Novel battery pole piece embossing structure

Abstract

The utility model relates to a novel battery pole piece knurling structure which comprises a knurling roller and an alignment roller, a plurality of transverse shaft rollers are uniformly arranged on the knurling roller in the circumferential direction, a plurality of spherical rollers are arranged on the transverse shaft rollers in an array mode, long grooves which are opposite to the transverse shaft rollers and equal to the transverse shaft rollers are formed in the alignment roller, the long grooves are inwards concaved, and pits which are opposite to the spherical rollers are formed in the long grooves. According to the utility model, the transverse shaft rollers are uniformly arranged in the circumferential direction of the embossing roller, the spherical rollers are arranged on the transverse shaft rollers and are matched with the corresponding alignment rollers with the long grooves and the pits to carry out embossing treatment on the pole piece, and the spherical rollers press concave parts on the pole piece to be used for storing electrolyte, so that lithium precipitation of the pole piece in a later cycle is improved; and a channel for rapidly draining the electrolyte is pressed on the pole piece through the transverse shaft roller and the long groove, and the electrolyte is pulled into the pole piece through capillary adsorption. The pole piece is rolled into a wave shape by the transverse shaft roller, a buffer space is reserved for later-stage pole piece expansion, the expansion stress at the corner is reduced, and the thickness expansion in the later period of circulation is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery manufacturing, and particularly relates to a novel embossing structure for battery electrode sheets. Background Art

[0002] Common lithium-ion battery manufacturing processes are divided into the stacking process and the winding process. The winding process is relatively mature, and in addition, the equipment cost is low and the automation degree is high. Most battery manufacturing enterprises use the winding process. However, after the battery produced by the winding process is filled with liquid and charged and discharged, the positive and negative electrode sheets rebound and expand, causing the electrode sheets inside the battery core to wrinkle and deform, thereby affecting the electrical performance and safety performance of the battery and seriously reducing the service life of the battery.

[0003] A common solution to improve the problem of electrode sheet wrinkling is to adopt the electrode sheet embossing process. The electrode sheet embossing process is to emboss and thicken the electrode sheet before winding, forming raised points of different shapes on the surface of the electrode sheet to make the electrode sheet thicker, leaving sufficient rebound space for the other electrode sheet. After the battery is filled with liquid, formed, and capacitanced, the reserved space can reduce the stress between the positive and negative electrode sheets to achieve the purpose of improving the electrode sheet wrinkling. The electrode sheet obtained by the existing embossing technology still has the problem of insufficient rebound space, and the stress between the positive and negative electrode sheets is still large, and the effect of improving the electrode sheet wrinkling problem is not good. In addition, there are still problems such as material dropping and tape breaking during the embossing process, and difficulty in winding the electrode sheet. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a novel embossing structure for battery electrode sheets in view of the deficiencies of the prior art. By embossing the electrode sheet before winding, a certain gap is formed between the positive and negative electrode sheets to relieve the deformation caused by the thickness expansion of the electrode sheet. At the same time, by optimizing the embossing pattern, the infiltration effect of the electrode sheet is improved, and lithium deposition at the corners of the electrode sheet is improved.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A novel embossing structure for battery electrodes includes an embossing roller and a registration roller. A number of transverse shafts are evenly arranged circumferentially on the embossing roller. A number of spherical rollers are arranged in an array on the transverse shafts. An equal number of long grooves opposite to the transverse shafts are provided on the registration roller. The long grooves are recessed inward, and pits opposite to the spherical rollers are provided in the long grooves. The electrode passes between the embossing roller and the registration roller. The embossing roller and the registration roller are engaged with each other. The transverse shafts and the spherical rollers can be respectively pressed into the long grooves and the pits to emboss corresponding patterns on the electrode, so as to form embossed patterns to optimize and improve the wetting effect of the electrode and improve lithium deposition at the corners of the electrode. This novel embossing structure for battery electrodes can be used as a rolling equipment or a winding equipment. When dealing with large-size electrodes, it can be used as an independent rolling equipment to perform overall embossing treatment on the electrodes, or as a part of a winding equipment for single separated electrodes to perform embossing treatment synchronously during the winding process of the electrodes. Both methods perform embossing operations on the electrodes to be processed through the embossing roller and the registration roller.

[0007] Preferably, a silica gel pad is provided on the surface of the embossing roller. The silica gel pad covers the transverse shafts. Through holes are provided on the silica gel pad. The spherical rollers are arranged in the through holes and protrude from the surface of the silica gel pad.

[0008] Preferably, the thickness of the silica gel pad is 0.5 - 5 mm. Specifically, the thickness of the silica gel pad is 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm or 5 mm, etc.

[0009] Preferably, the transverse shafts have the same length as the embossing roller. The length of the transverse shafts is 5 - 200 cm. The transverse shafts extend along the radial direction of the embossing roller. Specifically, the lengths of the transverse shafts and the embossing roller are 5 cm, 10 cm, 20 cm, 50 cm, 80 cm, 100 cm, 150 cm or 200 cm, etc. respectively, and can be adjusted accordingly according to the actual production requirements of the electrodes.

[0010] Preferably, the transverse shafts protrude 10 - 100 μm above the outer surface of the embossing roller. Specifically, the protruding height is 10 μm, 20 μm, 30 μm, 50 μm, 80 μm or 100 μm, etc. The transverse shafts cooperate with the long grooves on the registration roller to emboss the electrodes, and channels for quickly draining the electrolyte are pressed on the surface of the electrodes, and the electrolyte is drawn into the interior of the electrodes through capillary adsorption.

[0011] Preferably, at least two of the transverse shafts are equidistantly spaced circumferentially on the embossing roller. The number of the long grooves is equal to the number of the transverse shafts. The mutually symmetrical transverse shafts and long grooves are convenient for rolling out continuous various embossed grooves on the electrodes.

[0012] Preferably, the horizontal axis roller is a regular strip-shaped long roller protruding from the embossing roller, and its cross-section includes a semi-circular shape, a rectangular shape, or a triangular shape. The shape of the long groove matches the shape of the horizontal axis roller.

[0013] Preferably, the spherical rollers are a plurality of hemispherical protrusions arranged in an array protruding from the horizontal axis roller, and the diameter of the spherical rollers is 1-10 μm. Specifically, the diameter of the spherical rollers is 1 μm, 2 μm, 3 μm, 5 μm, 8 μm, 10 μm, etc. By pressing corresponding spherical pits on the electrode sheet, it is convenient to store the electrolyte flowing in the groove, and improve the lithium plating of the electrode sheet during later cycling.

[0014] Preferably, the center distance between two adjacent spherical rollers is 1-5 mm. Specifically, the center distance is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc., and can be appropriately arranged according to the length of the horizontal axis roller.

[0015] Preferably, the spherical rollers are provided with at least one row, and the spherical rollers are arranged on the outer surface of the horizontal axis roller. The number of spherical rollers in a single row is ten or more. It can be multiple rows of continuous spherical rollers arranged side by side, and the column spacing is the same as the center distance, or can be arranged correspondingly according to the shape of the horizontal axis roller.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: A novel battery electrode sheet embossing structure provided by the present invention has a horizontal axis roller evenly arranged circumferentially on the embossing roller, and spherical rollers are arranged on the horizontal axis roller. Matching with the corresponding alignment roller with a long groove and a pit, they cooperate with each other to emboss the electrode sheet. The concave parts pressed by the spherical rollers on the electrode sheet can be used to store the electrolyte, improving the lithium plating of the electrode sheet during later cycling. The horizontal axis roller and the long groove press out a channel for quickly draining the electrolyte on the electrode sheet, and the electrolyte is drawn into the interior of the electrode sheet through capillary adsorption. At the same time, due to the relatively deep texture of the horizontal axis roller, the electrode sheet is rolled into a wavy shape, reserving a buffer space for the later expansion of the electrode sheet, reducing the expansion stress at the corners, and reducing the thickness expansion during later cycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of Embodiment 1 of the present invention.

[0018] Figure 2 is a schematic structural diagram of Embodiment 2 of the present invention.

[0019] Figure 3 is a schematic structural diagram of Embodiment 3 of the present invention.

[0020] Figure 4 is an embossing effect diagram of the electrode sheet of Embodiment 1 of the present invention.

[0021] Reference Numerals:

[0022] 1. Embossing roller, 11. Horizontal shaft roller, 12. Spherical roller;

[0023] 2. Alignment roller, 21. Long groove, 22. Pit;

[0024] 3. Silicone pad, 31. Through hole. Detailed implementation mode

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment 1:

[0027] As Figure 1 and Figure 4 shown, a novel embossing structure for battery electrode sheets includes an embossing roller 1 and an alignment roller 2. A plurality of horizontal shaft rollers 11 are circumferentially and evenly arranged on the embossing roller 1, and a plurality of spherical rollers 12 are arranged in an array on the horizontal shaft rollers 11. On the alignment roller 2, an equal number of long grooves 21 opposite to the horizontal shaft rollers 11 are provided. The long grooves 21 are recessed inward, and pits 22 opposite to the spherical rollers 12 are provided in the long grooves 21. In this embodiment, the embossing roller 1 is provided with 4 horizontally shaft rollers 11 arranged circumferentially and evenly. The horizontal shaft rollers 11 are provided with single-row spherical rollers 12 arranged at equal distances. On the alignment roller 2, 4 long grooves 21 are correspondingly provided. Single-row pits 22 are provided in the long grooves 21. The embossing roller 1 and the alignment roller 2 can be engaged with each other. When the electrode sheet passes through them, embossing treatment can be performed on it to form a three-dimensional channel identical to the horizontal shaft rollers 11 and the spherical rollers 12.

[0028] Furthermore, a silicone pad 3 is provided on the surface of the embossing roller 1. The silicone pad 3 covers the horizontal shaft rollers 11. Through holes 31 are provided on the silicone pad 3. The spherical rollers 12 are inserted into the through holes 31 and protrude from the surface of the silicone pad 3. Specifically, when the spherical rollers 12 pass through the silicone pad 3, corresponding columnar supports are provided in the through holes 31, and then spherical rollers 12 are provided on the part protruding from the silicone pad 3. In this embodiment, the thickness of the silicone pad 3 is 1 mm. The through holes 31 are circular through holes 31, and the diameter of the through holes 31 is the same as the diameter of the spherical rollers 12.

[0029] Furthermore, the horizontal shaft rollers 11 are of the same length as the embossing roller 1. In this embodiment, the length of the horizontal shaft rollers 11 is 50 cm. The horizontal shaft rollers 11 extend along the radial direction of the embossing roller 1 to match the length of the corresponding electrode sheet.

[0030] Furthermore, the horizontal shaft rollers 11 are 20 μm higher than the outer surface of the embossing roller 1.

[0031] Further, the transverse axis rollers 11 are multiple symmetrically arranged transverse axis rollers 11. There are 4 transverse axis rollers 11 circumferentially arranged on the embossing roller 1, and the number of the long grooves 21 is equal to the number of the transverse axis rollers 11.

[0032] Further, the transverse axis roller 11 is a regular strip-shaped long roller protruding from the embossing roller 1. In this embodiment, the cross-section of the transverse axis roller 11 is semi-circular, that is, the overall shape of the transverse axis roller 11 is a semi-cylindrical shape protruding from the embossing roller 1. The shape of the long groove 21 matches the shape of the transverse axis roller 11, and it is also a semi-cylindrical groove with the same diameter. The semi-cylindrical transverse axis roller 11 forms continuous diversion grooves on the pole piece to achieve rapid drainage of the electrolyte, and the electrolyte is drawn into the interior of the pole piece through capillary adsorption. At the same time, due to the relatively deep texture of the transverse axis roller 11, the pole piece is rolled into a wavy shape, reserving a buffer space for the later expansion of the pole piece, reducing the expansion stress at the corners, and reducing the thickness expansion in the later stage of the cycle.

[0033] Further, the spherical rollers 12 are hemispherical protrusions arranged in a single row continuously and equidistantly protruding from the transverse axis rollers 11, and the diameter of a single spherical roller 12 is 3 μm. The spherical rollers 12 are arranged at the top of the semi-cylindrical transverse axis rollers 11.

[0034] Further, the center distance between two adjacent spherical rollers 12 is 2 mm. The continuously and evenly distributed spherical rollers 12 can form pits 22 on the pole piece to store the electrolyte, improving the lithium deposition on the pole piece in the later cycle.

[0035] Embodiment 2:

[0036] As Figure 2 shown, a new type of battery pole piece embossing structure includes an embossing roller 1 and a registration roller 2. A plurality of transverse axis rollers 11 are circumferentially and evenly arranged on the embossing roller 1, and a plurality of spherical rollers 12 are arranged in an array on the transverse axis rollers 11. The registration roller 2 is provided with an equal number of long grooves 21 opposite to the transverse axis rollers 11. The long grooves 21 are recessed inward, and pits 22 opposite to the spherical rollers 12 are provided in the long grooves 21. In this embodiment, the embossing roller 1 is provided with 4 circumferentially and evenly arranged transverse axis rollers 11, and the transverse axis rollers 11 are provided with spherical rollers 12 arranged in two rows equidistantly. On the registration roller 2, 4 long grooves 21 are correspondingly provided, and double-row pits 22 are provided in the long grooves 21. The embossing roller 1 and the registration roller 2 can be engaged with each other. When the pole piece passes through them, embossing treatment can be performed on the pole piece to form a three-dimensional channel identical to the transverse axis rollers 11 and the spherical rollers 12.

[0037] Furthermore, the embossing roller 1 is provided with a silicone pad 3 on its surface. The silicone pad 3 is wrapped around the transverse roller 11. The silicone pad 3 is provided with a through hole 31. The spherical roller 12 is inserted into the through hole 31 and protrudes from the surface of the silicone pad 3. Specifically, when the spherical roller 12 passes through the silicone pad 3, a corresponding columnar support is provided in the through hole 31. The spherical roller 12 is then provided on the portion protruding from the silicone pad 3. In this embodiment, the thickness of the silicone pad 3 is 1 mm, and the through hole 31 is a circular through hole 31 with the same diameter as the spherical roller 12.

[0038] Furthermore, the length of the transverse roller 11 is consistent with that of the embossing roller 1 . In this embodiment, the length of the transverse roller 11 is 50 cm. The transverse roller 11 extends radially along the embossing roller 1 to match the corresponding pole piece length.

[0039] Furthermore, the transverse roller 11 is 20 μm higher than the outer surface of the embossing roller 1 .

[0040] Furthermore, the transverse rollers 11 are multiple transverse rollers 11 arranged symmetrically, four transverse rollers 11 are arranged circumferentially on the embossing roller 1 , and the number of the long grooves 21 is equal to the number of the transverse rollers 11 .

[0041] Furthermore, the transverse roller 11 is a regular strip-shaped long roller protruding from the embossing roller 1. In this embodiment, the cross-section of the transverse roller 11 is triangular, that is, the overall shape of the transverse roller 11 is a triangular prism protruding from the embossing roller 1. The shape of the long groove 21 matches the shape of the transverse roller 11, and is also a triangular prism-shaped groove with the same diameter. A continuous guide groove is formed on the electrode through the triangular prism transverse roller 11 to achieve rapid drainage of the electrolyte, and the electrolyte is pulled into the interior of the electrode through capillary adsorption. At the same time, due to the deep texture of the transverse roller 11, the electrode is rolled into a wavy shape, reserving buffer space for the subsequent expansion of the electrode, reducing the expansion stress at the corners, and reducing the thickness expansion in the later stage of the cycle.

[0042] Furthermore, the spherical rollers 12 are double-row, continuous, and equidistantly arranged hemispherical protrusions protruding from the transverse roller 11 , and the diameter of a single spherical roller 12 is 3 μm. The spherical rollers 12 are disposed on two sides of the triangular prism transverse roller 11 .

[0043] Furthermore, the distance between the centers of two adjacent spherical rollers 12 is 2 mm. The continuously and evenly distributed spherical rollers 12 can form pits 22 on the electrode to store electrolyte, thereby improving lithium deposition on the electrode during later cycles.

[0044] Example 3:

[0045] like Figure 3As shown in the figure, a new type of embossing structure for battery electrodes includes an embossing roller 1 and a registration roller 2. A number of horizontal axis rollers 11 are evenly arranged circumferentially on the embossing roller 1. A number of spherical rollers 12 are arranged in an array on the horizontal axis rollers 11. On the registration roller 2, an equal number of long grooves 21 opposite to the horizontal axis rollers 11 are provided. The long grooves 21 are recessed inward, and pits 22 opposite to the spherical rollers 12 are provided in the long grooves 21. In this embodiment, there are 4 horizontally arranged axis rollers 11 evenly distributed circumferentially on the embossing roller 1. Single-row equally spaced spherical rollers 12 are provided on the horizontal axis rollers 11. On the registration roller 2, 4 long grooves 21 are correspondingly provided. Single-row pits 22 are provided in the long grooves 21. The embossing roller 1 and the registration roller 2 can be engaged with each other. When the electrode passes through them, embossing treatment can be performed on it to form a three-dimensional channel identical to the horizontal axis rollers 11 and the spherical rollers 12.

[0046] Further, a silica gel pad 3 is provided on the surface of the embossing roller 1. The silica gel pad 3 is coated on the horizontal axis rollers 11. Through holes 31 are provided on the silica gel pad 3. The spherical rollers 12 are inserted through the through holes 31 and protrude from the surface of the silica gel pad 3. Specifically, when the spherical rollers 12 pass through the silica gel pad 3, corresponding columnar supports are provided in the through holes 31, and then spherical rollers 12 are formed protruding from the silica gel pad 3. In this embodiment, the thickness of the silica gel pad 3 is 1 mm. The through holes 31 are circular through holes 31, and the diameter of the through holes 31 is the same as the diameter of the spherical rollers 12.

[0047] Further, the horizontal axis rollers 11 are of the same length as the embossing roller 1. In this embodiment, the length of the horizontal axis rollers 11 is 50 cm. The horizontal axis rollers 11 extend along the radial direction of the embossing roller 1 to match the length of the corresponding electrode.

[0048] Further, the horizontal axis rollers 11 are 20 μm higher than the outer surface of the embossing roller 1.

[0049] Further, the horizontal axis rollers 11 are multiple horizontally arranged axis rollers 11 that are symmetrically arranged. There are 4 horizontal axis rollers 11 arranged circumferentially on the embossing roller 1, and the number of long grooves 21 is equal to the number of horizontal axis rollers 11.

[0050] Further, the horizontal axis rollers 11 are regular strip-shaped long rollers protruding from the embossing roller 1. In this embodiment, the cross-section of the horizontal axis rollers 11 is rectangular, that is, the overall shape of the horizontal axis rollers 11 is a cuboid protruding from the embossing roller 1. The shape of the long grooves 21 matches the shape of the horizontal axis rollers 11, and is also a cuboid groove with the same diameter. Continuous diversion grooves are formed on the electrode by the cuboid horizontal axis rollers 11 to achieve rapid drainage of the electrolyte, and the electrolyte is drawn into the interior of the electrode through capillary adsorption. At the same time, since the horizontal axis rollers 11 have relatively deep patterns, the electrode is rolled into a wavy shape, reserving a buffer space for the later expansion of the electrode, reducing the expansion stress at the corners, and reducing the thickness expansion in the later stage of the cycle.

[0051] Furthermore, the spherical rollers 12 are hemispherical protrusions arranged in three consecutive rows side by side and equidistantly spaced, protruding from the horizontal axis roller 11. The diameter of a single spherical roller 12 is 3 μm. The three rows of spherical rollers 12 are evenly spaced on the upper surface of the cuboid horizontal axis roller 11.

[0052] Furthermore, the center distance between two adjacent spherical rollers 12 is 2 mm. The continuously and evenly distributed spherical rollers 12 can form pits 22 on the pole piece to store the electrolyte, improving the lithium plating of the pole piece during later cycles.

[0053] Based on the disclosure and teachings of the above specification, those skilled in the art to which the present utility model pertains can also make changes and modifications to the above embodiments. Therefore, the present utility model is not limited to the above specific embodiments, and any obvious improvements, substitutions, or variations made by those skilled in the art based on the present utility model fall within the protection scope of the present utility model. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present utility model.

Claims

1. A novel embossing structure for battery electrode sheets, characterized in that: It includes an embossing roller (1) and a registration roller (2). A number of transverse axis rollers (11) are circumferentially and evenly arranged on the embossing roller (1). A number of spherical rollers (12) are arranged in an array on the transverse axis rollers (11). The registration roller (2) is provided with an equal number of long grooves (21) opposite to the transverse axis rollers (11). The long grooves (21) are recessed inward, and there are pits (22) arranged opposite to the spherical rollers (12) in the long grooves (21).

2. The novel battery electrode sheet embossing structure according to claim 1, wherein: A silica gel pad (3) is provided on the surface of the embossing roller (1). The silica gel pad (3) covers the transverse axis rollers (11). Through holes (31) are provided on the silica gel pad (3). The spherical rollers (12) are inserted into the through holes (31) and protrude from the surface of the silica gel pad (3).

3. The novel battery electrode embossing structure according to claim 2, wherein: The thickness of the silica gel pad (3) is 0.5 - 5 mm.

4. The novel battery electrode embossing structure according to claim 1, characterized in that: The transverse axis rollers (11) are of the same length as the embossing roller (1), and the length of the transverse axis rollers (11) is 5 - 200 cm.

5. The novel battery electrode embossing structure according to claim 4, characterized in that: The transverse axis rollers (11) are 10 - 100 μm higher than the outer surface of the embossing roller (1).

6. The novel battery electrode embossing structure according to claim 5, wherein: At least two of the transverse axis rollers (11) are circumferentially and equidistantly spaced on the embossing roller (1), and the number of the long grooves (21) is equal to the number of the transverse axis rollers (11).

7. The novel battery electrode embossing structure according to claim 6, wherein: The transverse axis rollers (11) are regular strip-shaped long rollers protruding from the embossing roller (1), and their cross-sections include semi-circular, rectangular or triangular shapes. The shape of the long grooves (21) matches the shape of the transverse axis rollers (11).

8. The novel battery electrode sheet embossing structure according to claim 1, characterized in that: The spherical rollers (12) are a number of hemispherical protrusions arranged in an array protruding from the transverse axis rollers (11), and the diameter of the spherical rollers (12) is 1 - 10 μm.

9. The novel embossed structure of the battery electrode sheet according to claim 8, wherein: The center distance between two adjacent spherical rollers (12) is 1 - 5 mm.

10. The novel battery electrode sheet embossing structure according to claim 9, characterized in that: The spherical rollers (12) are provided with at least one column, and the spherical rollers (12) are arranged on the outer surface of the transverse axis rollers (11).

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