Pole piece coating gasket device
By designing an electrode coating pad device, the problem of miscibility between lithium iron phosphate slurry and ceramic slurry in lithium-ion battery production was solved, improving battery capacity and reducing material loss and strip breakage during production, and enhancing coating accuracy.
Patent Information
- Application Number
- CN202422734784.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-11
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-11-11
AI Technical Summary
In the production process of lithium-ion batteries, the mutual solubility of lithium iron phosphate slurry and ceramic slurry is serious, which leads to a decrease in the capacity of the finished battery and causes material loss and tape breakage during rolling and laser cutting.
An electrode coating pad device was designed, including an A coating pad and a B coating pad, which are used for coating the A and B sides of the electrode, respectively. By setting an L-shaped ceramic flow channel and a chamfer on the pad, the lithium iron phosphate and ceramic slurry are ensured to flow separately to avoid mutual solubility.
It effectively solves the problem of miscibility between lithium iron phosphate slurry and ceramic slurry, improves the problems of material loss and strip breakage during rolling, and enhances the accuracy of laser cutting.
Smart Images
Figure CN223465022U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of pole piece coating, particularly to a pole piece coating gasket device. BACKGROUND
[0002] In the production process of lithium ion batteries, pole piece coating is a particularly key process. With the rapid development of lithium ion batteries, there are higher requirements for pole pieces. For iron lithium system iron lithium slurry, due to the process design of ceramic edge coating, iron lithium slurry and ceramic slurry will be mutually soluble during high-speed coating, the boundary between the two slurries is not clear, and there is a gray mutual solubility area at the junction, which will cause mutual solubility area dropping and belt breaking problems in the rolling process and laser cutting process, and the ceramic has an insulating effect, the mutual solubility area cannot play a capacity, affecting the capacity of the finished battery. Lithium iron phosphate slurry and ceramic slurry are mutually soluble during drying, forming a gray area in the middle, so the gray area has part of the lithium iron slurry and cannot play a capacity. Figure 1a It is an A surface coating schematic diagram, the substrate is foil during coating, the reference surface is a plane, the ceramic flow channel 101 of the gasket corresponds to the spraying of ceramic slurry, and the iron lithium slurry flow channel 106 of the gasket corresponds to the spraying of iron lithium slurry; Figure 1b It is a B surface coating schematic diagram, the substrate is a single surface pole piece coated with the A surface during coating, since the thickness of the middle area and the edge thinning area of the A surface iron lithium is inconsistent (thick in the middle and thin at the edge), there is a height difference, so the reference surface is not a plane during B surface coating, the middle area of the iron lithium flow channel is close to the substrate (single surface pole piece), and the edge area of the iron lithium flow channel is far from the substrate (single surface pole piece). Since the A surface has been coated with iron lithium slurry and ceramic slurry during coating of the B surface, and there is a thinning area at the edge of the dry film of the A surface, there is a difference in the GAP value between the edge area and the middle area of the iron lithium slurry during B surface coating, and the B surface edge is not thinned or thicker than the normal area when using the same designed coating gasket for A / B surface coating, that is, there is more solvent at the junction of the iron lithium slurry and the ceramic slurry, and during the drying process, the ceramic area is dried first, but the iron lithium slurry at the junction is not dried, therefore, the iron lithium slurry continuously provides solvent to the ceramic area, thereby causing the phenomenon of mutual solubility of ceramic and iron lithium slurry, as shown in Figure 2 It is a pole piece cross section schematic diagram of the drying process, 1 is aluminum foil, 2 is ceramic, and 3 is iron lithium, and due to the distance difference in the above-mentioned B surface coating process, the B surface edge is thicker.
[0003] At present, the industry mainly changes the ceramic slurry formula, reduces the ceramic flow during coating, or separates the ceramic slurry from the iron lithium slurry without contact to solve the above-mentioned problems. These are compromises made when the coating process cannot be completely solved, but they are still far from the ideal state. Therefore, the industry currently urgently needs a technical means that can solve the mutual solubility problem of iron lithium slurry and ceramic slurry coating. CONTENT OF THE UTILITY MODEL
[0004] The utility model discloses a kind of polar piece coating gasket devices, including the A coating gasket for polar piece A face coating, the A coating gasket includes first gasket main body, two first side gaskets of L type structure are symmetrically arranged on first gasket main body, first flow guide groove is formed between two first side gaskets and main gasket, the surface of the first side gasket has first ceramic flow channel, the outside of the first ceramic flow channel has first chamfer, and the inside end of the first side gasket is connected with top end by the first chamfer;The first ceramic flow channel extends to the vertical portion of first side gasket connected with the first gasket main body by the top end of the first side gasket along the surface of the first side gasket in L type track, then cut off after extending a distance downwards again.
[0005] The utility model discloses a kind of polar piece coating gasket devices, including the A coating gasket for polar piece A face coating, the A coating gasket includes first gasket main body, two first side gaskets of L type structure are symmetrically arranged on first gasket main body, first flow guide groove is formed between two first side gaskets and main gasket, the surface of the first side gasket has first ceramic flow channel, the outside of the first ceramic flow channel has first chamfer, and the inside end of the first side gasket is connected with top end by the first chamfer;The first ceramic flow channel extends to the vertical portion of first side gasket connected with the first gasket main body by the top end of the first side gasket along the surface of the first side gasket in L type track, then cut off after extending a distance downwards again.
[0006] Wherein, two the first ceramic flow channel is symmetrically arranged, two the first chamfer is symmetrically arranged.
[0007] Wherein, the front and rear surfaces of the first chamfer are flush with the front and rear surfaces of the first side gasket.
[0008] Wherein, the first fixing portion is provided on the A coating gasket, and a plurality of first fixing holes are included for fixing the A coating gasket on the coating machine die head.
[0009] Wherein, the first holding portion is provided on the A coating gasket, and the first holding portion is a first protrusion located at both ends of the first gasket main body.
[0010] Wherein, the polar piece coating gasket device further includes a B coating gasket for polar piece B face coating, the B coating gasket includes second gasket main body, two second side gaskets of L type structure are arranged on second gasket main body, second flow guide groove is formed between two second side gaskets and second gasket main body, the surface of the second side gasket has second ceramic flow channel, the outside of the second ceramic flow channel has second chamfer and flying wing part, and the inside end of the second side gasket is connected with top end by the second chamfer;The second ceramic flow channel extends to the vertical portion of first side gasket connected with the first gasket main body by the top end of the second side gasket along the surface of the second side gasket in L type track, then cut off after extending a distance downwards again;The flying wing part is protruded on the inside end of the second side gasket and lower than the second chamfer, and the top of the flying wing part is connected with and flush with the top end of the second side gasket.
[0011] Wherein, two the second ceramic flow channel is symmetrically arranged, two the second chamfer is symmetrically arranged, and two the flying wing part is symmetrically arranged.
[0012] The second chamfered portion and the thickness of the flying wing portion are the thickness of the second side gasket.
[0013] The B coating gasket is provided with a second fixing portion, and a plurality of second fixing holes are arranged in the second fixing portion.
[0014] The B coating gasket is provided with a second holding portion, and the second holding portion is a second protruding portion arranged at two ends of the second gasket body.
[0015] The pole piece coating gasket device can effectively solve the mutual solubility of ceramic and iron lithium slurry, solve the mutual solubility problem of ceramic and iron lithium slurry in the positive electrode iron lithium slurry coating process, obviously improve the pole piece dropping and belt breaking problems in the mutual solubility area during rolling, and effectively improve the problem of laser cutting and edge recognition error. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1a is an A coating schematic diagram.
[0017] Figure 1b is a B coating schematic diagram.
[0018] Figure 2 is a pole piece cross section schematic diagram in the drying process.
[0019] Figure 3 is a schematic diagram of mutual solubility not occurring between iron lithium slurry and ceramic slurry.
[0020] Figure 4 is a schematic diagram of the A coating gasket.
[0021] Figure 5 is a partial enlarged schematic diagram of Figure 4 .
[0022] Figure 6 is a schematic diagram of the B coating gasket.
[0023] Figure 7 is a partial enlarged schematic diagram of Figure 6 . DETAILED DESCRIPTION
[0024] The utility model will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.
[0025] The inventors of the present application found through research that the internal driving force causing the ceramic slurry to pull towards the iron lithium slurry area during drying is surface tension. When the contact angle difference between the iron lithium slurry and the ceramic slurry exceeds 5°, mutual solubility is prone to occur during drying. When the contact angles of the iron lithium slurry and the ceramic slurry are similar, the surface tensions of the two are similar, and they reach a balance during drying, without mutual solubility.
[0026] During the coating of the pole piece, the internal driving force causing mutual solubility is the difference in surface tension, but the slurry system formula often cannot be easily changed, so it is necessary to solve the mutual solubility problem from the process of coating. Through experimental research, it is found that no matter what the surface tension of the iron lithium slurry is, when coating on the A surface, due to the existence of the thinning area, the pole piece thinning area quickly solidifies after entering the oven, without mutual solubility, as shown in Figure 3 Figure 3 The black area is iron lithium 3 and the white area is ceramic 2. Therefore, the inventors of the present application draw the technical inspiration that a thinning area also needs to exist on the B surface.
[0027] Through B surface coating of different slurries and comparison of slurry surface tension tests, the mechanism of mutual solubility is revealed. The results show that when the surface tension difference between the iron lithium slurry and the ceramic slurry is too large, the pulling force of the iron lithium slurry retraction during drying is greater than that of the ceramic slurry, thereby causing mutual solubility. When the surface tensions of the two are similar, the retraction forces of the two reach a balance during drying, without mutual solubility.
[0028] The positive pole piece of the battery contains iron lithium material and edge-coated ceramic material. The ceramic material is used to prevent the positive and negative edges of the battery from overlapping, thereby avoiding short circuits. The positive coating is completed by an extrusion die. If both iron lithium and ceramic slurries need to be coated, flow channels for the two kinds of slurries need to be designed on the coating gasket to distinguish them and prevent the two kinds of slurries from mixing inside the die.
[0029] Therefore, based on the above findings, the inventors of the present application propose a pole piece coating gasket device of the present application embodiment, which comprises an A coating gasket for A surface coating of the pole piece. The A coating gasket comprises a first gasket body 100, two first side gaskets 110 of L-shaped structure arranged symmetrically apart on the first gasket body, a first flow guide groove 106 formed between the two first side gaskets and the main gasket, a first ceramic flow channel 101 on the surface of the first side gasket 110, a first chamfer portion 103 on the outside of the first ceramic flow channel 101, and a first chamfer portion connecting the inside end and the top end of the first side gasket 110. The first ceramic flow channel 101 extends from the top end of the first side gasket along the surface of the first side gasket in an L-shaped trajectory, connects the first side gasket vertical portion of the first gasket body, and then extends downward for a distance before stopping.
[0030] In the present application, the through hole at the end of the first ceramic flow channel is connected to the ceramic valve outside the die, and the ceramic slurry flows into the die through the ceramic valve, then enters the first ceramic flow channel, and then is sprayed out of the die onto the substrate. The ceramic slurry and the lithium-iron slurry are two different feed ports.
[0031] In some embodiments, the two first ceramic flow channels 101 are symmetrically arranged, and the two first chamfered portions 103 are symmetrically arranged.
[0032] In some embodiments, the front and rear surfaces of the first chamfered portion 103 are flush with the front and rear surfaces of the first side gasket 110, that is, the right angles of the top end and the side end of the first side gasket are formed into a chamfered structure.
[0033] In some embodiments, the A coating gasket is provided with a first fixing portion, which includes a plurality of first fixing holes 104 for fixing the A coating gasket on the coating machine die.
[0034] In some embodiments, the A coating gasket is provided with a first holding portion 102, which is a first protruding portion 102 located at both ends of the first gasket main body 100.
[0035] In some embodiments, the pole piece coating gasket device further comprises a B coating gasket for coating the B surface of the pole piece, the B coating gasket comprising a second gasket main body 200, two L-shaped structure second side gaskets 210 arranged apart on the second gasket main body 200, a second flow guide groove 206 formed between the two second side gaskets 210 and the second gasket main body 200, the surface of the second side gasket 210 having a second ceramic flow channel 201, the outside of the second ceramic flow channel 201 having a second chamfered portion 203 and a flying wing portion 204, the second chamfered portion 203 connecting the inner end and the top end of the second side gasket 210; the second ceramic flow channel 201 extends from the top end of the second side gasket 210 along the L-shaped trajectory of the surface of the second side gasket to the first side gasket perpendicular portion connected to the first gasket main body 210, and then extends downward for a distance and stops; the flying wing portion 204 is protruding on the inner end of the second side gasket 210 and is lower than the second chamfered portion 203, the top of the flying wing portion 204 is connected to and flush with the top end of the second side gasket 210. Compared with the A coating gasket, the B coating gasket increases the flying wing portion 204.
[0036] In the present application, the through hole at the end of the second ceramic flow channel is connected to the ceramic valve outside the die, and the ceramic slurry flows into the die through the ceramic valve, then enters the second ceramic flow channel, and then is sprayed out of the die onto the substrate. The ceramic slurry and the lithium-iron slurry are two different feed ports.
[0037] In the embodiment of the application, the second chamfering part 203 has a certain thinning capacity in the coating process, and the thinning capacity is further strengthened after the flying wing part 204 is added.
[0038] In some embodiments, the two second ceramic flow channels 201 are symmetrically arranged, the two second chamfering parts 203 are symmetrically arranged, and the two flying wing parts 204 are symmetrically arranged.
[0039] In some embodiments, the thickness of the second chamfering part 203 and the flying wing part 204 is the thickness of the second side pad, for example, in an embodiment, the thickness of the second pad body 200 is 1 mm, the thickness of the second ceramic flow channel 201 is 0.5 mm, and the thickness of the flying wing part 204 is 0.5 mm.
[0040] In some embodiments, the B coating pad is provided with a second fixing part, which comprises a plurality of second fixing holes 205, for fixing the B coating pad on the coating machine die.
[0041] In some embodiments, the B coating pad is provided with a second holding part 202, which is a second convex part located at both ends of the second pad body 200.
[0042] In the embodiment, the A coating pad is used for A surface coating, and the B coating pad is used for B surface coating. The combination of the two can make the pole piece A and B surfaces have a thinning effect. The specific thinning amount can be adjusted according to the actual situation by adjusting the size of the first chamfering part 103, the second chamfering part 203 and the size of the flying wing part 104.
[0043] The embodiment of the application solves the mutual solubility of the B surface ceramic and the lithium iron slurry by differentially designing the A and B surface pads at a low cost, solves the mutual solubility problem of the ceramic and the lithium iron slurry in the positive lithium slurry coating process, significantly improves the pole piece dropping and belt breaking problems in the mutual solubility area during rolling, and effectively improves the laser cutting and edge recognition error problem.
[0044] The above shows and describes the basic principles and main features of the utility model and the advantages of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above-mentioned exemplary embodiments, and the utility model can be realized in other specific forms without departing from the spirit or basic characteristics of the utility model.
[0045] Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the utility model is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the utility model.
[0046] Furthermore, it should be understood that although the specification is described in terms of embodiments, not every embodiment includes every feature or implementation described herein. The specification can include implicit combinations of explicitly mentioned features and / or implicit combinations of implicitly mentioned features. Such combinations are also expressly included within the scope of the specification and an embodiment.
Claims
1. A pole piece coating shim device, characterized by, The application relates to a coating pad for coating the A surface of a pole piece, which comprises a first pad main body, two first side pads arranged in a symmetrical L-shaped structure on the first pad main body, a first flow guide groove formed between the two first side pads and the main pad, a first ceramic flow channel on the surface of the first side pad, a first chamfer part on the outer side of the first ceramic flow channel, and a first chamfer part connecting the inner side end and the top end of the first side pad; the first ceramic flow channel extends from the top end of the first side pad along the surface of the first side pad in an L-shaped track, extends to the vertical part of the first side pad connected with the first pad main body, and then extends downward for a distance and stops.
2. The pole piece coated gasket device of claim 1, wherein, The two first ceramic flow channels are arranged symmetrically, and the two first chamfer parts are arranged symmetrically.
3. The pole piece coated gasket device of claim 1, wherein, The front and back surfaces of the first chamfer part are flush with the front and back surfaces of the first side pad.
4. The pole piece coated gasket device of claim 1, wherein, A first fixing part is arranged on the A coating pad, and a plurality of first fixing holes are arranged in the first fixing part for fixing the A coating pad on a coating machine die head.
5. The pole piece coated gasket device of claim 1, wherein, A first holding part in the form of a first convex part is arranged at the two ends of the first pad main body.
6. The pole piece coated gasket device of any one of claims 1-5, wherein, The application also relates to a coating pad for coating the B surface of a pole piece, which comprises a second pad main body, two second side pads arranged in an L-shaped structure on the second pad main body, a second flow guide groove formed between the two second side pads and the second pad main body, a second ceramic flow channel on the surface of the second side pad, a second chamfer part and a flying wing part on the outer side of the second ceramic flow channel, the second chamfer part connecting the inner side end and the top end of the second side pad, the second ceramic flow channel extending from the top end of the second side pad along the surface of the second side pad in an L-shaped track, extending to the vertical part of the first side pad connected with the first pad main body, and then extending downward for a distance and stopping, and the flying wing part protruding from the inner side end of the second side pad and being lower than the second chamfer part, the top of the flying wing part being flush with the top end of the second side pad.
7. The pole piece coated gasket device of claim 6, wherein, The two second ceramic flow channels are arranged symmetrically, the two second chamfer parts are arranged symmetrically, and the two flying wing parts are arranged symmetrically.
8. The pole piece coated gasket device of claim 6, wherein, The thickness of the second chamfer part and the flying wing part is equal to the thickness of the second side pad.
9. The pole piece coated gasket device of claim 6, wherein, A second fixing part is arranged on the B coating pad, and a plurality of second fixing holes are arranged in the second fixing part for fixing the B coating pad on a coating machine die head.
10. The pole piece coated gasket device of claim 6, wherein, A second holding part in the form of a second convex part is arranged at the two ends of the second pad main body.