Intermittent valve structure and feeding device for improving coating scratch abnormity of lithium ion battery
Through the improved intermittent valve structure, the slurry enters the main valve directly and passes the relative movement of the main valve stem, solving the problem of soft particles caused by friction between the slurry and the valve stem during the lithium battery electrode sheet coating process, and achieving high-quality coating and production stability of the electrode sheet.
Patent Information
- Application Number
- CN202422289562.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-19
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-09-19
AI Technical Summary
During the production process of lithium batteries, soft particles are generated during the coating process of the electrode sheet due to the movement of the slurry and the intermittent valve stem, resulting in abnormal scratches, affecting the appearance and production continuity of the electrode sheet, and it is difficult to effectively solve the problem in the existing technology.
Using an improved intermittent valve structure, the slurry is directly entered into the main valve and the relative movement of the main valve stem is reduced, the movement stroke of the slurry in the intermittent valve is avoided, and the direct contact between the slurry and the safety valve stem is achieved. The slurry is coated and refluxed through the coordination between the main valve stem and the safety valve stem, reducing the generation of soft particles.
The incidence of abnormal coating scratches was significantly reduced, from 0.12% to 0.02%, improving the pass rate of the pole sheet and the continuous production.
Smart Images
Figure CN223165083U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lithium battery coating, and particularly relates to an intermittent valve structure and a feeding device for improving abnormal coating scratches of lithium ion batteries. Background Art
[0002] At present, the country is vigorously developing the new energy industry. Lithium batteries, as an important component of new energy, play an irreplaceable role in various industries. In the production process of lithium batteries, the stability and continuity of the electrode coating process have a huge impact on battery production capacity and qualification rate.
[0003] At present, slit-type dies are mostly used for coating power battery pole pieces. The working principle of this coating machine is that the slurry enters the coating die cavity through an intermittent valve. The slurry passes through the slit between the upper and lower dies under continuous pressure and covers the current collector (positive electrode: aluminum foil, negative electrode: copper foil). The distance between the die lip and the current collector determines the pole piece surface density. According to the current surface density process, the distance is mostly between 100 and 300 microns. In such a narrow distance, if there are small particles in the slurry or sediment flows between the die lip and the current collector, it will hinder the normal coating of the slurry at this position on the current collector, forming scratches and causing poor appearance of the pole piece. The pole piece involved in the scratch needs to be scrapped. At the same time, in order to eliminate the abnormality, the coating die is required to clean the accumulated material on the lip, thereby affecting the continuity of the rolling process.
[0004] The industry mainly improves the abnormal occurrence rate of electrode scratches by optimizing the cavity structure of the die, reducing the dead zone of slurry flow in the die, and then reducing the deposition of slurry on both sides of the die cavity. However, in addition to the formation of deposited slurry inside the die, the relative movement of the valve stem and slurry in the intermittent valve will also form soft slurry particles. As the coating speed increases, the mutual movement between the slurry and the valve stem will become more frequent, and the scratch abnormality will become more prominent. Moreover, based on the slurry flow characteristics and the continuity of long-term production, it is difficult to completely solve the problem of slurry deposition in the die. As the production capacity increases, the scratch abnormality increasingly affects the pass rate and battery cell cost. Utility Model Content
[0005] The utility model provides an intermittent valve structure and a feeding device for improving abnormal coating scratches on lithium-ion batteries, reducing the mutual movement of slurry and the valve stem in the intermittent valve, reducing the generation of soft particles, and thus reducing the occurrence of abnormal coating scratches.
[0006] The technical solution adopted by this utility model is:
[0007] An intermittent valve structure for improving abnormal coating scratches of lithium-ion batteries, comprising a main valve and a safety valve. The feed port of the main valve serves as a coating interface. One discharge port of the main valve is connected to the coating die head, and the other discharge port of the main valve is communicated with the feed port of the safety valve. The discharge port of the safety valve serves as a coating reflux port. In the present utility model, the main valve is used as the coating feed end, so that most of the slurry directly enters the coating die head from the main valve, reducing the movement stroke of the slurry in the intermittent valve, shortening the mutual movement time of the slurry and the valve stem, reducing the soft particles generated due to friction, and thus realizing the reduction of the incidence of abnormal coating scratches.
[0008] As a preferred embodiment of the present utility model, the main valve has a main valve cavity, a first feed port, a first discharge port, a second discharge port and a main valve stem. The main valve stem reciprocates in the main valve cavity. The first feed port, the first discharge port and the second discharge port are all communicated with the main valve cavity. And the first feed port serves as the coating inlet, the first discharge port is communicated with the coating die head, and the second discharge port is communicated with the feed port of the safety valve. The main valve stem has a first conduction position and a second conduction position during the movement. When the main valve stem is in the first conduction position, the first feed port, the main valve cavity and the first discharge port are communicated to form a coating material channel, and the second discharge port is closed. When the main valve stem is in the second conduction position, the first feed port, the main valve cavity and the second discharge port are communicated to form a material pre-reflux channel, and the first discharge port is closed. In the first conduction position, the slurry enters the main valve cavity from the first feed port, and then enters the coating die head from the first discharge port for coating. The second discharge port is closed, and the slurry does not flow at the safety valve, because the main function of the slurry is to realize coating, that is, more than 95% of the slurry will ultimately enter the main valve body and then be discharged from the coating die head. In the present utility model, the slurry directly enters from the main valve body. Compared with the traditional structure that first enters from the safety valve and then flows into the main valve, the mutual action time of the slurry and the valve stem is shortened, and the generation of soft particles is reduced.
[0009] As a preferred embodiment of the present utility model, the safety valve has a safety valve cavity, a safety feed port, a safety discharge port and a safety valve stem. The safety valve stem reciprocates in the safety valve cavity. The safety feed port and the safety discharge port are both communicated with the safety valve cavity. And the safety feed port is communicated with the second discharge port, and the safety discharge port serves as the coating reflux port. The safety valve stem has a third conduction position and a first cut-off position during the movement, and the moving direction of the safety valve stem is opposite to that of the main valve stem. When the safety valve stem is in the third conduction position, the safety feed port, the safety discharge port, the safety valve cavity and the material pre-reflux channel are communicated to jointly form a material reflux channel. When the safety valve stem is in the first cut-off position, the safety discharge port is closed. When coating is not required, the slurry enters the safety valve cavity of the safety valve from the second discharge port of the main valve, and then is discharged from the safety discharge port for reflux recovery. The proportion of the reflux slurry is relatively small, and it is not directly coated on the electrode sheet, so it will not cause scratches on the electrode sheet.
[0010] The present invention also provides an intermittent valve feeding device for improving abnormal coating scratches on lithium-ion batteries, comprising a feeding mechanism, an intermittent valve structure such as the one described above, and a buffer mechanism; the feeding mechanism is connected to the first feed port of the main valve; and the safety discharge port of the safety valve is connected to the buffer mechanism. The feeding mechanism directly supplies slurry to the main valve, and the main valve stem switches between two conduction positions to switch between slurry coating and slurry reflux functions. During coating, the slurry only moves relative to the main valve stem. Compared to conventional methods in which the slurry moves relative to both the safety valve stem and the main valve stem, this shortens the relative motion stroke and reduces the probability of soft slurry particles being generated, thereby reducing the incidence of coating scratches.
[0011] As a preferred embodiment of the present invention, the feeding mechanism includes a screw conveying pump, a filter, and a feeding pipeline. The discharge port of the screw conveying pump is connected to the feeding pipeline, which is equipped with a filter. The discharge port of the feeding pipeline is connected to the first discharge port. The feed port of the screw conveying pump is connected to the discharge port of the buffer mechanism. The buffer mechanism is a buffer tank. The refluxed slurry is discharged from the buffer tank by the screw conveying pump, filtered, and then fed to the main valve through the feeding pipeline. After the main valve is coated, the slurry flows from the main valve to the safety valve for slurry recovery.
[0012] The utility model changes the feeding mode of the transmission intermittent valve so that the slurry directly enters the main valve. The slurry used for coating only generates relative motion with the main valve stem. Compared with the original mode in which the slurry used for coating generates relative motion with both the valve stem of the safety valve and the valve stem of the main valve, the travel distance of the slurry in the intermittent valve is shortened, and the generation of soft particles is greatly reduced, thereby reducing the probability of abnormal scratches. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0014] Figure 1 It is a schematic diagram of the coordination relationship between slurry and intermittent valve in the prior art.
[0015] Figure 2 It is a schematic diagram of the feed of the intermittent valve in the prior art.
[0016] Figure 3 This is a schematic diagram of the coordination relationship between the slurry and the intermittent valve of the utility model.
[0017] Figure 4 This is a schematic diagram of the state of the intermittent valve during coating of the utility model.
[0018] Figure 5 This is a schematic diagram of the intermittent valve during reflux in the present invention.
[0019] Figure 6 This is a schematic diagram of the feeding of the intermittent valve of the present invention.
[0020] Figure 7 This is a comparison chart of the coating scratch defect rate before and after the intermittent valve improvement. DETAILED DESCRIPTION
[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0022] The utility model provides an embodiment of an intermittent valve structure for improving abnormal coating scratches on lithium-ion batteries, such as Figure 3-5 As shown in the figure, the solid arrow is the direction of slurry movement, and the dotted arrow is the direction of valve stem movement, including the main valve 1 and the safety valve 2.
[0023] The main valve 1 has a main valve chamber 11, a first feed port 12, a first discharge port 13, a second discharge port 14 and a main valve stem 15. The main valve stem 15 moves back and forth in the main valve chamber 11. This embodiment is demonstrated using vertical reciprocating movement as an example; the first feed port 12, the first discharge port 13, and the second discharge port 14 are all connected to the main valve chamber 11; and the first feed port 12 serves as a paint inlet, and the first discharge port 13 serves as a paint interface and is connected to the coating die head 3. The main valve stem 15 has a first conduction position and a second conduction position during the movement process.
[0024] The safety valve 2 has a safety valve chamber 21, a safety feed port 22, a safety discharge port 23 and a safety valve stem 24. The safety valve stem 24 moves back and forth in the safety valve chamber 21, with the same setting direction as the main valve stem 15, but the movement direction is opposite; the safety feed port 22 and the safety discharge port 23 are both connected to the safety valve chamber 21; and the safety feed port 22 is connected to the second discharge port 14, and the safety discharge port 23 serves as a paint reflux port; the safety valve stem 24 has a third conduction position and a first cut-off position during the movement process.
[0025] When the main valve stem 15 is in the first conduction position, the safety valve stem 24 is in the first cut-off position, that is, the main valve stem 15 moves upward and the safety valve stem 24 moves downward. Figure 4As shown, the first feed port 12, the main valve chamber 11, and the first discharge port 13 communicate to form a coating material channel, the second discharge port 14 is closed, and the safety discharge port 23 is closed; the slurry enters the main valve chamber from the first feed port and then enters the coating die head from the first discharge port for coating. The second discharge port is closed, and the slurry does not flow at the safety valve.
[0026] When the main valve stem 15 is in the second conduction position, the safety valve stem 24 is in the third conduction position, that is, the main valve stem 15 moves downward and the safety valve stem 24 moves upward, as Figure 5 shown, the first feed port 12, the main valve chamber 11, and the second discharge port 14 communicate to form a material pre-reflux channel, the first discharge port 13 is closed, and the safety feed port 22, the safety discharge port 23, the safety valve chamber 21, and the material pre-reflux channel communicate to jointly form a material reflux channel; the slurry enters the safety valve chamber of the safety valve from the second discharge port of the main valve and then is discharged from the safety discharge port for reflux recovery. The proportion of the reflux slurry is relatively small and it is not directly coated on the electrode sheet, so it will not cause scratches on the electrode sheet.
[0027] The present utility model also provides an embodiment of an intermittent valve feeding device for improving the abnormal coating scratches of a lithium-ion battery, as Figure 6 shown, including a feeding mechanism, an intermittent valve structure as described above, and a buffer mechanism; the feeding mechanism includes a screw conveyor pump 41, a filter screen 42, and a feeding pipeline 43. The discharge port of the screw conveyor pump 41 is communicated with the feeding pipeline 43, and a filter screen 42 is provided in the feeding pipeline 43; the discharge port of the feeding pipeline 43 is communicated with the first discharge port 13; the feed port of the screw conveyor pump 41 is communicated with the discharge port of the buffer mechanism. The buffer mechanism is a buffer tank 5. The feeding mechanism directly supplies the slurry to the main valve. The main valve stem realizes the switching of the slurry coating and the slurry reflux functions by switching between the two conduction positions. During coating, the slurry only generates relative movement with the main valve stem. Compared with the traditional situation where relative movement occurs with both the valve stem of the safety valve and the valve stem of the main valve, the relative movement stroke is shortened, and the probability of generating soft particles of the slurry is reduced, thereby enabling the reduction of the incidence of coating scratches. The reflux slurry is discharged from the buffer tank under the action of the screw conveyor pump, filtered, and then transported to the main valve through the feeding pipeline. After the main valve finishes coating, it flows into the safety valve for slurry recovery.
[0028] For the same specification of electrode sheets, coating is carried out and compared according to the existing structure and the structure of the present application. The comparison chart of the coating scratch defect rate before and after the improvement of the intermittent valve is shown in Figure 7. It can be seen from the figure that the coating scratch defect rate using the intermittent valve structure of the present application is reduced from 0.12% to 0.02%, improving the qualification rate.
[0029] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.
[0030] As described above, the above is only a preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution of the present utility model and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present utility model.
Claims
1. An intermittent valve structure for improving abnormal coating scratches of lithium-ion batteries, comprising a main valve (1) and a safety valve (2), characterized in that: The feed inlet of the main valve (1) serves as the coating interface. One discharge outlet of the main valve (1) is connected to the coating die head (3), and the other discharge outlet of the main valve (1) communicates with the feed inlet of the safety valve (2). The discharge outlet of the safety valve (2) serves as the coating return port.
2. The intermittent valve structure for improving the abnormal coating scratches of a lithium-ion battery according to claim 1, wherein: The main valve (1) has a main valve cavity (11), a first feed inlet (12), a first discharge outlet (13), a second discharge outlet (14), and a main valve stem (15). The main valve stem (15) reciprocates within the main valve cavity (11). The first feed inlet (12), the first discharge outlet (13), and the second discharge outlet (14) all communicate with the main valve cavity (11). And the first feed inlet (12) serves as the coating inlet, the first discharge outlet (13) is connected to the coating die head (3), and the second discharge outlet communicates with the feed inlet of the safety valve (2). The main valve stem (15) has a first conducting position and a second conducting position during movement. When the main valve stem (15) is in the first conducting position, the first feed inlet (12), the main valve cavity (11), and the first discharge outlet (13) communicate to form a coating material passage, and the second discharge outlet (14) is closed. When the main valve stem (15) is in the second conducting position, the first feed inlet (12), the main valve cavity (11), and the second discharge outlet (14) communicate to form a material pre - return passage, and the first discharge outlet (13) is closed.
3. The intermittent valve structure for improving the abnormal coating scratches of a lithium-ion battery according to claim 2, characterized in that: The safety valve (2) has a safety valve cavity (21), a safety feed inlet (22), a safety discharge outlet (23), and a safety valve stem (24). The safety valve stem (24) reciprocates within the safety valve cavity (21). The safety feed inlet (22) and the safety discharge outlet (23) both communicate with the safety valve cavity (21). And the safety feed inlet (22) is connected to the second discharge outlet (14), and the safety discharge outlet (23) serves as the coating return port. The safety valve stem (24) has a third conducting position and a first cut - off position during movement, and the moving direction of the safety valve stem (24) is opposite to that of the main valve stem (15). When the safety valve stem (24) is in the third conducting position, the safety feed inlet (22), the safety discharge outlet (23), the safety valve cavity (21), and the material pre - return passage communicate to jointly form a material return passage. When the safety valve stem (24) is in the first cut - off position, the safety discharge outlet (23) is closed.
4. An intermittent valve feeding device for improving abnormal coating scratches of lithium-ion batteries, characterized in that: It includes a feeding mechanism, the intermittent valve structure as claimed in claim 3, and a buffer mechanism. The feeding mechanism communicates with the first feed inlet of the main valve. The safety discharge outlet of the safety valve is connected to the buffer mechanism.
5. The intermittent valve feeding device for improving the abnormal coating scratches of lithium-ion batteries according to claim 4, wherein: The feeding mechanism includes a screw conveyor pump (41), a filter screen (42), and a feeding pipeline (43). The discharge outlet of the screw conveyor pump (41) is connected to the feeding pipeline (43), and a filter screen (42) is provided in the feeding pipeline (43). The discharge outlet of the feeding pipeline (43) communicates with the first discharge outlet (13). The feed inlet of the screw conveyor pump (41) communicates with the discharge outlet of the buffer mechanism.