Roll core pole piece hot pressing tool

Abstract

The utility model provides a roll core pole piece hot-pressing tool, the cross section of a roll core pole piece is provided with two oppositely arranged pressure-bearing surfaces and a corner surface connecting the two pressure-bearing surfaces, the hot-pressing tool comprises at least one hot-pressing plate, the hot-pressing plate is provided with a pressing part suitable for pressing the roll core pole piece, the pressing part is provided with a pressing surface and an avoiding surface, and the pressing surface and the avoiding surface are arranged on the corner surface. The pressing surface forms a plane suitable for pressing the pressure-bearing surface, the avoiding surface is arranged on at least one part of the outer contour of the pressing surface, and the avoiding surface corresponds to the corner surface in position so as to avoid the corner surface when the pressing part presses the roll core pole piece. According to the hot-pressing tool for the roll core pole piece, when the hot-pressing plate carries out hot-pressing shaping on the roll core pole piece, the avoiding face can avoid the corner face when the roll core pole piece is pressed, the corner of the roll core pole piece is prevented from being excessively folded, powder falling of the roll core pole piece at the corner is avoided, and the stability and the yield of products are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and more specifically to a hot pressing tool for winding core pole pieces. Background Art

[0002] During the battery production process, the electrode assembly consisting of the positive and negative electrode sheets and the separator is wound to form a core. Subsequently, the core is generally hot-pressed and shaped.

[0003] After hot pressing, the core will be folded 180° at the corner. The existing hot pressing plate is usually a flat structure. During hot pressing, the hot pressing plate will fold excessively at the corner of the electrode assembly, causing the negative electrode to lose powder at the corner. As a result, during subsequent battery charging, the negative electrode at the corner cannot be completely embedded in the sodium migrated from the positive electrode, causing sodium precipitation. Utility Model Content

[0004] The utility model provides a new technical solution for hot pressing tooling of a winding core pole piece, which can at least solve one problem in the prior art.

[0005] The utility model provides a hot pressing tool for a core winding pole piece, wherein the cross section of the core winding pole piece has two pressure-bearing surfaces arranged opposite to each other and a corner surface connecting the two pressure-bearing surfaces, the hot pressing tool comprises at least one hot pressing plate, the hot pressing plate is provided with a pressing portion suitable for pressing the core winding pole piece, the pressing portion has a pressing surface and an avoidance surface, the pressing surface is formed as a plane suitable for pressing the pressure-bearing surface, the avoidance surface is arranged on at least a part of the outer contour of the pressing surface, and the avoidance surface corresponds to the position of the corner surface so as to avoid the corner surface when the pressing portion presses the core winding pole piece.

[0006] Optionally, the avoidance surface is formed as an inclined surface that is bent relative to the plane where the pressing surface is located and faces away from the winding core pole piece.

[0007] Optionally, the avoidance surface is formed as an arc-shaped chamfer.

[0008] Optionally, the radius of the arc-shaped chamfer is in the range of 0.05 mm to 0.5 mm.

[0009] Optionally, the orthographic projection of the starting point of the avoidance surface on the plane where the pressure-bearing surface is located is located within the pressure-bearing surface.

[0010] Optionally, the distance between the starting point of the avoidance surface and the innermost corner of the winding core pole piece is 0.5 mm-1.5 mm.

[0011] Optionally, there are two avoidance surfaces, which are respectively arranged at positions on both sides of the pressing surface corresponding to the two corner surfaces.

[0012] Optionally, there are two hot pressing plates, and at least one of the hot pressing plates is provided with a pressing portion.

[0013] Optionally, each hot pressing plate is provided with a pressing portion.

[0014] Optionally, the two heat pressing plates are arranged opposite to each other and symmetrically.

[0015] According to the hot pressing tooling of the core-wound pole piece of the utility model, a pressing part is arranged on the hot pressing plate, and the pressing surface of the pressing part can press the core-wound pole piece normally, and the position of the avoidance surface corresponds to the position of the corner surface of the core-wound pole piece, so that when the hot pressing plate performs hot pressing and shaping on the core-wound pole piece, the avoidance surface can avoid the corner surface when pressing the core-wound pole piece, preventing the corner of the core-wound pole piece from being excessively folded in half, avoiding powder loss at the corner of the core-wound pole piece, and improving the stability and yield of the product.

[0016] Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0018] Figure 1 It is a schematic diagram of a hot pressing tool for winding core pole pieces according to an embodiment of the utility model;

[0019] Figure 2 It is a partial enlarged view of a core winding pole piece hot pressing tooling according to an embodiment provided by the utility model.

[0020] Reference numerals:

[0021] Core winding pole piece 10; pressure bearing surface 11; corner surface 12;

[0022] Hot pressing plate 20 ; pressing portion 21 ; pressing surface 22 ; avoidance surface 23 . DETAILED DESCRIPTION

[0023] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention.

[0024] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present invention, its application, or uses.

[0025] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0026] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0027] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0028] The following is a detailed description of the core winding pole piece hot pressing tooling according to an embodiment of the utility model in conjunction with the accompanying drawings.

[0029] like Figure 1 to Figure 2 As shown, according to the hot pressing tooling of the core-wound pole piece of the embodiment of the utility model, the cross section of the core-wound pole piece 10 has two oppositely arranged pressure-bearing surfaces 11 and a corner surface 12 connecting the two pressure-bearing surfaces 11. The hot pressing tooling includes at least one hot pressing plate 20, and the hot pressing plate 20 is provided with a pressing portion 21 suitable for pressing the core-wound pole piece 10. The pressing portion 21 has a pressing surface 22 and an avoidance surface 23. The pressing surface 22 is formed as a plane suitable for pressing the pressure-bearing surface 11. The avoidance surface 23 is provided at least partially on the outer contour of the pressing surface 22. The avoidance surface 23 corresponds to the position of the corner surface 12 so as to avoid the corner surface 12 when the pressing portion 21 presses the core-wound pole piece 10.

[0030] In other words, the core-wound pole piece hot pressing tooling according to the embodiment of the utility model can be used to perform hot pressing on the core-wound pole piece 10. The core-wound pole piece 10 can be a conventional sodium-ion battery core-wound pole piece 10. When the core-wound pole piece 10 is hot pressed to form a flat structure, its cross-section is roughly formed into an oblong shape. The oblong core-wound pole piece 10 has two large surfaces arranged opposite to each other, namely the pressure-bearing surface 11, and corners are respectively provided at both ends of the oblong structure, forming a corner surface 12.

[0031] The hot pressing tooling may be composed of at least one hot pressing plate 20, on which a pressing portion 21 is provided, and the pressing portion 21 may be used to press the core pole piece 10, so that the core pole piece 10 is formed from a wound columnar structure into a flat structure. Unlike the conventional core pole piece hot pressing tooling, in which the pressing structure completely covers the pressure-bearing surface 11 during pressing, the pressing surface 22 of the core pole piece hot pressing tooling of this embodiment is provided with an avoidance surface 23 on at least a portion of the outer contour, so that when the pressing portion 21 presses the core pole piece 10, the corner surface 12 of the core pole piece 10 can be avoided by the avoidance surface 23 and not pressed, thereby preventing the core pole piece 10 from falling off at the corner.

[0032] It should be noted that the number of the hot pressing plates 20 of the core winding pole piece hot pressing tooling according to the embodiment of the utility model can be one or two.

[0033] When the number of the hot pressing plate 20 is one, the core pole piece 10 is placed on a plane, and the hot pressing plate 20 is pressed against the plane. The pressing surface 22 of the hot pressing plate 20 fits the pressure-bearing surface 11 of the core pole piece 10, and the avoidance surface 23 of the hot pressing plate 20 corresponds to the corner surface 12 of the core pole piece 10. The hot pressing plate 20 is set with a suitable temperature and pressure to hot press the core pole piece 10.

[0034] When there are two hot pressing plates 20, the core pole piece 10 is placed on the pressing surface 22 of one of the hot pressing plates 10, and the other hot pressing plate 20 is pressed against the core pole piece 10, so that the pressing surfaces 22 of the two hot pressing plates 20 fit the pressure-bearing surface 11 of the core pole piece 10, and the avoidance surface 23 of the hot pressing plate 20 corresponds to the corner surface 12 of the core pole piece 10. Appropriate temperature and pressure are set for the hot pressing plate 20 to hot press the core pole piece 10.

[0035] Since an avoidance surface 23 is provided on the outer contour of the pressing surface 22 of the pressing portion 21 corresponding to the position of the corner surface 12 of the core-wound pole piece 10, when the hot pressing plate 20 performs hot pressing and shaping on the core-wound pole piece 10, the pressing portion 21 avoids the corner surface 12 to prevent excessive folding at the corner due to hot pressing, causing powder loss of the negative pole piece at the corner, resulting in the inability of the negative electrode at the corner to be completely embedded in the sodium migrated from the positive electrode after subsequent charging, causing sodium precipitation.

[0036] Therefore, according to the hot pressing tooling of the core pole piece of the embodiment of the utility model, by setting a pressing part 21 on the hot pressing plate 20, the pressing surface 22 of the pressing part 21 can press the core pole piece 10 normally, and the position of the avoidance surface 23 corresponds to the position of the corner surface of the core pole piece 10, so that when the hot pressing plate 20 performs hot pressing and shaping on the core pole piece 10, the avoidance surface 23 can avoid the corner surface 12 when pressing the core pole piece 10, preventing the corner of the core pole piece 10 from being excessively folded, avoiding powder loss at the corner of the core pole piece 10, and improving the stability and yield of the product.

[0037] In some optional embodiments, the avoidance surface 23 is formed as an inclined surface that is bent relative to the plane where the pressing surface 22 is located and faces away from the winding core pole piece 10 .

[0038] In other words, the pressing surface 22 of the hot pressing plate 20 is thinned at a position close to the corner surface 12 of the core-wound pole piece 10 to form an inclined surface that avoids facing away from the core-wound pole piece 10 , thereby forming an avoidance surface 23 .

[0039] In some optional embodiments, the avoidance surface 23 is formed as an arc-shaped chamfer, and the radius of the arc-shaped chamfer is in the range of 0.05 mm to 0.5 mm.

[0040] In other words, the avoidance surface 23 can be an arc shape or a conventional chamfer, which facilitates the processing of the avoidance surface and saves costs.

[0041] Further, the radius of the arc is in the range of 0.05mm-0.5mm. For example, the radius R of the arc can be any one of 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm or any range between two values. The arc size R can be measured by tools such as arc radius measuring ruler, vernier caliper, and R gauge.

[0042] In some optional embodiments, the orthographic projection of the starting point of the avoidance surface 23 on the plane where the pressure-bearing surface 11 is located is located inside the pressure-bearing surface 11. The distance between the starting point of the avoidance surface 23 and the innermost corner of the winding core pole piece 10 is 0.5 mm-1.5 mm.

[0043] In other words, in order to avoid excessive hot pressing of the corner surface 12 of the core pole piece 10 by the pressing surface 22 of the pressing portion 21 during hot pressing, the pressing surface 22 is completely in contact with the pressure-bearing surface 11, and the starting point of the avoidance surface 23 is set so that the orthographic projection of the plane where the pressure-bearing surface 11 is located is located within the pressure-bearing surface 11.

[0044] Furthermore, if Figure 2 As shown, the distance d between the starting point of the avoidance surface 23 and the innermost corner of the core pole piece 10 is 0.5-1.5 mm. For example, the distance d between the starting point of the avoidance surface 23 and the innermost corner of the core pole piece 10 can be any value among 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or any range value between two of them. The distance d between the starting point of the avoidance surface 23 and the innermost corner of the core pole piece 10 can be measured by tools such as a vernier caliper.

[0045] In some optional embodiments, there are two avoidance surfaces 23 , and the two avoidance surfaces 23 are respectively disposed at positions on both sides of the pressing surface 22 corresponding to the two corner surfaces 12 .

[0046] In other words, avoidance surfaces 23 are provided on both sides of the pressing surface 22 of the hot pressing plate 20 at positions corresponding to the two corner surfaces 12. During hot pressing shaping, the hot pressing plate 20 can better perform hot pressing shaping on the core electrode sheet 10, and the pressing portion 21 avoids the two corner surfaces 12 on both sides of the core electrode sheet 10 to prevent excessive folding at the corners due to hot pressing, causing powder loss of the negative electrode sheet at the corners, resulting in the inability of the negative electrode at the corner to be completely embedded in the sodium migrated from the positive electrode after subsequent charging, causing sodium precipitation.

[0047] In some optional embodiments, there are two hot pressing plates 20 , and at least one of the hot pressing plates 20 is provided with a pressing portion 21 .

[0048] In other words, there can be two hot pressing plates 20, which are arranged opposite to each other, and at least one hot pressing plate 20 is provided with a pressing portion 21. When only one hot pressing plate 20 is provided with a pressing portion 21, after the pressing portion 21 hot presses the pressure-bearing surface 11, the core-wound pole piece 10 is turned 180° and then pressed on the other surface. When both hot pressing plates 20 are provided with a pressing portion 21, the two hot pressing plates 20 are arranged opposite to each other, and the two pressure-bearing surfaces 11 of the core-wound pole piece 10 are pressed at the same time to complete the hot pressing shaping, thereby improving the work efficiency.

[0049] In summary, the core-wound pole piece hot pressing tooling of the utility model is provided with an avoidance surface 23 on the outer contour of the pressing surface 22 of the pressing portion 21 corresponding to the position of the corner surface 12 of the core-wound pole piece 10, so that when the hot pressing plate 20 performs hot pressing and shaping on the core-wound pole piece 10, the pressing portion 21 avoids the corner surface 12 to prevent excessive folding at the corner due to hot pressing, causing the negative pole piece to lose powder at the corner, resulting in the inability of the negative electrode at the corner to be completely embedded in the sodium migrated from the positive electrode after subsequent charging, causing sodium precipitation.

[0050] Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A hot pressing tool for a core winding pole piece, wherein the cross section of the core winding pole piece (10) has two oppositely arranged pressure-bearing surfaces (11) and a corner surface (12) connecting the two pressure-bearing surfaces (11), characterized in that: The hot pressing tool comprises at least one hot pressing plate (20), wherein the hot pressing plate (20) is provided with a pressing portion (21) suitable for pressing the core-wound pole piece (10), wherein the pressing portion (21) has a pressing surface (22) and an avoidance surface (23), wherein the pressing surface (22) is formed as a plane suitable for pressing the pressure-bearing surface (11), and the avoidance surface (23) is provided on at least a portion of the outer contour of the pressing surface (22), and the avoidance surface (23) corresponds to the position of the corner surface (12) so as to avoid the corner surface (12) when the pressing portion (21) presses the core-wound pole piece (10).

2. The core winding pole piece hot pressing tool according to claim 1, characterized in that: The avoidance surface (23) is formed as an inclined surface that is bent relative to the plane where the pressing surface (22) is located and faces away from the winding core pole piece (10).

3. The core winding pole piece hot pressing tool according to claim 2, characterized in that: The avoidance surface (23) is formed as an arc-shaped chamfer.

4. The core winding pole piece hot pressing tool according to claim 3, characterized in that: The radius of the arc chamfer is in the range of 0.05mm-0.5mm.

5. The core winding pole piece hot pressing tool according to claim 2, characterized in that: The orthographic projection of the starting point of the avoidance surface (23) on the plane where the pressure-bearing surface (11) is located is located inside the pressure-bearing surface (11).

6. The core winding pole piece hot pressing tool according to claim 5, characterized in that: The distance between the starting point of the avoidance surface (23) and the innermost circle corner of the winding core pole piece (10) is 0.5 mm to 1.5 mm.

7. The core winding pole piece hot pressing tool according to claim 1, characterized in that: There are two avoidance surfaces (23), and the two avoidance surfaces (23) are respectively arranged at positions corresponding to the two corner surfaces (12) on both sides of the pressing surface (22).

8. The core winding pole piece hot pressing tool according to claim 1, characterized in that: There are two hot pressing plates (20), and at least one of the hot pressing plates (20) is provided with a pressing portion (21).

9. The core winding pole piece hot pressing tool according to claim 8, characterized in that: A pressing portion (21) is provided on each hot pressing plate (20).

10. The core winding pole piece hot pressing tool according to claim 9, characterized in that: The two hot pressing plates (20) are arranged opposite to each other and symmetrically.

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