CN217664253U - Lithium battery diaphragm dispensing and coating device - Google Patents

Abstract

The utility model relates to a lithium battery diaphragm preparation technical field especially relates to a coating unit is glued to lithium battery diaphragm point. The utility model mainly comprises a coating transfer device, a feed amount controller and a plane bottom roller, wherein the coating transfer device comprises a sizing material containing device and a raised printing roller, the sizing material containing device is provided with a material containing groove for containing sizing material, and the roller surface of the raised printing roller is provided with a transfer salient point; the relief printing roller is positioned between the sizing material accommodating device and the plane bottom roller, and the transfer salient points are inserted into the material accommodating grooves at the contact positions of the relief printing roller and the sizing material accommodating device; the feeding amount controller is used for detecting and adjusting and controlling the feeding amount of the transfer salient points inserted into the material accommodating groove; the plane bottom roller is positioned at the lower side of the relief printing roller, and a film penetrating gap for a coating film to penetrate is arranged between the plane bottom roller and the relief printing roller. The thickness of the coating layer formed by coating by using the device is larger, and the thickness and the coverage rate of the glue dots are simply and conveniently controlled.

Description

Lithium battery diaphragm dispensing and coating device

Technical Field

The utility model relates to a lithium battery diaphragm preparation technical field especially relates to a coating unit is glued to lithium battery diaphragm point.

Background

In the fields of diaphragm and pole piece manufacturing in the battery industry, breathable film and non-woven fabric manufacturing in the sanitary packaging industry and protective film manufacturing in the electronic industry, a coating technology is required to be used for coating to form a non-full-surface covering type coating layer.

Taking diaphragm preparation in the battery industry as an example, because the lithium battery not only needs good thermal stability and bonding force between the diaphragm and the electrode, but also needs quick charging performance, and through the mode of non-full-coverage coating glue layer, the effective transmission of lithium ions can be realized in the non-polymer glue point hole area, the lithium ion conductivity of the diaphragm is improved, thereby improving the charge and discharge performance of the lithium battery, and prolonging the cycle life of the lithium battery.

In the prior art, the non-full-coverage type coating glue layer technology commonly adopted in the preparation of lithium battery separators generally comprises two types of PVDF (polyvinylidene fluoride, a highly non-reactive thermoplastic fluoropolymer) agglomeration shrinkage coating films and PVDF island-shaped spraying films: the surface of the diaphragm formed by the former utilizes the hydrophobicity of PVDF, the PVDF is prepared into an aggregate through the tension adjustment of the slurry, the slurry is quickly shrunk after contacting the membrane surface, the formation of the PVDF is not continuous, and the stability is poor due to the adjustment of the slurry; the latter throws PVDF to the diaphragm through high-speed rotation, forms island-shaped structures on the surface of the diaphragm so as to rivet the pole piece, but the shape is irregular. Therefore, the existing non-full-coverage glue layer coating technology in the preparation of the lithium battery diaphragm has various problems.

As described above, the non-full-coverage type coating glue layer used in the preparation of the existing lithium battery separator cannot accurately control the size of each glue dot, the distance between the glue dots, and the aggregation state, so that the discrete glue film layer formed has an influence on the control of the production quality and the quality of the subsequent winding. Therefore, the inventor of the application researches a preparation scheme of a non-full-coverage type coating diaphragm (which cannot be considered to be completely belonging to the prior art), and can form a flat and uniform local coating structure, so that a uniform point-shaped PVDF coating film is realized.

As shown in fig. 1, a sizing material for coating is fully distributed in a concave hole or a groove 011 on the roll surface of an anilox roll 01, and a liquid film layer with uniform thickness is formed; then, the liquid film layer is transferred to the transfer surface of the salient point 021 by utilizing the salient point 021 on the salient roller 02 in the process of contacting with the anilox roller 01, and in the transfer process, the transfer surface of the salient point 021 is in tangential contact with the roller surface of the anilox roller 01; finally, the flat bottom roller 03 is used for extruding the transfer surface of the salient points 021 on the embossing roller 02, the liquid film layer on the transfer surface of the salient points 021 is transferred to the diaphragm 04 which passes through the space between the flat bottom roller 03 and the embossing roller 02 and moves along the direction j, and therefore a uniform dot-shaped coating layer is formed on one side, facing the embossing roller 02, of the diaphragm 04.

The inventors of the present application have found that, by using the above-mentioned preparation scheme of the uniform "dot-like" coating of the separator, a local coating structure having a flat and uniform size can be formed on the separator, but only a liquid film layer having a small thickness (for example, a coating film having a thickness of 5 μm or less) can be formed, and the requirement of a thick coating film (for example, a coating film having a thickness of 10 μm or more) cannot be satisfied; in addition, different types of diaphragms require different liquid film thicknesses, the existing scheme can only adjust the spot coating thickness by replacing gravure rollers of different versions, but the mode is high in cost, complex to operate and time-wasting.

Disclosure of Invention

In order to meet the production requirements for preparing a coating layer with thicker thickness on a coating film in the battery industry, the sanitary packaging industry and the electronic industry, the utility model provides a lithium battery diaphragm dispensing and coating device, which comprises a coating transfer device, a feed quantity controller and a plane bottom roller, wherein the coating transfer device comprises a sizing material accommodating device and a relief printing roller, the sizing material accommodating device is provided with a material accommodating groove for storing and accommodating the sizing material, the roller surface of the relief printing roller is provided with transfer salient points, and the transfer salient points are suitable for being inserted into the material accommodating groove at the corresponding position on the sizing material accommodating device to transfer the diaphragm coating; the diaphragm coating forms coating adhesive drops coated on the transfer end faces of the transfer salient points, the planar bottom roller rotates reversely relative to the adhesive material accommodating device to drive the coating film to move, so that the coating adhesive drops on the transfer salient points are coated on the coating film and form a non-full-coverage coating layer on the coating film, and preferably, the adhesive material accommodating device is an anilox roller, a texturing roller or a smooth roller.

Further, when the lithium battery diaphragm dispensing coating device is used for coating the sizing material for coating on the coating film to form a coating layer, firstly, the sizing material for coating in the hopper is transferred into the material accommodating groove on the anilox roller by using the anilox roller, and a liquid film layer with uniform thickness is formed in the material accommodating groove on the roller surface of the anilox roller; then, by rotating the relief roller and the anilox roller, the transfer salient points on the relief roller are inserted into the material containing grooves on the anilox roller and leave the material containing grooves along with the rotation of the relief roller and the anilox roller, and meanwhile, the sizing material for coating is taken out of the material containing grooves by utilizing the tension of the sizing material for coating, and coating glue drops which are approximately spherical or ellipsoidal are formed at the transfer ends of the transfer salient points; finally, when the transfer salient points with the coating adhesive drops are transposed to the coating film passing through the film passing gap from the front side, the coating adhesive drops are mainly transferred and coated on the coating film under the action of tension difference, so that a non-all-surface covering type coating layer is formed on the coating film; it should be emphasized that the coating paste droplet is mainly transferred and dripped by using the tension difference between the gravure roll and the coating film, the dripping transfer effect is better when the tension difference is larger, and the technicians in the field also know that the self-gravity of the coating paste droplet and the centrifugal force formed along with the rotation of the gravure roll play a certain role in transferring and dripping onto the coating film.

Furthermore, the device also comprises a feeding amount controller and a plane bottom roller, wherein the feeding amount controller is used for detecting and adjusting and controlling the feeding amount of the transfer salient points on the salient roller inserted into the material containing groove; the plane bottom roller is located on the lower side of the raised plate roller, and a film penetrating gap for a coating film to penetrate is formed between the plane bottom roller and the raised plate roller. When the dispensing coating device is used for coating the sizing material for coating on the coating film to form a coating layer, firstly, the sizing material for coating in the hopper is transferred into the material accommodating groove on the anilox roller by using the anilox roller, and a liquid film layer with uniform thickness is formed in the material accommodating groove on the roller surface of the anilox roller; then, by rotating the relief roller and the anilox roller, the transfer salient points on the relief roller are inserted into the material containing grooves on the anilox roller and leave the material containing grooves along with the rotation of the relief roller and the anilox roller, and meanwhile, the coating sizing material is taken out of the material containing grooves by utilizing the tension of the coating sizing material, and coating sizing material drops which are approximately spherical or ellipsoidal are formed at the transfer ends of the transfer salient points; finally, when the transfer bumps with the coating adhesive droplets are transposed with the front side facing the coating film passing through the film passing gap, the coating adhesive droplets are dropped on the coating film mainly under the action of the tension difference, thereby forming a non-blanket coating layer on the coating film. In addition, in the preparation process, the feeding amount of the transfer salient points on the salient roll roller inserted into the material containing grooves on the anilox roller is adjusted and controlled by the feeding amount controller so as to adjust and control the thickness of the prepared coating layer. It can be known through the experiment that the thickness scope of the coating layer that adopts the utility model discloses lithium cell diaphragm point to glue coating device coating formation on the coating film is 2 mu m-30 mu m, compares in the coating layer that the thickness that prior art coating formed and is less than 5 mu m, and the thickness of the coating layer that the coating formed is great, and thickness control is simple and convenient.

Further, the lithium battery diaphragm dispensing and coating device can be further provided with a coating device, the coating device is abutted against the glue material containing device, so that the coating material forms a liquid film layer with uniform thickness on the surface of the glue material containing device, preferably, the coating device comprises a roller or a scraper, and when the roller is adopted, the roller is close to the roller surface of the anilox roller and is in contact with the coating glue material on the roller surface of the anilox roller to extrude and remove the redundant coating glue material to form the liquid film layer with uniform thickness in the meshes of the anilox roller in the rotating process of the anilox roller; when the scraper is adopted, the scraper is close to the roll surface of the anilox roll, and in the rotating process of the anilox roll, the scraper scrapes the coating on the roll surface of the anilox roll to remove the redundant coating rubber material to form a liquid film layer with uniform thickness in meshes of the anilox roll.

Preferably, the ratio Q of the inner diameter d1 of the material containing groove to the diameter d2 of the transfer end face of the transfer salient point is more than or equal to 1.5. In this way, the area of the transfer end face of the transfer salient point is far smaller than the cross section area of the material containing groove, so that the transfer end face of the transfer salient point is inserted into the material containing groove of the anilox roller, the coating adhesive is attached to the transfer end face of the transfer salient point by utilizing the tension of the coating adhesive and forms spherical or ellipsoidal coating adhesive drops, the coating adhesive drops do not extrude a coating film in the transfer process, and the coating adhesive drops are mainly dripped on the coating film through the tension difference effect formed by the coating adhesive drops on the anilox roller and the coating film which are made of different materials. Furthermore, the transfer end face of the transfer bump is a circular face, the diameter d2 of the transfer end face ranges from 20 μm to 1mm, and when the transfer bump is inserted into the material accommodating groove, the distance L between the transfer end face and the bottom of the material accommodating groove ranges from 20 μm to 250 μm. Therefore, use the utility model discloses coating device is glued to lithium cell diaphragm point when coating on the coating film forms the coating layer of non-comprehensive coverage formula, can avoid influencing the transfer of sizing material for the coating because of the transfer terminal surface undersize or too big of shifting the bump, the accessible adjustment simultaneously shifts the bump and inserts the degree of depth that holds in the material recess and shift the terminal surface promptly and hold the value of the interval L between the tank bottom of material recess and adjust the height that shifts the coating adhesive material droplet that forms on the bump, and then can adjust the thickness of the coating layer that the coating formed according to the height of coating adhesive material droplet. Therefore, adopt the utility model discloses when some glue coating unit formed the coating layer of non-comprehensive overlay type on the coating film, both made things convenient for the sizing material for the coating on the transfer reticulation roller, made things convenient for coating operating personnel to control the thickness of the coating layer that the coating formed again.

Preferably, the transfer salient point is a conical platform structure with a concave bus, a conical platform structure with a convex bus, a conical platform structure or a stepped platform structure, the stepped platform structure comprises a connection base and a transfer boss, and the cross section area of the transfer boss is smaller than that of the connection base. Further, the transfer boss is of a cylindrical structure, the connecting base is of a conical table-shaped structure, the height h1 of the cylindrical structure is less than or equal to 200 mu m, and the ratio N of the height h1 of the cylindrical structure to the diameter d2 of the transfer end face is less than or equal to 2.5. Therefore, the phenomenon that the transfer effect is influenced by the fact that the transfer lug boss is too thin and long in the process of transferring sizing materials, and further the later coating effect is influenced can be avoided.

Preferably, the feed amount controller can be selected from a grating ruler or other high-precision measuring means. Like this, select the grating chi for use as the feed volume controller, installation and easy operation, and detect control accuracy height, make things convenient for coating operating personnel to control the thickness of the coating layer of coating formation.

The utility model has the advantages of that:

when the coating film is coated to form a non-overall covering type coating layer, the thickness of the coating layer formed by coating is stable and uniform because the thickness of the liquid film layer formed by the coating sizing material in the material containing groove on the anilox roller is uniform; when the sizing material for coating is transferred, the transfer salient points on the relief printing roller are inserted into the material containing grooves on the anilox roller, the sizing material for coating is taken out of the material containing grooves by utilizing the tension action of the sizing material for coating, and coating sizing material drops are formed at the transfer ends of the transfer salient points, so that the sizing material for coating is convenient to transfer; meanwhile, the feeding amount of the transfer salient points inserted into the material accommodating groove is adjusted by a feeding amount controller according to coating requirements, so that the height of formed coating adhesive drops is conveniently controlled, and the thickness of a coating layer formed by coating is further conveniently controlled; in the process of moving the coating film, coating adhesive drops on the transfer salient points are dripped on the coating film, and coating points forming the coating film are formed on the coating film mainly under the action of tension difference between a relief printing roller made of different materials and the coating film by coating adhesive, so that the phenomenon that the thickness of the coating layer is reduced due to the fact that the coating adhesive drops are pressed in the coating process can be avoided, the thickness of the coating layer is ensured, the area of the coating points is properly increased by the coating adhesive on the side surfaces of the transfer salient points, and the coverage rate of the coating layer on the coating film is increased; in the field of preparation of lithium battery separators, the application of the coating method to production of the lithium battery separators is not found at present.

Drawings

FIG. 1 is a schematic view of a preparation apparatus used in a prior art method for preparing a non-blanket coating layer;

FIG. 2 is a schematic view of a non-blanket coating layer of relatively thin thickness;

FIG. 3 is a schematic illustration of preparing a thick, non-blanket coating layer;

fig. 4 is a schematic structural view of the dispensing and coating device for a lithium battery diaphragm of the present invention;

FIG. 5 is a schematic view of a dispensing coating apparatus including a dispensing control apparatus for dispensing;

fig. 6 is a schematic structural diagram of a transfer bump in the lithium battery separator dispensing and coating apparatus shown in fig. 4, wherein fig. 6 (a) is a schematic structural diagram of a transfer bump of a conical platform structure with a concave bus; FIG. 6 (b) is a schematic structural diagram of a transfer bump with a step structure; FIG. 6 (c) is a schematic structural diagram of a transfer bump of a convex-shaped tapered platform structure of a bus; FIG. 6 (d) is a schematic structural diagram of a transfer bump of a tapered mesa structure;

fig. 7 is a schematic front view of the transfer bump shown in fig. 6, wherein fig. 7 (a) is a schematic front view of the transfer bump with a tapered mesa structure having a concave bus; FIG. 7 (b) is a schematic front view of a transfer bump with a step-mesa structure; FIG. 7 (c) is a schematic front view of a transfer bump with a convex-shaped tapered platform structure; FIG. 7 (d) is a schematic front view of a transfer bump with a tapered mesa structure;

fig. 8 is a schematic front view of the transfer bump shown in fig. 6 with a coating paste drop, wherein fig. 8 (a) is a schematic front view of a transfer bump with a coating paste drop of a conical mesa structure with a concave bus; FIG. 8 (b) is a schematic front view of a transfer bump with a step structure having a coating paste drop; FIG. 8 (c) is a schematic front view of a transfer bump with a coating paste drop in a bus bar convex-cone structure; FIG. 8 (d) is a schematic front view of a transfer bump with a paste drop applied thereon in a tapered mesa configuration;

fig. 9 is a schematic diagram of a coating layer prepared by the dispensing coating device and the transfer bump of the tapered platform structure with the bus indent.

The numbers in the figure are: 01-anilox roller, 011-groove, 02-embossing roller, 021-bump, 03-plane bottom roller, 04-diaphragm and 05-coating layer;

1-anilox roller, 11-material accommodating groove, 2-embossing roller, 3-plane bottom roller, 31-film penetrating gap, 4-coating film, 5-second fine tuning platform, 6-second feeding amount controller, 7-first fine tuning platform, 8-first feeding amount controller, 09-coating adhesive material drop and 9-coating point;

21-transfer bumps, 211-transfer end faces, 2101-connection mounts, 2102-transfer bosses.

Detailed Description

As described in the background art, the present inventors have initially studied a production method for a non-full-coverage type coated separator, which can form a local coating structure having a uniform size and flatness on the separator, but can only form a thin liquid film layer (for example, a coating film having a thickness of 5 μm or less), and cannot satisfy the production requirements for a thick coating film (for example, a coating film having a thickness of 10 μm or more).

Therefore, after repeated experiments and intensive research, the inventor of the present application finds that the initially researched preparation scheme of the non-full-coverage type coating diaphragm mainly refers to the technical concept in the printing technology, and in order to ensure that a size-controllable liquid film layer is formed on the transfer surface of the salient point 021 on the relief roller 02 in the center of the transfer process, the area of the transfer surface of the salient point 021 is far larger than the area of the concave hole or the groove 011 on the anilox roller 01, namely the area of the transfer surface of the salient point 021 is far larger than the area of the liquid film layer formed in the concave hole or the groove 011 on the anilox roller 01. However, the present inventors have recognized that this should be an important reason why this production scheme leads to difficulty in forming a coating film having a relatively thick thickness, and refer specifically to the following.

FIGS. 2-3 are schematic illustrations of the development of a process for producing thinner and thicker coating layers, respectively. As shown in fig. 2, when the salient point 021 is used for coating the coating material glue drop, only a small amount of coating material can be obtained through the salient point 021, the area of the coating material glue drop is consistent with the size of the transfer surface of the salient point 021, so that only a coating layer 05 with the thickness of less than 10 μm can be formed on the diaphragm 04; as shown in fig. 3, since the liquid film layer is transferred from the letterpress roll 02 to the membrane 04 by pressing, the liquid film layer is flattened during the transfer process, and particularly when the thickness of the liquid film layer is large, for example, more than 5 μm, the coating layer 05 with a concave middle portion as shown in fig. 3 is formed on the membrane 04, and the thickness is very difficult to control or even impossible to form.

It should be noted that the above dispensing solution is not a prior art, but a specific implementation manner in the process of development by the inventor of the present application, and therefore, it is unlikely that those skilled in the art will recognize the existence of the above technical problem, i.e., the finding of the above technical problem is not obvious to those skilled in the art.

As analyzed above, in the initially developed preparation scheme of the non-full-coverage coating diaphragm, in the coating process, on one hand, because the area of the salient points on the relief printing roller is far larger than the area of the concave holes or the grooves on the anilox roller, the salient points can only contact with the anilox roller to obtain the coating on the anilox roller, and the salient points cannot pick the coating glue drops with larger volume, only a thin liquid film layer can be formed during spot coating; on the other hand, even if the coating amount is increased by changing the gravure roll (anilox roll), it is difficult to ensure a certain thickness by transferring the coating dots (or "coating dots") from the letterpress roll to the separator by imprinting.

To this end, the inventor of the present application has proposed a solution to the above-mentioned problems by changing the form of the bumps on the relief roll so that the bumps can be inserted into the grooves of the gravure roll (anilox roll) to obtain more glue, and by dropping the coating glue on the bumps on the coating film, the coating dots constituting the coating film are formed on the coating film mainly by the tension difference formed by the coating glue on the different materials.

In addition, aiming at the problems that different types of diaphragms require different liquid film thicknesses, and the prior art can only adjust the spot coating thickness by replacing different versions of gravure rollers, so that the cost is high, the operation is complicated, and the time is wasted, the inventor of the application further provides that the adjustment and control on the thickness and the shape of a glue material point formed by coating a glue material drop on a coating film can be realized by adjusting the feeding amount of a convex point on a relief roller inserted into a groove of a gravure roller (anilox roller) and adjusting the distance between the gravure roller and the coating film.

The embodiment of the utility model provides an use the point of preparing lithium battery diaphragm to glue the coating and explain as the example, and the field of the art personnel can understand, the utility model discloses a coating equipment is glued to point and coating method is not only applicable to lithium battery diaphragm's preparation, also can be applicable to the preparation of relevant rete in other trades (for example ventilated membrane and the manufacturing field of non-woven fabrics in the health packaging trade and the manufacturing field of the protection film in the electronics trade) equally.

As shown in fig. 4, the dispensing and coating device provided by the embodiment of the present invention includes an anilox roller 1 (a glue material containing device), a relief printing roller 2, a feeding amount controller (not shown in the figure), and a flat bottom roller 3, wherein the relief printing roller 2 is located between the anilox roller 1 and the flat bottom roller 3, the flat bottom roller 3 is located at the lower side of the relief printing roller 2, and a film penetrating gap 31 for a coating film 4 to pass through is provided between the flat bottom roller 3 and the relief printing roller 2. Wherein, the roll surface of the anilox roll 1 is provided with a material accommodating groove 11 for accommodating sizing material for coating. The material containing grooves 11 are circular grooves and are uniformly distributed on the surface of the anilox roller 1. When the coating compound is applied to the roll surface of the anilox roll 1, excess coating compound on the roll surface of the anilox roll 1 can be removed by squeezing or scraping, and a liquid film layer (not shown) with uniform thickness is formed in the mesh holes. The roll surface of the relief plate roll 2 is provided with a transfer bump 21, and at the position where the relief plate roll 2 contacts with the anilox roll 1, the transfer bump 21 is inserted into the material accommodating groove 11 at the corresponding position on the anilox roll 1. When the coating gum material is applied to the roll surface of the anilox roll 1 in this way, the gravure roll 2 is inserted into the receiving groove 11 by the transfer bumps 21 when rotating in the opposite direction to the anilox roll, and the coating gum material in the receiving groove 11 is carried out, and spherical or ellipsoidal coating gum material drops 09 are formed at the transfer end surfaces 211 of the transfer bumps 21. Preferably, when the transfer bump 21 on the relief roller 2 is inserted into the material accommodating groove 11 on the anilox roller 1 to transfer the sizing material for coating, the distance L between the transfer end surface 211 of the transfer bump 21 and the groove bottom of the material accommodating groove 11 ranges from 20 to 250 μm. Therefore, use the utility model discloses when coating formation non-comprehensive coverage's coating layer is glued to lithium cell diaphragm point coating unit on the coating film, the accessible adjustment shifts the degree of depth that bump 21 inserted into holding in the material recess 11 and shifts the transfer terminal surface 211 of bump 21 promptly and holds the value of the interval L between the tank bottom of material recess 11 and adjust the height that shifts coating adhesive droplet 09 that forms on bump 21, this height that coats adhesive droplet 09 indicates that coating adhesive droplet 09 is along shifting the central axis direction of bump 21 the farthest distance of transfer terminal surface 211 of bump 21 to the vertical distance that shifts terminal surface 211, thereby can adjust the thickness of the coating layer that the coating formed according to coating adhesive droplet 09, and then make things convenient for coating operating personnel to control the thickness of the coating layer that the coating formed.

Fig. 5 is a dispensing coating control device included in the dispensing coating device, which mainly includes: the first fine-tuning platform 7, the first feeding quantity controller 8, the second fine-tuning platform 5, the second feeding quantity controller 6, the abrasion detection device (not shown in the figure) and the first and second driving control devices (not shown in the figure), wherein the second driving control device is suitable for controlling and driving the gravure roll 1 and the letterpress roll 2 to rotate reversely, so that the transfer salient points 21 are sequentially inserted into the material accommodating groove 11, and the coating rubber material in the material accommodating groove 11 is taken out to form a coating rubber material droplet 09 coated on the transfer end face 211 of the transfer salient points; the second feeding amount controller 6 is suitable for detecting the feeding amount of the transfer salient points 21 inserted into the material accommodating groove 11 suitable for accommodating the sizing material for coating, controlling the second fine adjustment platform 5 to adjust the feeding amount according to the coating requirement, displaying and storing the numerical value of the adjusted feeding amount by a second display and storage device (not shown in the figure), and enabling the form of the coating sizing material drops 09 to correspond to the adjusted feeding amount; the material containing groove 11 is arranged on a gravure roller 1 contained in the dispensing coating device, the gravure roller 1 is arranged on the second fine tuning platform 5, and the feeding quantity controller comprises a displacement sensor and a grating ruler. The relief printing roller 2 included in the dispensing coating device is arranged on the first fine adjustment platform 7; the abrasion detection device detects an abrasion value of the transfer bump 21 and sends the abrasion value to the first feeding quantity controller 8, the first feeding quantity controller 8 is suitable for detecting the distance between the transfer bump 21 on the raised plate roller 2 and the plane bottom roller 3 and controlling the first fine tuning platform 7 to move according to the coating requirement and the abrasion degree so as to adjust the distance between the transfer bump 21 on the raised plate roller 2 and the plane bottom roller 3, and a first display and storage device (not shown in the figure) displays and stores the numerical value of the adjusted distance; the first driving control device is suitable for controlling the driving plane bottom roller 3 to rotate reversely relative to the gravure roller 2 to drive the coating film 4 to move, so that the coating adhesive droplets 09 coated on the transfer end surfaces 211 of the transfer bumps 21 are dripped on the coating film 4 under the action of tension difference to form coating points 9 on the coating film 4; the shape of the coating points 9 corresponds to the adjusted distance between the transfer bumps 21 and the plane bottom roller 3, and the shape of the coating points 9 comprises at least one of the diameter and the height.

It should be noted that, because the salient points of the embossing roller are used for a long time, the diameter of the salient points can be increased, the effect of the coated diaphragm is affected, and if the embossing roller needs to be replaced to a certain extent due to abrasion, the cost is increased. In the embodiment, the abrasion degree of the transfer salient points is detected, and the first fine adjustment platform is controlled to move according to the coating requirement and the abrasion degree so as to adjust the distance between the transfer salient points on the relief printing roller and the plane bottom roller, so that the form of the coating points formed on the coating film can still keep the expected effect, and the problem of cost increase caused by the fact that the transfer salient points on the relief printing roller need to be replaced due to deviation caused by abrasion in the prior art is solved.

The specific process of coating the coating film by using the dispensing coating control device to form the coating layer comprises the following steps:

firstly, driving the gravure roller 1 and the relief roller 2 to rotate reversely, so that the transfer bumps 21 are sequentially inserted into the material accommodating groove 11, taking out the coating rubber material in the material accommodating groove 11, and forming coating rubber material drops 09 coated on the transfer end surfaces 211 of the transfer bumps 21 due to different gluing viscosities and tension differences;

secondly, detecting and adjusting the feeding amount of the transfer salient points 21 inserted into the material containing grooves 11 suitable for containing the sizing materials for coating according to the coating requirements, displaying and storing the numerical value A of the adjusted feeding amount, wherein the diameter and the height of the coating sizing material drops 09 correspond to the adjusted feeding amount, and the material containing grooves 11 are arranged on the gravure roll 1 contained in the dispensing and coating device;

finally, detecting the abrasion value of the transfer salient point 21, detecting and adjusting the distance between the transfer salient point 21 on the embossing roller 2 and the plane bottom roller 3 included in the spot gluing device according to the coating requirement and the abrasion value, and displaying and storing the numerical value B of the adjusted distance; coating the coating adhesive drops 09 coated on the transfer end faces 211 of the transfer salient points 21 on the coating film 4 through the action of tension difference, so as to form first coating adhesive drops with the height of 1-50 mu m and the diameter of 50-1000 mu m on the coating film 4; the diameter and height of the coating spots 9 correspond to the adjusted pitch of the transfer bumps 21 and the planar base roll 3.

As shown in fig. 6, 7 and 8, the transfer bump 21 may be a bus bar concave tapered platform structure, a bus bar convex tapered platform structure, a tapered platform structure or a step platform structure. Preferably, the transfer end surface 211 of the transfer bump 21 is a circular surface, and the diameter d2 of the transfer end surface 211 ranges from 20 μm to 1mm. Therefore, use the utility model discloses coating device is glued to lithium cell diaphragm point when coating on the coating film and forming the coating layer of non-comprehensive coverage formula, can avoid influencing the transfer of sizing material for the coating because of the transfer terminal surface 211 undersize or too big that shift bump 21 makes things convenient for the transfer of sizing material for the coating on anilox roller 1. When the transfer bump 21 has a step structure, the transfer bump 21 includes a connection base 2101 and a transfer boss 2102, and the cross-sectional area of the transfer boss 2102 is smaller than that of the connection base 2101. In this way, the cross-sectional area of the transfer bump 21 at the transfer end surface 211 is small, and the cross-sectional area of the transfer end surface 211 is smallest compared to the cross-sectional area of other portions on the transfer bump 21, so that the transfer bump is inserted into the receiving groove 11 when contacting the anilox roll 1 to transfer the coating compound on the anilox roll 1. Preferably, the transfer boss 2102 is of a cylindrical structure, and the height h1 of the cylindrical structure is less than or equal to 200

Mum, and the ratio N of the height h1 to the diameter d2 of the cylindrical structure is less than or equal to 2.5, the connecting base 2101 is a tapered table structure, thus, the ratio N of the height h1 to the diameter d2 of the transfer boss 2102 which is set into the cylindrical structure is less than or equal to 2.5, which can prevent the transfer bump 21 from influencing the transfer effect due to the excessively long and thin transfer boss 2102 in the process of transferring the glue stock, and further influencing the later coating effect; in addition, the connection base 2101 is arranged in a tapered platform-shaped structure, which not only can effectively support the transfer boss 2102, but also is convenient to manufacture. The feeding amount controller is used for detecting and modulating the distance between the control embossing roller 2 and the anilox roller 1, and further adjusting and controlling the feeding amount of the transfer salient points 21 on the embossing roller 2 inserted into the material accommodating grooves 11 on the anilox roller 1. Preferably, the feed amount controller is optionally a grating ruler. Like this, select the grating chi for use as the feed volume controller, installation and easy operation, and detect control accuracy height, make things convenient for coating operating personnel to control the thickness of the coating layer of coating formation. Preferably, the ratio Q of the inner diameter d1 of the material containing groove 11 on the anilox roller 1 to the end surface diameter d2 of the transfer end of the transfer bump 21 on the relief roller 2 is more than or equal to 150%. In this way, the end area of the transfer end of the transfer bump 21 is far smaller than the cross-sectional area of the material containing groove 11, so that the transfer end of the transfer bump 21 can be inserted into the material containing groove 11 of the anilox roll 1, the coating adhesive is attached to the transfer end of the transfer bump by the tension of the coating adhesive and forms a spherical or ellipsoidal coating adhesive droplet 09, the coating adhesive droplet 09 does not extrude a coating film in the transfer process, the coating adhesive droplet 09 is dripped on the coating film mainly through the tension difference of the coating adhesive droplet 09 on different materials, and then the thickness of the coating layer formed by coating can be adjusted by adjusting the tension of the coating adhesive and the size of the coating adhesive droplet 09, which is simple and convenient.

In addition, the embodiment of the utility model provides an use some glue coating methods and coat the concrete process when forming the coating layer on the coating film:

firstly, a sizing material for coating is coated in the material containing grooves 11 on the roll surface of the anilox roll 1, and a liquid film layer with uniform thickness is formed in the material containing grooves 11 on the anilox roll 1. Preferably, the coating sizing material on the roll surface of the anilox roll 1 can be extruded or scraped by a roller or a scraper to form a uniform liquid film layer in the meshes, and when the roller is adopted, the roller is close to the roll surface of the anilox roll 1 and is in contact with the coating sizing material on the roll surface of the anilox roll 1 to extrude and remove the excessive coating sizing material to form a liquid film layer with uniform thickness in the meshes of the anilox roll 1 in the rotating process of the anilox roll 1; when a scraper is adopted, the scraper is close to the roll surface of the anilox roll 1, and in the rotating process of the anilox roll 1, the scraper scrapes the coating sizing material on the roll surface of the anilox roll 1 to remove the redundant coating sizing material to form a liquid film layer with uniform thickness in meshes of the anilox roll 1. Similarly, the anilox roller can be changed into a smooth roller or a roughened roller with larger surface adhesion, the thickness of the liquid film layer formed by coating can be adjusted by adjusting the distance between the roller or the scraper and the smooth roller or the roughened roller with larger surface adhesion according to the requirement, and the operation is simple and convenient.

Then, according to the coating requirements, the feed amount of the transfer bumps 21 on the embossing roller 2 inserted into the material accommodating grooves 11 on the anilox roller 1 is adjusted by using a feed amount controller, namely, the value of the distance L between the transfer end surfaces 211 of the transfer bumps 21 and the groove bottoms of the material accommodating grooves 11 is adjusted, and a driving device such as a driving motor is used for driving the anilox roller 1 and the letterpress roller 2 to rotate reversely, so that the transfer bumps 21 on the letterpress roller 2 are sequentially inserted into the material accommodating grooves 11 on the anilox roller 1 and the coating rubber in the material accommodating grooves 11 is taken out, and coating rubber drops 09 coated on the transfer end surfaces 211 of the transfer bumps 21 are formed;

finally, the planar bottom roller 3 is driven by the driving device to rotate reversely relative to the relief roller 2, so as to drive the coating film 4 located in the film penetrating gap 31 to move along the direction k, so that the coating adhesive drops 09 on the transfer bumps 21 on the relief roller 2 are coated on the coating film 4, and coating points forming a non-full-coverage coating layer are formed on the coating film 4. As shown in fig. 8, when the transfer bumps 21 on the gravure roll 2 have a tapered mesa structure with a concave bus, the coating dots 9 are formed in a semi-ellipsoidal shape on the coating film 4.

When the coating film is coated with the above-mentioned dispensing coating device to form a coating layer, a coating adhesive having a viscosity in a range of 300 pas to 15000 pas at normal temperature is preferred. Thus, when the sizing material for transfer coating is used, coating sizing material drops with the height ranging from 1 mu m to 50 mu m and the diameter ranging from 50 mu m to 1000 mu m can be formed on the transfer salient points, thereby meeting the requirement of coating and forming a coating layer with larger thickness.

Fig. 9 is a schematic view of a coating layer prepared when the dispensing and coating device of the embodiment of the present invention is used and the transfer bump is a tapered platform structure with a bus recessed inwards. As can be seen from fig. 9, the transfer bump hardly contacts the separator (coating film), but the transfer of the second dope droplet 09 is achieved mainly by the difference in tension, the first dope droplet 9 is formed on the separator, and the morphology of the formed first dope droplet 9 appears as an approximately spherical or ellipsoidal droplet.

Table 1 shows the comparison of the parameters of the diaphragm produced by the prior art and the diaphragm produced by the method, wherein the island-shaped sprayed film is produced by the fourth generation of rotary spraying, and the roller-coated shrinkage film is produced by the third generation of full-coating shrinkage; wherein each parameter represents a meaning: 1. the smaller the area density is, the more material is saved; 2. the higher the puncture strength, the better the strength, and the safer the battery; 3. the larger the conductivity value is, the faster the charging and discharging speed is; 4. the smaller the surface resistance value is, the smoother the lithium ion penetration is; 5. air permeability value: the shorter the time taken for a unit volume of gas to pass through the membrane at the site location area, the smoother the description.

Table 2 shows a comparison of the two spot coating techniques.

TABLE 1

Parameter(s)	Uniform spot coating film (this example)	Roller-coated shrink film	Island-shaped spray coating film
				Areal density (g/m 2)	15.01	15.85	17.15
Puncture strength (N)	7.43	6.95	7.2
				Ion conductivity (S/cm)	12.7*10-4	8.7*10-4	9.1*10-4
Surface resistance (omega)	1.71	2.36	3.23
				Air permeability value(s)	235	333	286

TABLE 2

Claims (10)

1. The lithium battery diaphragm dispensing and coating device is characterized by comprising a coating transfer device, wherein the coating transfer device comprises a sizing material accommodating device and a relief printing roller (2), a sizing material accommodating groove (11) for accommodating sizing materials is formed in the sizing material accommodating device, transfer salient points (21) are arranged on the roller surface of the relief printing roller (2), the transfer salient points (21) are suitable for being inserted into the sizing material accommodating groove (11) in the corresponding position on the sizing material accommodating device to transfer diaphragm coating, coating glue drops coated on a transfer end surface (211) of the transfer salient points (21) are formed by the diaphragm coating, and a planar bottom roller (3) reversely rotates relative to the sizing material accommodating device to drive a coating film (4) to move, so that the coating glue drops on the transfer salient points (21) are coated on the coating film (4) and form a non-full-coverage coating layer on the coating film (4).

2. The dispensing and coating device for the lithium battery diaphragm is characterized by further comprising a feeding amount controller and a plane bottom roller (3), wherein the plane bottom roller (3) is positioned at the lower side of the coating transfer device, a film penetrating gap (31) for a coating film (4) to pass through is arranged between the plane bottom roller (3) and the coating transfer device, and the feeding amount controller is used for detecting and adjusting and controlling the feeding amount of the transfer bumps (21) on the bump roller (2) inserted into the material containing grooves (11) in the material containing device.

3. The dispensing and coating device for the lithium battery diaphragm is characterized by further comprising a coating device, wherein the coating device is abutted against the glue material containing device, so that the coating forms a liquid film layer with uniform thickness on the surface of the glue material containing device.

4. The dispensing and coating device for the lithium battery diaphragm according to claim 3, wherein the coating device comprises a roller or a scraper which respectively presses or scrapes the glue containing device.

5. The dispensing and coating device for lithium battery separators according to claim 1, wherein the glue containing device comprises an anilox roller (1), a texturing roller or a smooth roller.

6. The dispensing and coating device for the lithium battery diaphragm is characterized in that the ratio Q of the inner diameter d1 of the material containing groove (11) to the diameter d2 of the transfer end surface (211) of the transfer bump (21) is more than or equal to 1.5.

7. The dispensing and coating device for the lithium battery diaphragm is characterized in that the transfer end surface (211) of the transfer bump (21) is a circular surface, the diameter d2 of the transfer end surface (211) ranges from 20 μm to 1mm, and when the transfer bump (21) is inserted into the material containing groove (11), the distance L between the transfer end surface (211) and the groove bottom of the material containing groove (11) ranges from 20 μm to 250 μm.

8. The dispensing and coating device for the lithium battery diaphragm as recited in claim 7, wherein the transfer bumps (21) are of a bus-concave conical platform structure, a bus-convex conical platform structure, a conical platform structure or a step platform structure.

9. The dispensing and coating device for the lithium battery diaphragm is characterized in that the stepped platform structure comprises a connecting base (2101) and a transfer boss (2102), the cross-sectional area of the transfer boss (2102) is smaller than that of the connecting base (2101), the transfer boss (2102) is of a cylindrical structure, the connecting base (2101) is of a conical platform-shaped structure, the height h1 of the cylindrical structure is less than or equal to 200 microns, and the ratio N of the height h1 of the cylindrical structure to the diameter d2 of the transfer end face is less than or equal to 2.5.

10. The lithium battery diaphragm dispensing and coating device of any one of claims 2-4, wherein the feed amount controller comprises a grating ruler.

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