CN216958090U - Negative pole piece calendering lithium-coating device - Google Patents

Abstract

The utility model provides a negative pole piece calendering and lithium coating device, which comprises a pair of transfer rollers formed in a cylindrical shape and a calendering mechanism, wherein a specified coating gap allowing a negative pole piece to pass is formed between the two transfer rollers; each calendaring mechanism is used for calendaring the lithium strip onto the carrier film and conveying the lithium strip to the laminating gap, and the side of the carrier film facing the lithium strip or the surface of the lithium strip is coated with a release agent. According to the negative pole piece calendaring lithium-coating device, the release agent is coated on the carrier film or the lithium tape, so that the release force is formed between the carrier film and the lithium tape, when the lithium tape on the carrier film is transferred onto the pole piece, the carrier film can be recovered, and the release agent is coated again after cleaning and drying, so that the lithium supplement cost is reduced.

Description

Negative pole piece calendering lithium-coating device

Technical Field

The utility model relates to the technical field of lithium ion batteries, in particular to a negative pole piece calendering lithium-coating device.

Background

With the improvement of living standard of people, automobiles become indispensable transportation means. However, while the automobile industry is rapidly developing and the automobile yield and keeping quantity are continuously increasing, the automobile also brings air pollution, namely automobile exhaust pollution. In many large and medium-sized cities, automobile exhaust emission has become a main air pollution source, but the number of automobiles still continues to increase greatly along with rapid economic development and increase of social needs. With the enhancement of environmental awareness of people, the reduction of automobile exhaust emission is particularly urgent.

Under the background, new energy vehicles which are cleaner and more environment-friendly than traditional vehicles are produced at the same time, and people are pursued at the beginning of birth. The lithium ion battery is the first choice of the new energy automobile power battery due to the advantages of high energy density, long cycle life, no memory effect and the like.

However, in the first charge and discharge process of the lithium ion battery electrode material, lithium loss caused by a Solid Electrolyte Interface (SEI) film reduces the energy density of the lithium ion battery, and the situation is particularly obvious in a silicon-based negative electrode material system. In addition, the loss of active lithium caused by side reaction in the circulation process can also cause the shortening of the circulation life, so that the lithium supplement to the pole piece is an effective means for improving the energy density and the circulation life of the lithium ion battery.

The lithium foil lithium supplementing technology has advantages in safety, cost and efficiency, and the Chinese invention patent CN105845896B discloses a split calendering disposable film laminating lithium supplementing device, wherein a carrier film is consumed in the lithium supplementing process, and the carrier film cannot be recycled, so that the lithium supplementing cost is too high.

SUMMERY OF THE UTILITY MODEL

In view of this, the present invention provides a lithium covering device for negative electrode sheet rolling, so as to reduce the lithium supplementing cost of the sheet.

In order to achieve the purpose, the technical scheme of the utility model is realized as follows:

a negative pole piece calendering lithium-coated device comprises:

a pair of transfer rollers formed in a cylindrical shape, a predetermined overlapping gap allowing the negative electrode sheet to pass being formed between the two transfer rollers;

a rolling mechanism configured to be provided in correspondence with two of the transfer rollers; each rolling mechanism is used for rolling the lithium strip onto the carrier film and conveying the lithium strip to the laminating gap; the side of the carrier film facing the lithium strip or the side of the lithium strip facing the carrier film is coated with a release agent.

Furthermore, the carrier film adopts one of a PET film, a polypropylene film, a PE protective film and a stainless steel foil.

Further, a coating mechanism for coating a release agent on the carrier film facing the lithium tape or the lithium tape facing the carrier film is provided on the transport path of the carrier film before the lithium tape is rolled.

Further, a processing device configured to process the surface of the rolled lithium ribbon is provided on the transport path of the rolled lithium ribbon upstream of the lamination gap.

Further, the processing device comprises at least one of an edge trimming device for modifying the lithium strip and a scraper mechanism.

Further, in order to realize stripe lithium supplement, raised stripes can be arranged on the surface of the transfer roller.

Further, the rolling mechanism includes a pair of rolling rolls formed in a cylindrical shape, and a prescribed rolling gap that allows the lithium ribbon to pass is formed between the two rolling rolls; and the carrier film retracting mechanism sequentially passes through the rolling gap and the laminating gap, and forms unwinding and winding through the carrier film retracting mechanism.

Further, a rejection film retracting mechanism is arranged on the other side of the lithium ribbon relative to the carrier film retracting mechanism; the rejection film passing through the rolling gap is unreeled and reeled by the rejection film reeling and unreeling mechanism; a coating mechanism for coating a release agent on the repellent film facing one side of the lithium belt or the lithium belt facing the repellent film is arranged on a path of the lithium belt before being rolled; and the release force between the rejection film and the lithium belt is smaller than that between the carrier film and the lithium belt.

Further, the rolling mechanism includes auxiliary rolling rolls corresponding to the number of the rolling rolls, each of the auxiliary rolling rolls is configured in a cylindrical shape having an axial center, and the auxiliary rolling rolls are held in contact with the respective corresponding auxiliary rolling rolls at a constant pressure.

Further, the roller diameter of the calendering roller is smaller than that of the transfer roller.

Compared with the prior art, the utility model has the following advantages:

(1) the negative pole piece calendering lithium-coating device comprises a pair of transfer rollers and a calendering mechanism, wherein a coating gap is formed between the transfer rollers, so that a lithium belt on a carrier film can be conveniently transferred onto a pole piece; calendering mechanism is provided with two, thereby can be convenient for all mend lithium to the two sides of pole piece, again because one side or the lithium strip surface coating towards the lithium strip of carrier film have the release agent, can be convenient for calendering back lithium strip transfer to the carrier film and by transfer to on the pole piece on the carrier film, simultaneously, owing to be that the coating of release agent makes and has the release force between carrier film and the lithium strip, after the lithium strip on the carrier film transferred to on the pole piece, the carrier film is recoverable, the coating release agent uses once more after wasing, the lithium cost of mending has been reduced.

(2) The carrier film adopts one of PET film, polypropylene membrane, PE protection film, stainless steel foil, all is current material, and the purchase of being convenient for is used, improves and mends lithium efficiency.

(3) Through the coating mechanism who sets up the release agent, can carry out the coating of release agent to the carrier membrane to the lithium area breaks away from the carrier membrane, and shifts to on the polar piece.

(4) By arranging the processing device on the conveying path of the lithium strip, the lithium strip can be conveniently processed, and the lithium strip can be conveniently transferred to the pole piece in the later step.

(5) The arrangement processing device comprises at least one of a trimming device and a scraper mechanism, modification processing can be conveniently carried out on the lithium belt, and the trimming device can be selected when the edge alignment degree of the pole piece belt needs to be improved; when the striped lithium supplement is required, a scraper mechanism can be selected.

(6) By forming the stripes on the surface of the transfer roller, the lithium strip on the carrier film can be transferred to the pole piece at the convex parts of the stripes of the transfer roller, and the lithium strip on the carrier film cannot be transferred to the pole piece at the concave parts of the stripes of the transfer roller, so that the stripe-shaped lithium supplement is realized.

(7) Through setting up the calendering mechanism including pressing extension roller and carrier membrane jack, press the setting of extension roller, can be convenient for become the lithium area by the roll film and depend on the carrier membrane, the setting of carrier membrane jack can be convenient for unreel and the rolling of carrier membrane, and then the lithium area of being convenient for shifts on the polar plate.

(8) Through setting up rejection film jack, can be convenient for to the rolling of rejection film with unreel, again because the type force of leaving between rejection film and lithium area is less than the type force of leaving between carrier film and lithium area for the lithium area after being prolonged by the pressure depends on the carrier film, and the existence of rejection film can prevent to depend on the roller of rolling in the one side that is not equipped with the carrier film by the lithium area after being prolonged.

(9) By arranging the auxiliary rolling roll, a certain pressure can be conveniently provided for the rolling roll in contact with the auxiliary rolling roll, and the lithium strip can be conveniently rolled into a film shape.

(10) The roll diameter of the calendering roll is smaller than that of the transfer roll, so that extension of the negative pole piece in the transfer process is avoided.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model, illustrate embodiments of the utility model and together with the description serve to explain the utility model and do not constitute a limitation of the utility model. In the drawings:

fig. 1 is a schematic structural diagram of a negative electrode sheet calendering lithium-coating device according to a first embodiment of the present invention;

fig. 2 is a schematic structural diagram of a negative electrode sheet calendering lithium-coating device according to a second embodiment of the utility model;

fig. 3 is a schematic structural diagram of a negative electrode sheet calendering lithium-coating device according to a third embodiment of the present invention;

fig. 4 is a schematic structural diagram of a negative electrode sheet calendering lithium-coating apparatus according to a fourth embodiment of the present invention;

description of reference numerals:

1. a lithium strip unwinding roller; 2. auxiliary calendering rolls; 3. a calendering roller; 7. a transfer roll; 8. a processing device; 9. a pole piece retracting and releasing mechanism; l, lithium tape; c1, repellent membrane; c2, carrier film; p, pole piece;

41. a rejection film unwinding roller; 42. a repellent film wind-up roll;

51. a carrier film unwinding roller; 52. a carrier film wind-up roll; 53. a carrier film backup roll;

61. a first coating device; 62. a second coating device;

91. a pole piece unwinding roller; 92. pole piece wind-up roll.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it should be noted that, if terms indicating orientation or positional relationship such as "upper", "lower", "inside", "outside", etc. appear, they are based on the orientation or positional relationship shown in the drawings and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the appearances of the terms first, second, etc. in this specification are not necessarily all referring to the same item, but are instead intended to cover the same item.

In addition, in the description of the present invention, the terms "mounted," "connected," and "connecting" are to be construed broadly unless otherwise specifically limited. For example, the connection can be fixed, detachable or integrated; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. To those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in conjunction with specific situations.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

Example one

The structure of the negative electrode sheet rolling lithium coating apparatus provided in this embodiment is shown in fig. 1, and includes a pair of transfer rollers 7 formed in a cylindrical shape, in which a predetermined laminating gap allowing the electrode sheet P to pass is formed between the two transfer rollers 7, and a rolling mechanism configured as two disposed corresponding to each transfer roller 7; each rolling mechanism is used for rolling the lithium strip L onto a carrier film C2 and conveying the lithium strip L to the laminating gap, and the side, facing the lithium strip L, of the carrier film C2 is coated with a release agent.

Transfer the compound clearance that forms between the roller 7, can be convenient for lithium area L on the carrier film C2 shifts to pole piece P on, and calendering mechanism is set up to two, can be convenient for all mend lithium to the two sides of pole piece P, because carrier film C2 has the release agent towards one side coating of lithium area L again, can be convenient for lithium area L on the carrier film C2 shifts to pole piece P on, simultaneously, because the coating that is the release agent makes and has the release force between carrier film C2 and the lithium area L, after lithium area L on carrier film C2 shifts to pole piece P, carrier film C2 is recoverable, it uses to coat the release agent once more after the washing, the cost of mended lithium is reduced.

Based on the above design concept, the two transfer rollers 7 of the negative electrode sheet calendering lithium-coating device of the embodiment are arranged at left and right intervals, the gap between the two transfer rollers 7 is the laminating gap, the transfer function is realized by controlling the distance and the pressure of the two transfer rollers, and the transfer pressure is 2-10T.

The pole piece retracting mechanism 9 comprises a pole piece unwinding roller 91 arranged on the front side of the transfer roller 7 and a pole piece winding roller 92 arranged on the rear side of the transfer roller 7, wherein the pole piece is unwound by the pole piece unwinding roller 91 and wound by the pole piece winding roller 92 after penetrating through the covering gap. The two rolling mechanisms are respectively arranged at the left side and the right side of the transfer roller 7.

The rolling mechanism includes a pair of rolling rollers 3, a lithium ribbon unwinding roller 1, a carrier film retracting mechanism, and a repellent film retracting mechanism. The casting rolls 3 are provided in a cylindrical shape, and a predetermined casting gap that allows the lithium strip L to pass therethrough is formed between the two casting rolls. In order to realize the calendering of the lithium strip, the linear velocity difference exists between the two calendering rollers, the linear velocity of the calendering roller at the rejection film side is less than that of the calendering roller at the carrier film side, and the linear velocity ratio is 0.05-0.2.

The lithium ribbon unwinding roll 1 is disposed at the rear side of the calendering roll 3, and the lithium ribbon unwound from the lithium ribbon unwinding roll 1 is rolled into a thin-film lithium ribbon by the calendering roll 3 after passing through a rolling gap, wherein the thickness of the lithium ribbon before rolling is 1 to 2mm, and the thickness of the lithium ribbon after rolling is 2 to 10 μm. In order to realize the calendering of the lithium strip, the linear speed difference exists between the two calendering rollers, the linear speed of the calendering roller at the rejection film side is less than that of the calendering roller at the carrier film side, and the linear speed ratio is 0.05-0.2.

The carrier film winding and unwinding mechanism includes a carrier film unwinding roller 51, a carrier film winding roller 52, and two carrier film auxiliary rollers 53 arranged at intervals, wherein the carrier film unwinding roller 51 is provided on the rear side of the press roller 3, the carrier film winding roller 52 is provided on the rear side of the transfer roller 7, the carrier film auxiliary roller 53 is provided on the front sides of the press roller 3 and the transfer roller 7, and after the carrier film unwound by the carrier film unwinding roller 51 passes through the rolling gap, the carrier film passes through the laminating gap again with the support assistance of the carrier film auxiliary rollers 53, and is finally wound by the carrier film winding roller 52.

Similarly, rejection film winding and unwinding mechanism includes rejection film unwinding roller and rejection film winding roller, and wherein the rejection film unwinding roller sets up in the rear side of pressing roller 3, and the rejection film winding roller sets up in the front side of pressing roller 3, and the rejection film C1 who unreels by the rejection film unwinding roller is worn through behind the calendering clearance and is rolled by the rejection film winding roller.

The carrier film retracting mechanism and the repelling film retracting mechanism are respectively arranged at two sides of the lithium belt, so that the repelling film C1 and the carrier film C2 are respectively arranged at two sides of the lithium belt. The repellent film C1 and the carrier film C2 are selected from PET films (poly terephthalic acid plastic films), PP films (polypropylene plastic films), PE films (polyethylene films), stainless steel foils and the like, are all existing materials, are convenient to purchase and use, and improve the lithium supplement efficiency.

In order to coat the release agent on the carrier film C2 and the repellent film C1, a second coating device 62 for coating the release agent on the carrier film C2 facing the lithium tape side is provided on the transport path of the carrier film C2 before the lithium tape is rolled, and similarly, a first coating device 61 for coating the release agent on the repellent film C1 facing the lithium tape side is provided on the transport path of the repellent film C1 before the lithium tape is rolled.

The release agent is selected from polymethylsiloxane and polyether, and simultaneously, a conductive agent, lithium salt or a mixture of the conductive agent and the lithium salt can be added in the release agent, so that the release agent has ionic, electronic or mixed conductivity, and the influence of the release agent on lithium ion diffusion is reduced. The amount of release agent coated on the repellent film C1 was greater than that on the carrier film C2, so that the release force between the repellent film C1 and the lithium tape was less than that between the carrier film C2 and the lithium tape.

The existence of the repellent film C1 prevents the rolled lithium ribbon from adhering to the roll 3 on the side where the carrier film C2 is not provided, and the release force between the repellent film C1 and the lithium ribbon is smaller than the release force between the carrier film C2 and the lithium ribbon, so that the rolled lithium ribbon adheres to the carrier film C2. After the repellent film C1 and the carrier film C2 are rolled, the release agent is cleaned, and the release agent is dried and then recycled, so that the cost for purchasing the carrier film C2 and the repellent film C1 is reduced.

Of course, in addition to the above arrangement, the first coating device 61 may not be provided, and in this case, the repellent film C1 only needs to be obtained by purchasing a finished product that has undergone a release treatment in the market and only needs to be subjected to a release agent coating treatment on the carrier film C2.

Further, the rolling mechanism further includes rolling auxiliary rolls 2 corresponding to the number of the rolling rolls, each rolling auxiliary roll 2 is configured in a cylindrical shape having an axial center, and the rolling auxiliary rolls 2 are held in contact with the respective corresponding rolling rolls at a constant pressure, so that a certain pressure is applied to the rolling rolls in contact with the rolling auxiliary rolls 2, thereby facilitating rolling of the lithium strip into a film shape. The lithium strip is rolled by controlling the distance and the pressure of the two rolling rolls, and the rolling force of the two rolling rolls is 5-20T.

In order to increase the degree of alignment of the edges of the lithium strip, a treatment device 8 is provided on the transport path of the rolled lithium strip upstream of the lamination gap, the treatment device 8 being configured to treat the surface of the rolled lithium strip. In the present embodiment in particular, the processing device 8 is arranged between two carrier film auxiliary rollers 53. The processing device 8 comprises an edge trimming device for modifying the lithium strip.

In order to improve the electrolyte infiltration effect of the pole piece, the lithium supplement mode can be stripe lithium supplement, in order to realize stripe lithium supplement, the surface of the transfer roller 7 can be designed with stripes which are transversely or vertically raised, the metal lithium at the raised position corresponding to the auxiliary belt is transferred onto the pole piece under the action of pressure, and the metal lithium residues at other positions are taken away by the carrier film C2.

In addition, when the stripe lithium is replenished, the transfer roller 7 can be a common roller, a scraper mechanism is arranged on the processing device 8, the scraper mechanism can remove partial lithium belts on the carrier film, and the lithium belts transferred to the pole piece are stripe-shaped after being rolled by the transfer roller 7.

Finally, in order to avoid the extension of the negative electrode pole piece caused by the transfer process, the diameter of the calendering roller is smaller than that of the transfer roller 7, preferably, the diameter of the calendering roller is 200mm, and the diameter of the transfer roller 7 is 500 mm.

Example two

As shown in fig. 2, this embodiment shows another implementation manner of the negative electrode sheet calendaring lithium coating apparatus, compared with the first embodiment, the difference is that the first coating apparatus and the second coating apparatus respectively coat the release agent on both sides of the lithium tape, and the similar effects as in the first embodiment can also be achieved.

EXAMPLE III

As shown in fig. 3, this embodiment shows another implementation manner of the negative electrode sheet calendaring lithium coating apparatus, compared with the first embodiment, the difference is that the first coating apparatus coats the side of the lithium tape facing the repellent film with the release agent, and the similar effect as the first embodiment can also be achieved.

Example four

As shown in fig. 4, this embodiment shows another implementation manner of the negative electrode sheet calendaring lithium coating apparatus, compared with the first embodiment, the difference is that the second coating apparatus coats the release agent on the side of the lithium tape facing the carrier film, and the similar effect as the first embodiment can also be achieved.

The negative pole piece calendering lithium-coating device can be applied to any negative pole systems such as graphite negative poles, soft carbon negative poles, hard carbon negative poles, nano silicon carbon negative poles, SiO-C composite negative poles and the like. The release agent is coated on the carrier film and the rejection film or the metal lithium strip, so that the release force is formed between the carrier film and the rejection film and between the carrier film and the lithium strip, after the lithium strip on the carrier film is transferred to the pole piece, the carrier film and the rejection film can be recovered, and after cleaning, the release agent is coated again for use, so that the lithium supplement cost is reduced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (10)

1. The utility model provides a negative pole piece calendering covers lithium device which characterized in that includes:

a pair of transfer rollers (7) formed in a cylindrical shape, wherein a predetermined overlapping gap allowing the pole piece (P) to pass through is formed between the two transfer rollers (7);

a rolling mechanism configured to be provided in two corresponding to each of the transfer rollers (7); each rolling mechanism is used for rolling the lithium strip (L) onto a carrier film (C2) and conveying the lithium strip to the laminating gap; the side of the carrier film (C2) facing the lithium strip (L) or the side of the lithium strip facing the carrier film is coated with a release agent.

2. The negative pole piece calendering lithium-coating device of claim 1, characterized in that:

the carrier film (C2) is one of a PET film, a polypropylene film, a PE protective film and a stainless steel foil.

3. The negative pole piece calendering lithium-coating device of claim 1, characterized in that:

the path of the lithium ribbon (L) before rolling is provided with a coating mechanism for coating a release agent on the side of the carrier film (C2) facing the side of the lithium ribbon (L) or the side of the lithium ribbon (L) facing the carrier film (C2).

4. The negative pole piece calendering lithium-coating device of claim 1, characterized in that:

a treatment device (8) is arranged on the conveying path of the lithium strip (L) after the pressing and combination upstream of the covering and combination gap, and the treatment device (8) is configured to treat the surface of the lithium strip (L) after the pressing and combination.

5. The negative pole piece calendering lithium-coating device of claim 4, characterized in that:

the processing device (8) comprises at least one of an edge trimming device for modifying the lithium strip (L) and a scraper mechanism.

6. The negative pole piece calendering lithium coating device of claim 1, characterized in that:

stripes are formed on the surface of the transfer roller (7).

7. The negative electrode sheet rolling lithium coating device according to any one of claims 1 to 6, wherein the rolling mechanism comprises:

a pair of rolling rolls formed in a cylindrical shape, the two rolling rolls forming a predetermined rolling gap therebetween that allows the lithium ribbon (L) to pass therethrough;

and the carrier film winding and unwinding mechanism is used for sequentially passing through the carrier film (C2) of the rolling gap and the laminating gap and is used for unwinding and winding through the carrier film unwinding mechanism.

8. The negative pole piece calendering lithium-coated device of claim 7, wherein the calendering mechanism comprises:

a repellent film retracting mechanism provided on the other side of the lithium tape (L) with respect to the carrier film retracting mechanism; the rejection film (C1) passing through the calendering gap is unreeled and reeled by the rejection film reeling and unreeling mechanism; a coating mechanism for coating a release agent on the repellent film (C1) facing the lithium tape (L) or the lithium tape (L) facing the repellent film (C1) on the path of the lithium tape (L) before rolling; the release force between the repellent film (C1) and the lithium tape (L) is smaller than the release force between the carrier film (C2) and the lithium tape (L).

9. The negative pole piece calendering lithium-coating device of claim 7, characterized in that:

the calendering mechanism includes auxiliary calendering rolls (2) corresponding to the number of calendering rolls, each auxiliary calendering roll (2) is configured in a cylindrical shape having an axial center, and the auxiliary calendering rolls (2) are held in contact with the respective corresponding calendering rolls at a constant pressure.

10. The negative pole piece calendering lithium-coating device of claim 7, characterized in that:

the diameter of the calendering roller is smaller than that of the transfer roller (7).

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