CN210805916U

CN210805916U - Lithium device is mended to pole piece

Info

Publication number: CN210805916U
Application number: CN201922021428.5U
Authority: CN
Inventors: 陈仕通; 谢斌; 费新路; 徐永强; 张予浙; 马林
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2019-11-21
Filing date: 2019-11-21
Publication date: 2020-06-19
Anticipated expiration: 2029-11-21

Abstract

The utility model provides a lithium device is mended to pole piece. The pole piece lithium supplementing device comprises a first lithium belt unwinding mechanism, a pole piece unwinding mechanism, a rolling mechanism, a first traction mechanism, a pole piece winding mechanism and a first coating mechanism. The first lithium belt unwinding mechanism is used for arranging a lithium belt, and the pole piece unwinding mechanism is used for arranging a pole piece. The roll pressing mechanism comprises a first calendering roll, a first laminating roll and a second laminating roll. The first traction mechanism is used for drawing the lithium belt to enter between the first calendering roller and the first laminating roller, and the pole piece winding mechanism is used for winding the pole piece and drawing the pole piece to pass through between the first laminating roller and the second laminating roller. The first coating mechanism is located upstream of the rolling mechanism in the traveling direction of the lithium belt, and the first coating mechanism is used for coating the surface of the lithium belt with a coating.

Description

Lithium device is mended to pole piece

Technical Field

The utility model relates to a battery production field especially relates to a lithium device is mended to pole piece.

Background

The lithium ion battery is widely applied to the fields of consumer electronics and electric automobiles due to the advantages of high energy density, long service life, greenness, no pollution and the like. However, the lithium ion battery forms a solid electrolyte film (SEI film) during the first charge and discharge process, and the solid electrolyte film consumes part of lithium, resulting in loss of lithium, and the irreversible first capacity loss directly results in loss of the capacity of the lithium ion battery.

SUMMERY OF THE UTILITY MODEL

In view of the problem that exists among the background art, the utility model aims to provide a lithium device is mended to pole piece, its benefit lithium that can realize the pole piece simplifies and mends lithium technology, saves the lithium area.

In order to realize the above purpose, the utility model provides a lithium device is mended to pole piece, it includes first lithium area unwinding mechanism, pole piece unwinding mechanism, rolling mechanism, a drive mechanism, pole piece winding mechanism and a coating mechanism. The first lithium belt unwinding mechanism is used for arranging a lithium belt, and the pole piece unwinding mechanism is used for arranging a pole piece. The roll pressing mechanism comprises a first calendering roll, a first laminating roll and a second laminating roll. The first traction mechanism is used for drawing the lithium belt to enter between the first calendering roller and the first laminating roller, and the pole piece winding mechanism is used for winding the pole piece and drawing the pole piece to pass through between the first laminating roller and the second laminating roller. The first coating mechanism is located upstream of the rolling mechanism in the traveling direction of the lithium belt, and the first coating mechanism is used for coating the surface of the lithium belt with a coating.

The first traction mechanism comprises a traction roller and a traction belt, and the traction belt is connected to the traction roller. The traction roller is positioned at the downstream of the first calendering roller along the tape moving direction of the lithium tape.

The pole piece lithium supplementing device further comprises a lubricating mechanism and a cleaning mechanism, and the lubricating mechanism and the cleaning mechanism are arranged along the rotating direction of the first laminating roller. The lubricating mechanism is used for coating a lubricant on the roller surface of the first laminating roller, and the cleaning mechanism is used for cleaning the roller surface of the first laminating roller.

The lubricating mechanism comprises two coating heads which are arranged at intervals along the axial direction of the first laminating roller.

The lubrication mechanism further includes a guide member to which the two coating heads are slidably provided in a direction parallel to an axial direction of the first laminating roller.

The roller diameter of the first calendering roller is smaller than that of the first laminating roller.

The ratio of the roll diameter of the first calendering roll to the roll diameter of the first laminating roll is 0.5-0.99.

The rolling mechanism further comprises a first supporting roller, and the first supporting roller and the first calendering roller are oppositely arranged and located on one side, far away from the first laminating roller, of the first calendering roller. The roll diameter of the first supporting roll is larger than that of the first calendering roll.

The first coating mechanisms are two groups and respectively coat two surfaces of the lithium strip with coatings. The two groups of first coating mechanisms contain release agents, and the surface roughness of the release agents in the two groups of first coating mechanisms is different.

The pole piece lithium supplementing device further comprises a second lithium belt unreeling mechanism, a second traction mechanism and a second coating mechanism. And the second lithium belt unreeling mechanism is used for arranging a lithium belt. The rolling mechanism further comprises a second calendering roller, and the second calendering roller and the second laminating roller are arranged oppositely. And the second traction mechanism is used for drawing the lithium strips provided by the second lithium strip unreeling mechanism to enter between the second calendering roller and the second laminating roller. And the second coating mechanism is used for coating the surface of the lithium belt provided by the second lithium belt unwinding mechanism.

The utility model has the advantages as follows: the lithium supplementing device can supplement lithium for the pole piece, and integrates the calendering process and the laminating process of the lithium belt, so that the lithium supplementing process is simplified, the occupied space is reduced, and the production cost is reduced. The coating is coated on the surface of the lithium belt, so that the lithium belt can be smoothly transferred to the surface of the pole piece. The traction mechanism may initially pull the lithium tape away from the belt to enable the coating mechanism to apply a coating to the surface of the lithium tape to prevent the lithium tape from adhering to the calendar roll and the laminating roll. Meanwhile, the traction mechanism can pull the lithium belt coated with the coating between the first calendaring roller and the first laminating roller, so that the lithium belt is prevented from being pulled in the whole process, and the waste of the lithium belt is reduced.

Drawings

Fig. 1 is a schematic diagram of an embodiment of a lithium replenishing device for a pole piece.

Fig. 2 is another schematic diagram of the pole piece lithium supplement device of fig. 1.

Fig. 3 is a schematic view of a lithium replenishing device for a pole piece in a lithium replenishing process.

Fig. 4 is a schematic diagram of a lubricating mechanism and a cleaning mechanism of the pole piece lithium supplementing device.

Fig. 5 is a schematic diagram of a lubrication mechanism of the pole piece lithium supplement device.

Fig. 6 is a schematic diagram of a cleaning mechanism of the pole piece lithium supplement device.

Fig. 7 is a schematic diagram of another embodiment of a pole piece lithium supplement device.

Fig. 8 is another schematic diagram of the pole piece lithium supplement device of fig. 7.

Fig. 9 is another schematic diagram of the pole piece lithium supplement device in the lithium supplement process.

Wherein the reference numerals are as follows:

1 first lithium strip unwinding mechanism

2 Pole piece unwinding mechanism

3-roller pressing mechanism

4 first traction mechanism

5 pole piece winding mechanism

6 first coating mechanism

7 lubricating mechanism

8 cleaning mechanism

9 second lithium strip unwinding mechanism

10 second traction mechanism

11 second coating mechanism

12 Pre-pressing roller

31 first calender roll

32 first clad roller

33 second clad roll

34 first support roller

35 second calender roll

36 second support roller

41 carry over pinch rolls

42 traction belt

71 coating head

72 guide member

81 scraper

82 cleaning member

83 dust suction component

L lithium belt

P pole piece

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In the description of the present application, unless explicitly stated or limited otherwise, the terms "first", "second", and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means more than two (including two); the term "coupled", unless otherwise specified or indicated, is to be construed broadly, e.g., "coupled" may be a fixed or removable connection or a connection that is either integral or electrical or signal; "connected" may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In the description of the present application, it should be understood that the terms "upper" and "lower" used in the description of the embodiments of the present application are used in a descriptive sense only and not for purposes of limitation. The present application is described in further detail below with reference to specific embodiments and with reference to the attached drawings.

The pole piece lithium supplementing device can be used for supplementing lithium on the pole piece P so as to improve the capacity and the cycle life of the lithium ion battery. The lithium supplementing process of the pole piece mainly comprises a rolling process and a laminating process. The rolling process is to roll the lithium tape thin to form a lithium film, and the laminating process is to laminate the lithium film to the surface of the pole piece P by rolling.

The pole piece P comprises a current collector and an active substance layer arranged on the surface of the current collector. The current collector may be a metal foil and the active material layer may include graphite or silicon.

Referring to fig. 1 and 2, the pole piece lithium supplementing device of the present application includes a first lithium belt unwinding mechanism 1, a pole piece unwinding mechanism 2, a rolling mechanism 3, a first traction mechanism 4, a pole piece winding mechanism 5, and a first coating mechanism 6.

The first lithium belt unreeling mechanism 1 is used for arranging a lithium belt L. The first lithium tape unwinding mechanism 1 comprises a lithium tape unwinding roller, and the lithium tape L can be connected to the lithium tape unwinding roller in a winding manner.

The pole piece unreeling mechanism 2 is used for setting a pole piece P. The pole piece unreeling mechanism 2 comprises a pole piece unreeling roller, and the pole piece P can be connected to the pole piece unreeling roller in a reeling mode.

The pole piece winding mechanism 5 is used for winding the pole piece P and drawing the pole piece P. The pole piece winding mechanism 5 comprises a pole piece winding roller which is a driving roller. When lithium is needed to be supplemented, the free end of the pole piece P can be connected to the pole piece winding roller, and the pole piece winding roller drives the pole piece P to move through rotation.

The rolling mechanism 3 includes a first calender roll 31, a first laminating roll 32, and a second laminating roll 33. The first calendar roll 31, the first laminating roll 32, and the second laminating roll 33 are all flat rolls. The first calendar roll 31, the first laminating roll 32 and the second laminating roll 33 may be arranged in order in the horizontal direction; of course, the first calender roll 31, the first laminating roll 32 and the second laminating roll 33 may be arranged in a vertical direction or in a triangular shape, as required. The nip between the first calender roll 31 and the first laminating roll 32 can be adjusted as desired, and the nip between the first laminating roll 32 and the second laminating roll 33 can be adjusted as desired.

The first calendar roll 31 and the first laminating roll 32 may be used to calendar the lithium ribbon L. When lithium supplement is needed, the lithium ribbon L may be drawn between the first reduction roll 31 and the first lamination roll 32, and the roll pressure between the first reduction roll 31 and the first lamination roll 32 thins the lithium ribbon L.

The first drawing mechanism 4 is used for drawing the lithium ribbon L into between the first reduction roll 31 and the first laminating roll 32. The pole piece winding mechanism 5 can draw the pole pieces P to pass through between the first laminating roller 32 and the second laminating roller 33.

The first coating mechanism 6 is located upstream of the rolling mechanism 3 in the traveling direction of the lithium belt L, and the first coating mechanism 6 is used to apply a coating on the surface of the lithium belt L. By providing a coating, the roughness of both surfaces of the lithium strip L can be changed; when the lithium tape L is rolled by the first calendaring roller 31 and the first laminating roller 32, the coating layer can reduce the adhesion between the lithium tape L and the first calendaring roller 31 and the adhesion between the lithium tape L and the first laminating roller 32, so that the thinned lithium tape L can adhere to the surface of the first laminating roller 32 with a small adhesion, and the separation of the lithium tape L from the first calendaring roller 31 and the separation of the lithium tape L from the first laminating roller 32 are facilitated.

The first pulling mechanism 4 comprises a pulling roll 41 and a pulling belt 42, the pulling belt 42 being connected to the pulling roll 41. The pulling roll 41 is located downstream of the first reduction roll 31 in the running direction of the lithium ribbon L. The pulling roll 41 is a drive roll. When the lithium belt L is required to be pulled, the pulling belt 42 may be connected to the lithium belt L, and then the pulling roller 41 drives the lithium belt L to move.

The lithium supplementing process of the pole piece lithium supplementing device of the present application in some embodiments is briefly described below.

When lithium needs to be supplemented to the pole piece P, a coil of the lithium tape L is arranged on the first lithium tape unwinding mechanism 1, and then the traction tape 42 is driven to pass through the space between the first calendering roller 31 and the first laminating roller 32, and the traction tape 42 is connected to the end of the lithium tape L.

And (3) setting the coil material of the pole piece P to be compensated with lithium to the pole piece unwinding mechanism 2, then drawing the pole piece P to pass through the space between the first laminating roller 32 and the second laminating roller 33, and connecting the end part of the pole piece P to the pole piece winding mechanism 5. And a pole piece winding roller of the pole piece winding mechanism 5 rotates and drives the pole piece P to move.

The drawing roller 41 rotates and drives the lithium belt L to run through the drawing belt 42. When the lithium ribbon L passes through the first coating means 6, the first coating means 6 coats the surface of the lithium ribbon L with a coating. Then, the lithium strip L coated with the coating layer is pulled by the first pulling mechanism 4 to enter between the first reduction roll 31 and the first combination roll 32. The nip between the first reduction roll 31 and the first laminating roll 32 is smaller than the thickness of the lithium strip L, so the first reduction roll 31 and the first laminating roll 32 can thin the lithium strip L. Under the action of the roller pressure, both surfaces of the lithium ribbon L are respectively adhered to the first reduction roller 31 and the first lamination roller 32.

As the first reduction roll 31 and the first laminating roll 32 rotate, the lithium ribbon L is separated from the first reduction roll 31 and adhered to the roll surface of the first laminating roll 32. Meanwhile, the thinned lithium ribbon L is separated from the traction ribbon 42.

Referring to fig. 3, as the first laminating roller 32 rotates, the lithium tape L adhered to the roller surface of the first laminating roller 32 enters between the first laminating roller 32 and the second laminating roller 33; the first laminating roller 32 and the second laminating roller 33 roll the pole piece P and the lithium belt L on the roll surface of the first laminating roller 32, so that the lithium belt L is laminated on the surface of the pole piece P, and lithium supplement of the pole piece P is realized.

The first coating mechanisms 6 are two groups and respectively coat two surfaces of the lithium strip L with coatings. The two groups of first coating mechanisms 6 each contain a release agent, and the release agents in the two groups of first coating mechanisms 6 have different surface roughness. The two sets of first coating mechanisms 6 apply a release agent to both surfaces of the lithium ribbon L, thereby forming a coating layer on both surfaces of the lithium ribbon L.

By providing different release agents in the two sets of first coating mechanisms 6, the adhesion between the lithium ribbon L and the first calender roll 31 can be made smaller than the adhesion between the lithium ribbon L and the first clad roll 32. Therefore, as the first reduction roll 31 and the first clad roll 32 rotate, the lithium ribbon L is separated from the first reduction roll 31 and adhered to the roll surface of the first clad roll 32.

When the first reduction roller 31 and the first laminating roller 32 roll the lithium ribbon L, the lithium ribbon L is actually broken into several pieces, but remains adhered to the surface of the first laminating roller 32. When the lithium belt L is broken by pressure, the connection between the traction belt 42 and the lithium belt L is failed, so that the traction belt 42 can automatically fall off, and the lamination process of the lithium belt L and the pole piece P cannot be interfered.

The lithium ribbon L is attached to the pole piece P after thinning by the roller pressure of the first and

second laminating rollers

32 and 33. Since the release agent can reduce the adhesion between the lithium tape L and the first clad roller 32, the adhesion between the lithium tape L and the pole piece P may be greater than the adhesion between the lithium tape L and the first clad roller 32. When the pole piece P passes through between the first laminating roller 32 and the second laminating roller 33, the lithium tape L is peeled off from the first laminating roller 32 by the pole piece P.

The pole piece lithium supplementing device integrates the rolling process and the laminating process of the lithium belt L together, so that the lithium supplementing process is simplified, the occupied space is reduced, and the production cost is reduced. The first coating mechanism 6 can coat a coating on the surface of the lithium strip L to reduce the difficulty in separating the lithium strip L from the first calendering roller 31 and the difficulty in separating the lithium strip L from the first laminating roller 32, and ensure that the lithium strip L can be smoothly transferred to the surface of the pole piece P.

If the first traction mechanism 4 is not provided, the lithium strip L needs to be manually drawn between the first reduction roller 31 and the first laminating roller 32, and the lithium strip L is pulled to move by the first reduction roller 31 and the first laminating roller 32. This may result in the first coating mechanism 6 failing to apply the coating layer on the initial segment of the lithium ribbon L, causing the initial segment of the lithium ribbon L to adhere to the surface of the first laminating roller 32 or the first calender roller 31; at this time, the initial segment of the lithium ribbon L cannot be transferred to the surface of the pole piece P, which results in waste of the lithium ribbon L, and simultaneously reduces the flatness of the roll surfaces of the first laminating roll 32 and the first calendering roll 31, which affects the calendering of the lithium ribbon L later.

In the present application, the first traction mechanism 4 may initially pull the lithium tape L to move, so that the first coating mechanism 6 can coat a coating on the surface of the lithium tape L, and prevent the lithium tape L from adhering to the first calendaring roller 31 and the first laminating roller 32, thereby avoiding waste of the lithium tape L.

The first coating mechanism 6 may employ one of transfer coating, extrusion coating, or screen printing coating. The distance between the coating head of the first coating mechanism 6 and the lithium strip L is adjustable, and the thickness of the coating on the lithium strip L can be controlled.

Referring to fig. 1 and 2, the lithium replenishing device for the pole piece further comprises two pre-pressing rollers 12. The two pre-press rolls 12 are located upstream of the first coating mechanism 6 in the running direction of the lithium belt L. The lithium strip L passes between the two pre-pressing rollers 12 and then passes through the first coating device 6. The two pre-pressing rollers 12 can pre-roll the lithium ribbon L to improve the thickness consistency of the lithium ribbon L, so that the effect of coating a release agent on the surface of the lithium ribbon L is remarkably improved, the lithium ribbon L is prevented from being scratched by a coating head of the first coating mechanism 6, and the problem of high requirement on the thickness consistency of the lithium ribbon L in the coating process is solved. The thickness uniformity of the lithium ribbon L is related to the manufacturing cost, and the requirement for the thickness uniformity of the lithium ribbon L is reduced, so that the cost of the incoming material of the lithium ribbon L can be reduced.

Under the rolling action of the prepressing roll 12, the compression amount of the lithium ribbon L is 10-20%. Since the amount of compression of the lithium ribbon L is small and does not easily adhere to the pre-press rolls 12, two pre-press rolls 12 may be disposed upstream of the first coating mechanism 6.

In the present application, the roller diameter of the first reduction roller 31 is smaller than the roller diameter of the first clad roller 32. The different-diameter rolling can be realized by matching the diameters of the large roller and the small roller. Compared with the same-diameter rolling, the reducing rolling can reduce the rolling force of the lithium tape L, increase the contact area between the first laminating roller 32 and the lithium tape L, improve the biting effect of the lithium tape L and the first calendering roller 31 and the biting effect of the lithium tape L and the first laminating roller 32, and enable the lithium tape L to be more easily adhered to the roller surface of the first laminating roller 32. In addition, as the roll diameter of the first clad roll 32 increases, the contact arc length between the lithium strip L and the first clad roll 32 can be increased when rolling the lithium strip L, and the lithium strip L is not easily slipped at a high speed.

In addition, with the increase of the roller diameter of the first laminating roller 32, the contact area and the contact arc length between the lithium tape L and the pole piece P can be increased in the laminating process, so that the adhesion effect between the lithium tape L and the pole piece P is improved.

The ratio of the roll diameter of the first calendering roll 31 to the roll diameter of the first laminating roll 32 is 0.5 to 0.99. The roller diameter of the first calendering roller 31 is 100mm-200mm, the roller diameter of the first laminating roller 32 is 200mm-400mm, and the roller diameter of the second laminating roller 33 is 200mm-400 mm.

In the rolling process of the lithium ribbon L, the linear speed of the first reduction roller 31 is smaller than the linear speed of the first lamination roller 32. Therefore, different-speed rolling can be realized, and the rolling force of the lithium strip L is reduced.

Since the roll diameter of the first reduction roll 31 is small, the first reduction roll 31 is easily deformed during the reduction, and the thickness uniformity of the reduction is reduced. Preferably, the roll pressing mechanism 3 of the present application further includes a first support roll 34, and the first support roll 34 is disposed opposite to the first calendering roll 31 and is located on a side of the first calendering roll 31 away from the first laminating roll 32. The first support roll 34 has a larger roll diameter than the first reduction roll 31.

The first supporting roll 34 and the first rolling roll 31 are in contact with each other and rotate relatively, so that the deformation of the first rolling roll 31 in the long-term use process can be reduced, the thickness consistency of the lithium strip L in rolling is improved, and the service life of the equipment is prolonged.

After the lithium ribbon L is laminated to the pole piece P, lithium chips and a release agent may remain on the roll surface of the first laminating roll 32, and if the lithium chips and the release agent are not removed in time, the rolling and laminating of the lithium ribbon L may be affected.

Therefore, the lithium device is mended to pole piece of this application still includes clearance mechanism 8, and clearance mechanism 8 is used for clearing up the roll surface of first compound roller 32. Specifically, the cleaning mechanism 8 includes a blade 81, a cleaning member 82, and a dust suction member 83. The blade edge of the doctor blade 81 is brought into contact with the roll surface of the first composite roll 32. The scraper 81 scrapes off lithium dust and a release agent remaining on the roll surface of the first laminating roll 32 as the first laminating roll 32 rotates. Referring to fig. 6, a dust suction member 83 may be positioned at a side of the scraper 81 to suck the scraped-off lithium dust and the release agent by a negative pressure. In the rotational direction of the first laminating roller 32, the cleaning member 82 is located downstream of the blade 81, and the cleaning member 82 is in contact with the roller surface of the first laminating roller 32 to further clean the roller surface of the first laminating roller 32. The cleaning member 82 may be a brush.

In order to facilitate the cleaning mechanism 8 to clean the roller surface of the first laminating roller 32, the pole piece lithium supplementing device further comprises a lubricating mechanism 7, and the lubricating mechanism 7 is used for coating a lubricant on the roller surface of the first laminating roller 32. The lubricating mechanism 7 and the cleaning mechanism 8 are arranged in the rotational direction of the first laminating roller 32. The lubricant can reduce the difficulty of scraping lithium chips and release agent by the scraper 81 and avoid scraping the roll surface of the first clad roll 32; meanwhile, under high-speed production, the lubricant can also avoid potential safety hazards such as smoking and fire caused by dry friction between the scraper 81 and residual lithium on the surface of the first clad roller 32.

During the rolling of the lithium ribbon L, the lithium ribbon L may be spread in its width direction. The extended region of the lithium tape L lacks a release agent, so that the edge of the lithium tape L in the width direction is not easily transferred to the surface of the pole piece P, but directly adheres to the surface of the first laminating roller 32. The remaining region has high adhesion strength with the first laminating roller 32, and the first laminating roller 32 is easily damaged by direct scraping with a doctor blade 81.

Therefore, referring to fig. 5, the lubrication mechanism 7 of the present application includes two applicator heads 71, and the two applicator heads 71 are arranged at intervals in the axial direction of the first laminating roller 32. The two coating heads 71 are used to coat the lubricant on the surface of the first laminating roller 32, and the coating area of each coating head 71 corresponds to the edge area of the lithium ribbon L. At this time, the lubricant can reduce the difficulty of scraping the lithium dust and the release agent by the scraper 81, and avoid scratching the roll surface of the first clad roll 32. The width of each coating head 7 can be adjusted, and the adjusting range can be 1mm-10 mm.

The lubrication mechanism 7 further includes a guide member 72, and the two coating heads 71 are slidably provided to the guide member 72 in a direction parallel to the axial direction of the first laminating roller 32. When the width specification of the lithium ribbon L is changed, it is only necessary to adjust the interval between the two coating heads 71 along the guide member 72. That is to say, the lubricating mechanism 7 of the present application satisfies the requirements of lithium belts L of different specifications, and has good versatility.

The pole piece lithium supplementing device is further provided with a cleaning mechanism 8 for cleaning the first calendering roller 31. The first reduction roll 31 hardly leaves lithium dust due to the difference in the release agent between the two surfaces of the lithium ribbon L; even if the lithium chips remain, the adhesion between the lithium chips and the first reduction roller 31 is small. Therefore, the scraper 81 and the cleaning member 82 of the cleaning mechanism 8 can clean the first rolling roller 31 well without providing the lubricating mechanism 7 for lubricating the first rolling roller 31.

Referring to fig. 7 to 9, the pole piece lithium supplementing device further includes a second lithium tape unwinding mechanism 9, a second traction mechanism 10, and a second coating mechanism 11.

The second lithium ribbon unwinding mechanism 9 is used for arranging the lithium ribbon L. The second lithium tape unwinding mechanism 9 includes a lithium tape unwinding roller to which the lithium tape L may be connected in a winding manner.

The rolling mechanism 3 further includes a second calendering roller 35, and the second calendering roller 35 is disposed opposite to the second laminating roller 33. The second traction mechanism 10 is used for drawing the lithium strips L provided by the second lithium strip unwinding mechanism 9 into a space between the second calendaring roller 35 and the second laminating roller 33. The second coating mechanism 11 is located upstream of the rolling mechanism 3 in the tape running direction of the lithium tape L supplied from the second lithium tape unwinding mechanism 9, and the second coating mechanism 11 is configured to coat the surface of the lithium tape L supplied from the second lithium tape unwinding mechanism 9 with a coating.

The second traction mechanism 10 may be identical to the first traction mechanism 4. Specifically, the second pulling mechanism 10 includes a pulling roll 41 and a pulling belt 42, and the pulling belt 42 is connected to the pulling roll 41.

The second calendar roll 35 and the second laminating roll 33 may be used to calendar the lithium ribbon L. When lithium supplement is needed, the lithium strip L can be drawn between the second reduction roll 35 and the second laminating roll 33, and the roll pressure between the second reduction roll 35 and the second laminating roll 33 thins the lithium strip L.

The second coating mechanisms 11 are two groups and respectively coat two surfaces of the lithium ribbon L with a coating. The two groups of second coating mechanisms 11 each contain a release agent, and the surface roughness of the release agent in the two groups of second coating mechanisms 11 is different. The two sets of second coating mechanisms 11 apply a release agent to both surfaces of the lithium ribbon L, thereby forming a coating layer on both surfaces of the lithium ribbon L.

By providing different release agents in the two sets of second coating mechanisms 11, the adhesion between the lithium tape L and the second reduction roll 35 can be made smaller than the adhesion between the lithium tape L and the second laminating roll 33. Therefore, as the second reduction roll 35 and the second clad roll 33 rotate, the lithium ribbon L is separated from the second reduction roll 35 and adhered to the roll surface of the second clad roll 33.

The lithium tape L adhered to the first laminating roller 32 and the lithium tape L adhered to the second laminating roller 33 are respectively laminated to both surfaces of the pole piece P, thereby supplementing lithium on both surfaces of the pole piece P.

The second traction mechanism 10 can initially pull the lithium tape L to move, so that the second coating mechanism 11 can coat a coating on the surface of the lithium tape L, prevent the lithium tape L from adhering to the second calendaring roller 35 and the second laminating roller 33, and avoid waste of the lithium tape L.

The second coating mechanism 11 and the first coating mechanism 6 may be the same mechanism.

The pole piece lithium supplementing device can further comprise two pre-pressing rollers 12 arranged on the upstream of the second coating mechanism 11 so as to roll the lithium strip L provided by the second lithium strip unwinding mechanism 9, and the thickness consistency of the lithium strip L is improved.

The roll diameter of the second calendering roll 35 is smaller than that of the second clad roll 33, so that reducing rolling is realized, and the rolling force of the lithium strip L is reduced. In the rolling process of the lithium strip L, the linear speed of the second rolling roller 35 is less than the linear speed of the second clad roller 33, so that different-speed rolling is realized, and the rolling force of the lithium strip L is reduced.

The roll pressing mechanism 3 of the present application further includes a second support roll 36, and the second support roll 36 is disposed opposite to the second calendering roll 35 and is located on one side of the second calendering roll 35 away from the second laminating roll 33. The roll diameter of the second support roll 36 is larger than that of the second reduction roll 35. The second support roll 36 can reduce the deformation of the second calendering roll 35 in the long-term use process, improve the thickness consistency of the lithium strip L calendering, and prolong the service life of the equipment.

The pole piece lithium supplementing device can also be provided with a lubricating mechanism 7 for lubricating the second laminating roller 33 and a cleaning mechanism 8 for cleaning the second laminating roller 33. The lubricating mechanism 7 for lubricating the second laminating roller 33 is the same as the lubricating mechanism 7 for lubricating the first laminating roller 32, and the cleaning mechanism 8 for cleaning the second laminating roller 33 is the same as the cleaning mechanism 8 for cleaning the first laminating roller 32.

The application also provides a pole piece lithium supplementing method. The pole piece lithium supplementing method comprises the following steps:

arranging a lithium belt L to a first lithium belt unwinding mechanism 1, and arranging a pole piece P to a pole piece unwinding mechanism 2;

connecting the end part of the lithium belt L to a first traction mechanism 4, wherein the first traction mechanism 4 pulls the lithium belt L to move and pass through a first coating mechanism 6, and the first coating mechanism 6 coats the surface of the lithium belt L with a coating;

the lithium strip L coated with the coating enters a space between the first calendaring roller 31 and the first laminating roller 32 under the traction of the first traction mechanism 4, the first calendaring roller 31 and the first laminating roller 32 rotate and thin the lithium strip L, and the lithium strip L is adhered to the roller surface of the first laminating roller 32 and separated from the first traction mechanism 4;

the pole piece P is drawn to pass through the space between the first laminating roller 32 and the second laminating roller 33 and is connected to the pole piece rolling mechanism 5;

the first and

second laminating rollers

32 and 33 roll the pole sheet P and the lithium tape L on the roll surface of the first laminating roller 32, thereby laminating the lithium tape L to the surface of the pole sheet P.

According to the pole piece lithium supplementing method, the rolling process and the laminating process of the lithium belt L are integrated, so that the lithium supplementing process is simplified, the occupied space is reduced, and the production cost is reduced. The first coating mechanism 6 can coat a coating on the surface of the lithium strip L to reduce the difficulty in separating the lithium strip L from the first calendering roller 31 and the difficulty in separating the lithium strip L from the first laminating roller 32, and ensure that the lithium strip L can be smoothly transferred to the surface of the pole piece P.

The first traction mechanism 4 can initially pull the lithium tape L to move, so that the first coating mechanism 6 can coat a coating on the surface of the lithium tape L, prevent the lithium tape L from adhering to the first calendaring roller 31 and the first laminating roller 32, and avoid waste of the lithium tape L.

In the pole piece lithium supplementing method, the linear speed of the first calendering roller 31 is smaller than that of the first laminating roller 32, so that different-speed rolling is realized, the rolling force of the lithium strip L is reduced, the energy consumption is reduced, the equipment load is reduced, and the service life of the equipment is prolonged.

Claims

1. A pole piece lithium supplementing device is characterized by comprising a first lithium belt unreeling mechanism (1), a pole piece unreeling mechanism (2), a rolling mechanism (3), a first traction mechanism (4), a pole piece reeling mechanism (5) and a first coating mechanism (6);

the first lithium belt unreeling mechanism (1) is used for arranging a lithium belt (L), and the pole piece unreeling mechanism (2) is used for arranging a pole piece (P);

the rolling mechanism (3) comprises a first rolling roller (31), a first laminating roller (32) and a second laminating roller (33);

the first traction mechanism (4) is used for drawing the lithium strip (L) to enter between the first calendering roller (31) and the first laminating roller (32), and the pole piece rolling mechanism (5) is used for rolling the pole piece (P) and drawing the pole piece (P) to pass through between the first laminating roller (32) and the second laminating roller (33);

the first coating mechanism (6) is located upstream of the rolling mechanism (3) along the traveling direction of the lithium belt (L), and the first coating mechanism (6) is used for coating the surface of the lithium belt (L).

2. The pole piece lithium supplement device of claim 1,

the first traction mechanism (4) comprises a traction roller (41) and a traction belt (42), and the traction belt (42) is connected to the traction roller (41);

the drawing roll (41) is located downstream of the first calendering roll (31) in the tape running direction of the lithium tape (L).

3. The pole piece lithium supplement device of claim 1,

the pole piece lithium supplementing device further comprises a lubricating mechanism (7) and a cleaning mechanism (8), wherein the lubricating mechanism (7) and the cleaning mechanism (8) are arranged along the rotating direction of the first laminating roller (32);

the lubricating mechanism (7) is used for coating lubricant on the roller surface of the first laminating roller (32), and the cleaning mechanism (8) is used for cleaning the roller surface of the first laminating roller (32).

4. The pole piece lithium supplementing device according to claim 3, characterized in that the lubricating mechanism (7) comprises two coating heads (71), and the two coating heads (71) are arranged at intervals along the axial direction of the first laminating roller (32).

5. The pole piece lithium supplementing device according to claim 4, wherein the lubricating mechanism (7) further comprises a guide member (72), and the two coating heads (71) are slidably provided to the guide member (72) in a direction parallel to the axial direction of the first laminating roller (32).

6. The pole piece lithium supplementing device according to claim 1, wherein the roller diameter of the first calendering roller (31) is smaller than the roller diameter of the first laminating roller (32).

7. The pole piece lithium supplementing device according to claim 6, wherein the ratio of the roller diameter of the first calendering roller (31) to the roller diameter of the first laminating roller (32) is 0.5-0.99.

8. The pole piece lithium supplement device of claim 6,

the rolling mechanism (3) further comprises a first supporting roller (34), wherein the first supporting roller (34) is arranged opposite to the first calendering roller (31) and is positioned on one side, far away from the first laminating roller (32), of the first calendering roller (31);

the roll diameter of the first supporting roll (34) is larger than that of the first rolling roll (31).

9. The pole piece lithium supplement device of claim 1,

the first coating mechanisms (6) are divided into two groups and respectively coat two surfaces of the lithium strip (L) with coatings;

the two groups of first coating mechanisms (6) contain release agents, and the surface roughness of the release agents in the two groups of first coating mechanisms (6) is different.

10. The pole piece lithium supplement device of any one of claims 1 to 9,

the pole piece lithium supplementing device further comprises a second lithium belt unreeling mechanism (9), a second traction mechanism (10) and a second coating mechanism (11);

the second lithium belt unreeling mechanism (9) is used for arranging a lithium belt (L);

the rolling mechanism (3) further comprises a second calendering roller (35), and the second calendering roller (35) is opposite to the second laminating roller (33);

the second traction mechanism (10) is used for drawing the lithium strips (L) provided by the second lithium strip unreeling mechanism (9) into a position between the second calendering roller (35) and the second laminating roller (33);

and along the tape moving direction of the lithium tape (L) provided by the second lithium tape unwinding mechanism (9), the second coating mechanism (11) is positioned at the upstream of the rolling mechanism (3), and the second coating mechanism (11) is used for coating the surface of the lithium tape (L) provided by the second lithium tape unwinding mechanism (9).