Lithium battery pole piece coating and heating integrated structure

Abstract

The utility model relates to a coating and heating integrated structure for a lithium battery pole piece. The coating and heating integrated structure comprises a feeding roller and a receiving roller, a drying mechanism, a tensioning transmission mechanism used for tensioning a base material and guiding the base material to move, and a coating head used for coating the base material with slurry to form a coating are arranged between the discharging roller and the receiving roller; the drying mechanism is arranged at the downstream of the coating head and is used for drying a coating on the base material; the drying mechanism comprises a plurality of heating rollers; the multiple heating rollers are distributed in the box body at intervals in the first direction and jointly support and guide a base material to advance in the first direction. And the heating roller is rotationally connected with the box body. According to the utility model, the temperature of the plurality of heating rollers is gradually increased along the conveying direction of the base material, and the heating condition of the coated base material is gradually increased, so that the coated base material can be prevented from being suddenly subjected to stronger heat to deform or crack, and the slurry is gradually heated; and the coated base material is heated in a more balanced manner, so that cracks generated in the drying process can be reduced.

Description

Technical Field

[0001] The utility model relates to the field of lithium batteries, in particular to an integrated structure for coating and heating a lithium battery pole piece. Background Art

[0002] In the production process of lithium batteries, pole piece coating is undoubtedly a crucial link. This process has a decisive impact on many key performances of lithium batteries, such as battery capacity, consistency and safety. Specifically, the effect of pole piece coating is directly related to the storage capacity, internal resistance, cycle life and overall safety of the battery. According to statistics in the industry, the proportion of battery failures caused by improper pole piece coating process is as high as more than 10% of the total failure of lithium batteries. Therefore, ensuring the quality of pole piece coating has become an indispensable part of manufacturing high-quality lithium batteries.

[0003] In short, the so-called pole piece coating is to evenly apply the carefully prepared slurry on the current collector and dry the solvent in the slurry through a specific process. In this process, the choice of coating method and the setting of control parameters are crucial. These parameters mainly include the control of coating drying temperature, the setting of coating surface density, the size of coating, and the adjustment of coating thickness. These parameters not only determine the success of the coating process itself, but are also directly related to the performance and quality of the final lithium battery.

[0004] Lithium battery pole pieces require a large amount of wet coating and are difficult to dry. In traditional methods, the efficiency of heat energy penetrating and conducting from the surface of the substrate to the coating material is low. Therefore, the coating is heated unevenly during the drying process, resulting in surface drying and prone to cracking, which ultimately restricts the drying effect after coating. Utility Model Content

[0005] In order to solve the above problems in the prior art, the utility model provides an integrated structure for coating and heating a lithium battery pole piece.

[0006] In order to achieve the above-mentioned purpose, the main technical solutions adopted by the utility model include:

[0007] A lithium battery pole piece coating and heating integrated structure, comprising a discharge roller and a receiving roller; a drying mechanism, a tensioning transmission mechanism for tensioning a substrate and guiding the movement of the substrate, and a coating head for coating a slurry on the substrate to form a coating are provided between the discharge roller and the receiving roller; the drying mechanism is arranged downstream of the coating head and is used to dry the coating on the substrate; the drying mechanism comprises a plurality of heating rollers; the plurality of heating rollers are distributed in a housing at intervals along a first direction, and jointly support and guide the substrate to move along the first direction; the heating rollers are rotatably connected to the housing.

[0008] Furthermore, the heating temperatures of the plurality of heating rollers increase sequentially along the first direction.

[0009] Furthermore, the tensioning transmission mechanism is arranged between the unwinding roller and the coating head.

[0010] Furthermore, the tensioning transmission mechanism includes a first guide roller, a second guide roller, a third guide roller, a first transmission roller, a second transmission roller, and a third transmission roller which are sequentially arranged along the traveling direction of the substrate.

[0011] Furthermore, the first guide roller and the second guide roller are arranged horizontally; the third guide roller is bent relative to the second guide roller; the first transmission roller and the third guide roller are arranged horizontally; the second transmission roller and the first transmission roller are arranged vertically; and the third transmission roller is bent relative to the second transmission roller.

[0012] Furthermore, a fourth transmission roller is provided between the coating head and the feeding end of the box.

[0013] Furthermore, the height of the fourth transmission roller is equivalent to the height of the heating roller; and the bottom end of the coating head is lower than the top transmission level of the fourth transmission roller.

[0014] Furthermore, the box body is provided with a plurality of blowing heads located above the heating roller for blowing hot air to dry the coating on the substrate; the air outlets of the blowing heads are arranged at an angle.

[0015] Furthermore, a plurality of transmission rollers are provided between the discharging end of the box body and the receiving roller.

[0016] The beneficial effects of the utility model are as follows: because the heating roller and the substrate are heated in contact, the tensioning transmission mechanism can increase the tension of the substrate to generate a certain binding force on the substrate, which can reduce the probability of the substrate generating drying stress and shrinking volume after drying, thereby reducing the probability of the pole piece curling and cracking. At the same time, the temperature of several heating rollers gradually increases along the conveying direction of the substrate, and the force of the hot air blown out by several blowing heads gradually increases along the conveying direction of the substrate. At this time, the heating condition of the substrate after coating is gradually increased, which can avoid the disadvantage of the substrate after coating suddenly being subjected to strong heat to produce drastic changes in the slurry, so that the slurry is gradually heated, which can make the substrate after coating heated more balanced, which helps to reduce the occurrence of cracks during the drying process; BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the implementation mode of the utility model, the drawings required for use in the implementation mode will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the structure of the utility model;

[0019] Description of reference numerals:

[0020] 100, substrate; 110, unwinding roller; 120, receiving roller; 10, drying mechanism; 11, heating roller; 12, box; 13, blowing head; 20, tensioning transmission mechanism; 21, first guide roller; 22, second guide roller; 23, third guide roller; 24, first transmission roller; 25, second transmission roller; 26, third transmission roller; 27, fourth transmission roller; 30, coating head; 40, transmission roller. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] For example, please refer to Figure 1 As shown:

[0025] A lithium battery pole piece coating and heating integrated structure, comprising a discharge roller 110 and a take-up roller 120 and a drying mechanism 10 located between the discharge roller 110 and the take-up roller 120, the discharge roller 110 is used to release the substrate 100 to be coated, the take-up roller 120 is used to shrink and wind the substrate 100 that has been coated and passed the density test, and the drying mechanism 10 is used to dry the coated substrate 100 so that the slurry is evenly coated on the substrate 100 (current collector); a tensioning transmission device for tensioning the substrate 100 and guiding the movement of the substrate 100 is provided between the discharge roller 110 and the coating head 30, the tensioning transmission device can pre-tension the substrate 100, generate a certain binding force on the substrate 100, and when the substrate 100 coated with the coating is dried, the probability of drying stress and shrinking volume can be reduced, thereby reducing the probability of curling and cracking of the pole piece, and ensuring the quality of the coating;

[0026] The drying mechanism 10 is arranged downstream of the coating head 30 and is used to dry the coating on the substrate 100. The drying mechanism 10 is composed of a plurality of heating rollers 11 arranged at intervals in a box 12. The heating rollers 11 are arranged at intervals along a first direction. Figure 1 The heating roller 11 can rotate relative to the box 12, and evenly heat the substrate 100 by rolling, and transfer the heat to the coating by the substrate 100 to achieve drying of the coating;

[0027] In some embodiments, the temperatures of several heating rollers 11 are kept consistent. Since the heating roller 11 indirectly heats the coating through the substrate 100 and the contact area between a single heating roller 11 and the substrate 100 is limited, the temperature of the heating roller 11 is set to a uniform temperature. This reduces the chances of cracks being generated during the drying process and the coated substrate 100 is heated more evenly.

[0028] In one embodiment, the heating temperatures of the plurality of heating rollers 11 are increased sequentially along the first direction X. At this time, the heating condition of the coated substrate 100 is gradually increased, which can avoid the disadvantage of the coated substrate 100 being suddenly subjected to strong heat to produce drastic changes in the slurry (such as cracks). The slurry is gradually heated, and the heating condition of the coated substrate 100 is gradually increased, which helps to reduce the occurrence of cracks during the drying process. Compared with the previous embodiment, the production quality of the electrode can be further improved.

[0029] It should be noted that the coating head 30 of the present invention only coats the upper end surface of the substrate 100. When the coated substrate 100 is moving, only the lower end surface is in contact with the heating roller 11, which can avoid the movement of the heating roller 11 from damaging the incompletely dried coating. The coating is dried by indirectly transferring heat to the coating through the heating roller 11, and the interval-arranged heating rollers 11 evenly support the substrate 100 to ensure the flatness of the substrate 100 during transmission.

[0030] In one embodiment, the tensioning and transmission mechanism 20 includes a first guide roller 21, a second guide roller 22, and a third guide roller 23 which are arranged in a bent manner in sequence along the traveling direction of the substrate 100. The first guide roller 21 and the second guide roller 22 are arranged horizontally, and the two together support the substrate 100. The third guide roller 23 is arranged in a bent manner relative to the second guide roller 22. A first transmission roller 24, a second transmission roller 25, and a third transmission roller 26 are arranged behind the third guide roller 23. The first transmission roller 24 and the third guide roller 23 are arranged horizontally, the second transmission roller 25 and the first transmission roller 24 are arranged vertically, and the third transmission roller 26 is arranged in a bent manner relative to the first transmission roller 24 and the second transmission roller 25. The first transmission roller 24, the second transmission roller 25, and the third transmission roller 26 together assist the substrate 100 to move forward. A coating head 30 is arranged above the third transmission roller 26, and the coating head 30 is used to evenly coat the slurry on the substrate 100. Through the tensioning and transmission mechanism 20, the substrate 100 can be pre-stretched and tightened to ensure the quality of the coating after drying;

[0031] In one embodiment, a fourth transmission roller 27 is provided between the coating head 30 and the feeding end of the box body 12, and the height of the fourth transmission roller 27 is equivalent to the height of the heating roller 11; the bottom end of the coating head 30 is lower than the top transmission level of the fourth transmission roller 27; that is, the fourth transmission roller 27 also plays the role of a tensioning wheel at this time, further tensioning the substrate 100 coated with the coating to enter the drying mechanism 10, pre-stretching the substrate 100, and ensuring the quality of the coating after drying;

[0032] In one embodiment, the box body 12 is further provided with a plurality of blowing heads 13 located above the heating roller 11 for blowing hot air to dry the coating on the substrate 100; the air outlet of the blowing head 13 is arranged at an angle; the air outlet of the blowing head 13 is arranged at an angle including: Figure 1 The blowing head 13 is tilted to the left, that is, the air outlet of the blowing head 13 is arranged toward the first direction, and the blowing head 13 is also tilted to the right (not shown in the figure).

[0033] A plurality of blowing heads 13 are arranged in the box body 12 of the drying mechanism 10 above the substrate 100. The blowing heads 13 are located above the heating roller 11. The blowing heads 13 are evenly spaced and arranged. The blowing heads 13 are used to blow out hot air to dry the substrate 100 passing through the drying box, thereby solving the problem of uneven heating of the coating on the substrate 100 during the drying process, which is prone to cracks.

[0034] Specifically, the blowing direction of the blowing head 13 is inclined. In some embodiments, the blowing direction of the blowing head 13 is arc-shaped, so that the hot air is blown in a certain direction onto the substrate 100 after coating, which can make the slurry on the surface of the substrate 100 more uniformly preheated, and the blowing area is larger, and the blowing preheating effect is better.

[0035] In other embodiments, the temperature of several heating rollers 11 gradually increases along the conveying direction of the substrate 100, and the force of the hot air blown by several blowing heads 13 gradually increases along the conveying direction of the substrate 100. At this time, the heating condition of the coated substrate 100 gradually increases, which can avoid the disadvantage that the coated substrate 100 is suddenly subjected to strong heat to produce drastic changes in the slurry, so that the slurry is gradually heated, which can make the coated substrate 100 heated more balanced, which helps to reduce the occurrence of cracks during the drying process.

[0036] It should be noted that in the present application, the upper surface of the substrate 100 is a coating layer, and there is no coating layer on the lower surface, so a blower head 13 is arranged on the upper side for directly blowing hot air to dry the coating material, and a heating roller 11 is arranged on the lower side for indirectly conducting heat for uniform drying. The blower head 13 and the heating roller 11 are non-contact drying with the coating material, and will not cause damage to the coating.

[0037] In one embodiment, a plurality of transmission rollers 40 are arranged behind the drying box and in front of the receiving roller 120. The plurality of transmission rollers 40 jointly assist the movement of the substrate 100, so that the substrate 100 after coating and heating and drying treatment is more easily wound onto the receiving roller 120, thereby improving the transmission efficiency of the substrate 100.

[0038] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A lithium battery pole piece coating and heating integrated structure, characterized in that: The invention comprises a feeding roller (110) and a receiving roller (120); a drying mechanism (10), a tensioning transmission mechanism (20) for tensioning a substrate (100) and guiding the substrate (100) to move, and a coating head (30) for coating a slurry on the substrate (100) to form a coating are arranged between the feeding roller (110) and the receiving roller (120); the drying mechanism (10) is arranged downstream of the coating head (30) and is used to dry the coating on the substrate (100); the drying mechanism (10) comprises a plurality of heating rollers (11); the plurality of heating rollers (11) are spaced apart in a box (12) along a first direction and jointly support and guide the substrate (100) to move along the first direction; the heating rollers (11) are rotatably connected to the box (12).

2. The lithium battery pole piece coating and heating integrated structure according to claim 1, characterized in that: The heating temperatures of the plurality of heating rollers (11) increase sequentially along the first direction.

3. The lithium battery pole piece coating and heating integrated structure according to claim 1, characterized in that: The tensioning transmission mechanism (20) is arranged between the unwinding roller (110) and the coating head (30).

4. The lithium battery pole piece coating and heating integrated structure according to claim 3, characterized in that: The tensioning transmission mechanism (20) comprises a first guide roller (21), a second guide roller (22), a third guide roller (23), a first transmission roller (24), a second transmission roller (25), and a third transmission roller (26) which are sequentially arranged along the traveling direction of the substrate (100).

5. The lithium battery pole piece coating and heating integrated structure according to claim 4, characterized in that: The first guide roller (21) and the second guide roller (22) are arranged horizontally; the third guide roller (23) is arranged in a bent manner relative to the second guide roller (22); the first transmission roller (24) and the third guide roller (23) are arranged horizontally; the second transmission roller (25) and the first transmission roller (24) are arranged vertically; and the third transmission roller (26) is arranged in a bent manner relative to the second transmission roller (25).

6. The lithium battery pole piece coating and heating integrated structure according to claim 1, characterized in that: A fourth transmission roller (27) is provided between the coating head (30) and the feeding end of the box (12).

7. The lithium battery pole piece coating and heating integrated structure according to claim 6, characterized in that: The height of the fourth transmission roller (27) is equivalent to the height of the heating roller (11); the bottom end of the coating head (30) is lower than the top transmission level of the fourth transmission roller (27).

8. The lithium battery pole piece coating and heating integrated structure according to claim 1, characterized in that: The box body (12) is also provided with a plurality of blowing heads (13) located above the heating roller (11) and used for blowing hot air to dry the coating on the substrate (100); the air outlets of the blowing heads (13) are arranged at an angle.

9. The lithium battery pole piece coating and heating integrated structure according to claim 7, characterized in that: A plurality of transmission rollers (40) are provided between the material discharging end of the box body (12) and the material receiving roller (120).

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