CN221201256U - Lithium supplementing device - Google Patents

Abstract

The application relates to a lithium supplementing device, which comprises a first unreeling mechanism, a second unreeling mechanism and a covering mechanism, wherein the first unreeling mechanism is used for unreeling a first lithium belt; the second unreeling mechanism is used for unreeling a second lithium belt; the laminating mechanism comprises a first calendaring roller, a first laminating roller and a second laminating roller, wherein the first calendaring roller and the first laminating roller are used for rolling the first lithium belt and the second lithium belt, so that the first lithium belt and the second lithium belt are attached to the roller surface of the first laminating roller and are axially distributed along the first laminating roller, and the first laminating roller and the second laminating roller are used for rolling the pole piece, so that the first lithium belt and the second lithium belt are transferred onto the first surface of the pole piece. The lithium supplementing device provided by the embodiment of the application can effectively supplement the utilization rate of a lithium process, and improves the production efficiency of the battery.

Description

Lithium supplementing device

Technical Field

The application relates to the technical field of battery manufacturing, in particular to a lithium supplementing device.

Background

Along with the development of new energy technology, the application of the battery is more and more extensive, the battery has higher energy density, higher safety, long service life and environmental protection to the social environment, and the battery has been widely applied to the aspects of passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, power stations, engineering manufacture, intelligent appliances and the like, and simultaneously promotes the technical development and research of communication terminals, medical appliances, energy development and the like.

An important process in the production process of lithium batteries is formation, and the purpose of the process is to form a solid electrolyte membrane (SEI film) on the surface of a negative electrode of a lithium battery in the first charging process. However, the formation of the SEI film consumes a part of lithium, thereby causing a loss of lithium material and thus a decrease in battery capacity. In addition, in the cyclic use process of the lithium battery, the SEI film can be continuously consumed and repaired, dead lithium in the anode and the cathode can be continuously increased, the capacity of the battery is continuously reduced, and the cycle life of the battery is reduced.

In order to reduce capacity reduction caused by irreversible consumption of lithium ions in the first charge and discharge and cyclic use of the battery, a part of active lithium is pre-supplemented to a negative electrode plate of the lithium ion battery, so that the performance of the lithium ion battery is improved.

The lithium supplementing process has important influence on the production process of the battery, and how to improve the utilization rate of the process and the production efficiency of the battery is a technical problem to be solved urgently.

Disclosure of utility model

The embodiment of the application provides a lithium supplementing device which can effectively supplement the utilization rate of a lithium process and improve the production efficiency of a battery.

In a first aspect, an embodiment of the present application provides a lithium supplementing device, where the lithium supplementing device includes a first unreeling mechanism, a second unreeling mechanism, and a covering mechanism, where the first unreeling mechanism is used for unreeling a first lithium strip; the second unreeling mechanism is used for unreeling a second lithium belt; the laminating mechanism comprises a first calendaring roller, a first laminating roller and a second laminating roller, wherein the first calendaring roller and the first laminating roller are used for rolling the first lithium belt and the second lithium belt, so that the first lithium belt and the second lithium belt are attached to the roller surface of the first laminating roller and are axially distributed along the first laminating roller, and the first laminating roller and the second laminating roller are used for rolling the pole piece, so that the first lithium belt and the second lithium belt are transferred onto the first surface of the pole piece.

According to the technical scheme, the first lithium strip is unreeled through the first unreeling mechanism, the second lithium strip is unreeled through the second unreeled mechanism, the two lithium strips correspond to the pole piece with wider width, the first lithium strip and the second lithium strip can be rolled together and then are covered on the first surface of the pole piece together, the pole piece after being covered with lithium is divided into two or more parts, a plurality of pole pieces can be obtained, two or more pieces are produced in the same time, the utilization rate of a lithium supplementing procedure is increased in speed, and the production efficiency of a battery is improved.

In some embodiments, the first unwind mechanism comprises a first unwind shaft and the second unwind mechanism comprises a second unwind shaft, the first unwind shaft and the second unwind shaft being coaxially disposed.

In some embodiments, the first unreeling shaft and the second unreeling shaft are coaxially arranged, and the traveling directions of the first lithium belt and the second lithium belt are the same, so that the uniformity of the interface of the pole piece after lithium coating is improved.

In some embodiments, the first and second unwind shafts are interconnected.

In the technical scheme, the first unreeling shaft and the second unreeling shaft are connected with each other, so that the first unreeling shaft and the second unreeling shaft can synchronously rotate, one of the first unreeling shaft or the second unreeling shaft can be controlled to rotate by only one driving piece, the other unreeling shaft or the second unreeling shaft can rotate along with the first unreeling shaft or the second unreeling shaft, and the number of components is saved.

In some embodiments, the first unwind shaft and the second unwind shaft are integrally formed.

In the technical scheme, the first unreeling shaft and the second unreeling shaft are integrally formed. The production and the manufacture are convenient, and the process of connecting the first unreeling shaft with the second unreeling shaft is saved.

In some embodiments, the first unwind mechanism comprises a first unwind shaft and the second unwind mechanism comprises a second unwind shaft, the first unwind shaft being off-axis and parallel to the second unwind shaft.

Among the above-mentioned technical scheme, first unwinding shaft and the different axle setting of second unwinding shaft, first unwinding shaft and second unwinding shaft can independent operation, and first unwinding shaft and second unwinding shaft can have different unwinding speeds, even first lithium area and second lithium area's reel footpath are inconsistent, through the unwinding speed of adjusting first unwinding shaft and second unwinding shaft respectively, also can keep first lithium area and second lithium area have the same tape running speed in its direction of tape running, and suits with the tape running speed of pole piece. By the arrangement, the risk of splitting the pole piece can be reduced, and the consistency of extension of the first lithium band and the second lithium band is improved.

In some embodiments, the lithium supplementing device further comprises a coating mechanism, the coating mechanism is arranged between the first unreeling mechanism and the covering mechanism along the tape running direction of the first lithium tape, the coating mechanism is arranged between the second unreeling mechanism and the covering mechanism along the tape running direction of the second lithium tape, and the coating mechanism is used for coating a release agent to one side of the first lithium tape facing the first covering roller and one side of the second lithium tape facing the first covering roller.

In the above technical scheme, before the first lithium band and the second lithium band are sent between the first calendaring roller and the first laminating roller, a release agent is coated on one side of the first lithium band facing the first laminating roller and one side of the second lithium band facing the second laminating roller through a coating mechanism, and the release agent can change the roughness of one side of the first lithium band facing the first laminating roller and the roughness of one side of the second lithium band facing the second laminating roller. The first lithium belt and the second lithium belt which are rolled by the first rolling roller and the first laminating roller are attached to the roller surface of the first laminating roller with smaller adhesive force, and meanwhile, the first lithium belt and the second lithium belt are easy to separate from the surface of the first laminating roller and are laminated on the first surface of the pole piece when passing between the first laminating roller and the second laminating roller.

In some embodiments, the lithium supplementing device further comprises a first coating mechanism and a second coating mechanism, wherein the first coating mechanism is arranged between the first unreeling mechanism and the covering mechanism along the tape running direction of the first lithium tape, and the first coating mechanism is used for coating a release agent to one side of the first lithium tape facing the first covering roller; along the tape running direction of the second lithium tape, the second coating mechanism is arranged between the second unreeling mechanism and the covering mechanism, and the second coating mechanism is used for coating a release agent on one side of the second lithium tape facing the first covering roller.

Among the above-mentioned technical scheme, first lithium area and second lithium area do not share coating mechanism, and first coating mechanism and second coating mechanism independent operation are convenient for control coating precision, promote the lithium effect of mending.

In some embodiments, the first calender rolls are provided in two, one for rolling the first lithium strip and the other for rolling the second lithium strip.

Among the above-mentioned technical scheme, first lithium area and second lithium area do not share a calendering roller, and two first calendering rollers independent operation are convenient for control the calendering speed of two first calendering rollers respectively, improve the control precision of calendering, and control is more nimble.

In some embodiments, the two first calender rolls are offset in the circumferential direction of the first laminating roll.

Among the above-mentioned technical scheme, two first calender rolls are around the circumference interval arrangement of first laminating roller, so arrange, can keep two first calender rolls mutually independent work's flexibility and to the control accuracy of calendering, can also reduce two first calender rolls' risk of mutual interference.

In some embodiments, the lithium replenishment device further comprises a third unreeling mechanism for unreeling a third lithium strip and a fourth unreeling mechanism for unreeling a fourth lithium strip; the laminating mechanism further comprises a second calendaring roller, the second calendaring roller and the second laminating roller are used for rolling the third lithium belt and the fourth lithium belt, so that the third lithium belt and the fourth lithium belt are attached to the surface of the second laminating roller and are axially distributed along the second laminating roller, and the first laminating roller and the second laminating roller are used for rolling the pole piece, so that the third lithium belt and the fourth lithium belt are transferred onto the second surface of the pole piece.

According to the technical scheme, on the basis that the first lithium belt and the second lithium belt are covered on the first surface of the pole piece through the matching of the first unreeling mechanism, the second unreeling mechanism and the first calendaring roller, the third lithium belt and the fourth lithium belt are covered on the second surface of the pole piece through the matching of the third unreeling mechanism, the fourth unreeling mechanism and the second calendaring roller. Therefore, the first surface lithium coating and the second surface lithium coating can be synchronously performed, the lithium coating efficiency is higher, the utilization rate of the lithium supplementing process is further improved, and the production efficiency of the battery is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a lithium supplementing device according to some embodiments of the present application;

FIG. 2 is a schematic view illustrating another angle of a lithium supplementing device according to some embodiments of the present application;

FIG. 3 is a schematic illustration of a first lithium strip and a second lithium strip overlaying a pole piece according to some embodiments of the present application;

FIG. 4 is a schematic illustration of a first unwind spool coupled to a second unwind spool in accordance with some embodiments of the present application;

FIG. 5 is a schematic diagram of a lithium-supplementing device according to other embodiments of the present application;

FIG. 6 is a schematic diagram illustrating the different axes of the first and second reels according to some embodiments of the present application;

Fig. 7 is a schematic structural diagram of a lithium supplementing device according to still other embodiments of the present application;

fig. 8 is a schematic structural diagram of a lithium supplementing device according to still other embodiments of the present application;

FIG. 9 is a schematic view of a first coating mechanism and a second coating mechanism according to still other embodiments of the present application;

Fig. 10 is a schematic structural diagram of a lithium supplementing device according to still other embodiments of the present application;

fig. 11 is a schematic structural diagram of a lithium supplementing device according to still other embodiments of the present application.

Icon: 100-lithium supplementing device; 10-a first unreeling mechanism; 11-a first unreeling shaft; 20-a second unreeling mechanism; 21-a second unreeling shaft; 30-a covering mechanism; 31-a first laminating roller; 32-a second laminating roller; 33-a first calender roll; 34-a second calendaring mechanism; 35-a first pressure roller; 40-a coating mechanism; 41-a first coating mechanism; 42-a second coating mechanism; 60-auxiliary film; 61-an auxiliary film coating mechanism; 62-an auxiliary film winding mechanism; 63-an auxiliary film unreeling mechanism; 70-a third unreeling mechanism; 80-a fourth unreeling mechanism; 90-scraping knife; 1-a first lithium band; 2-a second lithium band; 3-a third lithium band; 5-pole pieces; 51-a first surface; 52-a second surface; z-direction of tape travel; x-axis direction.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of the present application, it should be noted that, unless explicitly stated and limited otherwise, the term "connected" should be interpreted broadly, and for example, it may be a fixed connection, a removable connection, or an integral connection; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

The term "plurality" as used herein refers to two or more (including two).

In the present application, the battery cell may include, but is not limited to, a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like. The battery cells include, but are not limited to, cylinders, flat bodies, rectangular solids, or other shapes, etc. The battery cells generally comprise cylindrical battery cells, square battery cells, soft package battery cells and the like in a packaging mode.

Reference to a battery in accordance with an embodiment of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly consists of a positive plate, a negative plate and a separation membrane. The battery cell mainly relies on metal ions to move between the positive and negative electrode plates to operate. The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes out of the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes out of the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is used as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the high current is passed without fusing, the number of positive electrode lugs is multiple and stacked together, and the number of negative electrode lugs is multiple and stacked together. The material of the separator may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may be a roll-to-roll structure or a lamination structure, and embodiments of the present application are not limited thereto.

In the lithium supplementing procedure, because the lithium strip has a certain thickness, the ultrathin lithium strip is required to be rolled to be covered on the pole piece, the rolling of lithium foils with different thicknesses is generally realized by controlling the pressure, the speed and the like between two pressing rollers, and one roll of the lithium strip is covered on one surface of the pole piece, and the other roll of the lithium strip is covered on the other surface of the pole piece, so that one piece is produced.

The utilization rate of the lithium supplementing process can be improved by improving the rolling speed, but after the rolling speed reaches the upper limit, the utilization rate of the lithium supplementing process is difficult to improve again, the production efficiency of the pole piece is limited, and the production efficiency of the battery is limited.

In view of this, in order to improve the problem of low utilization rate in the lithium supplementing process, the embodiment of the application provides a technical scheme that the lithium supplementing device comprises a first unreeling mechanism, a second unreeling mechanism and a covering mechanism, wherein the first unreeling mechanism is used for unreeling a first lithium belt; the second unreeling mechanism is used for unreeling a second lithium belt; and covering the first lithium belt and the second lithium belt on the same surface of the pole piece, and arranging the first lithium belt and the second lithium belt along the width direction of the pole piece. Through providing the wider pole piece of width, cover first lithium area and second lithium area and close on the wider pole piece of width, and two rolls of lithium area are arranged along the axial of first laminating roller, once only can make up lithium for the wider pole piece, and the pole piece after laminating has wider width.

Referring to fig. 1 to 3, fig. 1 is a schematic structural diagram of a lithium supplementing device 100 according to some embodiments of the present application; fig. 2 is a schematic view illustrating another angle of the lithium supplementing device 100 according to some embodiments of the present application; fig. 3 is a schematic view of a first lithium strip 1 and a second lithium strip 2 coated with a pole piece 5 according to some embodiments of the present application.

The embodiment of the application provides a lithium supplementing device 100, wherein the lithium supplementing device 100 comprises a first unreeling mechanism 10, a second unreeling mechanism 20 and a covering mechanism 30.

The first unreeling mechanism 10 is used for unreeling the first lithium strip 1, and the second unreeling mechanism 20 is used for unreeling the second lithium strip 2.

The laminating mechanism 30 includes a first calender roll 33, a first laminating roll 31, and a second laminating roll 32, the first calender roll 33 and the first laminating roll 31 being for rolling the first lithium strip 1 and the second lithium strip 2 so that the first lithium strip 1 and the second lithium strip 2 are attached to the roll surface of the first laminating roll 31 and are arranged along the axial direction X of the first laminating roll 31, the first laminating roll 31 and the second laminating roll 32 being for rolling the pole piece 5 so that the first lithium strip 1 and the second lithium strip 2 are transferred onto the first surface 51 of the pole piece 5.

The first unreeling mechanism 10 and the second unreeling mechanism 20 are mechanisms for unreeling lithium bands, the first unreeling mechanism 10 is used for unreeling the first lithium bands 1, the second unreeling mechanism 20 is used for unreeling the second lithium bands 2, the first unreeling mechanism 10 and the second unreeling mechanism 20 are used for unreeling different lithium bands, and the structure of the first unreeling mechanism 10 and the structure of the second unreeling mechanism 20 can be the same or different.

As shown in fig. 1, the first calender roll 33, the first laminating roll 31, and the second laminating roll 32 are arranged in this order, and the first calender roll 33 and the second laminating roll 32 are provided on both sides of the first laminating roll 31. The first rolling roller 33 and the first laminating roller 31 cooperate to roll the first lithium strip 1 and the second lithium strip 2 into an ultrathin lithium strip. It should be appreciated that the lithium strips have a certain plasticity, when the first lithium strip 1 and the second lithium strip 2 are fed between the first calender roll 33 and the first laminating roll 31, that is, when the first lithium strip 1 and the second lithium strip 2 are positioned in the nip between the first calender roll 33 and the first laminating roll 31, the first lithium strip 1 and the second lithium strip 2 are stretched due to being pressed and form a film-like structure, so that they are easily laminated on the surface of the pole piece 5 in the subsequent lithium laminating process; of course, the nip between the first lithium strip 1 and the second lithium strip 2 needs to be smaller than the thickness of the lithium strips, so that the first lithium strip 1 and the second lithium strip 2 can be calendered.

The first lithium strip 1 and the second lithium strip 2 after the first calender roll 33 and the first laminating roll 31 are adhered to the roll surface of the first laminating roll 31 and are arranged along the axial direction X of the first laminating roll 31. The first calender roll 33 and the first laminating roll 31 may have different rotational speeds and diameters so that the first lithium belt 1 and the second lithium belt 2 are adhered to the roll surface of the first laminating roll 31, but it is also possible that the roughness of the roll surface of the first laminating roll 31 is larger than the roughness of the roll surface of the first calender roll 33, thereby enabling the first lithium belt 1 and the second lithium belt 2 to be adhered to the roll surface of the first laminating roll 31 without being adhered to the roll surface of the first calender roll 33.

The first lithium belt 1 and the second lithium belt 2 are attached to the roller surface of the first laminating roller 31 and are arranged along the axial direction X of the first laminating roller 31, so that the first lithium belt 1 and the second lithium belt 2 do not overlap on the roller surface of the first laminating roller 31, and the first lithium belt 1 and the second lithium belt 2 are not covered with each other.

The first and second laminating rollers 31, 32 are used to roll the pole piece 5 such that the first and second lithium strips 1, 2 are transferred onto the first surface 51 of the pole piece 5. It should be understood that the width direction of the pole piece 5 is parallel to the axial direction X of the first laminating roller 31, and the first lithium strip 1 and the second lithium strip 2 are arranged along the width direction of the first pole piece 5 on the first surface 51.

Specifically, as the first laminating roller 31 rotates, the first lithium strip 1 and the second lithium strip 2 laminated on the roller surfaces of the first laminating roller 31 are fed between the first laminating roller 31 and the second laminating roller 32, that is, the first lithium strip 1, the second lithium strip 2 and the pole piece 5 are simultaneously located in the roller gap of the first laminating roller 31 and the second laminating roller 32. Compared with the roller surface of the first laminating roller 31, the surface of the pole piece 5 is provided with an active substance layer, so that the surface roughness is larger, the adhesion force between the first lithium belt 1 and the pole piece 5 is larger than the adhesion force between the first lithium belt 1 and the first laminating roller 31, the adhesion force between the second lithium belt 2 and the pole piece 5 is larger than the adhesion force between the second lithium belt 2 and the first laminating roller 31, when the second laminating roller 32 and the first laminating roller 31 are used for laminating, the first lithium belt 1 and the second lithium belt 2 are contacted with the pole piece 5 and are subjected to rolling, the first lithium belt 1 and the second lithium belt 2 are attached to the pole piece 5, and as the pole piece 5 is conveyed, the pole piece 5 pulls the lithium belt, and the roller surface of the first laminating roller 31 of the lithium belt is peeled off, so that the lithium lamination of the pole piece 5 is realized, and the lithium supplementing process of the pole piece 5 is completed.

As shown in fig. 3, the pole piece 5 has a first surface 51 and a second surface 52 opposite to each other in the thickness direction, and both the first surface 51 and the second surface 52 may be covered with lithium, and the first surface 51 is described in the first surface 51 of the present embodiment, and in other embodiments, the first surface 51 and the second surface 52 may be covered with lithium simultaneously.

The width of the pole piece 5 should be larger than the sum of the width of the first lithium band 1 and the width of the second lithium band 2, i.e. the width of the pole piece 5 of this embodiment is larger than the width of the first lithium band 1, the width of the pole piece 5 is also larger than the width of the second lithium band 2, and the first surface 51 can completely receive the first lithium band 1 and the second lithium band 2.

The first calender roll 33 and the first lamination roll 31 are used for rolling the first lithium strip 1 and the second lithium strip 2 so that the first lithium strip 1 and the second lithium strip 2 are attached to the roll surface of the first lamination roll 31 and are arranged along the axial direction X of the first lamination roll 31, and the first lamination roll 31 and the second lamination roll 32 are used for rolling the pole piece 5 so that the first lithium strip 1 and the second lithium strip 2 are transferred onto the first surface 51 of the pole piece 5. The first calendaring roller 33, the first cladding roller 31 and the second cladding roller 32 are matched, so that the calendaring of the lithium belt and the cladding of the pole piece 5 can be synchronously carried out, the utilization rate of the lithium supplementing process can be improved, and the number of equipment parts can be simplified.

Because the width of the lithium strip is limited, one lithium strip corresponds to one pole piece 5 for production, in this embodiment, the first lithium strip 1 is unreeled through the first unreeling mechanism 10, the second lithium strip 2 is unreeled through the second unreeled mechanism 20, two lithium strips correspond to one pole piece 5 with wider width, the first lithium strip 1 and the second lithium strip 2 can be rolled together, and then are covered on the first surface 51 of the pole piece 5 together, the pole piece 5 after lithium coating is divided into two or more parts, a plurality of pole pieces 5 can be obtained, two or more pieces are produced in the same time, the utilization rate of the lithium supplementing procedure is improved in speed, and the production efficiency of the battery is improved.

It should be appreciated that the lithium replenishment device 100 may include additional unreeling mechanisms in addition to the first unreeling mechanism 10 and the second unreeling mechanism, and that multiple unreeling mechanisms may unreel multiple lithium strips that are attached to the first surface 51 of the pole piece 5. And the lithium is supplemented for the pole piece 5 with wider width, and the pole piece 5 after lithium supplementation is divided into more than one part, so that a plurality of pole pieces 5 can be produced in the same time. Illustratively, in fig. 3, two pole pieces 5 are obtained by cutting along the direction P at the gap of the first lithium strip 1 and the second lithium strip 2. Fig. 3 shows the first lithium strip 1 and the second lithium strip 2 spaced apart along the direction X, it being understood that in other embodiments there may be no gap between the first lithium strip 1 and the second lithium strip 2 along the width direction X of the pole piece 5.

The specific lithium supplementing process of the lithium supplementing device is as follows; the first unreeling mechanism 10 unreels the first lithium strip 1 between the first calender roll 33 and the first laminating roll 31, the second unreeling mechanism 20 unreels the second lithium strip 2 between the first calender roll 33 and the first laminating roll 31, the first calender roll 33 and the first laminating roll 31 calender the first lithium strip 1 and the second lithium strip 2, and the first lithium strip 1 and the second lithium strip 2 are aligned in the axial direction X of the first laminating roll 31 between the first calender roll 33 and the first laminating roll 31. Through the first calendaring roller 33 and the first cladding roller 31, the first lithium belt 1 and the second lithium belt 2 are both clad on the roller surface of the first cladding roller 31, and along with the rotation of the first cladding roller 31, the first lithium belt 1 and the second lithium belt 2 enter between the first cladding roller 31 and the second cladding roller 32, the first cladding roller 31 and the second cladding roller 32 roll the pole piece 5, and the first lithium belt 1 and the second lithium belt 2 are clad on the surface of the pole piece 5. On the pole piece 5, the first lithium strip 1 and the second lithium strip 2 are arranged along the width direction X of the pole piece 5.

In some embodiments, the lithium supplementing device 100 may further include a conveying mechanism (not shown in the drawings) for conveying the first lithium strip 1 and the second lithium strip 2 between the first calendaring roller 33 and the first laminating roller 31.

Referring to fig. 1, in some embodiments, the first unwind mechanism 10 includes a first unwind shaft 11 and the second unwind mechanism 20 includes a second unwind shaft 21, the first unwind shaft 11 and the second unwind shaft 21 being coaxially disposed.

The first unwind shaft 11 and the second unwind shaft 21 are coaxial, meaning that the first unwind shaft 11 is coaxial with the second unwind shaft 21 in the direction X.

The first unreeling shaft 11 and the second unreeling shaft 21 are coaxially arranged, and the tape running directions Z of the first lithium tape 1 and the second lithium tape 2 are the same, so that the consistency of the interfaces of the pole pieces 5 after lithium coating is improved.

Referring to fig. 4, fig. 4 is a schematic diagram of a connection between a first unwind shaft 11 and a second unwind shaft 21 according to some embodiments of the present application. In some embodiments, the first unwind shaft 11 and the second unwind shaft 21 are interconnected.

The first unwind shaft 11 and the second unwind shaft 21 may be connected by bonding and welding.

The first unreeling shaft 11 and the second unreeling shaft 21 are connected with each other, so that the first unreeling shaft 11 and the second unreeling shaft 21 can synchronously rotate, one of the first unreeling shaft 11 or the second unreeling shaft 21 can be controlled to rotate by one driving piece, and the other unreeling shaft can rotate along with the first unreeling shaft 11 or the second unreeling shaft 21, so that the number of components is saved.

In some embodiments, the first unwind shaft 11 and the second unwind shaft 21 are integrally formed. The production and the manufacture are convenient, and the process of connecting the first unreeling shaft 11 with the second unreeling shaft 21 is saved.

In some embodiments, the first unwind shaft 11 and the second unwind shaft 21 are coaxially arranged, the first unwind shaft 11 being uncoupled from the second unwind shaft 21 such that the first unwind shaft 11 and the second unwind shaft 21 operate independently of each other, each of which may have a different unwinding speed. The unreeling speed refers to a speed at which the first unreeling shaft 11 and the second unreeling shaft 21 rotate one turn together.

When the diameters of the lithium strips to be unreeled are inconsistent, if the first lithium strip 1 and the second lithium strip 2 are unreeled at the same unreeling speed, the first lithium strip 1 and the second lithium strip 2 are different in the feeding direction Z, the lithium strip with high feeding speed is easy to crack, and the lithium strip with slow feeding speed is easy to crack. Therefore, the first unreeling shaft 11 and the second unreeling shaft 21 independently operate, and the first unreeling shaft 11 and the second unreeling shaft 21 can have different unreeling speeds, and even if the reel diameters of the first lithium band 1 and the second lithium band 2 are not uniform, the first lithium band 1 and the second lithium band 2 can be kept to have the same tape running speed in the Z direction and to be adapted to the tape running speed of the pole piece 5 by adjusting the unreeling speeds of the first unreeling shaft 11 and the second unreeling shaft 21, respectively. The risk of cracking the pole piece 5 is reduced, and the uniformity of rolling is improved.

Referring to fig. 5 and 6, fig. 5 is a schematic structural diagram of a lithium supplementing device 100 according to other embodiments of the present application; fig. 6 is a schematic diagram illustrating the structure of the first reel 11 and the second reel 21 according to some embodiments of the present application.

In some embodiments, the first unwind mechanism 10 comprises a first unwind shaft 11 and the second unwind mechanism 20 comprises a second unwind shaft 21, the first unwind shaft 11 being off-axis from and parallel to the second unwind shaft 21.

In the angle shown in fig. 5, the second lithium strip 2 is obscured by the first lithium strip 1, the second lithium strip 2 being not visible. The first unwinding shaft 11 and the second unwinding shaft 21 are arranged along the tape running direction Z of the lithium tape.

The first unreeling shaft 11 and the second unreeling shaft 21 are arranged in different shafts, the first unreeling shaft 11 and the second unreeling shaft 21 can work independently, the first unreeling shaft 11 and the second unreeling shaft 21 can have different unreeling speeds, and even if the reeling diameters of the first lithium strip 1 and the second lithium strip 2 are inconsistent, the first lithium strip 1 and the second lithium strip 2 can be kept to have the same tape running speed in the tape running direction Z by respectively adjusting the unreeling speeds of the first unreeling shaft 11 and the second unreeling shaft 21, and the first lithium strip 1 and the second lithium strip 2 are adaptive to the tape running speed of the pole piece 5. By the arrangement, the cracking risk of the pole piece 5 can be reduced, and the expansion consistency of the first lithium band 1 and the second lithium band 2 is improved.

Referring to fig. 7, fig. 7 is a schematic structural diagram of a lithium supplementing device 100 according to still another embodiment of the present application. In some embodiments, the first unwind mechanism 10 includes a first unwind shaft 11, the second unwind mechanism 20 includes a second unwind shaft 21, the first unwind shaft 11 and the second unwind shaft 21 are disposed off-axis and parallel to each other, and the first unwind shaft 11 and the second unwind shaft 21 are circumferentially spaced around the first laminating roller 31.

Unlike the embodiment shown in fig. 5, the first reel and the second reel are arranged along the tape running direction Z such that, in the X direction, the first lithium tape 1 and the second lithium tape 2 are coplanar, and the first lithium tape 1 and the second lithium tape 2 can share one coating mechanism 40 (mentioned later). In this embodiment, the first unwinding shaft 11 and the second unwinding shaft 21 are circumferentially spaced around the first laminating roller 31, the first lithium strip 1 and the second lithium strip 2 are located at different stations, the first calendaring roller 33a and the first laminating roller 31 calendar the first lithium strip 1, the first calendaring roller 33b and the first laminating roller 31 calendar the second lithium strip 2, the control precision of the calendaring thickness of the first lithium strip 1 and the second lithium strip 2 is higher, the first lithium strip 1 and the second lithium strip 2 can use different coating mechanisms 40, the coating speed is adapted to the tape running speed of the lithium strip, and the control of the coating thickness of the release agent is more accurate.

Referring to fig. 8, fig. 8 is a schematic structural diagram of a lithium supplementing device 100 according to still other embodiments of the present application. In some embodiments, the lithium supplementing device 100 further includes a coating mechanism 40, the coating mechanism 40 is disposed between the first unreeling mechanism 10 and the laminating mechanism 30 along the tape running direction Z of the first lithium tape 1, the coating mechanism 40 is disposed between the second unreeling mechanism 20 and the laminating mechanism 30 along the tape running direction Z of the second lithium tape 2, and the coating mechanism 40 is used for coating the release agent to the side of the first lithium tape 1 facing the first laminating roller 31 and the side of the second lithium tape 2 facing the first laminating roller 31.

Before the first lithium strip 1 and the second lithium strip 2 are fed between the first calender roll 33 and the first laminating roll 31, a release agent is applied by the coating mechanism 40 to the side of the first lithium strip 1 facing the first laminating roll 31 and the side of the second lithium strip 2 facing the second laminating roll 32, the release agent being capable of changing the roughness of the side of the first lithium strip 1 facing the first laminating roll 31 and the roughness of the side of the second lithium strip 2 facing the second laminating roll 32. So that the first lithium strip 1 and the second lithium strip 2 which are rolled by the first rolling roller 33 and the first laminating roller 31 are adhered to the roller surface of the first laminating roller 31 with small adhesive force, and the first lithium strip 1 and the second lithium strip 2 are easily separated from the surface of the first laminating roller 31 and are laminated on the first surface 51 of the pole piece 5 when passing between the first laminating roller 31 and the second laminating roller 32.

In some embodiments, the coating mechanism 40 is an oiling roller.

In some embodiments, the release agent is silicone oil.

Referring to fig. 9, fig. 9 is a schematic view of a first coating mechanism 41 and a second coating mechanism 42 according to still other embodiments of the present application. In some embodiments, the lithium supplementing device 100 includes a first coating mechanism 41 and a second coating mechanism 42, the first coating mechanism 41 is disposed between the first unreeling mechanism 10 and the laminating mechanism 30 along the tape running direction Z of the first lithium tape 1, and the first coating mechanism 41 is used for coating the release agent to the side of the first lithium tape 1 facing the first laminating roller 31; the second coating mechanism 42 is disposed between the second unreeling mechanism 20 and the laminating mechanism 30 along the tape running direction Z of the second lithium tape 2, and the second coating mechanism 42 is used for coating the release agent to the side of the second lithium tape 2 facing the first laminating roller 31.

In this embodiment, the first lithium belt 1 and the second lithium belt 2 do not share the coating mechanism 40, and the first coating mechanism 41 and the second coating mechanism 42 work independently, so as to control the coating precision and improve the lithium supplementing effect.

In some embodiments, two first calender rolls 33 are provided, one first calender roll 33 for rolling the first lithium strip 1 and the other first calender roll 33 for rolling the second lithium strip 2.

The first lithium belt 1 and the second lithium belt 2 do not share one rolling roller, the two first rolling rollers 33 work independently, rolling speeds of the two first rolling rollers 33 are controlled conveniently, rolling control precision is improved, and control is flexible.

Referring to fig. 7, in some embodiments, two first calender rolls 33 are disposed offset in the circumferential direction of the first laminating roll 31.

That is, the two first rolling rollers 33 are arranged at intervals around the circumference of the first laminating roller 31, so that the flexibility of the two first rolling rollers 33 working independently of each other and the control accuracy of rolling can be maintained, and the risk of the two first rolling rollers 33 interfering with each other can be reduced.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a lithium supplementing device 100 according to still another embodiment of the present application. In some embodiments, lithium replenishment device 100 further comprises an auxiliary film 60, an auxiliary film coating mechanism 61, an auxiliary film winding mechanism 62, and an auxiliary film unwinding mechanism 63. The auxiliary film coating mechanism 61 is for coating oil to a side of the auxiliary film 60 facing the first laminating roller 31, the auxiliary film unreeling mechanism 63 is for unreeling the auxiliary film 60, the auxiliary film reeling mechanism 62 is for reeling the auxiliary film 60 and drawing the auxiliary film 60 to pass between the first calender roller 33 and the first laminating roller 31, the auxiliary film 60 is for spacing the first calender roller 33 from the first lithium strip 1, and the auxiliary film 60 is for spacing the first calender roller 33 from the second lithium strip 2. In this way, the first lithium strip 1 and the second lithium strip 2 can be prevented from adhering to the first calender roll 33, and the first lithium strip 1 and the second lithium strip 2 can be smoothly adhered to the roll surface of the first laminating roll 31.

Referring to fig. 10, in some embodiments, the lithium supplementing device 100 further includes a pressure roller disposed on a side of the first calendaring roller 33 facing away from the first laminating roller 31, the first calendaring roller 33 being located between the pressure roller and the first laminating roller 31. The rolling direction of the pressure roller is opposite to the rolling direction of the first calender roller 33.

In order to calender a lithium strip better, the roll diameter of the first calender roll 33 is generally configured to be smaller than that of the first laminating roll 31, and the presence of a roll diameter difference tends to cause the first calender roll 33 to deviate in a direction away from the first laminating roll 31, which results in insufficient pressing force between the first calender roll 33 and the first laminating roll 31, affecting uniformity of calendering of the lithium strip. The provision of the pressure roller can restrict the first calender roller 33 from being inexpensive in a direction away from the first laminating roller 31, improve the uniformity of calendering, and improve the uniformity of the interface of the lithium strip after calendering.

Referring to fig. 10, in some embodiments, the lithium supplementing device 100 further includes a scraper 90, where the scraper 90 abuts against the roller surface of the first laminating roller 31, and the scraper 90 is used to scrape off the lithium band (the lithium band that is not laminated to the pole piece 5) remaining on the roller surface of the first laminating roller 31, so as to reduce the risk of the lithium band sticking to the first laminating roller 31 for heating and igniting.

In some embodiments, the lithium replenishment device 100 may further comprise a tension detection mechanism for detecting the tension of the first lithium strip 1 and the second lithium strip 2 to characterize whether the tension of the first lithium strip 1 and the second lithium strip 2 is in a suitable state.

Referring to fig. 11, fig. 11 is a schematic structural diagram of a lithium supplementing device 100 according to still other embodiments of the present application. In some embodiments, the lithium replenishment device 100 further comprises a third unreeling mechanism 70 and a fourth unreeling mechanism 80, the third unreeling mechanism 70 for unreeling the third lithium strip 3, and the fourth unreeling mechanism 80 for unreeling the fourth lithium strip. The laminating mechanism 30 further includes a second calender roll, the second calender roll and the second laminating roll 32 are used for rolling the third lithium strip 3 and the fourth lithium strip so that the third lithium strip 3 and the fourth lithium strip are attached to the surface of the second laminating roll 32 and are arranged along the axial direction X of the second laminating roll 32, and the first laminating roll 31 and the second laminating roll 32 are used for rolling the pole piece 5 so that the third lithium strip 3 and the fourth lithium strip are transferred onto the second surface 52 of the pole piece 5.

The same principle of fit as the first calender roll 33 and the first laminating roll 31, the third lithium band 3 and the fourth lithium band pass between the second laminating roll 32 and the second calender roll and adhere to the surface of the second laminating roll 32, and the third lithium band 3 and the fourth lithium band pass between the second laminating roll 32 and the first laminating roll 31 and adhere to the second surface 52 of the pole piece 5.

The first lithium band 1 and the second lithium band 2 are covered on the first surface 51 of the pole piece 5 by the cooperation of the first unreeling mechanism 10, the second unreeling mechanism 20 and the first calendaring roller 33, and the third lithium band 3 and the fourth lithium band are covered on the second surface 52 of the pole piece 5 by the cooperation of the third unreeling mechanism 70, the fourth unreeling mechanism 80 and the second calendaring roller. The lithium coating on the first surface 51 and the lithium coating on the second surface 52 can be synchronously performed, so that the lithium coating efficiency is higher, the utilization rate of the lithium supplementing process is further improved, and the production efficiency of the battery is improved.

In some embodiments, the present application also provides a lithium replenishment device 100, the lithium replenishment device 100 comprising a first unreeling mechanism 10, a second unreeling mechanism 20, a third unreeling mechanism 70, a fourth unreeling mechanism 80, a coating mechanism 40, and a laminating mechanism 30. The first unreeling mechanism 10 is used for unreeling the first lithium strip 1, and the second unreeling mechanism 20 is used for unreeling the second lithium strip 2. The laminating mechanism 30 includes a first calender roll 33, a second calender roll, a first laminating roll 31, and a second laminating roll 32, the first calender roll 33 and the first laminating roll 31 being for rolling the first lithium strip 1 and the second lithium strip 2 so that the first lithium strip 1 and the second lithium strip 2 are attached to the roll surface of the first laminating roll 31 and are arranged along the axial direction X of the first laminating roll 31, the first laminating roll 31 and the second laminating roll 32 being for rolling the pole piece 5 so that the first lithium strip 1 and the second lithium strip 2 are transferred onto the first surface 51 of the pole piece 5. The first unreeling mechanism 10 includes a first unreeling shaft 11, the second unreeling mechanism 20 includes a second unreeling shaft 21, and the first unreeling shaft 11 and the second unreeling shaft 21 are coaxially disposed. The coating mechanism 40 is disposed between the first unreeling mechanism 10 and the laminating mechanism 30 along the traveling direction Z of the first lithium belt 1, and the coating mechanism 40 is disposed between the second unreeling mechanism 20 and the laminating mechanism 30 along the traveling direction of the second lithium belt 2, and the coating mechanism 40 is used for coating the release agent to the side of the first lithium belt facing the first laminating roller 31 and the side of the second lithium belt facing the first laminating roller 31. The third unreeling mechanism 70 is used for unreeling the third lithium strip 3, and the fourth unreeling mechanism 80 is used for unreeling the fourth lithium strip. The second calender roll and the second lamination roll 32 are used for rolling the third lithium strip 3 and the fourth lithium strip so that the third lithium strip 3 and the fourth lithium strip are attached to the surface of the second lamination roll 32 and are arranged along the axial direction X of the second lamination roll 32, and the first lamination roll 31 and the second lamination roll 32 are used for rolling the pole piece 5 so that the third lithium strip 3 and the fourth lithium strip are transferred onto the second surface 52 of the pole piece 5.

In some embodiments, the present application also provides a lithium replenishment device 100, the lithium replenishment device 100 comprising a first unreeling mechanism 10, a second unreeling mechanism 20, a third unreeling mechanism 70, a fourth unreeling mechanism 80, a coating mechanism 40, and a laminating mechanism 30. The first unreeling mechanism 10 is used for unreeling the first lithium strip 1, and the second unreeling mechanism 20 is used for unreeling the second lithium strip 2. The laminating mechanism 30 includes a first calender roll 33, a second calender roll, a first laminating roll 31, and a second laminating roll 32, the first calender roll 33 and the first laminating roll 31 being for rolling the first lithium strip 1 and the second lithium strip 2 so that the first lithium strip 1 and the second lithium strip 2 are attached to the roll surface of the first laminating roll 31 and are arranged along the axial direction X of the first laminating roll 31, the first laminating roll 31 and the second laminating roll 32 being for rolling the pole piece 5 so that the first lithium strip 1 and the second lithium strip 2 are transferred onto the first surface 51 of the pole piece 5. The first unreeling mechanism 10 comprises a first unreeling shaft 11, the second unreeling mechanism 20 comprises a second unreeling shaft 21, and the first unreeling shaft 11 and the second unreeling shaft 21 are arranged in a different shaft and parallel to each other. The coating mechanism 40 is disposed between the first unreeling mechanism 10 and the laminating mechanism 30 along the traveling direction of the first lithium belt 1, and the coating mechanism 40 is disposed between the second unreeling mechanism 20 and the laminating mechanism 30 along the traveling direction of the second lithium belt 2, and the coating mechanism 40 is used for coating the release agent to the side of the first lithium belt facing the first laminating roller 31 and the side of the second lithium belt facing the first laminating roller 31. The third unreeling mechanism 70 is used for unreeling the third lithium strip 3, and the fourth unreeling mechanism 80 is used for unreeling the fourth lithium strip. The second calender roll and the second lamination roll 32 are used for rolling the third lithium strip 3 and the fourth lithium strip so that the third lithium strip 3 and the fourth lithium strip are attached to the surface of the second lamination roll 32 and are arranged along the axial direction X of the second lamination roll 32, and the first lamination roll 31 and the second lamination roll 32 are used for rolling the pole piece 5 so that the third lithium strip 3 and the fourth lithium strip are transferred onto the second surface 52 of the pole piece 5.

In some embodiments, the present application also provides a lithium replenishment device 100, the lithium replenishment device 100 comprising a first unreeling mechanism 10, a second unreeling mechanism 20, a third unreeling mechanism 70, a fourth unreeling mechanism 80, a coating mechanism 40, and a laminating mechanism 30. The first unreeling mechanism 10 is used for unreeling the first lithium strip 1, and the second unreeling mechanism 20 is used for unreeling the second lithium strip 2. The laminating mechanism 30 includes a first calender roll 33, a second calender roll, a first laminating roll 31, and a second laminating roll 32, the first calender roll 33 and the first laminating roll 31 being for rolling the first lithium strip 1 and the second lithium strip 2 so that the first lithium strip 1 and the second lithium strip 2 are attached to the roll surface of the first laminating roll 31 and are arranged along the axial direction X of the first laminating roll 31, the first laminating roll 31 and the second laminating roll 32 being for rolling the pole piece 5 so that the first lithium strip 1 and the second lithium strip 2 are transferred onto the first surface 51 of the pole piece 5. The first unreeling mechanism 10 comprises a first unreeling shaft 11, the second unreeling mechanism 20 comprises a second unreeling shaft 21, and the first unreeling shaft 11 and the second unreeling shaft 21 are arranged in a different shaft and parallel to each other. The first rolling rollers 33 are provided in two, one first rolling roller 33 for rolling the first lithium belt 1 and the other rolling roller for rolling the second lithium belt 2. The coating mechanism 40 is disposed between the first unreeling mechanism 10 and the laminating mechanism 30 along the traveling direction of the first lithium belt 1, and the coating mechanism 40 is disposed between the second unreeling mechanism 20 and the laminating mechanism 30 along the traveling direction of the second lithium belt 2, and the coating mechanism 40 is used for coating the release agent to the side of the first lithium belt facing the first laminating roller 31 and the side of the second lithium belt facing the first laminating roller 31. The third unreeling mechanism 70 is used for unreeling the third lithium strip 3, and the fourth unreeling mechanism 80 is used for unreeling the fourth lithium strip. The second calender roll and the second lamination roll 32 are used for rolling the third lithium strip 3 and the fourth lithium strip so that the third lithium strip 3 and the fourth lithium strip are attached to the surface of the second lamination roll 32 and are arranged along the axial direction X of the second lamination roll 32, and the first lamination roll 31 and the second lamination roll 32 are used for rolling the pole piece 5 so that the third lithium strip 3 and the fourth lithium strip are transferred onto the second surface 52 of the pole piece 5.

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

The above embodiments are only for illustrating the technical solution of the present application, and are not intended to limit the present application, and various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. A lithium supplementing device, comprising:

the first unreeling mechanism is used for unreeling the first lithium belt;

the second unreeling mechanism is used for unreeling a second lithium belt;

The laminating mechanism comprises a first calendaring roller, a first laminating roller and a second laminating roller, wherein the first calendaring roller and the first laminating roller are used for rolling the first lithium belt and the second lithium belt, so that the first lithium belt and the second lithium belt are attached to the roller surface of the first laminating roller and are axially distributed along the first laminating roller, and the first laminating roller and the second laminating roller are used for rolling the pole piece, so that the first lithium belt and the second lithium belt are transferred onto the first surface of the pole piece.

2. The lithium replenishment device according to claim 1, wherein the first unreeling mechanism comprises a first unreeling shaft, the second unreeling mechanism comprises a second unreeling shaft, and the first unreeling shaft and the second unreeling shaft are coaxially arranged.

3. The lithium supplementing device of claim 2, wherein the first unreeling shaft and the second unreeling shaft are connected to each other.

4. A lithium supplementing device according to claim 3, wherein the first unreeling shaft and the second unreeling shaft are integrally formed.

5. The lithium replenishment device according to claim 1, wherein the first unreeling mechanism comprises a first unreeling shaft, the second unreeling mechanism comprises a second unreeling shaft, and the first unreeling shaft and the second unreeling shaft are arranged in different shafts and are parallel to each other.

6. The lithium supplementing device of claim 1, wherein the lithium supplementing device further comprises:

The coating mechanism is arranged between the first unreeling mechanism and the covering mechanism along the tape running direction of the first lithium tape, the coating mechanism is arranged between the second unreeling mechanism and the covering mechanism along the tape running direction of the second lithium tape, and the coating mechanism is used for coating release agent to one side of the first lithium tape facing the first covering roller and one side of the second lithium tape facing the first covering roller.

7. The lithium supplementing device of claim 1, wherein the lithium supplementing device further comprises:

The first coating mechanism is arranged between the first unreeling mechanism and the covering mechanism along the tape running direction of the first lithium tape and is used for coating a release agent on the side, facing the first covering roller, of the first lithium tape;

The second coating mechanism is arranged between the second unreeling mechanism and the covering mechanism along the tape moving direction of the second lithium tape, and is used for coating a release agent on one side of the second lithium tape facing the first covering roller.

8. The lithium supplementing device according to claim 1, wherein two first rolling rollers are provided, one for rolling the first lithium belt and the other for rolling the second lithium belt.

9. The lithium supplementing device according to claim 8, wherein the two first calender rolls are arranged in a staggered manner in the circumferential direction of the first laminating roll.

10. The lithium replenishment device according to any one of claims 1 to 7, further comprising a third unreeling mechanism for unreeling a third lithium strip and a fourth unreeling mechanism for unreeling a fourth lithium strip;

The laminating mechanism further comprises a second calendaring roller, the second calendaring roller and the second laminating roller are used for rolling the third lithium belt and the fourth lithium belt, so that the third lithium belt and the fourth lithium belt are attached to the surface of the second laminating roller and are axially distributed along the second laminating roller, and the first laminating roller and the second laminating roller are used for rolling the pole piece, so that the third lithium belt and the fourth lithium belt are transferred onto the second surface of the pole piece.