CN218498102U

CN218498102U - Composite current collector preparation device

Info

Publication number: CN218498102U
Application number: CN202222368203.9U
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Shanghai Pioneer Huineng Technology Co ltd
Current assignee: Shanghai Pioneer Huineng Technology Co ltd
Priority date: 2022-09-06
Filing date: 2022-09-06
Publication date: 2023-02-17
Anticipated expiration: 2032-09-06

Abstract

The utility model relates to a compound mass flow body preparation facilities, including unwinding mechanism, preliminary treatment mechanism, coating mechanism and trimming mechanism. The pretreatment mechanism forms an active area in the middle of the surface of the base material belt through selective pretreatment, and forms a blank area on the two side edges of the base material belt along the width direction, and the blank area is an untreated area, so the edges of the two sides of the base material belt cannot be damaged. In addition, in the process of forming the metal layer by the coating mechanism, the operation is only carried out on the active region, and the metal layer is not formed on the blank region. Damage such as perforation to the base material tape when the metal layer is formed often occurs at the edge of the metal layer. Therefore, the damage to the edge of the base material strip can be reduced as much as possible in the preparation process, so that the high mechanical strength of the base material strip is maintained. Furthermore, damage to the edge position of the metal layer can be cut off by the trimming mechanism. Therefore, the yield can be obviously promoted to above-mentioned compound mass flow body preparation facilities.

Description

Composite current collector preparation device

Technical Field

The utility model relates to a lithium battery equipment technical field, in particular to compound mass flow body preparation facilities.

Background

In view of the weight reduction of lithium batteries, the improvement of energy density of batteries, and the like, attention is increasingly paid to composite current collectors using polymer materials as substrates. The composite current collector comprises a base material and metal layers formed on the upper surface and the lower surface of the base material, and is of a sandwich structure, the base material plays a supporting role, and the metal layers on the two sides play a conducting role.

At present, the common preparation method is to deposit metal films with a certain thickness on two sides of a base material by a physical vapor deposition method, and then electroplate or chemically plate the base material with the metal films formed on the two sides, so that the metal films on the two sides are thickened until the conductivity and the physical properties of the composite current collector meet the requirements of the lithium battery.

Vacuum physical vapor deposition is accompanied by high temperature, and the base material is easy to deform, wrinkle, bubble flee, perforate, become brittle and the like under the high-temperature environment. Moreover, the substrate is very thin and light, and the substrate is easily perforated and damaged by the impact of high energy particles during vacuum sputtering, corrosion during chemical plating, and edge current effect during electroplating. In particular, in the roll-to-roll manufacturing process, the base material is subjected to the tension of the tape, so that the damage to the edge of the base material is likely to cause the tape to break. Therefore, the existing method causes low yield when preparing the composite current collector.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a composite current collector manufacturing apparatus capable of improving yield in order to solve the above problems.

A composite current collector preparation apparatus comprising:

an unwinding mechanism for supplying a base material tape;

the pretreatment mechanism is used for forming an active area in the middle of the surface of the base material belt and forming a blank area on the two side edges of the base material belt along the width direction, and the active area and the blank area are strip-shaped and extend along the length direction of the base material belt;

a coating mechanism for forming a metal layer on the active region;

and the edge cutting mechanism is used for cutting off the edge parts of the two sides of the metal layer in the width direction or the blank areas so as to obtain the composite current collector.

In one embodiment, the unwinding mechanism can continuously unwind the base material tape, and the composite current collector manufacturing apparatus further includes a winding mechanism, and the winding mechanism can continuously wind the composite current collector.

In one embodiment, the preprocessing mechanism comprises:

the coarsening mechanism is used for coarsening the middle part of the surface of the base material belt;

an activation treatment mechanism for applying a sensitizing activation solution to the roughened region to form the active region;

wherein, the two side edges of the base material belt along the width direction are not coarsened and the area which is not coated with the sensitizing and activating solution forms the blank area.

In one embodiment, the preprocessing mechanism comprises:

a roughening mechanism for roughening a plurality of strip-shaped regions on the surface of the base material belt, the strip-shaped areas are positioned in the middle of the surface of the base material strip and are arranged at intervals along the width direction of the base material strip;

an activation treatment mechanism for coating a sensitizing activation solution on the strip-shaped region after the roughening treatment to form the active region;

and the white areas are formed between adjacent strip-shaped areas which are not subjected to coarsening treatment and are not coated with sensitizing activating solution.

In one embodiment, the winding mechanism comprises a multi-section winding roller, the multi-section winding roller comprises a plurality of sub-rollers connected with each other, and a locking mechanism is arranged between every two adjacent sub-rollers.

In one embodiment, a plurality of the sub-rollers are detachably connected to each other, and the number of the sub-rollers is the same as the number of the strip-shaped areas.

In one embodiment, the composite current collector preparation device is used for preparing a negative composite current collector, and the coating mechanism includes:

an electroless plating mechanism for electroless plating the base material strip to form a metal film attached to the active region;

and the electroplating mechanism is used for electroplating the base material belt subjected to chemical plating so as to form the metal layer with preset thickness on the surface of the metal film.

In one embodiment, the electroplating mechanism electroplates the base material belt by adopting a brush plating mode.

In one embodiment, the composite current collector preparation device is used for preparing a positive composite current collector, and the coating mechanism is used for performing electroless plating on the base material strip so as to form the metal layer with a preset thickness in the active area.

In one embodiment, the coating device further comprises a passivation mechanism positioned between the coating mechanism and the edge cutting mechanism, and the passivation mechanism is used for forming an anti-oxidation layer on the surface of the metal layer facing away from the base material strip.

According to the preparation device of the composite current collector, the pretreatment mechanism forms the active area in the middle of the surface of the base material belt through selective pretreatment, the blank leaving areas are formed on the edges of the two sides of the base material belt along the width direction, and the blank leaving areas are areas which are not treated, so that the edges of the two sides of the base material belt cannot be damaged. In addition, in the process of forming the metal layer by the coating mechanism, the operation is only carried out on the active region, and the metal layer is not formed on the blank region. Damage such as perforation to the base material tape when the metal layer is formed often occurs at the edge of the metal layer. Therefore, the damage to the edge of the base material strip can be reduced as much as possible in the preparation process, so that the high mechanical strength of the base material strip is maintained. Furthermore, damage to the edge position of the metal layer can be cut off by the trimming mechanism. Therefore, the yield can be obviously promoted to above-mentioned compound mass flow body preparation facilities.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic block diagram of a composite current collector manufacturing apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of an unwinding mechanism in the composite current collector preparation apparatus shown in fig. 1;

fig. 3 is a schematic structural view of a roughening mechanism in the composite current collector preparation apparatus shown in fig. 1;

FIG. 4 is a schematic structural diagram of a roughening mechanism in another embodiment;

fig. 5 is a schematic structural diagram of an activation processing mechanism in the composite current collector preparation apparatus shown in fig. 1;

fig. 6 is a schematic structural diagram of an electroless plating mechanism in the composite current collector preparation apparatus shown in fig. 1;

fig. 7 is a schematic structural diagram of an electroplating mechanism in the composite current collector preparation apparatus shown in fig. 1;

fig. 8 is a schematic block diagram of a composite current collector manufacturing apparatus according to another embodiment;

fig. 9 is a schematic structural view of a composite current collector manufactured in an embodiment of the present invention;

fig. 10 is a top view of a composite current collector made in another example;

fig. 11 is a schematic cross-sectional view of the composite current collector shown in fig. 10;

fig. 12 is a schematic view of a scene corresponding to a processing flow of the composite current collector manufacturing apparatus shown in fig. 1;

FIG. 13 is a detailed view of scene (d) through scene (e) shown in FIG. 12;

fig. 14 is a schematic structural view of a multi-segment wind-up roll according to an embodiment of the present invention.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

The utility model provides a compound mass flow body preparation facilities, this compound mass flow body preparation facilities can make as shown in figure 9 compound mass flow body 200. The composite current collector 200 includes a base material tape 210 and metal layers 220 on opposite surfaces of the base material tape 210.

The base material tape 210 is an insulating material, and may be any of polymer materials such as polyethylene terephthalate, polypropylene, polyamide, polyimide, polyvinyl chloride, and polystyrene. The strip of base material 210 is in the form of a film, which is supportive and typically has a thickness of between 2 μm and 12 μm. The metal layer 220 is conductive and typically has a thickness of 700nm to 2000nm. The composite current collector 200 may be used for both a positive electrode and a negative electrode of a lithium battery, and is different from the metal layer 220 in material.

When the composite current collector 200 is used as a negative electrode current collector, the material of the metal layer 220 is generally copper or copper alloy. In addition, the metal layer 220 may be a multi-layered composite structure having copper in a mass ratio of not less than 80%. When the composite current collector 200 is used as a positive current collector, the metal layer 220 is generally made of aluminum or aluminum alloy. Similarly, the metal layer 220 may be a multi-layer composite structure having an aluminum mass ratio of not less than 80%.

Referring to fig. 1, a composite current collector manufacturing apparatus 300 according to an embodiment of the present invention includes an unwinding mechanism 310, a pretreatment mechanism 320, and a coating mechanism 330, an edge cutting mechanism 340.

An unwind mechanism 310 is used to provide the strip of base material 210. Specifically, the base material strip 210 is generally unreeled in the form of a material strip, and the provided base material strip 210 is fed along a preset direction, where the feeding direction is the length direction of the base material strip 210, and a direction perpendicular to the length direction is the width direction of the base material strip 210. This step corresponds to scenario (a) shown in fig. 12.

Referring to fig. 2, in the embodiment, the unwinding mechanism 310 includes an unwinding roller 311, a first belt splicing device 312, a first deviation rectifying device 313 and a first tension adjusting device 314.

The base material strip 210 can be stored in the form of a roll at an unwinding roller 311 and can be unwound from the unwinding roller 311, and the first splicing device 312 can ensure the continuity of unwinding the base material strip 210. The first tension adjusting means 314 is generally constituted by a plurality of rollers, and the relative distance between the plurality of rollers is adjustable. When the tape-feeding speed of each process fluctuates, the multiple rollers approach or separate from each other, so that the buffering or releasing of the base material tape 210 can be realized, and the tension of the base material tape 210 can be maintained stable. In addition, to change the direction of the base material web 210, the unwinding mechanism 310 typically includes a plurality of guide rollers (not shown).

The pre-treatment mechanism 320 is used to form an active region 201 in the middle of the surface of the base material strip 210 and a blank region 202 on the two side edges of the surface of the base material strip 210 in the width direction, and the active region 201 and the blank region 202 are in a strip shape and extend along the length direction of the base material strip 210.

Since the material properties of the base material tape 210 are significantly different from those of metals, the adhesion of the surface to the metal material is poor, and it is difficult to form the metal layer 220 meeting the requirements by directly performing operations such as plating on the surface of the base material tape 210. Therefore, the surface of the base material strip 210 needs to be pretreated before coating to obtain the active region 201, and the purpose of the pretreatment is to enhance the adhesion of the surface of the base material strip 210 to the metal material. This step corresponds to scenario (b) shown in fig. 12.

It should be noted that the pretreatment does not treat the entire surface of the base material strip 210. Specifically, the pretreatment is only performed on the central region of the surface of the base material strip 210, and the treated region is the active region 201, so that the adhesion capability to the metal material is improved. The blank regions 202 are formed by not performing a pretreatment on both side edges in the width direction of the surface of the base material tape 210. In this way, the edges of the base material strip 210 on both sides are generally not damaged during the pre-treatment process, thereby avoiding or reducing the occurrence of defects such as perforations in the edges of the base material strip 210. Wherein the central region refers to the area between the blank areas 202 on either side of the strip of base material 210.

Both the active area 201 and the blank area 202 extend along the length of the base material strip 210. In general, the active region 201 is integrated and located in the middle region of the base material tape 210, and the blank regions 202 are distributed only on two sides of the base material tape 210, so that the composite current collector 200 is manufactured in a single structure as shown in fig. 12 (e).

Specifically, in the present embodiment, the preprocessing mechanism 320 includes a roughening mechanism 321 and an activating mechanism 322. The roughening mechanism 321 is used for roughening the middle part of the surface of the base material belt 210; the activation processing mechanism 322 is used for coating the sensitization activation liquid on the area after the surface roughening processing of the base material belt 210 to form the active area 201. Wherein, the two side edges of the base material strip 210 along the width direction are not coarsened and the area which is not coated with the sensitizing activation liquid forms the blank area 202.

Before the roughening treatment, a degreasing treatment may be performed as necessary. The roughening treatment may be physical roughening, chemical roughening, or a combination of physical roughening and chemical roughening. The specific way of physical coarsening comprises laser etching, ultraviolet irradiation, plasma irradiation, corona treatment and the like on a preset area. The specific mode of chemical coarsening comprises soaking a preset area by adopting one or more aqueous solutions of hydrogen peroxide, sulfuric acid, chromic acid and potassium permanganate. And, after chemical coarsening, cleaning and drying can be carried out according to specific conditions.

After the roughening treatment, a microstructure is formed in the corresponding area, and the microstructure can increase the roughness of the surface of the base material strip 210, so that the adhesion capacity to the metal material is improved. After the roughening treatment is completed, the activation mechanism 322 may apply the sensitizing activation solution to the roughened region by precision coating. Specifically, the sensitizing and activating solution may be an aqueous solution containing one or more ions or colloids of copper, tin, silver, platinum, palladium and manganese. After the sensitization process, the adhesion capability of the central area of the surface of the base material strip 210 and the metal material is further increased, so that the desired active area 201 is obtained.

After the activation treatment of the central portion of the surface of the base material tape 210, the base material tape 210 may be optionally subjected to washing and drying operations.

In addition, in other embodiments, a plurality of active regions 201 arranged at intervals in the width direction of the base material strip 210 may be formed on the surface of the base material strip 210, and in addition to the blank regions 202 distributed on both sides of the base material strip 210 in the width direction, the blank regions 202 are also formed between two adjacent active regions 201. Therefore, the temperature of the molten metal is controlled, after forming the metal layer 220 on the active area 201 of the base material strip 210, a plurality of structures similar to the zebra stripes are obtained as shown in fig. 10 and 11.

Specifically, in this embodiment, the roughening mechanism 321 is configured to roughen a plurality of strip-shaped regions on the surface of the base material strip 210, where the strip-shaped regions are located in the middle of the surface of the base material strip 210 and are spaced apart from each other in the width direction of the base material strip 210; the activation processing mechanism 322 is used to apply a sensitizing activation solution to the stripe-shaped region after the roughening processing to form the active region 201. The areas of the base material strips 210 between adjacent strip-shaped areas, which are not roughened and not coated with the sensitizing activation solution, form the blank areas 202.

As such, the active regions 201 of the surface of the base material strip 210 are plural and arranged at intervals in the width direction of the base material strip 210. Besides the blank areas 202 distributed on both sides of the base material strip 210 in the width direction, the blank areas 202 are also formed between two adjacent active areas 201.

The plating mechanism 330 is used to form the metal layer 220 on the active region 201. Specifically, the coating mechanism 330 may form the metal layer 220 on the active region 201 of the surface of the base material strip 210 by various coating methods, such as physical vapor deposition, chemical plating, electroplating, and the like.

In the present embodiment, the plating mechanism 330 includes an electroless plating mechanism 331 and an electroplating mechanism 332. The electroless plating mechanism 331 is configured to perform electroless plating on the base material strip 210 to form the metal film 221 attached to the active region 201, which corresponds to scenario (c) shown in fig. 12; the electroplating mechanism 332 is configured to electroplate the electroless-plated base material strip 210 to form a metal layer 220 with a preset thickness on the surface of the metal film 221, where this step corresponds to scenario (d) shown in fig. 12.

It should be noted that aluminum is chemically active and is easily oxidized rapidly by combining with oxygen during electroplating. Therefore, the above-mentioned forming method of the metal layer 220 is generally only suitable for preparing the negative electrode current collector, and the prepared metal layer 220 is a copper layer, a copper alloy layer or a multi-layer composite structure containing copper.

In the case of electroless plating, the base material tape 210 may be immersed in a metal electroless plating solution, which may be a copper plating solution, a nickel plating solution, or a copper-nickel alloy plating solution, one or more times. The metal film 221 that may be formed after electroless plating may be a nickel plated layer, a copper nickel alloy layer, or a combination thereof. The thickness of the metal film 221 is much smaller than that of the metal layer 220, generally between 20nm and 400nm, and the sheet resistance of the metal film 221 may be 200m Ω/square to 1000m Ω/square. After electroless plating and before electroplating, the metal film 221 is typically cleaned and baked. In addition, the metal film 221 may be subjected to an acidification treatment as necessary.

The electroplating is to deposit a metal material on the surface of the metal film 221, so as to gradually thicken the metal film 221 until a metal layer 220 with a desired thickness is obtained. Illustratively, the thickness of the metal layer 200 may be 700nm to 2000nm. At this time, the sheet resistance of the metal layer 200 is 1m Ω/square to 180m Ω/square, and has good conductivity. When the metal film 221 and the metal layer 220 are made of the same material, the finally obtained metal layer 220 is integrated with the metal film 221.

Electroless plating can successfully form a thin metal film 221 on the surface of the non-metallic base material strip 210, thereby providing a basis for subsequent formation of the metal layer 220. Moreover, the electroless plating environment is milder and less aggressive to the surface of the base material strip 210 relative to physical vapor deposition. Compared with chemical plating, the electroplating process has higher efficiency in forming the metal layer 220, and the formed metal layer 220 is more compact and has better conductivity. Therefore, the plating mechanism 330 can combine the advantages of the electroless plating process and the electroplating process.

In addition, compared with the vacuum physical vapor deposition equipment, the difference between the film forming conditions of the chemical plating mechanism 331 and the film forming conditions of the electroplating mechanism 332 are smaller, so that the connection is convenient to form a whole-line roll-to-roll production line. The material belt of the base material belt 210 can directly enter the electroplating mechanism 332 from the output end of the chemical plating mechanism 331, and the buffer memory for too long time can be avoided in the process, so that the formation of an oxidation film on the surface of the base material belt 210 by water and oxygen in the air is effectively avoided, and the quality of a final product is ensured.

Further, in the present embodiment, the electroplating mechanism 332 performs electroplating on the base material strip 210 by means of brush plating. Because the brush plating does not need a plating bath, the plating mechanism 332 has a simple structure, small floor space and low cost. Moreover, when brush plating is adopted, the non-plating area (i.e. the margin area 202) does not need to be covered with a protective material, so that the operation flow can be simplified, and the preparation efficiency is improved.

It should be noted that in other embodiments, before the electroless plating, an adhesion layer may be formed on the active region 201, and the adhesion layer may perform a transition function to form a strong bonding force with both the polymer and the metal material. Illustratively, the adhesive layer may include a polyurethane-based adhesive.

Since the coating means 330 forms the metal layer 220 in the active area 201, i.e. in the middle of the strip of base material 210, the white areas 202 do not form the metal layer 220. Therefore, the perforation or breakage caused by the edge current effect during electroplating will be mainly concentrated at the central portion of the base material strip 210 corresponding to the edge of the metal layer 220, and the edge of the base material strip 210 will maintain a good integrity. The central portion of the base material strip 210 has less effect on the mechanical strength of the base material strip 210 than the edge portion, so that the base material strip 210 is less prone to breakage or breakage during the running process. In addition, since the base material belt 210 with undamaged edges can bear larger tension, the belt moving speed of the base material belt 210 can be increased on the premise of ensuring continuous belt moving, and thus the preparation efficiency of the composite current collector 200 can be further increased.

The trimming mechanism 340 is used to cut off edge portions or blank areas 202 on both sides of the metal layer 220 in the width direction to produce the composite current collector 200.

Since the blank region 202 does not have a conductive property, it cannot be used as an electrode and needs to be cut out before preparing an electrode. When the trimming mechanism 340 performs the trimming operation, only the portion of the base material tape 210 corresponding to the margin area 202 may be trimmed, or a portion of the metal layer 220 may be trimmed at the same time as the margin area 202 is trimmed.

Specifically, the trimming mechanism 340 includes a trimming assembly 341, the trimming assembly 341 may be a cutter and a driving member, and the trimming assembly 341 may trim the edges of the base material strip 210 or the metal layer 220. In addition, the trimming mechanism 340 further includes an edge-trim collecting assembly 342, and the edge-trim collecting assembly 342 can collect waste materials cut by the trimming assembly 341.

As shown in fig. 10 and 13, in the present embodiment, when the margin area 202 is cut, the trimming unit 341 of the trimming mechanism 340 is cut along the dotted line, so that the cut width is larger than the width of the margin area 202, and the edge portions of the metal layer 220 on both sides in the width direction can be cut. Thus, the trimming mechanism 340 can remove the damage to the edge of the metal layer 220 in the process of removing the blank area 202, so as to obtain the composite current collector 200 with better quality and significantly improve the yield of the composite current collector 200.

Specifically, in the present embodiment, the composite current collector manufacturing apparatus 300 further includes a passivation mechanism (not shown) located between the coating mechanism 330 and the edge cutting mechanism 340, and the passivation mechanism is configured to form an anti-oxidation layer on the surface of the metal layer 220. The anti-oxidation layer may be a passivation layer formed on the metal layer 220 after passivation, so that the metal layer 220 has better oxidation resistance. Specifically, the passivation mechanism may include a passivation bath, into which the composite current collector 200 may be introduced and the metal layer 220 may be surface passivated by a solution containing chromium or nickel.

Referring to fig. 1 again, in the present embodiment, the composite current collector manufacturing apparatus 300 further includes a winding mechanism 350. Wherein the unwinding mechanism 310 is capable of continuously unwinding the base material tape 210; and the winding mechanism 350 can continuously wind the composite current collector 200. The pretreatment mechanism 320, the coating mechanism 330 and the edge cutting mechanism 340 are disposed between the unwinding mechanism 310 and the winding mechanism 350. Thus, the composite current collector manufacturing apparatus 300 can continuously manufacture the composite current collector 200 roll-to-roll, which is beneficial to improving efficiency.

The rolled composite current collector 200 can be stored in a roll material form and can be directly rolled when in use. Obviously, in other embodiments, the rolling step may be omitted, and the prepared composite current collector 200 may be directly subjected to the next process such as coating or slicing, so as to prepare the lithium battery electrode.

The winding mechanism 350 generally has a structure substantially the same as that of the unwinding mechanism 310, and only the tape running direction is different. However, in the embodiment where the plurality of strip-shaped regions are present on the surface of the base material strip 210 and the plurality of active regions 201 are formed by the plurality of strip-shaped regions, since the metal layer 220 forms a plurality of structures on the surface of the base material strip 210 as shown in fig. 10 and 11, a plurality of composite current collectors 200 can be obtained at the same time after being cut by the trimming assembly 340.

At this time, as shown in fig. 14, the winding mechanism 350 in this embodiment includes a multi-segment winding roller 351, the multi-segment winding roller 351 includes a plurality of sub-rollers 3511 connected to each other, and a locking mechanism (not shown) is provided between the adjacent sub-rollers 3511. The locking mechanism enables the plurality of sub-rollers 3511 to rotate synchronously. Thus, the plurality of sub-rollers 3511 can simultaneously roll up the plurality of composite current collectors 200.

Further, particularly in this embodiment, a plurality of sub-rollers 3511 are detachably connected to each other, and the number of the sub-rollers 3511 is the same as the number of the strip regions. After the winding is completed, the sub-rollers 3511 can be disassembled, so that the composite current collectors 200 respectively wound on the plurality of sub-rollers 3511 can be conveniently used.

The working process of the above-mentioned composite current collector manufacturing apparatus 300 will be described below with reference to several specific negative current collector manufacturing processes:

1. a Cu/PET/Cu negative electrode current collector with the width of 1200 mm.

The unreeling mechanism 310 provides polyethylene terephthalate (PET material belt) with the thickness of 6 microns and the width of 1750mm, and the tape feeding speed of the PET material belt is about 40m/min;

the pretreatment mechanism 320 firstly uses a corona treatment mode to carry out roughening treatment on the middle 1300mm width area of the PET material belt, and the corona power is about 360W to 1200W; then, coating a sensitizing and activating solution in a coarsening area in the 1300mm width range in the middle of the PET material belt in an ink-jet printing mode, wherein the sensitizing and activating solution is AgNO containing 1 g/L-2 g/L ₃ An aqueous solution of (a). After the sensitizing and activating solution is coated, surface activation is carried out through double-sided ultraviolet irradiation, and the area in the 1300mm width range in the middle of the PET material belt becomes an active area 201;

the chemical plating mechanism 331 immerses the PET material belt with the activated surface into a metal chemical plating solution for chemical plating, wherein the chemical plating temperature is generally controlled between 35 ℃ and 53 ℃, and the metal chemical plating solution is an aqueous solution containing 10g/L to 15g/L of copper sulfate, 18g/L to 24g/L, EDTA (ethylenediamine tetraacetic acid) 8g/L to 12g/L of potassium ferrocyanide, 0.02g/L to 0.03g/L of potassium ferrocyanide, 2.5g/L to 3.5g/L of formaldehyde, 6g/L to 7g/L of sodium hydroxide, 3g/L to 6g/L of sodium carbonate and a small amount of other additives. After a certain time, obtaining a copper-containing metal film 221 in the active area 201 of the PET material belt;

the electroplating mechanism 332 is used for carrying out brush copper plating on the chemically plated PET material belt and thickening the metal film 221 until the thickness reaches 700nm to 2000nm. Wherein the plating solution for brushing copper plating is an aqueous solution containing 150 g/L-250 g/L of copper sulfate, 50 g/L-70 g/L of sulfuric acid and a small amount of other additives. The tape-feeding speed of the PET material tape is 30-50 m/min when the electric brush is used for copper plating, so that a tension control mechanism needs to be arranged for caching and releasing so as to match the tape-feeding of each process;

after the brush plating is completed, the obtained metal layer 220 is washed with deionized water, then is immersed in an aqueous solution containing chromate or dichromate for passivation, and finally is washed again with deionized water and dried. Then, the trimming mechanism 340 cuts out 275mm wide materials from both sides of the PET material tape in the width direction, so as to obtain 1200mm wide negative electrode current collectors.

2. Cu/PET/Cu negative current collector with width of 700mm

The unwinding mechanism 310 provides a PET material belt with the thickness of 4.5 microns and the width of 1200 mm;

the pretreatment mechanism 320 firstly adopts ethanol to carry out oil removal treatment and drying on the PET material belt in an oil removal cleaning pool, then coats a roughening solution which contains 80 g/L-120 g/L sulfuric acid and 100 g/L-250 g/L chromic anhydride and has the temperature of 40-50 ℃ on the middle 800mm width area of the PET material belt in a gravure coating mode to carry out chemical roughening, and after roughening, uses deionized water with the temperature of 40-50 ℃ to carry out cleaning and hot air drying; and then coating a sensitizing and activating solution on the coarsened area in a gravure coating mode, wherein the sensitizing and activating solution is a palladium colloid solution containing 0.5-1.5 g/L of palladium chloride, 30-40 g/L of stannous chloride and 260-320 ml/L of concentrated hydrochloric acid. After activation, cleaning the PET material belt by using 35 g/L-55 g/L aqueous solution containing sulfuric acid to enable the area in the middle of the PET material belt within the width range of 800mm to become an active area 201;

the chemical plating mechanism 331 immerses the surface-activated PET material strip into a metal chemical plating solution for chemical nickel plating, wherein the temperature of the chemical nickel plating is generally controlled to be 75-90 ℃, and the metal plating solution is an aqueous solution containing 23-30 g/L of nickel sulfate, 25-35 g/L of sodium hypophosphite, 15-23 g/L of malic acid, 12-24 g/L of sodium acetate and a small amount of other additives and having a pH value of 4.8-5.6. When the chemical nickel plating is carried out, the tape moving speed of the PET material tape is about 35m/min. After electroless nickel plating, a metal film 221 containing nickel is obtained in the activation region 201;

after being cleaned by an aqueous solution containing 35 g/L-55 g/L of sulfuric acid, the PET material belt is immersed into a metal chemical plating solution again for chemical copper plating, wherein the temperature of the chemical copper plating is generally controlled between 65 ℃ and 73 ℃, and the metal plating solution is an aqueous solution containing 10 g/L-15 g/L of copper sulfate, 38 g/L-47 g/L of EDTA disodium salt, 3.5 g/L-4.5 ml/L of formaldehyde and 2.6 g/L-3.7 g/L of sodium hydroxide and having the pH value of 11.5-12.5. When the chemical copper plating is carried out, the tape moving speed of the PET material tape is between 30m/min and 50m/min. After electroless copper plating, a layer of copper-containing metal film is formed on the surface of the original nickel-containing metal film;

after the PET material belt is cleaned by the aqueous solution containing 35 g/L-55 g/L of sulfuric acid, the electroplating mechanism 332 performs brush plating and passivation in the same manner as described above, so that the metal layer 220 with a preset thickness can be formed in the active region 201. Then, the trimming mechanism 340 cuts off the material with the width of 250mm from both sides of the PET material tape in the width direction, so as to obtain the negative electrode current collector with the width of 700 mm.

3. 1100mm wide Cu/PP/Cu negative electrode current collector

The unwinding mechanism 310 provides polypropylene (PP material belt) with the thickness of 8 microns and the width of 1600mm, and the tape feeding speed of the PP material belt is about 43m/min;

the pretreatment mechanism 320 adopts a femtosecond laser etching treatment mode to carry out surface roughening on the middle area within 1200mm width range of the PP material belt, and then coats a sensitizing activation solution on the roughened area within 1200mm width range of the PP material belt in an ink-jet printing mode, wherein the sensitizing activation solution is a copper colloid solution containing 20-30 g/L of copper sulfate, 8-12 g/L of gelatin, 6-9 g/L of sodium borohydride and 15-25 ml/L of n-butyl alcohol. After activation, cleaning the PP material belt by using an aqueous solution containing 35 g/L-55 g/L concentrated sulfuric acid to enable the middle area of the PP material belt within the width range of 1200mm to become an active area 201;

the plating mechanism 330 performs chemical plating, brush plating and passivation in the same manner as the preparation of the negative electrode current collector of the above-mentioned type 1, so as to form a metal layer 220 with a predetermined thickness in the active region 201. Then, the trimming mechanism 340 cuts off 250mm wide materials from both sides of the PP material tape in the width direction, so as to obtain 1100mm wide negative electrode current collectors.

Through actual detection, the products and processing parameters of the three negative current collectors are as follows:

as can be seen from the above table, the square resistivity of the three negative current collectors prepared by the composite current collector preparation apparatus 300 all meets the requirements of lithium batteries, and the first pass rate reaches 95% -98%, the yield reaches more than 97%, and the preparation speed can reach 30 m/min-50 m/min. It can be seen that the above-mentioned composite current collector preparation device 300 has the advantages of high yield and high efficiency.

As mentioned above, the plating method of combining the chemical plating and the electroplating adopted by the plating mechanism 330 is not suitable for forming the metal layer 220 containing aluminum, i.e. for preparing the positive electrode current collector, because the chemical property of aluminum is special.

To solve this problem, referring to fig. 8, in another embodiment, a plating mechanism 330 is used to perform electroless plating on the base material strip 210 to form a metal layer 220 with a predetermined thickness in the active region 201. Compared with the previous embodiment, the plating mechanism 332 is omitted from the plating mechanism 330, so the electroless plating time needs to be prolonged. Also, there is a difference in the type of metal electroless plating solution used for electroless plating.

Specifically, the metal electroless plating solution may be a molten salt aluminum plating solution or the like. After a long period of electroless plating, the plating mechanism 330 can directly form an aluminum layer, an aluminum alloy layer or a multi-layer composite structure containing aluminum with a predetermined thickness in the active region 201. The working process of the above-mentioned composite current collector manufacturing apparatus 300 will be described below with reference to a specific positive current collector manufacturing process:

the unreeling mechanism 310 provides a PET material belt with the thickness of 6 microns and the width of 1750mm, and the tape feeding speed of the PET material belt is about 40m/min;

the pretreatment mechanism 320 firstly uses a corona treatment mode to perform 1300mm width range in the middle of the PET material beltCoarsening the area in the periphery, wherein the corona power is 360-1200W; then, a sensitizing and activating solution is coated on the coarsening area within the range of 1300mm width in the middle by an ink-jet printing mode, wherein the sensitizing and activating solution is AgNO containing 1 g/L-2 g/L ₃ An aqueous solution of (a). After the sensitizing and activating solution is coated, performing surface activation through double-sided ultraviolet irradiation, so that the area in the 1300mm width range in the middle of the PET material belt becomes an active area 201;

the coating mechanism 330 immerses the surface-activated PET material belt into a metal chemical plating solution for chemical aluminum plating, the chemical plating temperature is generally controlled to be 15-45 ℃, the metal chemical plating solution is AlCl3-EMIC, and the belt moving speed of the PET material belt during chemical plating is about 40m/min. After a certain period of time, an aluminum-containing metal layer 220 with a preset thickness can be obtained in the active region 201 of the PET tape;

the trimming mechanism 340 respectively cuts out 275mm wide materials from both sides of the PET material belt in the width direction, so as to obtain 1200mm wide Al/PET/Al positive electrode current collector.

Referring also to fig. 3, in one embodiment, the roughening mechanism 321 includes a physical roughening element 3211 and guide rollers 3212 located at the upstream and downstream ends of the material roughening element 3211.

The physical roughening assembly 3211 is generally provided with two oppositely disposed surfaces for simultaneously roughening both sides of the strip of base material 210. The physical roughening component 3211 may be a laser emitter, an ultraviolet emitter, a plasma emitter, a corona component, or the like. The base material belt 210 unwound by the unwinding mechanism 310 can enter the working range of the physical coarsening assembly 3211 after being guided by the guide roller 3212 at the upstream end to coarsen the middle of the surface of the base material belt 210, and the base material belt 210 is guided out by the guide roller 3212 at the downstream end after coarsening is completed.

Referring to fig. 4, in another embodiment, the roughening mechanism 321 includes an oil removing tank 3213, at least two chemical roughening coating devices 3214, a first drying and heating device 3215, a second tension adjusting device 3216, and a first cleaning tank 3217.

The chemical roughening coating device 3214 may be coated with a chemical roughening solution by gravure coating, inkjet printing, extrusion coating, spraying, or the like, and the chemical roughening solution may be an aqueous solution containing one or more of hydrogen peroxide, sulfuric acid, chromic acid, and potassium permanganate. The heating mode of the first drying and heating device 3215 may be hot air heating, infrared heating, laser heating, or a combination thereof.

In order to achieve smooth feeding, the roughening mechanism 321 is generally provided with a plurality of guide rollers (not shown) for changing the feeding direction of the base material tape 210. Moreover, in order to prevent the base material belt 210 from carrying out the cleaning agent, a liquid interception roller (not shown) is further disposed at the output end of each of the oil removal tank 3213 and the first cleaning tank 3217, and the cleaning agent in the first cleaning tank 3217 may be deionized water.

Referring to fig. 5, in the present embodiment, the activation processing mechanism 322 includes at least two activation solution coating devices 3221, an activation and drying heating device 3222, a third tension adjusting device 3223, and a second cleaning tank 3224.

The activating liquid coating device 3221 may apply the activating sensitization liquid by gravure coating, inkjet printing, extrusion coating, spray coating, etc., and the sensitization activating liquid may be an aqueous solution containing one or more ions or colloids of copper, tin, silver, platinum, palladium, manganese. The activating and drying heating means 3222 may be activated by heating, ultraviolet irradiation, hot air heating, infrared heating, laser heating, or a combination thereof. In addition, the activation processing mechanism 322 is also typically provided with a plurality of guide rollers (not shown) to change the direction of travel of the base material web 210. Moreover, a liquid interception roller (not shown) is also disposed at the output end of each second cleaning pool 3224, and the cleaning agent in the second cleaning pool 3224 may be deionized water.

Referring to fig. 6, in the embodiment, the chemical plating mechanism 331 includes a chemical plating bath 3311, a stirring device 3312 and a temperature control device 3313 disposed in the chemical plating bath 3311, a fourth tension adjusting device 3314, a third cleaning bath 3315, a drying device 3316, and an on-line thickness measuring device 3317.

The stirring device 3312 may be paddle stirring, ultrasonic stirring or air-flow stirring, and the online thickness measuring device 3317 adopts non-contact type thickness measurement, such as laser thickness measurement, X-ray thickness measurement, beta-ray thickness measurement, eddy current measurement or resistance value thickness measurement. In addition, in order to realize smooth feeding, the electroless plating mechanism 331 is generally provided with a plurality of guide rollers (not shown) for changing the feeding direction of the base material tape 210. Moreover, in order to prevent the base material belt 210 from carrying out the liquid, the output end of each of the

electroless plating baths

3311 and 3315 is further provided with a cutoff roller (not shown), and the cleaning agent in the third cleaning bath 3315 may be deionized water.

The plating mechanism 332 in this embodiment employs a brush plating apparatus. Referring to fig. 7, in the embodiment, the electroplating mechanism 332 includes a cathode roll device 3321, an anode brush device 3322, a power control device 3323, a plating solution supply and recovery device 3324, a fourth cleaning pool 3325, a second drying device 3326, and a second on-line thickness measuring device 3327.

The cathode roller device 3321 and the anode brush device 3322 are two and are used for respectively coating the front surface and the back surface of the base material strip 210. The cathode roller device 3321, the anode brush device 3322, and the power supply control device 3323 are electrically connected and controlled. The cathode roller device 3321 includes a non-conductive cathode back roller and a conductive cathode roller; the shape of the anode brush device 3322 is matched with that of the cathode roller device 3321, and the anode brush device comprises an anode backing roller and an anode sheath. Wherein, the anode sheath can be made of porous fabric. The plating solution liquid supply and recovery device 3324 comprises a plating solution storage tank, a stirring assembly, a temperature control assembly, a plating solution recovery tank, a filtering device, a liquid supply pump and a nozzle. The second drying device 3326 and the second on-line thickness measuring device 3327 have the same structure and function as the above-mentioned drying device 3316 and the on-line thickness measuring device 3317, respectively.

In addition, in order to achieve smooth tape running, the plating mechanism 332 is generally provided with a plurality of guide rollers (not shown) for changing the direction of the base material tape 210. Moreover, in order to prevent the base material strip 210 from carrying out the liquid, a liquid interception roller (not shown) is further disposed at the output end of each fourth cleaning pool 3325, and the cleaning agent in the fourth cleaning pool 3325 may be deionized water.

The chemical plating mechanism 331 and the electroplating mechanism 332 can be chemical plating equipment and electroplating equipment commonly used in the prior art, and therefore detailed structures and working processes of the chemical plating mechanism 331 and the electroplating mechanism 332 are not described herein again.

In the above composite current collector manufacturing apparatus 300, the pretreatment mechanism 320 forms the active region 201 in the middle of the surface of the base material strip 210 through selective pretreatment, and forms the blank regions 202 on the two side edges of the base material strip 210 in the width direction, and the blank regions 202 are regions that are not treated, so the edges of the two sides of the base material strip 210 are not damaged. In addition, the plating mechanism 330 only operates on the active region 201 during the process of forming the metal layer 220, and the metal layer 220 is not formed in the margin region 202. Damage such as a through hole to the base material tape 210 when the metal layer 220 is formed is often present at an edge of the metal layer 220. It can be seen that damage to the edges of the strip of base material 210 during the manufacturing process can be minimized, thereby maintaining a high mechanical strength of the strip of base material 210. Also, damage to the edge position of the metal layer 220 may be cut by the trimming mechanism 340. Therefore, the yield of the composite current collector manufacturing device 300 can be remarkably improved.

Compare with traditional metal foil current collector, the composite current collector 200 that adopts above-mentioned composite current collector preparation facilities 300 to prepare still has following advantage: the base material belt 210 made of polymer is used as a support, so that the use of metal is reduced, the weight can be reduced by 40-70%, the energy density of the battery is improved, and the potential of cost reduction is realized under the situation of high price of metal; and, the flexibility and processability of the composite current collector 200 may also be improved. Finally, under abnormal conditions, such as internal short circuit, physical puncture, etc., the composite current collector 200 may be open-circuited, thereby improving the safety performance of the battery.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A composite current collector manufacturing apparatus, comprising:

an unwinding mechanism for supplying a base material tape;

a coating mechanism for forming a metal layer on the active region;

2. The composite current collector preparation apparatus according to claim 1, wherein the unwinding mechanism is capable of continuously unwinding the base material tape, and the composite current collector preparation apparatus further comprises a winding mechanism capable of continuously winding the composite current collector.

3. The composite current collector preparation apparatus of claim 1, wherein the pre-treatment mechanism comprises:

4. The composite current collector preparation apparatus of claim 1, wherein the pre-treatment mechanism comprises:

the coarsening mechanism is used for coarsening a plurality of strip-shaped areas on the surface of the base material belt, and the strip-shaped areas are positioned in the middle of the surface of the base material belt and are arranged at intervals along the width direction of the base material belt;

5. The composite current collector preparation apparatus according to claim 4, further comprising a winding mechanism, wherein the winding mechanism comprises a multi-segment winding roller, the multi-segment winding roller comprises a plurality of sub-rollers connected with each other, and a locking mechanism is disposed between adjacent sub-rollers.

6. The composite current collector preparation apparatus of claim 5, wherein a plurality of the sub-rollers are detachably connected to each other, and the number of the sub-rollers is the same as the number of the strip-shaped regions.

7. The composite current collector preparation apparatus according to any one of claims 1 to 6, wherein the composite current collector preparation apparatus is configured to prepare a negative composite current collector, and the coating mechanism comprises:

8. The composite current collector preparation apparatus of claim 7, wherein the electroplating mechanism electroplates the strip of base material using brush plating.

9. The composite current collector preparation device according to any one of claims 1 to 6, wherein the composite current collector preparation device is used for preparing a positive composite current collector, and the coating mechanism is used for performing electroless plating on the base material strip so as to form the metal layer with a preset thickness on the active area.

10. The composite current collector preparation device according to any one of claims 1 to 6, further comprising a passivation mechanism located between the plating mechanism and the edge cutting mechanism, the passivation mechanism being configured to form an oxidation resistant layer on a surface of the metal layer facing away from the base material strip.