CN216849991U

CN216849991U - Lithium supplementing device for negative pole piece of lithium battery

Info

Publication number: CN216849991U
Application number: CN202220229925.3U
Authority: CN
Inventors: 李云明; 高飞; 杨红新
Original assignee: Svolt Energy Technology Co Ltd
Current assignee: Svolt Energy Technology Co Ltd
Priority date: 2022-01-27
Filing date: 2022-01-27
Publication date: 2022-06-28
Anticipated expiration: 2032-01-27

Abstract

The utility model provides a lithium battery negative pole piece mends lithium device, including a pair of transfer roller, two calendering mechanisms and two protection film jack mechanisms, wherein form the regulation between two transfer rollers, allow covering of negative pole piece through to close the clearance, calendering mechanism and transfer roller one-to-one, form the calendering clearance of regulation between calendering roller and the transfer roller, in order to calendering the lithium area and paste and cover on the transfer roller, protection film jack mechanism and calendering roller one-to-one, the protection film in line warp calendering clearance becomes to unreel and the rolling via protection film unreel machine configuration. Lithium battery negative pole piece mend lithium device, through setting up protection film jack, can be convenient for unreel and the rolling of protection film, because the protection film is after the rolling, through wasing the stoving back, can reuse, practiced thrift and mended the lithium cost, in addition, because calendering roller and transfer form the calendering clearance between the roller, the lithium area subsides after the calendering cover is on shifting the roller, does not use the carrier film, further reduction mend the lithium cost.

Description

Lithium supplementing device for negative pole piece of lithium battery

Technical Field

The utility model relates to a lithium ion battery technical field, in particular to lithium battery negative pole piece mends lithium device.

Background

With the improvement of living standard of people, automobiles become indispensable transportation means for people. 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, the 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, active lithium loss caused by side reaction in the circulating process can also cause the shortening of the circulating life, so that the lithium supplement to the pole piece is an effective means for improving the energy density and the circulating 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-covering lithium supplementing device, which consumes a carrier film in the lithium supplementing process, but the price of the carrier film is high, so that the lithium supplementing cost is too high.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model aims at providing a negative pole piece calendering covers lithium device to can reduce the pole piece and mend lithium cost.

In order to achieve the above purpose, the technical scheme of the utility model is realized like this:

a lithium battery negative pole piece lithium supplementing device comprises:

a pair of transfer rollers formed in a cylindrical shape, a predetermined overlapping gap allowing the negative electrode tab to pass through 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 provided with a rolling roller, the rolling roller is arranged on a conveying path of the lithium strip, and a specified rolling gap is formed between the rolling roller and the transfer roller so as to roll and paste the lithium strip on the transfer roller;

a protective film retracting mechanism configured to be provided in correspondence with two of the calender rolls; the protective film passing through the calendering gap is unreeled and reeled through the protective film unreeling mechanism; the surface of the lithium strip on the side of the protective film, which faces away from the calendering roller, or the side of the protective film, which faces the protective film, is coated with a release agent.

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

Further, a first coating mechanism for coating a release agent on the surface of the protective film or the lithium belt on the protective film side facing away from the calendering roll is arranged on the protective film conveying path on the upstream of the calendering gap.

Further, the first coating mechanism is configured as a coating roller having an axis as a rotation center.

Further, the protective film retracting mechanism includes an auxiliary roller configured in a cylindrical shape having an axis, and the auxiliary roller is held in contact with the reduction roller at a constant pressure.

Further, the distance between the calendering roll and the transfer roll is adjustable.

Further, a treatment device is provided in a circumferential direction of the transfer roll, the treatment device being configured to treat a surface of the transfer roll.

Further, the processing device includes at least one of a cleaning device that cleans the surface of the transfer roller, an edge-trimming device, and a doctor mechanism.

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

Further, the roll diameter ratio of the calendering roll to the transfer roll is 1:2 to 5.

Further, the diameter of the calendering roller is 100 mm-200 mm.

Further, a release agent is adhered between the lithium belt and the transfer roller.

Further, a second coating mechanism for coating a release agent on the lithium ribbon facing the transfer roller side is provided on the lithium ribbon conveying path upstream of the rolling gap.

Further, the release agent is polymethylsiloxane or polyether.

Compared with the prior art, the utility model discloses following advantage has:

(1) lithium battery negative pole piece mend lithium device, including a pair of transfer roller, calendering mechanism and protection film jack, calendering mechanism is totally two, it sets up to correspond two transfer rollers respectively, and be provided with the calendering clearance between calendering roller and transfer roller, can be convenient for paste the back lithium area of calendering and cover on the transfer roller, and finally shift the pole piece through the transfer roller, and the setting of protection film jack, can be convenient for unreel and the rolling of protection film, prevent to press the back lithium area of rolling and paste and cover on the calendering roller, because the protection film is after the rolling, after wasing the stoving, can reuse, the benefit lithium cost of having practiced thrift, in addition, compare in the conventional art, do not use the carrier film when mending lithium in this scheme, further reduction mends the lithium cost.

(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, reduces material preparation time, improves and mends lithium efficiency.

(3) Through set up first coating mechanism on the protection film transfer path of calendering clearance upper reaches, can be convenient for carry out the coating of release agent to protection film or the lithium area towards the protection film, because first coating mechanism sets up and is deviating from calender roll one side, prevent that the lithium area from pasting and cover on the calender roll.

(4) The processing device is arranged in the circumferential direction of the transfer roller and comprises at least one of a cleaning device, a trimming device and a scraper mechanism, wherein the cleaning device is used for cleaning residual metal lithium residues on the surface of the calendering transfer roller, the trimming mechanism is used for scraping the serrated metal lithium on the edge of the lithium belt, the lithium supplementing alignment degree of a pole piece is improved, and the scraper mechanism can be used for conveniently scraping partial lithium belt to realize the striped lithium supplementing.

(5) The roll diameter of the calendering roll is smaller than that of the transfer roll, so that the extension of the negative pole piece in the transfer process can be avoided. The roll diameter ratio of the calendering roll to the transfer roll is 1: 2-5, the roll diameter of the calendering roll is 100-200 mm, and the roll diameter of the transfer roll is 300-500 mm, so that the metal lithium calendering can be better realized, and the extension of a negative electrode is avoided.

(6) The diameter of the calendering roller is 100 mm-200 mm, which is the diameter of the existing common compression roller and is convenient to obtain.

(7) The linear speed of the calendering roller is less than that of the transfer roller, and the linear speed ratio is 1: 4-20, and can realize the rolling preparation of the metal lithium in the shape of transverse stripes.

(8) By providing a release agent between the lithium ribbon and the transfer roll, the lithium ribbon can be easily detached from the transfer roll and transferred to the pole piece.

(9) Through setting up second coating mechanism, can be convenient for carry out the coating of release agent to the lithium area.

(10) The release agent is polymethyl siloxane or polyether, which is the existing material, is convenient to purchase and use, and improves the lithium supplement efficiency.

Drawings

The accompanying drawings, which form a part of the present disclosure, are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and together with the description serve to explain the present disclosure. In the drawings:

fig. 1 is a schematic structural diagram of a lithium supplementing device for a negative electrode plate of a lithium battery according to a first embodiment of the present invention;

fig. 2 is a schematic structural diagram of a lithium supplementing device for a negative electrode plate of a lithium battery according to an embodiment of the present invention;

description of reference numerals:

1. a lithium strip unwinding roller; 2. an auxiliary roller; 3. a calender roll; 4. a transfer roll; 5. a second coating mechanism; 6. a cleaning device; 7. a scraper mechanism; l, lithium tape; C. a protective film; p, pole piece

31. A protective film unwinding roller; 32. a protective film wind-up roll;

81. a pole piece unwinding roller; 82. pole piece wind-up roll.

Detailed Description

It should be noted that, in the present invention, 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", "inner", "outer", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, 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. The specific meaning of the above terms in the present invention can be understood in conjunction with the specific situation for a person of ordinary skill in the art.

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

The embodiment relates to a lithium supplementing device for a lithium battery negative pole piece, which comprises a pair of transfer rollers, a calendaring mechanism and a protective film retracting mechanism, wherein a specified covering gap allowing the negative pole piece to pass through is formed between the two transfer rollers, the calendaring mechanism is structured to be two corresponding to each transfer roller, each calendaring mechanism is provided with a calendaring roller, the calendaring rollers are arranged on a conveying path of a lithium strip L, and a specified calendaring gap is formed between the calendaring rollers and the transfer rollers so as to calendar and paste the lithium strip L on the transfer rollers, so that the calendered lithium strip L can be conveniently pasted on the transfer rollers and finally transferred to the pole piece P through the transfer rollers.

The protection film C in the row of passing through the calendering clearance forms via the protection film unreeling mechanism and unreels and roll, can be convenient for receive and release of protection film C, prevent that the lithium area L after calendering from pasting and covering on the calendering roller, and protection film C deviates from one side of calendering roller or the metal lithium area coating towards the protection film side has the mold release, because protection film C is by the rolling back, after the washing is dried, can reuse, practiced thrift and mended the lithium cost. In addition, compare in traditional technique, do not use the carrier membrane when mending lithium in this scheme, further reduction mend lithium cost.

Based on the above design concept, an exemplary structure of the lithium supplement device for the negative electrode plate of the lithium battery of the embodiment is shown in fig. 1, two transfer rollers 4 are arranged in bilateral symmetry, and two calendering rollers 3 are respectively arranged at the left side and the right side of the two transfer rollers 4. In order to roll the lithium ribbon L, there is a linear velocity difference between the rolls and the transfer roll 4, the linear velocity of the rolls is lower than that of the transfer roll 4, and the linear velocity ratio is 1:20, but it is needless to say that the linear velocity ratio may be other suitable ratios than 1:20, such as 1:15, 1:10, 1:5, or 1: 4.

In order to facilitate the winding and unwinding of the pole pieces P, the device is further provided with a pole piece winding and unwinding mechanism which comprises a pole piece unwinding roller 81 arranged on the front side of the transfer roller 4 and a pole piece winding roller 82 arranged on the rear side of the transfer roller 4, the pole pieces P which are unwound by the pole piece unwinding roller 81 are wound by the pole piece winding roller 82 after passing through the covering gap, and the lithium belt L is transferred to the pole pieces P from the transfer roller 4 in the period.

Two lithium area unreeling roller 1 divide and establish in the both sides of transferring roller 4, correspond one of them calendering mechanism respectively, and the lithium area L that is unreeled by lithium area unreeling roller 1 passes through the calendering clearance for calendering roller 3 and transferring roller 4 mangle lithium area L, make lithium area L be the film form.

Two protective film retracting mechanisms are respectively arranged on two sides of the transfer roller 4, and each protective film retracting mechanism comprises a protective film unwinding roller 31, a protective film winding roller 32 and an auxiliary roller 2. The protective film unwinding roller 31 is arranged on the rear side of the calendering roller, and the protective film winding roller 32 is arranged on the front side of the calendering roller, so that the protective film C passes through the calendering gap after being unwound by the protective film unwinding roller 31 and is finally wound by the protective film winding roller 32.

In order to facilitate lithium supplement to the pole piece P, the device is further provided with a coating mechanism 5, and the amount of the release agent between the lithium belt L and the transfer roller 4 is less than that between the lithium belt L and the protective film C by controlling the coating amount of the release agent, so that the lithium belt L can be attached to the transfer roller when the release roller is calendered, and the lithium belt L can be conveniently transferred to the pole piece P when the release roller is transferred.

Specifically, the coating mechanism includes a first coating mechanism and a second coating mechanism. The first coating mechanism is arranged on the conveying path of the protective film C at the upstream of the calendering gap and can coat the parting agent on the protective film C at the side away from the calendering roller. By applying the release agent to the protective film C, the release force between the protective film C and the lithium tape L can be reduced, and the lithium tape L rolled into a film shape is attached to the transfer roll 4.

The second coating mechanism is arranged on a lithium strip L conveying path at the upstream of the calendering gap, the release agent is coated on the lithium strip L facing to one side of the transfer roller 4, and the coating roller can move, so that the release agent can be coated on the lithium strips L with different thicknesses. While the release agent is coated on the side surface of the lithium ribbon L close to the transfer roller 4, the release agent is also coated in the thickness direction of both sides of the lithium ribbon L.

The protective film C is made of a common PET film (a poly-p-phthalic plastic film), a PP film (a polypropylene plastic film), a PE film (a polyethylene film), a stainless steel foil, or the like, and is used after being treated with the release agent. In addition, the protective film C can also purchase a PET film, a PP film, a PE film and a stainless steel foil which are processed on the outer surfaces, certain cost is increased compared with the use of a common film, and lithium supplement efficiency can be improved to a certain extent.

In order to improve the lithium supplementing efficiency, the release agent can be selected from polymethylsiloxane or polyether, the two materials are conventional release agents and are convenient to purchase and use, the time required by lithium supplementing can be reduced due to the convenient acquisition of the release agent, and the lithium supplementing efficiency is improved. Meanwhile, a conductive agent, a lithium salt or a mixture of the conductive agent and the lithium salt can be added into 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.

In addition, the auxiliary roller 2 is preferably 200-500mm in diameter and is configured in a cylindrical shape having an axial center. The auxiliary roller 2 keeps contact with the calendering roller with a constant pressure, so that the auxiliary roller 2 can increase the calendering force on the one hand, and the auxiliary calendering roller can calender the lithium strip L, and on the other hand, the auxiliary calendering roller can also move, so that the adjustment of the distance between the calendering roller and the transfer roller 4 is facilitated, and the lithium strip L with different thicknesses can be calendered conveniently.

Specifically, in the embodiment, the position of the transfer roll 4 arranged on the left side is fixed and is not adjustable, the position of the calendering roll and the position of the auxiliary roll 2 arranged on the right side are adjustable, the calendering rolls and the corresponding auxiliary rolls 2 are synchronously adjusted, the calendering function is realized by controlling the distance and the pressure between the calendering roll and the transfer roll 4, the calendering force is 4-20T, and the transfer function is realized by adjusting the distance and the pressure between the two transfer rolls 4, and the transfer force is 2-10T.

As a preferable aspect, a processing device configured to process the surface of the transfer roller 4, including at least one of a cleaning device 6 that cleans the surface of the transfer roller 4, an edge-trimming device, and a blade mechanism 7, is provided in the circumferential direction of the transfer roller 4. The cleaning device 6 comprises a scraper and a suction nozzle, and can be used for scraping and sucking away residual lithium metal residues on the surface of the transfer roller 4. The trimming devices are respectively arranged at the left side and the right side of the transfer roller 4 and are used for scraping ultra-thin metal lithium with jagged edges and improving the alignment degree of lithium supplement.

In order to improve the electrolyte infiltration effect of the pole piece P, the lithium supplement mode can be stripe lithium supplement, and in order to realize the stripe lithium supplement, a comb-shaped stripe scraper mechanism 7 can be further arranged between the two trimming mechanisms to realize the preparation of the lithium belt L, so that the lithium belt L is arranged in a zebra shape, wherein the width of the strip lithium in the lithium belt L is 0-4mm, and the distance between the strip lithium is 0-4 mm.

And finally, in order to better realize the metal lithium rolling and avoid the extension of the pole piece P caused by the transfer process, the roll diameter of the rolling roll is smaller than that of the transfer roll 4. As a preferable mode, the ratio of the rolling roll to the transfer roll 4 is 1: 2-5, the diameter of the calendering roller is 100-200 mm, and the diameter of the transfer roller is 300-500 mm.

Example two

As shown in fig. 2, this embodiment shows another implementation manner of a lithium supplementing device for a negative electrode plate of a lithium battery, and compared with the first embodiment, the difference is that the first coating mechanism is transplanted to a metal lithium strip facing a protection film side, and a release agent is coated on the side of the lithium strip facing the protection film, so that similar effects to those of the first embodiment can also be achieved.

The utility model discloses a lithium battery negative pole piece mends lithium device can be applied to various negative pole systems such as graphite negative pole, soft carbon negative pole, hard carbon negative pole, nanometer silicon carbon negative pole, the compound negative pole of SiO-C. The two calendering mechanisms are respectively arranged corresponding to the two transfer rollers 4, and a calendering gap is arranged between the calendering roller 3 and the transfer roller 4, so that the calendered lithium belt L can be conveniently pasted on the transfer roller 4 and finally transferred to the pole piece through the transfer roller 4. And protection film jack's setting, can be convenient for unreel and the rolling of protection film, prevent that the lithium area L after the calendering from pasting and covering on calender roll 3, because the protection film is rolled up the back, through wasing the back of drying, can reuse, practiced thrift and mended lithium cost, in addition, compare in traditional technique, do not use the carrier film when mending lithium in this scheme, further reduction mended lithium cost.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

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

a pair of transfer rollers (4) formed in a cylindrical shape, wherein a predetermined overlapping gap allowing the negative electrode plate to pass through is formed between the two transfer rollers (4);

a rolling mechanism configured to correspond to two of the transfer rollers (4); each rolling mechanism is provided with a rolling roller which is arranged on a conveying path of the lithium strip (L), and a specified rolling gap is formed between the rolling roller and the transfer roller (4) so as to roll and paste the lithium strip (L) on the transfer roller (4);

a protective film retracting mechanism configured to be provided in correspondence with two of the calender rolls; the protective film (C) passing through the calendering gap is uncoiled and coiled through the protective film uncoiling mechanism; and a release agent is coated on one side of the protective film (C) departing from the calendering roller.

2. The lithium supplementing device for the negative pole piece of the lithium battery as recited in claim 1, characterized in that:

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

3. The lithium supplementing device for the negative pole piece of the lithium battery as recited in claim 1, characterized in that:

and a first coating mechanism for coating a parting agent on the protective film (C) on the side away from the calendering rollers or a lithium strip on the side facing the protective film is arranged on the conveying path of the protective film (C) on the upstream of the calendering gap.

4. The lithium supplementing device for the negative pole piece of the lithium battery as recited in claim 1, characterized in that:

a processing device is arranged on the circumferential direction of the transfer roller (4), and the processing device comprises at least one of a cleaning device (6) for cleaning the surface of the transfer roller (4), a trimming device and a scraper mechanism (7).

5. The lithium supplementing device of the negative pole piece of the lithium battery as claimed in claim 1, wherein the device is characterized in that

The roll diameter of the calendering roll is smaller than that of the transfer roll, and the roll diameter ratio of the calendering roll to the transfer roll is 1: 2-5, the roll diameter of the calendering roll is 100-200 mm, and the roll diameter of the transfer roll is 300-500 mm, so that the metal lithium calendering can be better realized, and the extension of a negative electrode is avoided.

6. The lithium battery negative pole piece lithium supplementing device according to claim 1, wherein the linear speed of the calendering roller is less than that of the transfer roller, and the linear speed ratio of the calendering roller to the transfer roller is 1: 4-20, and can realize the rolling preparation of the metal lithium in the shape of transverse stripes.

7. The lithium battery negative pole piece lithium supplementing device of claim 6, characterized in that:

the diameter of the calendering roller is 100 mm-200 mm.

8. The lithium supplementing device for the negative electrode plate of the lithium battery as claimed in any one of claims 1 to 7, wherein:

and a release agent is adhered between the lithium belt (L) and the transfer roller (4).

9. The lithium supplementing device for the negative pole piece of the lithium battery as recited in claim 8, characterized in that:

and a second coating mechanism (5) for coating a parting agent on the lithium belt (L) facing the side of the transfer roller (4) is arranged on the lithium belt (L) conveying path at the upstream of the rolling gap.

10. The lithium supplementing device for the negative pole piece of the lithium battery as recited in claim 9, characterized in that:

the release agent is polymethylsiloxane or polyether.