Patent Description:
Achieving energy conservation and emission reduction is the key to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages in energy conservation and being more environmentally friendly. For the electric vehicles, battery technology is an important factor to their development.

<CIT>, which forms the basis for the preamble of claim <NUM>, relates to a rolling device comprising a first roller and a second roller, and the first roller and the second roller are arranged on the two sides of the pole piece in the thickness direction. The first roller is provided with a plurality of concave parts, the pole piece comprises a plurality of insulating coating areas and a plurality of tabs, and in the projection in the thickness direction of the pole piece, at least part of the insulating coating areas and the projection of the tabs are located in the projection range of the concave parts.

<CIT> relates to an electrode sheet manufacturing device comprising a conveying device that conveys an electrode material; and a press device <NUM> that presses the electrode material. The press device comprises a pair of press roles. The first press role comprises a first convex part fitted with a second concave part through an uncoated part. The second press role comprises the second convex part fitted to the first concave part through the uncoated part. The first convex part and the first concave part are provided through a whole periphery of the first press role. The second convex part and the second concave part are provided through the whole periphery of the second press role.

<CIT> relates to a cold pressing extension mechanism comprising a traction assembly and a compression roller assembly which are arranged along the conveying path of the cold pressing extension mechanism. The traction assembly is used for pulling the first part of thefilm in the width direction and comprises a first driven roller and a first driving roller which are arranged in pairs, the first driving roller is used for being in transmission connection with a first driving device, and the first driven roller is used for rotating along with movement of the film.

<CIT> relates to a method of controlling the shape of rolled objects in the rolling of plate, sheet, strip and the like through the adjustment of the quantity of a crown made on the rolling roll by heating the inside of the center hole made along the center axis of the rolling roll.

In the development of battery technology, how to improve the production efficiency of batteries is an urgent technical problem to be solved in the battery technology.

The present invention provides a system comprising an electrode plate extension device and an electrode plate, along with an electrode plate manufacturing apparatus, which can improve the production efficiency of batteries.

In a first aspect, the present invention provides a system as set out in claim <NUM>.

In the above solution, when the electrode plate passes between the first roller and the second roller, the protrusion acts on the uncoated region and exerts a certain pressure on the uncoated region, and with the support of the groove on the uncoated region, the uncoated region is subjected to plastic deformation while ensuring the safety, thereby achieving the effects of flattening folds of the uncoated region and extending the uncoated region. Therefore, the risk of breaking the electrode plate in the subsequent cold-pressing procedure is reduced, the production capacity of electrode plates is improved, and thus the production efficiency of batteries is improved.

According to some embodiments of the present invention, the protrusion has a complementary shape to the groove.

In the above solution, the uncoated region is subjected to plastic deformation under the action of the pressure of the protrusion to fit a surface of the groove, so that the folds of the uncoated region are effectively flattened, and the uncoated region is extended.

According to some embodiments of the present invention, a surface of the protrusion has an arc-shaped transition into the outer peripheral surface of the first body, and a surface of the groove has an arc-shaped transition into the outer peripheral surface of the second body.

In the above solution, since the surface of the protrusion has an arc-shaped transition into the outer peripheral surface of the first body, and the surface of the groove has an arc-shaped transition into the outer peripheral surface of the second body, it is possible to avoid damage to the uncoated region that is caused by a large height difference between the uncoated region and the coated region of the electrode plate after the uncoated region is subjected to a depressing tension from the protrusion, thereby ensuring the safety of the electrode plate.

According to some embodiments of the present invention, a dimension of the protrusion in a length direction of the first roller is W, which satisfies <NUM> ≤ W ≤ <NUM>.

In the above solution, the protrusion has a width greater than or equal to <NUM> and less than or equal to <NUM>, so as to correspond to widths of the uncoated regions on electrode plates of different specifications.

According to some embodiments of the present invention, a dimension by which the protrusion protrudes from the outer peripheral surface of the first body is H, which satisfies <NUM> ≤ H ≤ <NUM>.

In the above solution, since a different extension rate of the uncoated region is required to reach for the electrode plate of each specification, the height range of the protrusion is limited, the different heights of the protrusions indicate different extension rates obtained after the uncoated region is rolled by the protrusions, and the greater the height of the protrusion, the greater the extension rate.

According to some embodiments of the present invention, a plurality of protrusions are provided, which are distributed at intervals in an axial direction of the first body; and a plurality of grooves are provided, which are distributed at intervals in an axial direction of the second body, and which are in one-to-one correspondence with the protrusions.

In the above solution, by providing the plurality of protrusions and the plurality of grooves to roll a plurality of uncoated regions on the electrode plate simultaneously, the efficiency of solving the problems relating to folds and extensing the uncoated regions are effectively improved, the production capacity of electrode plates is improved, and thus the production efficiency of batteries is improved.

According to some embodiments of the present invention, the electrode plate extension device further comprises: a heating portion, configured to heat the uncoated region.

In the above solution, by heating the uncoated region, the residual stress and tensile strength of the uncoated region are reduced, and the flexibility is improved, so as to ensure that when the protrusion and the groove act on the uncoated region, the uncoated region can be subjected to plastic deformation under a small depressing tension so as to be extended and stretched, then the folds of the uncoated region are effectively flattened, the risk of breakage of the electrode plate in the subsequent cold-pressing procedure is reduced, and the production capacity of electrode plates is improved.

According to some embodiments of the present invention, the heating portion is arranged inside the first body and/or the second body.

In the above solution, when the electrode plate passes between the first roller and the second roller, the heating portion inside the first body and/or the second body may heat the uncoated region to improve the extension and stretching efficiency of the uncoated region. Moreover, since the heating portion is arranged inside the first body and/or the second body, it is possible that the electrode plate extension device has a compact structure and a low space occupancy, thereby avoiding wasting space.

According to some embodiments of the present invention, the heating portion is independent of the first roller and the second roller.

In the above solution, since the heating portion is independent of the first roller and the second roller, it is possible to heat the uncoated region independently, to ensure the heating effect of the uncoated regions. Moreover, since there is no need for the first roller and the second roller to be provided with the heating portion, the first roller and the second roller have a simple structure, and the manufacturing cost of the first roller and the second roller is effectively reduced.

According to some embodiments of the present invention, in a feeding direction of the electrode plate, the heating portion is arranged upstream of the first roller and the second roller.

In the above solution, as the electrode plate passes between the first roller and the second roller, the uncoated region of the electrode plate is heated by the heating portion, so that the residual stress and tensile strength of the uncoated region are reduced, and the flexibility is improved. Therefore, when the protrusion and the groove act on the uncoated region, the uncoated region can be subjected to plastic deformation under a small depressing tension so as to be extended and stretched, then the folds of the uncoated region are effectively flattened, the risk of breakage of the electrode plate in the subsequent cold-pressing procedure is reduced, and the production capacity of electrode plates is improved.

According to some embodiments of the present invention, the heating portion is a magnetic induction heating portion or a far infrared heating portion.

In the present invention, the electrode plate extension device further comprises: a third roller, located on the side of the second roller facing away from the first roller, and configured to support the second roller.

In the above solution, the third roller is an idler roller, which is configured to support the weight of the second roller and the first roller, so that the first roller stably exerts a depressing tension to the uncoated region, and the effective plastic deformation of the uncoated region is ensured.

According to some embodiments of the present invention, one of the first roller and the second roller is a driving roller and the other is a driven roller.

In the above solution, when the first roller is the driving roller and the second roller is the driven roller, the first roller rotates actively to provide the depressing tension for the uncoated region, and the second roller is rotated passively to provide support for the uncoated region. Alternatively, when the first roller is the driven roller and the second roller is the driving roller, the second roller rotates actively, provides support for the uncoated region, and drives the first roller to rotate such that the first roller provides the depressing tension for the uncoated region.

According to some embodiments of the present invention, the electrode plate extension device further comprises: an adjusting mechanism, connected to the driving roller and configured to adjust a tension exerted by the driving roller to the electrode plate.

In the above solution, by adjusting the tension exerted by the driving roller to the electrode plate through the adjusting mechanism, it is possible to adjust the extension rate of the uncoated region, so as to adapt to the requirements of electrode plates of different specifications.

In a second aspect, the present invention further provides an electrode plate manufacturing apparatus, comprising: a system according to any embodiment in the first aspect; and a cold-pressing device, configured to cold-press an electrode plate, the cold-pressing device being arranged downstream of the electrode plate extension device in a feeding direction of the electrode plate.

In the above solution, after an uncoated region of the electrode plate is subjected to extension and fold removal by the electrode plate extension device, it is possible to reduce the risk of breakage of the electrode plate during cold-pressing in the cold-pressing device, thereby improving the production capacity of electrode plates.

Some of the additional aspects and advantages of the present invention will be set forth in the following description, and some will become apparent from the following description, or be learned by practice of the present application.

In order to more clearly describe the technical solutions of the embodiments of the present invention, the accompanying drawings required in the embodiments will be described briefly below. It should be understood that the following accompanying drawings illustrate only some embodiments of the present invention and therefore should not be construed as a limitation on the scope thereof.

List of reference signs: <NUM> - First roller; <NUM> - First body; <NUM> - Protrusion; <NUM> - Second roller; <NUM> - Second body; <NUM> - Groove; <NUM> - Heating portion; <NUM> - Third roller; <NUM> - Straight section; <NUM> - Arc section; <NUM> - First section; <NUM> - Second section; <NUM> - Arc-shaped section; <NUM> - Straight edge section; <NUM> - Third section; <NUM> - Fourth section; <NUM> - Electrode plate; <NUM> - Uncoated region; <NUM> - Coated region.

In order to make the objectives, technical solutions and advantages of embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the embodiments described are some of, rather than all of, the embodiments of the present invention.

Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs. The terms used in the description of the present application are merely for the purpose of describing specific embodiments, but are not intended to limit the present application. The terms "comprise", "have" and any variations thereof in the description and the claims of the present application as well as the brief description of the drawings described above are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and the claims of the present application or the foregoing accompanying drawings are used for distinguishing between different objects, rather than describing a particular order or a primary-secondary relationship.

In the present application, "embodiment" mentioned means that the specific features, structures or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase at various locations in the description does not necessarily refer to the same embodiment, or an independent or alternative embodiment mutually exclusive of another embodiment. Those skilled in the art should understand, in explicit and implicit manners, that an embodiment described in the present application may be combined with another embodiment.

In the description of the present application, it should be noted that, the terms "mounted", "connected", "connect", or "attached" should be interpreted in a broad sense unless otherwise explicitly defined and limited. For example, they may be a fixed connection, a detachable connection, or an integral connection; or may be a direct connection, an indirect connection by means of an intermediate medium, or internal communication between two elements. For those of ordinary skills in the art, the specific meanings of the foregoing terms in the present application may be understood according to specific circumstances.

The term "and/or" in the present application is merely a description of the associated relationship of associated objects, representing that three relationships may exist, for example, A and/or B, may be expressed as: A exists, both A and B exist, and B exists. In addition, the character "/" in the present application generally indicates that the associated objects before and after the character are in a relationship of "or".

In the present application, "a plurality of" means two or more (including two), similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of pieces" means two or more pieces (including two pieces).

A battery mentioned in the present application refers to a single physical module comprising one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module, a battery pack, etc..

The battery cell comprises an electrode assembly and an electrolyte solution. The electrode assembly is composed of a positive electrode plate, a negative electrode plate, and a separator. The battery cell operates mainly by relying on movements of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate comprises a positive current collector and a positive active material layer, a surface of the positive current collector is coated with the positive active material layer, a portion of the current collector that is not coated with the positive active material layer protrudes from a portion of the current collector that is coated with the positive active material layer, and the portion of the current collector that is not coated with the positive active material layer serves as a positive tab. Taking a lithium-ion battery as an example, the material of the positive current collector may be aluminum, and the positive active material may be lithium cobalt oxides, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode plate comprises a negative current collector and a negative active material layer, a surface of the negative current collector is coated with the negative active material layer, a portion of the current collector that is not coated with the negative active material layer protrudes from a portion of the current collector that is coated with the negative active material layer, and the portion of the current collector that is not coated with the negative active material layer serves as a negative tab. The material of the negative current collector may be copper, and the negative active material may be carbon, silicon, etc. In order to ensure that no fusing occurs when a large current passes, a plurality of positive tabs are stacked together, and a plurality of negative tabs are stacked together. The separator has electronic insulation and is configured to isolate the adjacent positive electrode plate and negative electrode plate to prevent a short circuit between the adjacent positive electrode plate and negative electrode plate. The separator has a large number of through micropores, which can ensure the free passage of electrolyte ions and have good permeability to lithium ions, so the separator substantially cannot block the lithium ions. The separator may be made of PP (polypropylene), PE (polyethylene), etc..

A preparation process of an electrode plate generally comprises slurry preparation, coating, cold-pressing, tab die-cutting and other procedures. The coating procedure comprises applying the stirred active material to the current collector, such that the current collector has a coated region coated with the active material layer and an uncoated region not coated with the active material layer, and the uncoated region serves as a tab after being subjected to treatment (for example, through the tab die-cutting procedure). Generally, in order to improve the coating efficiency, a roller coating process is often used. The term 'roller coating' may be interpreted a rotating roller serves as a carrier of the active material, the active material forms a wet film with a certain thickness on a surface of the rotating roller, and then the surface of the current collector is coated with the active material by means of contact of the rotating roller with the current collector during rotating. The cold-pressing procedure is to roll an electrode plate with the active material adhered thereto by a cold-pressing device, so that the coated material is tighter, the energy density is increased, and the consistency of thickness is ensured; and dust and humidity are also further controlled.

As mentioned above, the coating efficiency may be improved through the roller coating process, however, electrode plates subjected to coating by using the roller coating process are prone to electrode plate breakage in the cold-pressing procedure. The inventors have found that the reason for the occurrence of electrode plate breakage is that in the coating procedure, the coated region is subjected to pressure from the rotating roller, while the uncoated region is not subjected to the pressure from the rotating roller, resulting in different extension rates between the coated region and the uncoated region, and causing the production of folds in the uncoated region, so the electrode plate is prone to breakage in the cold-pressing procedure, affecting the production capacity of electrode plates.

In view of this, in order to reduce the risk of breakage of electrode plates in the cold-pressing procedure and improve the production capacity of the electrode plates, after thorough research, the inventors have designed an electrode plate extension device, comprising a first roller and a second roller. The first roller comprises a first body and a protrusion. The protrusion is provided on an outer peripheral surface of the first body and extends in a circumferential direction of the first body. The second roller comprises a second body and a groove. The groove is provided in an outer peripheral surface of the second body and extends in a circumferential direction of the second body. The first roller and the second roller are arranged in parallel, an electrode plate passes between the first roller and the second roller so as to be fed, and the protrusion and the groove correspond to two opposite sides of uncoated region of the electrode plate in a thickness direction respectively. When the electrode plate is fed between the first roller and the second roller, the uncoated region may be subjected to plastic deformation under the combined action of the protrusion and the groove so as to flatten folds of the uncoated region. Moreover, the uncoated region is extended, so that the extension rate of the uncoated region is consistent with or approximatively consistent with that of the coated region.

In the above solution, the first body and the second body correspond to two opposite sides of the coated region of the electrode plate in the thickness direction, and the protrusion and the groove correspond to the two opposite sides of the uncoated region of the electrode plate in the thickness direction. When the electrode plate is fed between the first roller and the second roller, the protrusion protruding from the first body may act on the uncoated region and exert a certain pressure on the uncoated region, and with the support of the groove on the uncoated region, the uncoated region is subjected to plastic deformation while ensuring the safety, thereby achieving the effects of flattening folds of the uncoated region and extending the uncoated region. Therefore, the risk of breakage of the electrode plate in the subsequent cold-pressing procedure is reduced, the production capacity of electrode plates is improved, and thus the production efficiency of batteries is improved.

The electrode plate extension device disclosed in the embodiments of the present invention is configured for fold removal and extension of the uncoated region of the electrode plate. The electrode plate extension device may be part of the structure of an electrode plate manufacturing apparatus. The electrode plate manufacturing apparatus may further comprise the cold-pressing device. The electrode plate may be cold-pressed by the cold-pressing device after being operated by the electrode plate extension device, completing the cold-pressing procedure of the electrode plate.

According to some embodiments of the present invention, referring to <FIG>, <FIG> is a schematic diagram of an electrode plate extension device for use in a system according to some embodiments of the present invention, <FIG> is a perspective view of the electrode plate extension device for use in as system according to some embodiments of the present invention, <FIG> is an enlarged view of part A in <FIG>, and <FIG> is a schematic diagram of a protrusion <NUM> and a groove <NUM> for use in as system according to some embodiments of the present invention.

The electrode plate extension device comprises a first roller <NUM> and a second roller <NUM>. The first roller <NUM> comprises a first body <NUM> and a protrusion <NUM>. The protrusion <NUM> is provided on an outer peripheral surface of the first body <NUM> and extends in a circumferential direction of the first body <NUM>. The second roller <NUM> comprises a second body <NUM> and a groove <NUM>. The groove <NUM> is provided in an outer peripheral surface of the second body <NUM> and extends in a circumferential direction of the second body <NUM>. The first roller <NUM> and the second roller <NUM> are arranged in parallel. A gap for allowing the passage of an electrode plate <NUM> is formed between the first roller <NUM> and the second roller <NUM>. The protrusion <NUM> is positioned corresponding to the groove <NUM>, and the protrusion <NUM> is configured to press against an uncoated region <NUM> of the electrode plate <NUM> to cause a plastic deformation of the uncoated region <NUM>.

The first roller <NUM> is a component arranged opposite the second roller <NUM>, central axes of the first roller <NUM> and the second roller <NUM> are parallel to each other, and the gap for allowing the passage and feeding of the electrode plate <NUM> is reserved between the first roller and the second roller. The first roller <NUM> and the second roller <NUM> may be arranged in such a way that the first roller <NUM> is located above the second roller <NUM>; alternatively, the first roller <NUM> is located below the second roller <NUM>. Optionally, the embodiments of the present invention are described by taking the example that the first roller <NUM> is located above the second roller <NUM>.

The first body <NUM> is in a cylindrical shape, and a central axis thereof is the central axis of the first roller <NUM>. The protrusion <NUM> protrudes from the outer peripheral surface of the first body <NUM> and encircles the first body <NUM>. The protrusion <NUM> corresponds to the uncoated region <NUM> of the electrode plate <NUM>, and the first body <NUM> corresponds to a coated region <NUM> of the electrode plate <NUM>. That is, when the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, the protrusion <NUM> acts on a surface of the uncoated region <NUM> of the electrode plate <NUM>, and the first body <NUM> acts on a surface of the coated region <NUM> of the electrode plate <NUM>.

The second body <NUM> is in a cylindrical shape, and a central axis thereof is the central axis of the second roller <NUM>. The groove <NUM> is recessed from the outer peripheral surface of the second body <NUM> and encircles the second body <NUM>. The groove <NUM> corresponds to the surface of the uncoated region <NUM> facing away from the protrusion <NUM>, and the second body <NUM> corresponds to the surface of the coated region <NUM> facing away from the first body <NUM>.

By plastic deformation is meant that when the protrusion <NUM> and the groove <NUM> act on the uncoated region <NUM>, folds of the uncoated region <NUM> can be flattened, and the uncoated region <NUM> is extended.

In the above solution, when the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, the protrusion <NUM> acts on the uncoated region <NUM> and exerts a certain depressing tension on the uncoated region <NUM>, and with the support of the groove <NUM> on the uncoated region <NUM>, the uncoated region <NUM> is subjected to plastic deformation while ensuring the safety, thereby achieving the effects of flattening folds of the uncoated region <NUM> and extending the uncoated region <NUM>. Therefore, the risk of breakage of the electrode plate <NUM> in the subsequent cold-pressing procedure process is reduced, the production capacity of electrode plates <NUM> is improved, and thus the production efficiency of batteries is improved.

According to some embodiments of the present invention, the protrusion <NUM> has a complementary shape to the groove <NUM>.

The wording "the protrusion <NUM> has a complementary shape to the groove <NUM>"may be interpreted the protrusion <NUM> protrudes toward the groove <NUM>, and when the uncoated region <NUM> is located between the protrusion <NUM> and the groove <NUM> and any position of the surface of the protrusion <NUM> acts on the uncoated region <NUM>, the uncoated region <NUM> can be brought into close contact with the surface of the groove <NUM>.

In the above solution, the uncoated region <NUM> is subjected to plastic deformation under the depressing tension from the protrusion <NUM> to fit the surface of the groove <NUM>, so that the folds of the uncoated region <NUM> are effectively flattened, and the uncoated region <NUM> is extended.

According to some embodiments of the present invention, as shown in <FIG> is a schematic diagram of the protrusion <NUM> and the groove <NUM> for use in as system according to other embodiments of the present invention.

The surface of the protrusion <NUM> has an arc-shaped transition into the outer peripheral surface of the first body <NUM>, and the surface of the groove <NUM> has an arc-shaped transition into the outer peripheral surface of the second body <NUM>.

The wording "the surface of the protrusion <NUM> has an arc-shaped transition into the outer peripheral surface of the first body <NUM>" may be interpreted the protrusion <NUM> protrudes from the surface of the first body <NUM>, and a height difference between the protrusion and the first body is compensated by an arc-shaped structure. In <FIG>, the transition between the surface of the protrusion <NUM> and the outer peripheral surface of the first body <NUM> is not arc-shaped transition, but may be regarded as right-angled transition. "The surface of the protrusion <NUM> having an arc-shaped transition into the outer peripheral surface of the first body <NUM>" can be intuitively understood by comparing <FIG>, <FIG>.

Similarly, the wording "the surface of the groove <NUM> has an arc-shaped transition into the outer peripheral surface of the second body <NUM>" may be interpreted as: the groove <NUM> is recessed from the surface of the second body <NUM>, and a height difference between the groove and the second body is compensated by an arc-shaped structure.

In the above solution, since the surface of the protrusion <NUM> has an arc-shaped transition into the outer peripheral surface of the first body <NUM>, and the surface of the groove <NUM> has an arc-shaped transition into the outer peripheral surface of the second body <NUM>, it is possible to avoid damage to the uncoated region <NUM> that is caused by a large height difference between the uncoated region and the coated region of the electrode plate <NUM> after the uncoated region is subjected to a depressing tension from the protrusion <NUM>, ensuring the safety of the electrode plate <NUM>.

In some embodiments, the protrusion <NUM> and the groove <NUM> may be in various shapes, including but not limited to: an arc-edge and round-cornered type, an arc-edge and right-angled type, an arc-edge and wide-angled type, a semi-straight-edge and round-cornered type, a straight-edge and round-cornered type, a straight-edge and right-angled type, etc..

The protrusion <NUM> and the groove <NUM> shown in <FIG> are of an arc-edge and round-cornered type. The term 'arc-edge' may be interpreted as: the protrusion <NUM> has a transition into the surface of the first body <NUM> via an arc edge, and the groove <NUM> has a transition into the surface of the second body <NUM> via an arc edge. By round-cornered is meant that the surface of the protrusion <NUM> facing the groove <NUM> is arc-shaped, and the surface of the groove <NUM> facing the protrusion <NUM> is arc-shaped.

The protrusion <NUM> and the groove <NUM> shown in <FIG> are of an arc-edge and wide-angled type. Taking the protrusion <NUM> as an example for illustration, by arc-edge and wide-angled is meant that the protrusion <NUM> has a transition into the first body <NUM> via arc edges, the protrusion <NUM> comprises a straight section <NUM> and arc sections <NUM>, and the straight section <NUM> is connected to the arc edges via the arc sections <NUM>.

Referring to <FIG> is a schematic diagram of a protrusion <NUM> and a groove <NUM> of an arc-edge and right-angled type for use in as system according to some embodiments of the present invention. The protrusion <NUM> and the groove <NUM> shown in <FIG> are of the arc-edge and right-angled type. Taking the protrusion <NUM> as an example for illustration, by arc-edge and right-angled is meant that the protrusion <NUM> has a transition into the first body <NUM> via arc edges, the protrusion <NUM> comprises a first section <NUM> and second sections <NUM>, the first section <NUM> and the second sections <NUM> are both straight sections, and the first section <NUM> is connected to the arc edges via the second sections <NUM>.

Referring to <FIG> is a schematic diagram of a protrusion <NUM> and a groove <NUM> of a semi-straight-edge and round-cornered type for use in as system according to some embodiments of the present invention. The protrusion <NUM> and the groove <NUM> shown in <FIG> are of the semi-straight-edge and round-cornered type. Taking the protrusion <NUM> as an example for illustration, the protrusion <NUM> is arc-shaped, and edges of the protrusion <NUM> are directly connected to the surface of the first body <NUM>, without transition of an arc-shaped structure (arc edge) therebetween.

Referring to <FIG> is a schematic diagram of a protrusion <NUM> and a groove <NUM> of a straight-edge and round-cornered type for use in as system according to some embodiments of the present invention. The protrusion <NUM> and the groove <NUM> shown in <FIG> are of the straight-edge and round-cornered type. Taking the protrusion <NUM> as an example for illustration, the protrusion <NUM> comprises an arc-shaped section <NUM> and straight edge sections <NUM>, the straight edge sections <NUM> are located at two ends of the arc-shaped section <NUM>, and the arc-shaped section <NUM> is connected to the surface of the first body <NUM> via the straight edge sections <NUM>.

Referring to <FIG> is a schematic diagram of a protrusion <NUM> and a groove <NUM> of a straight-edge and right-angled type for use in as system according to some embodiments of the present invention. The protrusion <NUM> and the groove <NUM> shown in <FIG> are of a straight-edge and right-angled type. Taking the protrusion <NUM> as an example for illustration, the protrusion <NUM> comprises a third section <NUM> and fourth sections <NUM>, the fourth sections <NUM> are located at two ends of the third section <NUM>, the fourth sections <NUM> are perpendicular to the third section <NUM>, the third section <NUM> is connected to the surface of the first body <NUM> via the fourth sections <NUM>, and the fourth sections <NUM> are perpendicular to the surface of the first body <NUM>.

In some embodiments, when the surface of the protrusion <NUM> has an arc-shaped transition into the outer surface of the first body <NUM>, that is, when a rounded angle is provided between the protrusion <NUM> and the first body <NUM>, the rounded angle has a dimension of R (which can be seen in <FIG>), which satisfies <NUM> ≤ R ≤ <NUM>. In some embodiments, R may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM>.

In the above solution, the rounded angle is provided between the protrusion <NUM> and the first body <NUM> to adapt to an electrode plate <NUM> with an insulating layer arranged between the uncoated region <NUM> and the coated region <NUM>. By limiting the dimension range of the rounded angle to correspond to a dimension of the insulating layer, the insulating layer is prevented from being damaged when the protrusion <NUM> depresses the uncoated region <NUM>.

According to some embodiments of the present invention, a dimension of the protrusion <NUM> in a length direction of the first roller <NUM> is W, which satisfies <NUM> ≤ W ≤ <NUM>.

The dimension of the protrusion <NUM> in the length direction of the first roller <NUM> is a width of the protrusion <NUM>, and the width of the protrusion <NUM> corresponds to a width of the uncoated region <NUM>, so that the protrusion <NUM> can act on any position of the uncoated region <NUM> when acting on the uncoated region <NUM>. Uncoated regions <NUM> of electrode plates <NUM> of different specifications have different widths. Generally, the value range of the widths of the uncoated regions <NUM> of the electrode plates <NUM> of different specifications is <NUM> - <NUM>, and the value range of the width W of the protrusion <NUM> is defined to adapt to the electrode plates <NUM> of different specifications. Correspondingly, a dimension of the groove <NUM> in a length direction of the second roller <NUM> is consistent with the width of the protrusion <NUM>.

In the above solution, the width of the protrusion <NUM> is greater than or equal to <NUM> and less than or equal to <NUM>, so as to correspond to the widths of the uncoated regions <NUM> on the electrode plates <NUM> of different specifications. The value of the width (W) of the protrusions <NUM> may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>.

In some embodiments, the width (W) of the protrusion <NUM> may be <NUM> to adapt to an uncoated region <NUM> with a width of <NUM>; the width (W) of the protrusion <NUM> may be <NUM> to adapt to an uncoated region <NUM> with a width of <NUM>; the width (W) of the protrusion <NUM> may be <NUM> to adapt to an uncoated region <NUM> with a width of <NUM>; and the width (W) of the protrusion <NUM> may be <NUM> to adapt to an uncoated region <NUM> with a width of <NUM>.

According to some embodiments of the present invention, referring to <FIG>, a dimension by which the protrusion <NUM> protrudes from the outer peripheral surface of the first body <NUM> is H, which satisfies <NUM> ≤ H ≤ <NUM>.

The dimension by which the protrusion <NUM> protrudes from the outer peripheral surface of the first body <NUM> is a height of the protrusion <NUM>, and the height of the protrusion <NUM> corresponds to the extension rate of the uncoated region <NUM>. Since a different extension rate of the uncoated region <NUM> is required to reach for each type of electrode plate <NUM>, the protrusions <NUM> of different heights correspond to the uncoated regions <NUM> of different extension rates. The higher the height of the protrusion <NUM>, the higher the extension rate of the uncoated region <NUM> after the protrusion <NUM> act on the uncoated region <NUM>. Correspondingly, a dimension by which the groove <NUM> is recessed from the outer peripheral surface of the second body <NUM> is consistent with the height of the protrusion <NUM>.

In the above solution, since a different extension rate of the uncoated region <NUM> is required to reach for the electrode plate <NUM> of each specification, the height range of the protrusion <NUM> is limited, the different heights of the protrusions <NUM> indicate different extension rates obtained after the uncoated region <NUM> is rolled by the protrusions <NUM>, and the greater the height of the protrusion <NUM>, the greater the extension rate. In some embodiments, the height (H) of the protrusion <NUM> may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM>.

According to some embodiments of the present invention, referring to <FIG>, and <FIG> is a schematic diagram of an electrode plate <NUM> according to some embodiments of the present invention.

A plurality of protrusions <NUM> are provided, and the plurality of protrusions <NUM> are distributed at intervals in an axial direction of the first body <NUM>. A plurality of grooves <NUM> are provided, the plurality of grooves <NUM> are distributed at intervals in an axial direction of the second body <NUM>, and the grooves <NUM> are in one-to-one correspondence with the protrusions <NUM>.

As shown in <FIG>, in order to improve the coating efficiency, a roller coating process is adopted for coating in a stripe coating manner, so as to form a plurality of uncoated regions <NUM> arranged at intervals on the electrode plate <NUM>. In the subsequent procedure, the electrode plate <NUM> is divided into a plurality of parts by cutting.

The plurality of protrusions <NUM> and the plurality of grooves <NUM> are provided to correspond to the plurality of uncoated regions <NUM> on a current collector.

In the above solution, by providing the plurality of protrusions <NUM> and the plurality of grooves <NUM> to roll the plurality of uncoated regions <NUM> on the electrode plate <NUM> simultaneously, the efficiency of solving the problems about folds and extension of the uncoated regions <NUM> is effectively improved, the production capacity of electrode plates <NUM> is improved, and thus the production efficiency of batteries is improved.

According to some embodiments of the present invention, referring to <FIG>, the electrode plate extension device further comprises a heating portion <NUM>. The heating portion <NUM> is configured to heat the uncoated region <NUM>.

The heating portion <NUM> is a component capable of producing heat to heat the uncoated region <NUM>.

When only the protrusion <NUM> and the groove <NUM> are used to act on the uncoated region <NUM>, the exerted pressure is large, the tolerance (fracture tensile strength) of the uncoated region <NUM> is greatly reduced due to the limited ductility of the uncoated region <NUM>, and a foil has high residual stress after calendering, which is not conducive to removal of folds and is likely to cause breakage in the subsequent cold-pressing procedure of the electrode plate <NUM>. Especially when the uncoated region <NUM> has pinholes, bumpy spots, damaged edges, and other unavoidable problems arising from transportation, the extension effect of the uncoated region <NUM> is poor if the uncoated region <NUM> is pressed only by means of the protrusion <NUM> and the groove <NUM>. For this reason, the uncoated region <NUM> is heated by the heating portion <NUM>. After the uncoated region <NUM> is heated, the tensile strength is reduced, the flexibility is improved, and when the protrusion <NUM> and groove <NUM> act, the uncoated region <NUM> is easily extended and stretched under a small tension, reducing the risk of breakage.

In the above solution, by heating the uncoated region <NUM>, the residual stress and tensile strength of the uncoated region <NUM> are reduced, and the flexibility is improved, so as to ensure that when the protrusion <NUM> and the groove <NUM> act on the uncoated region <NUM>, the uncoated region <NUM> can be subjected to plastic deformation under a small depressing tension so as to be extended and stretched, then the folds of the uncoated region <NUM> are effectively flattened, the risk of breakage of the electrode plate <NUM> in the subsequent cold-pressing procedure is reduced, and the production capacity of electrode plates <NUM> is improved.

According to some embodiments of the present invention, referring to <FIG>, the heating portion <NUM> is arranged inside the first body <NUM> and/or the second body <NUM>.

The wording "the heating portion <NUM> is arranged inside the first body <NUM> and/or the second body <NUM>" may be interpreted as: the heating portion <NUM> is arranged inside the first body <NUM>; or the heating portion <NUM> is arranged inside the second body <NUM>; or heating portions <NUM> are arranged inside the first body <NUM> and the second body <NUM> respectively.

In some embodiments, the heating portion <NUM> may be an inner heating roller arranged inside the first body <NUM> and/or the second body <NUM>. The inner heating roller may be of a resistance heating structure.

The wording "the heating portion <NUM> is arranged inside the first body <NUM> and/or the second body <NUM>" may also be interpreted as the heating portion <NUM> being part of the structure of the first roller <NUM>; or the heating portion <NUM> being part of the structure of the second roller <NUM>; or each of the first roller <NUM> and the second roller <NUM> having the heating portion <NUM>. That is, when the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, the uncoated region <NUM> can be heated by the first roller <NUM> and/or the second roller <NUM>. In some embodiments, a heating mode of the first roller <NUM> and/or the second roller <NUM> may be: a steam heating roller heating technology, a heat conduction oil heating roller heating technology, an electric heating pipe heating roller heating technology or a resistance wire heating roller heating technology. The steam heating roller heating technology, the heat conduction oil heating roller heating technology, the electric heating pipe heating roller heating technology or the resistance wire heating roller heating technology is an existing conventional roller heating technology, which will thus not be described in detail in the embodiments of the present invention.

In the above solution, when the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, the heating portion <NUM> located in the first body <NUM> and/or the second body <NUM> heats the uncoated region <NUM> by heating the protrusion <NUM> on the first body <NUM> or the groove <NUM> in the second body <NUM>, so that the extension and stretching efficiency of the uncoated region <NUM> is improved (when the heating portions <NUM> are arranged on inner walls of the first body <NUM> and the second body <NUM> respectively, the first roller <NUM> and the second roller <NUM> can heat the uncoated region <NUM> simultaneously, so that the uncoated region <NUM> has a remarkable heating effect). Moreover, since the heating portion <NUM> is arranged inside the first body <NUM> and/or the second body <NUM>, it is possible that the electrode plate extension device has a compact structure and a low space occupancy, thereby avoiding wasting space.

According to some other embodiments of the present invention, referring to <FIG> is a perspective view of an electrode plate extension device for use in as system according to some other embodiments of the present invention. The heating portion <NUM> is independent of the first roller <NUM> and the second roller <NUM>.

The wording "the heating portions <NUM> are independent of the first roller <NUM> and the second roller <NUM>" may be interpreted as: the heating portion <NUM> is an independent component. In <FIG>, two heating portions <NUM> are exemplarily drawn, and the two heating portions <NUM> are located above the uncoated regions <NUM> to heat the corresponding uncoated regions <NUM>. In other embodiments, the heating portions <NUM> may be located below the uncoated regions <NUM>.

In the above solution, since the heating portion <NUM> is independent of the first roller <NUM> and the second roller <NUM>, it is possible to heat the uncoated region <NUM> independently, to ensure the heating effect of the uncoated regions <NUM>. Moreover, since there is no need for the first roller <NUM> and the second roller <NUM> to be provided with the heating portion <NUM>, the first roller <NUM> and the second roller <NUM> have a simple structure, and the manufacturing cost of the first roller <NUM> and the second roller <NUM> is effectively reduced.

According to some embodiments of the present invention, in a feeding direction of the electrode plate <NUM>, the heating portion <NUM> is arranged upstream of the first roller <NUM> and the second roller <NUM>.

The wording "the heating portion <NUM> is arranged upstream of the first roller <NUM> and the second roller <NUM>" may be interpreted as: the electrode plate <NUM> passes through the heating portion <NUM> and then passes between the first roller <NUM> and the second roller <NUM>. That is, the uncoated region <NUM> is firstly heated by the heating portion <NUM> and then rolled by the protrusion <NUM> and the groove <NUM>.

In the above solution, as the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, the uncoated region <NUM> of the electrode plate <NUM> is heated by the heating portion <NUM>, so that the residual stress and tensile strength of the uncoated region <NUM> are reduced, and the flexibility is improved. Therefore, when the protrusion <NUM> and the groove <NUM> act on the uncoated region <NUM>, the uncoated region <NUM> can be subjected to plastic deformation under a small depressing tension so as to be extended and stretched, then the folds of the uncoated region <NUM> are effectively flattened, the risk of breakage of the electrode plate <NUM> in the subsequent cold-pressing procedure is reduced, and the production capacity of electrode plates <NUM> is improved.

According to some embodiments of the present invention, the heating portion <NUM> is a magnetic induction heating portion <NUM> or a far infrared heating portion <NUM>.

The magnetic induction heating portion <NUM> heats the uncoated region <NUM> based on the principle of magnetic induction heating. The far infrared heating portion <NUM> heats the uncoated region <NUM> by means of infrared thermal radiation. The heating mode of the magnetic induction heating portion <NUM> or the far infrared heating portion <NUM> is an existing conventional heating mode, which will thus not be described in detail in the present application.

In the present invention, referring to <FIG> and <FIG>, the electrode plate extension device further comprises a third roller <NUM>. The third roller <NUM> is located on the side of the second roller <NUM> facing away from the first roller <NUM>, and is configured to support the second roller <NUM>.

A central axis of the third roller <NUM> is parallel to the central axis of the second roller <NUM>. Generally, the first roller <NUM> is located above the second roller <NUM>, and the second roller <NUM> is located above the third roller <NUM>.

In the above solution, the third roller <NUM> is an idler roller, which is configured to support the weight of the second roller <NUM> and the first roller <NUM>, so that the first roller <NUM> stably exerts a depressing tension to the uncoated region <NUM>, and the effective plastic deformation of the uncoated region <NUM> is ensured.

According to some embodiments of the present invention, one of the first roller <NUM> and the second roller <NUM> is a driving roller and the other is a driven roller.

The driving roller is a roller capable of rotating actively, and the driven roller is a roller that follows the rotation under the action of the driving roller. Referring to <FIG>, the first roller <NUM> is the driving roller, and the first roller <NUM> has a driving shaft in <FIG>. Referring to <FIG>, the second roller <NUM> is the driving roller, and the second roller <NUM> has a driving shaft in <FIG>.

In the above solution, when the first roller <NUM> is the driving roller and the second roller <NUM> is the driven roller, the first roller <NUM> rotates actively to provide the depressing tension for the uncoated region <NUM>, and the second roller <NUM> is rotated passively to provide support for the uncoated region <NUM>. Alternatively, when the first roller <NUM> is the driven roller and the second roller <NUM> is the driving roller, the second roller <NUM> rotates actively, provides support for the uncoated region <NUM>, and drives the first roller <NUM> to rotate such that the first roller <NUM> provides the depressing tension for the uncoated region <NUM>.

According to some embodiments of the present invention, the electrode plate extension device further comprises: an adjusting mechanism (not shown) connected to the driving roller and configured to adjusting the tension exerted by the driving roller to the electrode plate <NUM>.

In the above solution, by adjusting the tension exerted by the driving roller to the electrode plate <NUM> through the adjusting mechanism, it is possible to adjust the extension rate of the uncoated region <NUM>, so as to adapt to the requirements of electrode plates <NUM> of different specifications.

According to some embodiments, the present invention further provides an electrode plate manufacturing apparatus, comprising the system described above and a cold-pressing device. The cold-pressing device is configured to cold-press an electrode plate <NUM>, so as to complete a cold-pressing procedure of the electrode plate <NUM>. The cold-pressing device is arranged downstream of the electrode plate extension device in a feeding direction of the electrode plate <NUM>.

In the above solution, after an uncoated region <NUM> of the electrode plate <NUM> is subjected to extension and fold removal by the electrode plate extension device, it is possible to reduce the risk of breakage of the electrode plate <NUM> during cold-pressing in the cold-pressing device, thereby improving the production capacity of electrode plates <NUM>.

According to some embodiments of the present invention referring to <FIG>, some embodiments of the present invention provide an electrode plate extension device that is located upstream of the cold-pressing device and configured to perform extension and fold removal on the uncoated region <NUM> of the electrode plate <NUM>. The electrode plate extension device comprises a first roller <NUM>, a second roller <NUM>, and a third roller <NUM> arranged one above another. The electrode plate <NUM> passes through a gap between the first roller <NUM> and the second roller <NUM> so as to be fed. The third roller <NUM> is an idler roller for supporting the second roller <NUM>, so as to ensure the stability of the first roller <NUM> and the second roller <NUM>. The first roller <NUM> is a driving roller, and comprises a first body <NUM> and protrusions <NUM> (three protrusions <NUM> are provided, and the three protrusions <NUM> are arranged at intervals in an axial direction of the first body <NUM>). The protrusions <NUM> are arranged on an outer peripheral surface of the first body <NUM> and extend in a circumferential direction of the first body <NUM>. A heating portion <NUM> is arranged inside the first body <NUM>, and the heating portion <NUM> can heat the first body <NUM> and the protrusions <NUM>. The second roller <NUM> is a driven roller, and comprises a second body <NUM> and grooves <NUM>. The grooves <NUM> are provided in an outer peripheral surface of the second body <NUM> and extend in a circumferential direction of the second body <NUM>. A heating portion <NUM> is also arranged inside the second body <NUM>, and the heating portion <NUM> can heat the second body <NUM> and the grooves <NUM>. The heating portions <NUM> inside the first roller <NUM> and the second roller <NUM> are both electromagnetic heating rollers arranged inside the first body <NUM> and the second body <NUM> respectively. Since the first roller <NUM> and the second roller <NUM> both have the heating portions <NUM>, the uncoated regions <NUM> of the electrode plate <NUM> can be heated when the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, and the flexibility of the uncoated region <NUM> is improved. In this way, during feeding of the electrode plate <NUM>, the protrusions <NUM> act on the uncoated regions <NUM> and exert a certain depressing tension to calender the uncoated regions to fit the grooves <NUM>, thereby achieving the effects of flattening folds and extending a foil, and reducing the breakage rate of the electrode plate <NUM> in the cold-pressing procedure. The protrusions <NUM> have the complementary shape to the grooves <NUM>. The protrusions <NUM> and the grooves <NUM> are of an arc-edge and round-cornered type. A dimension W of the protrusions <NUM> in a length direction of the first roller <NUM> is <NUM>. The protrusions <NUM> protrude from the outer peripheral surface of the first body <NUM> by a dimension H of <NUM>. When rounded angles are provided between the protrusions <NUM> and the first body <NUM>, a dimension R of the rounded angles is <NUM>.

According to some embodiments of the present invention, referring to <FIG> and <FIG>, some embodiments of the present application provide an electrode plate extension device that is located upstream of the cold-pressing device and configured to perform extension and fold removal on the uncoated region <NUM> of the electrode plate <NUM>. The electrode plate extension device comprises a first roller <NUM>, a second roller <NUM>, and a third roller <NUM> arranged one above another. The electrode plate <NUM> passes through a gap between the first roller <NUM> and the second roller <NUM> so as to be fed. The third roller <NUM> is an idler roller for supporting the second roller <NUM>, so as to ensure the stability of the first roller <NUM> and the second roller <NUM>. The first roller <NUM> is a driven roller, and comprises a first body <NUM> and protrusions <NUM> (two protrusions <NUM> are provided, and the two protrusions <NUM> are arranged at intervals in an axial direction of the first body <NUM>). The protrusions <NUM> are arranged on an outer peripheral surface of the first body <NUM> and extend in a circumferential direction of the first body <NUM>. The second roller <NUM> is a driving roller and comprises a second body <NUM> and grooves <NUM>. The grooves <NUM> are provided in an outer peripheral surface of the second body <NUM> and extend in a circumferential direction of the second body <NUM>. The electrode plate extension device further comprises heating portions <NUM>. The heating portions <NUM> are magnetic induction heating portions <NUM>, for heating the uncoated regions <NUM> independently of the first roller <NUM> and the second roller <NUM>. The heating portions <NUM> are located upstream of the first roller <NUM> and the second roller <NUM>, so that the uncoated regions <NUM> are heated before the electrode plate <NUM> passes between the first roller <NUM> and the second roller <NUM>, and the flexibility of the uncoated regions <NUM> is improved. In this way, during feeding of the electrode plate <NUM>, the protrusions <NUM> act on the uncoated regions <NUM> and exert a certain depressing tension to calender the uncoated regions to fit the grooves <NUM>, thereby achieving the effects of flattening folds and extending a foil, and reducing the breakage rate of the electrode plate <NUM> in the cold-pressing procedure. The protrusions <NUM> have the complementary shape to the grooves <NUM>. The protrusions <NUM> and the grooves <NUM> are of an arc-edge and wide-angled type. A dimension W of the protrusions <NUM> in a length direction of the first roller <NUM> is <NUM>. The protrusions <NUM> protrude from the outer peripheral surface of the first body <NUM> by a dimension H of <NUM>. When rounded angles are provided between the protrusions <NUM> and the first body <NUM>, a dimension R of the rounded angles is <NUM>.

Claim 1:
A system comprising an electrode plate extension device and an electrode plate, wherein
the electrode plate comprises a coated region coated with an active material layer and an uncoated region; and
the electrode plate extension device comprises:
a first roller (<NUM>), comprising a first body (<NUM>) and a protrusion (<NUM>), the protrusion (<NUM>) being provided on an outer peripheral surface of the first body (<NUM>) and extending in a circumferential direction of the first body (<NUM>); and
a second roller (<NUM>), comprising a second body (<NUM>) and a groove (<NUM>), the groove (<NUM>) being provided in an outer peripheral surface of the second body (<NUM>) and extending in a circumferential direction of the second body (<NUM>),
wherein the first roller (<NUM>) and the second roller (<NUM>) are arranged in parallel, a gap for allowing the passage of the electrode plate (<NUM>) is formed between the first roller (<NUM>) and the second roller (<NUM>), the protrusion (<NUM>) is positioned corresponding to the groove (<NUM>), and the protrusion (<NUM>) is configured to press against the uncoated region (<NUM>) of the electrode plate (<NUM>) to cause a plastic deformation of the uncoated region (<NUM>); the system being characterized in that
the electrode plate extension device further comprises a third roller (<NUM>), located on the side of the second roller (<NUM>) facing away from the first roller (<NUM>), and configured to support the second roller (<NUM>).