Coating back roller and pole piece preparation system

Abstract

The utility model provides a coating back roller and a pole piece preparation system. The coating back roller comprises a back roller body, the back roller body comprises a first die area roller section, a second die area roller section and a third die area roller section which are arranged in the axial direction, the radial size of the third die area roller section is larger than that of the first die area roller section, and the second die area roller section is connected with the first die area roller section and the third die area roller section; and the radial size from the first die area roller section to the third die area roller section is gradually increased. According to the coating back roller disclosed by the embodiment of the invention, the radial size of the third mold area roller section is larger than that of the first mold area roller section, and the radial size of the second mold area roller section is gradually increased from the first mold area roller section to the third mold area roller section, so that a prepared pole piece automatically forms a shape with a thick middle part and a thin edge, and the influence caused by a thick edge effect is relieved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a coating back roller and a pole piece preparation system. Background Art

[0002] In the field of batteries, the slurry coating method is generally used to prepare the battery pole piece. Due to surface tension, the slurry will migrate to the uncoated area at the edge of the slurry layer. Therefore, after the pole piece is dried, the migrated slurry will make the edge thickness of the slurry layer greater than the middle area. This phenomenon in the pole piece manufacturing process is generally called the "thick edge effect".

[0003] During the rolling process of the pole piece, the thick edge effect will cause stress concentration at the edge of the slurry layer, affecting the service life and safety of the battery. Secondly, the pole piece with the thick edge effect defect will show serious warping after rolling and pressing, which will also affect the subsequent slitting and winding process of the pole piece. In addition, the thick edge effect will also cause the cathode capacity at the edge of the prepared lithium-ion battery to exceed the specification after the cathode pole piece is assembled into a battery cell. During the charging process, the anode area corresponding to the edge of the cathode mold area is prone to lithium deposition.

[0004] In order to eliminate the "thick edge effect", an external thinning device is generally provided to thin the slurry layer at the edge of the pole piece. Utility Model Content

[0005] In view of the above problems, the present application provides a coating back roller and a pole piece preparation system to alleviate the thick edge effect phenomenon produced during the pole piece manufacturing process.

[0006] In a first aspect, the present application provides a coating back roller, comprising: a back roller main body, comprising a first mold area roller segment, a second mold area roller segment and a third mold area roller segment arranged along the axial direction, wherein the radial dimension of the third mold area roller segment is greater than the radial dimension of the first mold area roller segment, the second mold area roller segment connects the first mold area roller segment and the third mold area roller segment, and the radial dimension gradually increases from the first mold area roller segment to the third mold area roller segment.

[0007] In the technical solution of the embodiment of the present application, the back roller body of the coating back roller includes a first mold area roller segment, a second mold area roller segment and a third mold area roller segment, the second mold area roller segment connects the first mold area roller segment and the third mold area roller segment, and the radial dimension of the third mold area roller segment is set to be greater than the radial dimension of the first mold area roller segment, and the radial dimension of the second mold area roller segment gradually increases from the first mold area roller segment to the third mold area roller segment. Such a design makes it possible that when the pole piece is prepared, the thickness of the pole piece portion corresponding to the second mold area roller segment is less than the thickness of the pole piece portion on the first mold area roller segment, and the thickness of the pole piece prepared on the second mold area roller segment gradually decreases from the first mold area roller segment to the third mold area roller segment, thereby realizing the thinning of the thickness of the edge of the pole piece, which is beneficial to reduce the influence of the thick edge effect on the quality of the pole piece. The coating back roller of the present application enables the prepared pole piece to automatically form a morphology with a thick middle and thin edges. This setting can reduce the external thinning device, which is beneficial to improve production efficiency and reduce costs.

[0008] In some embodiments, the coating backing roll further includes an adjustment device configured to change a size of at least one of the first die land roll segment, the second die land roll segment, and the third die land roll segment.

[0009] By setting an adjustment device to change the size of at least one of the first mold area roller segment, the second mold area roller segment and the third mold area roller segment, the thickness and width of the pole piece corresponding to each roller segment can be adjusted to adapt to different production requirements and improve the flexibility and controllability of pole piece preparation.

[0010] In some embodiments, the adjustment device is disposed inside the backing roller body.

[0011] The arrangement of the adjusting device inside the back roller body makes the coating back roller structure compact and isolates the adjusting device from the external environment, thereby extending the service life of the adjusting device; the adjusting device and the pole piece are separated by the back roller body, which coordinates the adjusting movement of the adjusting device and the transmission of the pole piece on the coating back roller, so that the two do not interfere with each other and save space.

[0012] In some embodiments, the adjustment device is drivingly connected to at least one of the first mold area roll segment, the second mold area roll segment, and the third mold area roll segment, and is configured to drive at least one of the first mold area roll segment, the second mold area roll segment, and the third mold area roll segment to displace and / or deform relative to other mold area roll segments to change the size of at least one of the first mold area roll segment, the second mold area roll segment, and the third mold area roll segment.

[0013] The adjustment device is drivingly connected to at least one of the first mold area roller segment, the second mold area roller segment and the third mold area roller segment to change the size of at least one of the first mold area roller segment, the second mold area roller segment and the third mold area roller segment, which is conducive to achieving precise control of electrode preparation, improving the flexibility and compatibility of coating back rollers to prepare electrode sheets, and reducing the cost of replacing the entire coating back roller due to different production needs.

[0014] In some embodiments, the adjustment device includes: a first adjustment portion, the first adjustment portion is configured to drive the first mold area roller segment to move along the axial direction; and / or a second adjustment portion, the second adjustment portion is configured to drive at least one of the second mold area roller segment and the third mold area roller segment to deform.

[0015] The first adjustment part and / or the second adjustment part can facilitate flexible control of the sizes of the first mold area roller segment, the second mold area roller segment and the third mold area roller segment. Adjusting the axial movement of the first mold area roller segment can mainly change the width size of the prepared pole piece. Adjusting the deformation of at least one of the second mold area roller segment and the third mold area roller segment can mainly change the thickness size of the thinning area of ​​the prepared pole piece corresponding to the second mold area roller segment 112.

[0016] In some embodiments, the adjustment device includes the first adjustment part, which includes a screw, which is threadedly connected to the end face of the first mold area roller segment, and the screw is configured to be rotatably arranged around the axis of the coating back roller to drive the first mold area roller segment to move by changing the matching position of the screw and the first mold area roller segment.

[0017] The first die zone roller segment is driven by a screw, and the structure is stable and easy to adjust and assemble and disassemble.

[0018] In some embodiments, the back roller body includes a deformable sleeve for forming the surface of the second mold area roller segment and the surface of the third mold area roller segment, and the deformable sleeve is connected to the first mold area roller segment; the adjustment device includes the second adjustment part, and the second adjustment part includes: a plurality of support plates, the plurality of support plates are evenly distributed on the radial inner side of the second mold area roller segment along the circumference of the coating back roller and form an annular structure as a whole to support the deformable sleeve, one end of the plurality of support plates is connected to the end surface of the first mold area roller segment close to the second mold area roller segment; and a support plate position adjustment mechanism, which is drivingly connected to each of the support plates and is configured to change the spacing of the plurality of support plates away from one end of the first mold area roller segment so that the deformable sleeve follows the plurality of support plates to deform.

[0019] A plurality of support plates and a support plate position adjustment mechanism are provided to drive the support plates so as to change the interval between the plurality of support plates at one end away from the first mold area roller segment. When the interval becomes larger, the radial dimension of the second mold area roller segment is increased, and when the interval becomes smaller, the radial dimension of the second mold area roller segment is decreased. The deformable sleeve is synchronously contracted or expanded according to the change in the interval size of the support plates, so that the change in the radial dimension of the second mold area roller segment of the coating back roller is continuous and accurate. The deformable sleeve supports the current collector film, so as to improve the flatness of the current collector film when supported on the deformable sleeve.

[0020] In some embodiments, the support plate position adjustment mechanism includes: a moving member, movably arranged along the axial direction; a rotating member, a first end of the rotating member is hinged to the moving member, and a second end of the rotating member is hinged to the support plate, and the support plate position adjustment mechanism is configured to change the spacing of one end of the multiple support plates away from the first mold area roller segment by driving the rotating member to rotate through the movement of the moving member.

[0021] The movable member translates to drive the rotating member to rotate relative to the movable member, and causes the support plate to rotate around the connection with the first mold area roller segment, thereby changing the spacing of multiple support plates away from one end of the first mold area roller segment. This design simplifies complex movements and changes complex radial dimensional changes by controlling linear movement, thereby facilitating precise adjustment of the support plate spacing, thereby facilitating precise adjustment of the radial dimensions of the second mold area roller segment.

[0022] In some embodiments, a plurality of support plates are formed into a truncated cone structure when there is no interval along the circumferential direction. The truncated cone structure makes the radial dimension of the coating back roller evenly increase from the first mold area roller segment to the third mold area roller segment, which is conducive to making the outer surface of the second mold area roller segment closer to a truncated cone shape, and is conducive to improving the uniformity of the slurry coating of the pole piece corresponding to the second mold area roller segment along the length direction of the pole piece.

[0023] In some embodiments, the backing roller body includes a plurality of the first mold area roller segments, and the second mold area roller segment and the third mold area roller segment are respectively disposed at two ends of each of the first mold area roller segments.

[0024] By setting up multiple first mold area roller segments, multiple pole pieces arranged along the axial direction of the coating back roller can be produced at one time to improve the output and production efficiency; the second mold area roller segment and the third mold area roller segment are respectively set at both ends of the first mold area roller segment to simultaneously perform thinning processing on both ends of the pole piece, and a pole ear area for forming the pole ear of the electrode can be formed at the position corresponding to the third mold area roller segment.

[0025] In some embodiments, one third mold zone roller segment is included between two adjacent first mold zone roller segments, and the third mold zone roller segment is configured to have an axial dimension greater than or equal to twice the height of the pole lug of the pole piece.

[0026] The pole ear areas corresponding to the pole ears of the pole pieces on both sides are formed by the same third mold area roller segment. This design can shorten the axial size of the coating back roller and effectively utilize the axial space.

[0027] In some embodiments, an outer surface of a connection between the second mold area roller segment and the first mold area roller segment forms a transition fillet; and / or an outer surface of a connection between the second mold area roller segment and the third mold area roller segment forms a transition fillet.

[0028] The second mold area roller segment is connected to the first mold area roller segment and / or the third mold area roller segment through a transition fillet, so that a smooth transition can be achieved at the boundary, which helps to prevent the pole piece from being scratched and causing the belt to break.

[0029] In some embodiments, the coating back roller further includes a core rod extending in the axial direction, the core rod is located in the second mold area roller segment and the third mold area roller segment, and the adjustment device is installed on the core rod.

[0030] Providing a core rod and installing the adjusting device on the core rod can enable the adjusting device to be stably installed inside the back roller body, which is beneficial for the adjusting device to stably and accurately adjust the size of each mold area roller segment.

[0031] In some embodiments, the adjustment device includes a first adjustment portion, which is configured to drive the first mold area roller segment to move along the axial direction relative to the core rod; the coating back roller also includes a guide portion, which is configured to guide the movement direction of the first mold area roller segment relative to the core rod and / or limit the first mold area roller segment to rotate around its own axis relative to the core rod.

[0032] The coating back roller includes a guide portion, which is conducive to limiting the movement direction and / or movement range of the first mold area roller segment relative to the second mold area roller segment and the third mold area roller segment when driving the first mold area roller segment to move, and is conducive to maintaining the overall structure of the coating back roller from undesirable deformation due to the movement of the first mold area roller segment.

[0033] In some embodiments, the guide portion includes: a first guide structure, which is arranged on one of the core rod and the first mold area roller segment; and a second guide structure, which is arranged on the other of the core rod and the first mold area roller segment, the first guide structure and the second guide structure are slidably matched along the axial direction, and / or the first guide structure and the second guide structure are matched without relative rotation along the circumference of the coating back roller.

[0034] The first guide structure and the second guide structure of the guide part are respectively arranged on the core rod and the first mold area roller segment, which can reduce the number of parts used to form the guide part and / or reduce the space occupied by the guide part on the basis of realizing the guiding and / or limiting functions.

[0035] The second aspect of the present application provides a pole piece preparation system, which includes the coating back roller in the above embodiment, the coating back roller is used to carry and convey the current collector film of the pole piece, so that the current collector film is attached to the outer surfaces of the first mold area roller segment, the second mold area roller segment and the third mold area roller segment adjacent to the back roller body to produce deformation; and

[0036] A coating die head, comprising a slurry outlet opposite to the first mold area roll segment and the second mold area roll segment of the coating back roller, is configured to coat the slurry for forming a coating layer on the collector film of the back roller body through the slurry outlet, so that the coating die head coats the slurry with normal thickness at the position of the collector film corresponding to the first mold area roll segment, coats the slurry with gradually reduced thickness at the position of the collector film corresponding to the second mold area roll segment, and does not coat the slurry at the position of the collector film corresponding to the third mold area roll segment.

[0037] This design causes the current collector film to deform in the thickness direction on the coating back roller, and be covered by the coated slurry at the positions corresponding to the first mold area roller segment and the second mold area roller segment, forming a coating layer with a large middle thickness and a small edge thickness in the area where the pole piece is formed on the current collector film; the radial dimension of the second mold area roller segment of the back roller body gradually increases in the direction extending toward the third mold area roller segment, so that the thickness of the coating layer corresponding to the second mold area roller segment gradually decreases, achieving the effect of thinning the edge of the pole piece.

[0038] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure. In the drawings:

[0040] Figure 1 This is a schematic diagram of the structure of the coating backing roller of some embodiments of the present application;

[0041] Figure 2 It is a schematic diagram of a partial cross-sectional structure of a coating backing roller along the axial direction in some embodiments of the present application, wherein an adjustment device is shown;

[0042] Figure 3 This is a schematic diagram of the structure of a support plate in a coating backing roller in some embodiments of the present application;

[0043] Figure 4 A schematic diagram of a partial structure of a pole piece preparation system according to some embodiments of the present application;

[0044] Figure 5 A schematic diagram of the process of preparing a pole piece in some embodiments of the present application;

[0045] Figure 6 This is a schematic diagram of the partial cross-sectional structure of the coating back roller along the axial direction of some embodiments of the present application, in which the guide portion is shown.

[0046] The reference numerals in the specific implementation manner are as follows:

[0047] 100. Coating back roller;

[0048] 110, back roller body, 111, first mold area roller segment, 111A, guide hole, 112, second mold area roller segment, 113, third mold area roller segment, 114, deformable sleeve;

[0049] 1211, screw rod, 1221, moving part, 1222, rotating part, 1223, supporting plate, first driving device M1, second driving device M2;

[0050] 130, core rod, 131, guide rod;

[0051] 300, coating die head, 310, gasket, 320, slurry outlet;

[0052] 400, slurry;

[0053] 500. Current collector film;

[0054] 600. Conveyor roller. DETAILED DESCRIPTION

[0055] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0057] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0058] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0059] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0060] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0061] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0062] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0063] The excellent high energy density and high power density of lithium-ion batteries give lithium-ion batteries longer battery life and stronger instantaneous output capacity, which meets the needs of electric vehicles, consumer electronics, energy storage systems and other fields. And driven by environmental protection policies, lithium-ion batteries shine in the new energy vehicle industry due to their low carbon emission characteristics, and their market share continues to grow, and market demand is also constantly expanding.

[0064] Lithium-ion batteries generally use a slurry coating method to prepare electrode sheets. The positive and negative electrode active materials (such as lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate or graphite, etc.) are mixed with a binder (such as polyvinylidene fluoride, PVDF, etc.) and a conductive agent (such as carbon black, etc.) in proportion and the above powdered materials are evenly dispersed and stirred into a slurry using a solvent to prepare a slurry. The prepared slurry is coated on the current collector film to form an electrode. The current collector film coated with the slurry is then dried in a drying oven or a hot air drying tunnel to form a firmly attached coating layer on the current collector.

[0065] In order to alleviate the "thick edge effect" problem in which the thickness of the edge of the coating layer after the electrode is dried is greater than the thickness of the middle area, this scheme designs a coating back roller with radial size differences in the surface area, and utilizes the physical properties that the surface of the current collector film can fit on the coating back roller and match the outer surface shape of the coating back roller, so that the current collector film is shaped into an inverted trapezoid with a low middle part and high two sides along the axial direction of the coating back roller corresponding to the position of the coating slurry before coating the slurry. When the current collector film is fitted to the coating back roller, the cross-section of the coating layer formed by the slurry along the axial direction of the coating back roller also presents an inverted trapezoidal cross-sectional shape at the beginning. Since the slurry on both sides of the coating layer is less than the slurry in the middle at the beginning, the coating layer along the axial direction A of the coating back roller presents a cross-sectional shape that is thick in the middle (that is, high in the middle) and thin on both sides (that is, low on both sides) after the current collector film is flattened, thereby finally achieving the effect of thinning the edge of the coating layer of the electrode.

[0066] The coating back roller is used for the preparation of pole pieces. The pole piece is a key component inside the battery and is divided into a positive pole piece and a negative pole piece. The positive pole piece is used to participate in the oxidation reaction during the discharge process, and the negative pole piece is used to participate in the reduction reaction during the charging process. Both the positive and negative pole pieces can be strip-shaped pole pieces. The pole piece is composed of a composite material (slurry 400 in this application) formed by mixing a current collector film (current collector film 500 in this application) with an active material, a conductive agent and a binder coated thereon. The composite material is used to form an electrode.

[0067] The electrode preparation system includes a coating back roller and a coating die. The coating back roller is used to carry and convey the current collector film of the electrode. The coating die is used to apply slurry to the current collector film, generally including a gasket protruding in the direction close to the coating back roller, and the slurry outlet is set between two adjacent gaskets. The slurry is output from the slurry outlet and coated on the current collector film.

[0068] According to some embodiments of the present application, a coating back roller 100 for preparing a pole piece is provided. The coating back roller 100 includes a back roller body 110. The back roller body 110 includes a first mold area roller segment 111, a second mold area roller segment 112, and a third mold area roller segment 113 arranged along the axial direction A. The radial dimension of the third mold area roller segment 113 is greater than the radial dimension of the first mold area roller segment 111. The second mold area roller segment 112 connects the first mold area roller segment 111 and the third mold area roller segment 113, and the radial dimension gradually increases from the first mold area roller segment 111 to the third mold area roller 13.

[0069] like Figure 1 As shown in , the axial direction A in the figure is the axial direction of the coating back roller 100.

[0070] The first mold area roller segment 111 and the third mold area roller segment 113 are both cylindrical in space. The second mold area roller segment 112 is a truncated cone in space.

[0071] The coating backing roller 100 may include a plurality of first die zone roller segments 111, such as Figure 1 The three first die zone roll segments 111 are shown; the coating backing roll 100 may also include only one first die zone roll segment 111 .

[0072] There may be a third die zone roller segment 1 between two adjacent first die zone roller segments 111. The total length of the coating backing roller 100 is not limited and can be comprehensively designed according to the production requirements and the size of the work site.

[0073] By setting the radial dimension of the third mold area roller segment 113 to be larger than the radial dimension of the first mold area roller segment 111, and setting the radial dimension of the second mold area roller segment 112 connecting the first mold area roller segment 111 and the third mold area roller segment 113 to gradually increase from the first mold area roller segment 111 to the third mold area roller segment 113, a spatial shape in which the coating layer of the slurry is thick in the middle and thin on both sides can be formed at the position corresponding to the slurry coating, which can effectively avoid the thick edge effect problem during slurry coating. This is extremely beneficial for the pole piece prepared by the slurry coating method.

[0074] According to some embodiments of the present application, the coating backing roller 100 may further include an adjusting device configured to change the size of at least one of the first die area roller segment 111 , the second die area roller segment 112 , and the third die area roller segment 113 .

[0075] It should be understood that the adjustment device of the coating backing roller 100 changes the size of at least one of the first mold zone roller segment 111, the second mold zone roller segment 112 and the third mold zone roller segment 113, for example, may include changing the width or radial size of at least one of the mold zone roller segments. For example, the adjustment device may change the radial size of the second mold zone roller segment 112, and simultaneously change the diameter of the third mold zone roller segment 113 without changing the width. For another example, the adjustment device may change the radial size of the second mold zone roller segment 112, and simultaneously change the diameter and width of the third mold zone roller segment 113. For another example, the adjustment device may only change the width of the second mold zone roller segment 112, or the adjustment device may only change the width of the third mold zone roller segment 113.

[0076] By providing an adjustment device to change the radial dimension or width of at least one of the first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113, the outer surface shape of the coating back roller 100 can be changed, thereby adjusting the thickness and width of the coating layer of the pole piece or a partial area of ​​the coating layer.

[0077] According to some embodiments of the present application, optionally, the adjustment device is disposed inside the back roller body 110 .

[0078] Further references Figure 2 The second mold area roller segment 112 and the third mold area roller segment 113 have cavities inside, and the adjustment device is arranged in the cavity.

[0079] The second mold area roller segment 112 and the third mold area roller segment 113 have cavities inside, and the adjustment device is arranged in the cavity, which is conducive to preventing the adjustment device from contacting the outside world, and preventing humid air or external impurities from entering the coating back roller 100 and damaging the adjustment device. The adjustment process of the adjustment device on at least one of the first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113 is completed inside the back roller body 110, and is independent of the coating process of the pole piece outside the back roller body 110, which is conducive to preventing the adjustment process of the adjustment device and the pole piece coating process from affecting each other.

[0080] According to some embodiments of the present application, optionally, the adjusting device is drivingly connected to at least one of the first mold area roller segment 111, the second mold area roller segment 112, and the third mold area roller segment 113. The adjusting device can drive at least one of the first mold area roller segment 111, the second mold area roller segment 112, and the third mold area roller segment 113 to displace and / or deform relative to other mold area roller segments to change the size of at least one of the first mold area roller segment 111, the second mold area roller segment 112, and the third mold area roller segment 113.

[0081] The adjustment device is drivingly connected to at least one of the first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113 to change the size of at least one of the first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113, which is conducive to achieving precise control of electrode preparation, improving the flexibility and compatibility of the coating back roller 100 in preparing electrode sheets, and reducing the cost of replacing the entire coating back roller 100 due to different production needs.

[0082] In some embodiments, the adjustment device can drive the first mold zone roller segment 111 to move relative to the third mold zone roller segment 113 and change the width of the third mold zone roller segment 113. Figure 1 The coating back roller 100 has a plurality of first mold area roller segments 111. Taking one of the third mold area roller segments 113 as a reference, the adjusting device drives the first mold area roller segment 111 located on the left side of the third mold area roller segment 113 to move leftward, and at the same time drives the first mold area roller segment 111 located on the right side of the third mold area roller segment 113 to move rightward, and maintains the second mold area roller segment 112 relative to the first mold area roller segment 111 to remain stationary. At this time, the width of the third mold area roller segment 113 increases.

[0083] In this application, the axial direction A and Figure 2 and Figure 6 The left and right directions correspond to the left and right directions of Figure 2 and Figure 6 The "left" and "right" shown in the figure are the same.

[0084] In some embodiments, the adjusting device can change the radial dimensions of the second mold zone roller segment 112 and the third mold zone roller segment 113. For example, the adjusting device increases the width and reduces the radial dimension of the second mold zone roller segment 112, while reducing the diameter of the third mold zone roller segment 113, thereby increasing the overall width and thickness of the thinned area corresponding to the second mold zone roller segment 112 of the coating layer formed by the coating slurry.

[0085] According to some embodiments of the present application, the adjusting device may include a first adjusting portion and a second adjusting portion. The first adjusting portion drives the first mold zone roller segment 111 to move along the axial direction A. The second adjusting portion drives at least one of the second mold zone roller segment 112 and the third mold zone roller segment 113 to deform.

[0086] The first adjustment portion and / or the second adjustment portion facilitates flexible control of the sizes of the first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113. Adjusting the movement of the first mold area roller segment 111 along the axial direction A can mainly change the width size of the prepared pole piece. Adjusting the deformation of at least one of the second mold area roller segment 112 and the third mold area roller segment 113 can mainly change the thickness size of the thinned area of ​​the prepared pole piece.

[0087] The deformation of the second mold zone roller segment 112 includes, for example: the width of the second mold zone roller segment 112 decreases and the diameter of the end surface close to the third mold zone roller segment 113 connected thereto increases; or, the width of the second mold zone roller segment 112 increases and the diameter of the end surface close to the third mold zone roller segment 113 connected thereto decreases. The deformation of the third mold zone roller segment includes, for example: the width of the third mold zone roller segment 113 increases or decreases, and the diameter of the third mold zone roller segment 113 changes. The second adjustment unit can drive the second mold zone roller segment 112 to deform; or, drive the third mold zone roller segment 113 to deform; or, drive the deformation of the second mold zone roller segment 112 and the third mold zone roller segment 113 at the same time.

[0088] According to some embodiments of the present application, optionally, the adjusting device includes a first adjusting portion. The first adjusting portion includes a screw 1211. The screw 1211 is threadedly connected to the end surface of the first mold area roller segment 111. The screw 1211 is configured to be rotatably arranged around the axis of the coating back roller 100 to drive the first mold area roller segment 111 to move by changing the matching position of the screw 1211 and the first mold area roller segment 111.

[0089] The first die zone roller segment 111 is driven by a screw rod, and the structure is stable and convenient for adjustment and assembly and disassembly.

[0090] A first driving device M1 may be provided to drive the screw rod 1211 to rotate. The first driving device M1 is, for example, a stepping motor.

[0091] Reference Figure 2 or Figure 6 When the coating backing roller 100 includes two first mold area roller segments 111, a first driving device M1 can be arranged between the two first mold area roller segments 111, and both ends of the first driving device M1 are respectively connected to a screw rod 1211. The first driving device M1 can simultaneously drive the screw rods 1211 at both ends to rotate, so as to drive the two first mold area roller segments 111 at both sides to move simultaneously in a direction away from the first driving device M1 or simultaneously move to a side close to the first driving device M1.

[0092] According to some embodiments of the present application, optionally, the back roller body 110 includes a deformable sleeve 114 for forming the surface of the second mold area roller segment 112 and the surface of the third mold area roller segment 113. The deformable sleeve 114 is connected to the first mold area roller segment 111. The adjustment device includes a second adjustment part. The second adjustment part includes a plurality of support plates 1223 and a support plate position adjustment mechanism. The plurality of support plates 1223 are evenly distributed on the radial inner side of the second mold area roller segment 112 along the circumference of the coating back roller 100 and form an annular structure that supports the deformable sleeve 114 as a whole. One end of the plurality of support plates 1223 is connected to the end surface of the first mold area roller segment 111 close to the second mold area roller segment 112. The support plate position adjustment mechanism is drivingly connected to each support plate 1223 and is configured to change the interval of one end of the plurality of support plates 1223 away from the first mold area roller segment 111, so that the deformable sleeve 114 follows the plurality of support plates 1223 to deform.

[0093] A plurality of support plates 1223 and a support plate position adjustment mechanism are provided to drive the support plates 1223 so as to change the interval between the plurality of support plates 1223 at one end away from the first mold area roller segment 111. When the interval becomes larger, the radial dimension of the second mold area roller segment 112 is increased, and when the interval becomes smaller, the radial dimension of the second mold area roller segment 112 is decreased. The deformable sleeve 114 is synchronously contracted or expanded according to the change in the interval size of the support plates 1223, so that the change in the radial dimension of the second mold area roller segment 112 of the coating back roller 100 is continuous and accurate. The deformable sleeve 114 supports the current collector film 500, so as to improve the flatness of the current collector film 500 when supported on the deformable sleeve 114.

[0094] The support plate 1223 can be made of wood, metal, high molecular polymer, etc. The length and thickness of the support plate 1223 can be comprehensively designed according to the space size, the specifications of the prepared pole piece, the manufacturing process, the cost, etc. The support plate 1223 can be connected to the first mold area roller segment 111 in a hinged manner, and the other end forms a free end.

[0095] The deformable sleeve 114 can be an organic elastic film, which is arranged to fit the outer surface of the support plate 1223 and has a thickness equal to the distance between the outer surface edge of the support plate 1223 at the connection point between the support plate 1223 and the first mold area roller segment 111 and the outer surface of the first mold area roller segment 111.

[0096] The deformable sleeve 114 can be made of PTFE, PP, PE, PET, PA or other materials that can ensure that the surface of the third mold area roller segment 113 of the coating backing roller 100 is flat and elastic.

[0097] A deformable sleeve 114 is disposed between two adjacent first mold area roller segments 111, and both sides of the deformable sleeve 114 can be fixedly connected to the end faces of the two first mold area roller segments 111 by means of adhesion, embedding, etc. The support force of the support plates 1223 of the two adjacent second mold area roller segments 112 on the deformable sleeve 114 located on the support plates 1223 is used to form a truncated cone body at the part where the deformable sleeve 114 and the support plates 1223 are attached, and a cylinder is formed between the support plates 1223 on both sides. The support plate position adjustment mechanism drives the support plate 1223 to rotate around the end connected to the first mold area roller segment 111, and the shape of the deformable sleeve 114 changes accordingly. For example, the support plate position adjustment mechanism drives the support plate 1223 to rotate in the direction away from the axis of the back roller body 110, and the intervals of the ends of the multiple support plates 1223 away from the first mold area roller segment 111 become larger, the radial size of the part formed into a truncated cone becomes larger and the height of the truncated cone (corresponding to the width of the second mold area roller segment 112) becomes smaller, and the diameter and width of the part formed into a cylinder (corresponding to the third mold area roller segment 113) are both larger. It should be understood that the adjustment device is arranged inside the back roller body 110, that is, arranged inside the deformable sleeve 114.

[0098] Through the rotation of the support plate 1223, the sizes of the second mold area roller segment 112 and the third mold area roller segment 113 change continuously, which is convenient for changing the size of the coating back roller 100 according to different needs to prepare pole pieces of different specifications; the deformable sleeve 114 is arranged on the outside of the support plate 1223, and the outer contours of the second mold area roller segment 112 and the third mold area roller segment 113 are formed by the deformable sleeve 114, so that the deformable sleeve 114 protects the internal structure and makes the surfaces of the second mold area roller segment 112 and the third mold area roller segment 113 forming the coating position smoother, which is beneficial to the preparation of pole pieces.

[0099] According to some embodiments of the present application, optionally, the support plate position adjustment mechanism includes a moving member 1221 and a rotating member 1222. The moving member 1221 is movably arranged along the axial direction A. The first end of the rotating member 1222 is hinged to the moving member 1221, and the second end is hinged to the support plate 1223. The support plate position adjustment mechanism is configured to change the interval of one end of the plurality of support plates 1223 away from the first mold area roller segment 111 by driving the rotating member 1222 to rotate through the movement of the moving member 1221.

[0100] The second adjusting part includes a second driving device M2, which is drivingly connected to the moving member 1221 to drive the moving member 1221 to translate. The second driving device M2 includes, for example, a linear motor.

[0101] like Figure 2 or Figure 6As shown, optionally, one end of the moving member 1221 is connected to the second driving device M2, and the other end extends along the axial direction A toward the direction close to the first mold area roller segment 111, and the end surface of the first mold area roller segment 111 is the movement limit position of the moving member 1221. One end of the rotating member 1222 is hinged to the side of the moving member 1221 close to the first mold area roller segment 111, for example, hinged to the end of the moving member 1221 that can contact the first mold area roller segment 111. The other end of the rotating member 1222 is hinged to the side of the support plate 1223 close to the third mold area roller segment 113, for example, hinged to the end of the support plate 1223 away from the first mold area roller segment 111. Figure 2 Taking the movement of the moving part 1221 on the left side to the left as an example, the movement of the moving part 1221 to the left will drive the end of the rotating part 1222 hinged with the support plate 1223 to rotate toward the moving part 1221, and the end of the support plate 1223 away from the first mold area roller segment 111 driven by the rotating part 1222 also moves toward the moving part 1221. The spacing between the ends of the multiple support plates 1223 away from the first mold area roller segment 111 is reduced, the radial size of the second mold area roller segment 112 is reduced, and the thinned area of ​​the coating layer of the prepared pole piece is thickened.

[0102] Reference Figure 2 or Figure 6 When the coating backing roller 100 includes two first mold area roller segments 111, a second driving device M2 may be disposed between the two first mold area roller segments 111, and both ends of the second driving device M2 are respectively connected to a moving member 1221. The second driving device M2 may simultaneously drive the moving members 1221 at both ends to move, so as to drive the multiple support plates 1223 at both sides to open or contract simultaneously, so as to simultaneously change the sizes of the second mold area roller segments 112 and the third mold area roller segments 113 at both sides.

[0103] In some embodiments, the moving member 1221 is optionally a moving sleeve, and a plurality of rotating members 1222 are distributed along the circumference of the moving sleeve to respectively connect a plurality of support plates 1223. Controlling the movement of the moving member 1221 can control the rotation of the rotating member 1222. Such a control method is conducive to saving structural space. The rotation of the support plate 1223 can be driven by the short-distance movement of the moving member 1221, which saves axial space and is also conducive to the precise control of the support plate position adjustment mechanism.

[0104] According to some embodiments of the present application, optionally, a plurality of support plates 1223 form a truncated cone structure when there is no gap in the circumferential direction.

[0105] Optionally, when the movable member 1221 moves toward the corresponding first mold area roller segment 111 to the limit position of movement abutting against the first mold area roller segment 111, the ends of the plurality of support plates 1223 away from the first mold area roller segment 111 fit together, and the plurality of support plates 1223 form a truncated cone structure without any interval along the circumferential direction, and at this time, the radial dimension of the second mold area roller segment 112 is the smallest.

[0106] The truncated cone structure makes the radial dimension of the coating back roller 100 increase uniformly from the first mold area roller segment 111 to the third mold area roller segment 113, which is beneficial to make the outer surface of the second mold area roller segment 112 closer to the truncated cone shape, and is beneficial to improve the uniformity of the slurry coating along the length direction of the pole piece corresponding to the second mold area roller segment 122.

[0107] According to some embodiments of the present application, optionally, the backing roller body 110 includes a plurality of first mold area roller segments 111. The two ends of each first mold area roller segment 111 are respectively provided with a second mold area roller segment 112 and a third mold area roller segment 113.

[0108] By setting up multiple first mold area roller segments 111, multiple pole pieces arranged axially along the coating back roller 100 can be produced at one time to improve the output and production efficiency; the second mold area roller segment 112 and the third mold area roller segment 113 are respectively set at both ends of the first mold area roller segment 111, so that the two ends of the pole piece can be thinned at the same time, and a pole ear area for forming the pole ear of the electrode can be formed at the position corresponding to the third mold area roller segment 113.

[0109] Optionally, refer to Figure 1 The back roller body 110 includes three first mold area roller segments 111, six second mold area roller segments 112 and four third mold area roller segments 113 along the axial direction A. Two second mold area roller segments 112 and three third mold area roller segments 113 are connected to each first mold area roller segment 111 on both sides. Both ends of the back roller body 110 are third mold area roller segments 113.

[0110] Corresponding to each first die zone roller segment 111, a pole piece can be produced, that is, Figure 1 The coating back roller 100 shown can produce three pole pieces at the same time, which is conducive to improving the output; the pole ear for forming the electrode can be formed at the position corresponding to the third mold area roller segment 113.

[0111] According to some embodiments of the present application, optionally, a third mold zone roller segment 113 is included between two adjacent first mold zone roller segments 111, and the axial dimension of the third mold zone roller segment 113 is greater than or equal to twice the height value of the pole lug of the pole piece.

[0112] Only one third die zone roller segment 113 is disposed between two adjacent first die zone roller segments 111 . Such a design can shorten the axial dimension of the coating backing roller 100 and effectively utilize the axial space.

[0113] According to some embodiments of the present application, optionally, the outer surface of the connection between the second mold area roller segment 112 and the first mold area roller segment 111 forms a transition fillet, and / or the outer surface of the connection between the second mold area roller segment 112 and the third mold area roller segment 113 forms a transition fillet.

[0114] The cross-sectional dimensions at the joints of the roller segments in each die area are prone to sudden changes, forming sharp right angles or edges, and the pole pieces are easily scratched and broken. Using transition fillets instead of right angles can help reduce the damage rate of the pole pieces.

[0115] According to some embodiments of the present application, optionally, the coating backing roller 100 further includes a core rod 130 extending along the axial direction A. The core rod 130 is located in the second mold area roller segment 112 and the third mold area roller segment 113 . The adjustment device is installed on the core rod 130 .

[0116] Reference Figure 2 As shown, the core rod 130 is arranged in the radial middle part of the back roller body 110 along the axis of the back roller body 110. The first adjusting part of the adjusting device is installed in the core rod 130. The second adjusting part is installed around the core rod 130, and the moving member 1222 of the second adjusting part can be slidably matched with the core rod 130 and move left and right on the core rod 130.

[0117] The core rod 130 is provided to support the adjusting device and improve the driving stability and accuracy of the adjusting device.

[0118] According to some embodiments of the present application, optionally, the adjusting device includes a first adjusting portion. The first adjusting portion drives the first mold area roller segment 111 to move relative to the core rod 130 along the axial direction A. The coating back roller 100 also includes a guide portion. The guide portion is configured to guide the moving direction of the first mold area roller segment 111 relative to the core rod 130 and / or limit the first mold area roller segment 111 from rotating around its own axis relative to the core rod 130.

[0119] Optionally, the guide portion may be configured as a sliding fit structure, such as a slide groove and a slider that fits with the slide groove, a sleeve and a rod that fits with the sleeve, and the like.

[0120] The coating back roller 100 includes a guide portion, which is conducive to limiting the movement direction and / or movement range of the first mold area roller segment 111 relative to the second mold area roller segment 112 and the third mold area roller segment 113 when driving the first mold area roller segment 111 to move, and is conducive to maintaining the overall structure of the coating back roller 100 without undesired deformation due to the movement of the first mold area roller segment 111.

[0121] According to some embodiments of the present application, the guide portion may optionally include a first guide structure and a second guide structure. The first guide structure is disposed on one of the core rod 130 and the first mold area roller segment 111. The second guide structure is disposed on the other of the core rod 130 and the first mold area roller segment 111. The first guide structure and the second guide structure are slidably matched along the axial direction A, and / or the first guide structure and the second guide structure are matched along the circumference of the coating back roller 100 without relative rotation.

[0122] For example, the first guide structure and the second guide structure may be, for example, a guide rod 131 disposed along the axial direction A and a guide hole 111A slidably matched with the guide rod 131. Figure 6 The guide hole 111A is arranged on the first mold area roller segment 111 , and the guide rod 131 is arranged on the core rod 130 .

[0123] The first guide structure and the second guide structure of the guide part are respectively arranged on the core rod 130 and the first mold area roller segment 111, which is conducive to realizing the guiding and / or limiting functions, improving the stability of the movement of the first mold area roller segment 111, and can reduce the number of components used to form the guide part and / or reduce the space occupied by the guide part.

[0124] According to some embodiments of the present application, the second aspect of the present application further provides a pole piece preparation system. Figure 4 and Figure 5 The pole piece preparation system includes the coating back roller 100 and the coating die 300 described in any of the above schemes. The coating back roller 100 is used to carry and convey the current collector film 500 of the pole piece, so that the current collector film 500 is attached to the outer surface of the adjacent first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113 of the back roller body 110 to produce deformation. The coating die 300 is used to coat the slurry 400 for forming a coating layer on the current collector film 500.

[0125] The coating die 300 includes a slurry outlet 320 opposite to the first die zone roll segment 111 and the second die zone roll segment 112 of the coating backing roll 100. The coating die 300 coats the slurry 400 for forming a coating layer on the current collector film 500 of the backing roll body 110 through the slurry outlet 320, so that the coating die 100 coats the slurry 400 with normal thickness at the position of the current collector film 500 corresponding to the first die zone roll segment 111, coats the slurry 400 with gradually reduced thickness at the position of the current collector film 500 corresponding to the second die zone roll segment 112, and does not coat the slurry 400 at the position of the current collector film 500 corresponding to the third die zone roll segment 113.

[0126] The coating die head 300 is arranged parallel to the coating back roller 100. The slurry outlet 320 is in the shape of an elongated strip, and the width can be set according to the width of the coating layer of the electrode. Each slurry outlet 320 is aligned with a first mold area roller segment 111 and two second mold area roller segments 112 connected thereto in the length direction. A gasket 310 is arranged between two adjacent slurry outlets 320, and the position of the gasket 310 corresponds to the position of the third mold area roller segment 113. The electrode preparation system also includes a conveying roller 600, which is arranged downstream of the coating back roller 100, and the conveying roller 600 is a cylindrical roller for extending the current collector film 500.

[0127] Before the coating die 300 coats the slurry 400, the current collector film 500 is first transferred to the coating back roller 100 and fits with the outer surface of the back roller body 110. After confirming that the coating back roller 100 is aligned with the coating die 300, the slurry 400 flows out from the slurry outlet 320 of the coating die 300 and is coated on the current collector film 500 corresponding to the first mold area roller segment 111 and the second mold area roller segment 112. At this time, the cross-section of the slurry 400 on the current collector film 500 presents a shape that is thick in the middle and thin on both sides. Subsequently, the current collector film 500 coated with the slurry 400 is transferred to the transmission roller 600 and is extended. The slurry 400 also deforms with the current collector film 500, thereby achieving the effect of thinning the edge of the electrode.

[0128] The following combination Figures 1 to 6 The embodiments of the present application are described in detail.

[0129] See also Figures 1 to 3 Some embodiments of the present application provide a coating backing roller 100. The coating backing roller 100 includes a backing roller body 110 and an adjusting device. The backing roller body 110 includes a first mold area roller segment 111, a second mold area roller segment 112, and a third mold area roller segment 113. The deformable sleeve 114 of the coating backing roller 100 forms the main body of the first mold area roller segment 111 and the second mold area roller segment 112.

[0130] For the convenience of description below, the positions of the pole pieces corresponding to the pole pieces prepared by the first mold area roller segment 111, the second mold area roller segment 112 and the third mold area roller segment 113 are respectively referred to as the normal mold area, the thinning area and the pole ear area.

[0131] One end or both ends of the deformable sleeve 114 are connected to the adjacent first mold area roller segment 111 , and the outer surface of the deformable sleeve 114 forms the outer surface of the second mold area roller segment 112 and the third mold area roller segment 113 .

[0132] The adjusting device is disposed in the backing roller body 110 and includes a first adjusting portion and a second adjusting portion.

[0133] The first adjustment part includes a first driving device M1 and a screw 1211. The first driving device M1 is a stepping motor, one end of the screw 1211 is connected to the first driving device M1, and the other end is threadedly connected to the end of the first mold area roller segment 111. The motor controls the screw 1211 to rotate and drive the first mold area roller segment 111 to move along the axial direction A.

[0134] The second adjustment part includes 8 support plates 1223 that can be arranged in a truncated cone shape and a support plate adjustment mechanism. The support plate adjustment mechanism includes a second drive device M2, moving parts 1221 located on both sides of the second drive device M2, and 8 support rods as rotating parts 1222. The moving part 1221 is a moving sleeve and is sleeved on the core rod 130, and the second drive device M2 is a linear motor. A plurality of support rods are evenly distributed on the radial outer side of the moving sleeve along the circumferential direction, one end of each support rod is hinged on the moving sleeve, and the other end is hinged on the end of the corresponding support plate 1223 away from the first mold area roller segment 111. The linear motor drives the movable sleeve to move to the side away from the first mold area roller segment 111, so that the angle θ between the support rod and the movable sleeve increases, and the end of the support plate 1223 away from the first mold area roller segment 111 moves toward the direction away from the movable sleeve, and the gap between the ends of the adjacent support plates 1223 away from the first mold area roller segment 111 is enlarged, and the radial size of the second mold area roller segment 112 increases. At the same time, the support plate 1223 pulls the deformable sleeve 114 to increase the width of the third mold area roller segment 113, thereby reducing the thickness and width of the thinning area, and increasing the width of the tab area. If the width of the tab area is to remain unchanged, the first adjustment part can drive the first mold area roller segments 111 on both sides to move inward.

[0135] In some other embodiments, referring to Figure 6 , the adjustment device also includes a guide portion. The guide portion includes a first guide structure and a second guide structure. In this embodiment, the first guide structure is a guide rod 131 provided on the core rod 130, and the second guide structure is a guide hole 111A provided on the first mold area roller segment 111. Through the sliding fit between the guide rod 131 and the guide hole 111A, the first mold area roller segment 111 moves leftward or rightward along the axial direction A under the drive of the first adjustment portion, and because the guide rod 131 and the guide hole 111A are eccentrically arranged relative to the axis of the coating back roller 100, the first mold area roller segment 111 will not rotate relative to the core rod 130 due to the torque generated by the threaded connection.

[0136] According to some embodiments of the present application, see Figure 4 and Figure 5 The present application provides a pole piece preparation system including the above-mentioned coating back roller 100.

[0137] The pole piece preparation system also includes a coating die 300. The coating die 300 includes a slurry outlet 320 and a gasket 310. The coating die 300 coats the slurry 400 for forming a coating layer on the current collector film 500 through the slurry outlet 320. During coating, the coating die 300 is directly opposite to the coating back roller 100, and the current collector film 500 is located between the coating die 300 and the coating back roller 100. The slurry 400 flows out from the slurry outlet 320 of the coating die 300 and is loaded on the current collector film 500. The thickness of the slurry 400 coated on the surface of the current collector film 500 can also be regulated by controlling the distance between the current collector film 500 and the coating die 300. The pole piece prepared by using the coating back roller 100 has a thinning area whose distance from the slurry outlet 320 gradually decreases from the side close to the normal mold area to the side close to the pole ear area, and the thickness of the formed slurry coating layer gradually decreases, thereby achieving the effect of thinning the edge of the pole piece.

[0138] After coating is completed, under the action of the belt traction force, the electrode sheet is stretched on the conveying roller 600 and gradually extends in the width direction, and the current collector film 500 becomes flat, thereby obtaining a electrode sheet with a flat bottom and a coating layer that is thick in the middle and thin on both sides.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present disclosure rather than to limit it. Although the present disclosure has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present disclosure can still be modified or some technical features can be replaced by equivalents, which should all be included in the scope of the technical solution for protection requested by the present disclosure.

Claims

1. A coating backing roller for pole piece preparation, characterized in that: include: A back roller body (110) comprises a first mold area roller segment (111), a second mold area roller segment (112) and a third mold area roller segment (113) arranged along an axial direction (A), wherein a radial dimension of the third mold area roller segment (113) is greater than a radial dimension of the first mold area roller segment (111), the second mold area roller segment (112) connects the first mold area roller segment (111) and the third mold area roller segment (113), and the radial dimension gradually increases from the first mold area roller segment (111) to the third mold area roller segment (113).

2. The coating backing roller according to claim 1, characterized in that: Also included is an adjustment device configured to change the size of at least one of the first mold area roll segment (111), the second mold area roll segment (112), and the third mold area roll segment (113).

3. The coating backing roller according to claim 2, characterized in that: The adjusting device is arranged inside the backing roller body (110).

4. The coating backing roller according to claim 3, characterized in that: The adjusting device is drivingly connected to at least one of the first mold area roller segment (111), the second mold area roller segment (112) and the third mold area roller segment (113), and is configured to drive at least one of the first mold area roller segment (111), the second mold area roller segment (112) and the third mold area roller segment (113) to displace and / or deform relative to other mold area roller segments so as to change the size of at least one of the first mold area roller segment (111), the second mold area roller segment (112) and the third mold area roller segment (113).

5. The coating backing roller according to claim 3, characterized in that: The regulating device comprises: a first adjusting portion, the first adjusting portion being configured to drive the first mold zone roller segment (111) to move along the axial direction (A); and / or A second adjustment portion, wherein the second adjustment portion is configured to drive at least one of the second mold area roller segment (112) and the third mold area roller segment (113) to deform.

6. The coating backing roller according to claim 5, characterized in that: The adjusting device comprises the first adjusting part, the first adjusting part comprises a screw (1211), the screw (1211) is threadedly connected to the end face of the first mold area roller segment (111), and the screw (1211) is configured to be rotatably arranged around the axis of the coating back roller (100) so as to drive the first mold area roller segment (111) to move by changing the matching position of the screw (1211) and the first mold area roller segment (111).

7. The coating backing roller according to claim 5, characterized in that: The backing roller body (110) comprises a deformable sleeve (114) for forming the surface of the second mold area roller segment (112) and the surface of the third mold area roller segment (113), and the deformable sleeve (114) is connected to the first mold area roller segment (111); The adjusting device comprises the second adjusting part, and the second adjusting part comprises: a plurality of support plates (1223), wherein the plurality of support plates (1223) are evenly distributed on the radial inner side of the second mold area roller segment (112) along the circumference of the coating back roller (100) and integrally form an annular structure supporting the deformable sleeve (114), and one end of the plurality of support plates (1223) is connected to an end surface of the first mold area roller segment (111) close to the second mold area roller segment (112); and The support plate position adjustment mechanism is drivingly connected to each of the support plates (1223) and is configured to change the spacing between the ends of the multiple support plates (1223) away from the first mold area roller segment (111) so that the deformable sleeve (114) follows the multiple support plates (1223) to deform.

8. The coating backing roller according to claim 7, characterized in that: The support plate position adjustment mechanism comprises: A moving member (1221) is movably arranged along the axial direction (A); A rotating member (1222), wherein a first end of the rotating member (1222) is hinged to the moving member (1221), a second end of the rotating member (1222) is hinged to the support plate (1223), and the support plate position adjustment mechanism is configured to change the spacing of one end of the plurality of support plates (1223) away from the first mold area roller segment (111) by driving the rotating member (1222) to rotate through the movement of the moving member (1221).

9. The coating backing roller according to claim 7, characterized in that: The multiple support plates (1223) form a truncated cone structure when there is no interval along the circumferential direction.

10. The coating backing roller according to any one of claims 1 to 9, characterized in that: The backing roller body (110) comprises a plurality of the first mold area roller segments (111), and the second mold area roller segment (112) and the third mold area roller segment (113) are respectively disposed at two ends of each of the first mold area roller segments (111).

11. The coating backing roller according to claim 10, characterized in that: A third mold area roller segment (113) is included between two adjacent first mold area roller segments (111), and the third mold area roller segment (113) is configured to have an axial dimension greater than or equal to twice the height value of the pole lug of the pole piece.

12. The coating backing roller according to any one of claims 1 to 9, characterized in that: The outer surface of the connection between the second mold area roller segment (112) and the first mold area roller segment (111) forms a transition fillet; and / or The outer surface of the connection between the second mold area roller segment (112) and the third mold area roller segment (113) forms a transition fillet.

13. The coating backing roller according to any one of claims 2 to 9, characterized in that: It also includes a core rod (130) extending along the axial direction (A), the core rod (130) is located in the second mold area roller segment (112) and the third mold area roller segment (113), and the adjustment device is installed on the core rod (130).

14. The coating backing roller according to claim 13, characterized in that: The adjusting device comprises a first adjusting portion, wherein the first adjusting portion is configured to drive the first mold zone roller segment (111) to move relative to the core rod (130) along the axial direction (A); The coating back roller (100) further comprises a guide portion, wherein the guide portion is configured to guide the movement direction of the first mold area roller segment (111) relative to the core rod (130) and / or limit the first mold area roller segment (111) from rotating around its own axis relative to the core rod (130).

15. The coating backing roller according to claim 14, characterized in that: The guide portion comprises: a first guide structure, disposed on one of the core rod (130) and the first mold zone roller segment (111); and The second guide structure is arranged on the other of the core rod (130) and the first mold area roller segment (111), and the first guide structure and the second guide structure are slidably matched along the axial direction (A), and / or the first guide structure and the second guide structure are matched without relative rotation along the circumference of the coating back roller.

16. A pole piece preparation system, characterized in that: include: The coating back roller according to any one of claims 1 to 15, wherein the coating back roller is used to carry and convey the current collector film (500) of the pole piece, so that the current collector film (500) is in contact with the outer surfaces of the first mold area roller segment (111), the second mold area roller segment (112) and the third mold area roller segment (113) adjacent to the back roller body (110) to produce deformation; and A coating die (300) comprises a slurry outlet (320) opposite to the first die zone roller segment (111) and the second die zone roller segment (112) of the coating back roller, and is configured to coat the slurry (400) for forming a coating layer on the current collector film (500) of the back roller body (110) through the slurry outlet (320), so that the coating die coats the slurry (400) with a normal thickness at a position of the current collector film (500) corresponding to the first die zone roller segment (111), coats the slurry (400) with a gradually reduced thickness at a position of the current collector film (500) corresponding to the second die zone roller segment (112), and does not coat the slurry (400) at a position of the current collector film (500) corresponding to the third die zone roller segment (113).

Images