flow control valve, which includes a valve body 1. The valve body 1 has an inlet 41 and an outlet 42. Two partitions 5 are provided inside the valve body 1, dividing the internal space of the valve body 1 into a first cavity 11, a second cavity 12, and a third cavity 13. An adjusting component 2 is provided in the third cavity 13. The first cavity 11 is connected to the feed inlet 41, the second cavity 12 is connected to the discharge outlet 42, and the two partition plates 5 are provided with connecting holes 51 on the same side, so that the first cavity 11, the second cavity 12 and the third cavity 13 are connected to each other through the connecting holes 51. The regulating assembly 2 includes a valve core 21, a plunger 22, and a piston rod 23. Both the valve core 21 and the plunger 22 are in clearance fit with the inner wall of the third cavity 13. The valve core 21 is located on the side close to the connecting hole 51, and the plunger 22 is located on the other side away from the connecting hole 51. The cavity 14 between the valve core 21 and the plunger 22 remains closed. One end of the piston rod 23 is connected to the plunger 22, and the other end protrudes from the side of the valve body 1 away from the valve core 21.

[0021] For ease of explanation, Figure 1 Taking the horizontally placed constant pressure feeding device as an example, the inlet 41 and outlet 42 are located on the left and right sides of the valve body 1, respectively. The two partitions 5 are vertically arranged inside the valve body 1. The connecting holes 51 on the partitions 5 are located near the lower end of the valve body 1, and the connecting holes 51 on the two partitions 5 are opposite each other and on the same horizontal line. During operation, as the slurry pressure changes in real time during slurry supply, the valve core 21 either partially blocks the connecting hole 51 or moves upwards completely, no longer blocking the connecting hole 51.

[0022] To ensure that the cavity 14 between the valve core 21 and the plunger 22 remains closed and to prevent the closure from being disrupted when the valve core 21 moves up or down, the relationship between the height H of the valve core 21 and the distance L from the upper part of the connecting hole 51 to the bottom of the valve body 1 is as follows: the height H of the valve core 21 should not be less than the distance L from the upper part of the connecting hole 51 to the bottom of the valve body 1, i.e., H≥L.

[0023] During operation, the cavity 14 between the valve core 21 and the plunger 22 remains closed, and the internal air pressure is constant. This internal air pressure can be adjusted before production. After adjustment, the air pressure P1 in the cavity 14 is equal to the normal supply pressure of the slurry.

[0024] When the slurry supply pressure P 实 When changes occur: such as an increase in slurry supply pressure, i.e., P 实 >P1, the internal pressure in the cavity 14 between the valve core 21 and the plunger 22 pushes the valve core 21 downward, reducing the effective passage area of ​​the connecting hole 51. The pressure of the flowing slurry increases accordingly, and the plunger 22 is also pushed downward, causing the final slurry supply pressure to gradually decrease until it equals the preset normal slurry supply pressure; if the slurry supply pressure decreases, then P 实 <P1, the slurry pushes the valve core 21 upward, increasing the effective passage area of ​​the connecting hole 51. The pressure of the flowing slurry decreases adaptively, while the plunger 22 is also driven downward, causing the final slurry supply pressure to gradually increase until it equals the preset normal slurry supply pressure. This achieves adaptive pressure regulation; the overall structure is simple and can control the slurry pressure.

[0025] In addition, in order to better monitor the pressure inside the cavity 14 between the valve core 21 and the plunger 22, such as Figure 3 As shown, a pressure sensor 31 can be installed in the cavity 14 between the valve core 21 and the plunger 22, and the pressure sensor 31 is fixed on the partition plate 5. The pressure sensor 31 can provide real-time feedback on the internal pressure. When the adaptive adjustment is slow or the pressure adjustment requirement cannot be met in extreme cases, the position of the plunger 22 can be adjusted by manually adjusting the piston rod 23 so that the internal pressure of the cavity 14 reaches the preset pressure value. In a stable state, the internal pressure of the cavity 14 is equal to the slurry pressure. At this time, the piston rod 23 is locked (the locking structure can be fastened by an external limiting plate or bolts, which is not the focus of this application and will not be described in detail here). The effective passage path of the connecting hole 51 is also locked, thus enabling manual adjustment of the slurry pressure.

[0026] Additionally, based on the feedback signal from the pressure sensor 31, electric adjustment can also be performed via the controller 32 and the drive unit 33. The power shaft of the drive unit 33 is connected to the piston rod 23, and the output control terminal of the controller 32 is electrically connected to the drive unit 33. By manually operating the controller 32, the drive unit 33 is made to work, thereby controlling the piston rod 23 to move up or down (here, since the drive unit 33 has a motion locking effect, the aforementioned limit plate or bolt fastening measures can be eliminated). As long as the pressure inside the cavity 14 is finally brought to the preset pressure value, the purpose of adjusting the slurry pressure can be achieved.

[0027] In addition, based on a certain calculation program setting, the signal output terminal of the pressure sensor 31 is connected to the input terminal of the controller 32. The controller 32, according to the magnitude of the feedback pressure signal, can output a control signal through analog circuits (such as comparators and signal amplifiers) or through digital chips (such as preset stepped drive signals according to different pressure ranges). After receiving the signal from the controller 32, the drive unit 33 can adjust the travel displacement of the drive shaft and adjust the position of the internal plunger 22. The drive unit 33 can be a cylinder or a servo motor, whichever is chosen based on control accuracy or cost considerations.

[0028] In one embodiment, the adjusting assembly 2 is disposed at the upper end of the valve body 1. The adjusting assembly 2 includes a sealing and fixing device 24, which is disposed on the outer side of the upper end of the valve body 1. The piston rod 23 is disposed parallel to the partition 5, and the other end of the piston rod 23 passes through the sealing and fixing device 24.

[0029] In one embodiment, a baffle 25 is provided in the cavity 14 between the valve core 21 and the plunger 22. The baffle 25 is used to limit the downward limit position of the plunger 22, and the baffle 25 is fixedly connected to the two partitions 5. The baffle 25 protrudes partially from the inner wall of the partition 5, leaving a gap in the middle or at the edge, so that the plunger 22 and even the valve core 21 can be limited without affecting the gas flow in the cavity 14.

[0030] A reflux port 43 is provided on the outer wall of the first cavity 11. A pressure limiting valve is provided on the reflux port 43. The pressure limiting valve is connected to the storage tank or return tank through the reflux pipe, which can further ensure the constant supply pressure to a certain extent.

[0031] In summary, the constant-pressure feeding device of this application can adaptively adjust the slurry supply pressure during the electrode coating process, enabling the slurry to be uniformly coated on the electrode, thereby ensuring the consistency and uniformity of the coating thickness and improving the performance and operational stability of the lithium battery. Furthermore, the constant-pressure feeding device of this application can be used in new electrode coating equipment as well as for retrofitting existing coating equipment, with low retrofitting costs.

[0032] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the protection scope of this utility model.

Claims

1. A constant-pressure feeding device for coating lithium battery electrodes, suitable for slot coating equipment, the slot coating equipment comprising a storage tank, a feeding pipe, a conveying pump, and a coating die arranged according to the material flow direction, characterized in that, The constant pressure feeding device includes a flow control valve, which comprises a valve body with an inlet and an outlet. Two partitions are installed inside the valve body, dividing its internal space into a first chamber, a second chamber, and a third chamber. An adjustment assembly is installed in the third chamber. The first cavity is connected to the feed inlet, and the second cavity is connected to the discharge outlet. The two partitions are provided with connecting holes on the same side, through which the first cavity, the second cavity, and the third cavity are connected to each other. The regulating assembly includes a valve core, a plunger, and a piston rod. Both the valve core and the plunger are in clearance fit with the inner wall of the third cavity. The valve core is located on the side close to the connecting hole, and the plunger is located on the other side away from the connecting hole. The cavity between the valve core and the plunger remains closed. One end of the piston rod is connected to the plunger, and the other end protrudes from the side of the valve body away from the valve core.

2. The lithium battery electrode coating constant pressure feeding device according to claim 1, characterized in that, The inlet and outlet are located on the left and right sides of the valve body, respectively, and the two partitions are vertically arranged inside the valve body.

3. The lithium battery electrode coating constant pressure feeding device according to claim 1, characterized in that, The connecting hole on the partition is located near the lower end of the valve body.

4. The lithium battery electrode coating constant pressure feeding device according to any one of claims 1 to 3, characterized in that, The regulating component is located at the upper end of the valve body.

5. The lithium battery electrode coating constant pressure feeding device according to claim 4, characterized in that, The adjusting assembly includes a sealing and fixing device, which is disposed on the upper outer side of the valve body. The piston rod is disposed parallel to the partition plate, and the other end of the piston rod passes through the sealing and fixing device.

6. The lithium battery electrode coating constant pressure feeding device according to claim 1, characterized in that, A baffle is provided in the cavity between the valve core and the plunger. The baffle is used to limit the downward limit of the plunger. The baffle is fixedly connected to the two partitions.

7. The lithium battery electrode coating constant pressure feeding device according to claim 1, characterized in that, The cavity between the valve core and the plunger remains closed, and the internal air pressure is constant.

8. The lithium battery electrode coating constant pressure feeding device according to claim 1, characterized in that, A pressure sensor is installed in the cavity between the valve core and the plunger.

9. The lithium battery electrode coating constant pressure feeding device according to claim 8, characterized in that, It includes a controller and a drive unit, wherein the power shaft of the drive unit is connected to the piston rod, and the output control terminal of the controller is electrically connected to the drive unit.

10. The lithium battery electrode coating constant pressure feeding device according to claim 9, characterized in that, The signal output terminal of the barometric pressure sensor is connected to the input terminal of the controller.

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