Composite current collector preparation method and device

Abstract

The invention discloses a preparation method and device of a composite current collector, and the preparation method of the composite current collector comprises the following steps: carrying out baking treatment on a polymer film raw material to obtain a base film; the preparation method comprises the following steps: adding a pre-plating layer on the surface of a base film through pre-plating treatment, carrying out film plating treatment on one side, far away from the base film, of the pre-plating layer, and plating a metal thickening layer to obtain a base material; winding the base material to obtain a roll material, and after winding of the roll material is completed, slitting the whole roll material through a slitting machine to obtain a sub-roll material; and carrying out surface modification treatment on the split coil material to obtain the composite current collector. According to the preparation method of the composite current collector, a single evaporation process is adopted for film coating, the process is simple, the film coating efficiency is high, the film forming quality is high, the film coating efficiency is improved through one-time film coating on the front face and the back face, meanwhile, the interface bonding force can be improved through pre-coating in an induction type heating mode, and the film forming quality is improved. And the coating efficiency is ensured, and the coating quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of material processing, and in particular to a method and device for preparing a composite current collector. Background Art

[0002] With the continuous progress of battery technology, traditional current collector materials have certain limitations in terms of electrical conductivity, mechanical strength, and production cost, and cannot meet the pursuit of modern battery technology for high energy density, long life, and low cost.

[0003] Composite current collectors have gradually received wide attention due to their advantages such as high safety, high energy density, low cost, long life, and good compatibility. However, the mainstream processes for preparing current composite collectors are relatively complex, mostly combining physical vapor deposition and chemical deposition, with complex processes, low preparation efficiency, and physical properties.

[0004] Therefore, in order to improve the preparation efficiency and product quality of composite current collectors, it is necessary to develop new preparation processes, optimize material selection and structural design, so as to promote the further development of composite current collector technology. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a method and device for preparing a composite current collector that overcomes the above problems or at least partially solves the above problems.

[0006] Other features and advantages of the present invention will become apparent through the following detailed description, or be learned in part through the practice of the present invention.

[0007] According to a first aspect of an embodiment of the present invention, there is provided a method for preparing a composite current collector, the method for preparing the composite current collector comprising the following steps:

[0008] S1, baking a polymer film raw material to obtain a base film;

[0009] S2, adding a pre-plated layer on the surface of the base film through pre-plating treatment, and performing coating treatment on the side of the pre-plated layer away from the base film to deposit a metal thickening layer to obtain a base material;

[0010] S3, winding the base material to obtain a wound material, and after the winding of the wound material is completed, cutting the whole wound material through a slitter to obtain a slit wound material;

[0011] S4, performing surface modification treatment on the slit wound material after slitting to obtain a composite current collector.

[0012] In some embodiments of the present invention, in the above-mentioned step S1, the above-mentioned polymer film raw material is placed in an oven for baking treatment. The baking time is 12 h, and the baking temperature is 30 - 120 °C.

[0013] In some embodiments of the present invention, in the above-mentioned step S2, a plurality of graphite crucibles are used to form an evaporation source, and the upper and lower surfaces of the base film are respectively pre-coated by an induction heating method through a vacuum coating machine, so that a pre-coating layer is added to the surface of the base film.

[0014] In some embodiments of the present invention, in the above-mentioned step S2, the above-mentioned base film with a pre-coating layer after pre-coating is placed on the unwinding roller of an induction vacuum evaporation device; the metal raw material is fed into the crucible by wire feeding, and the above-mentioned metal raw material is heated by resistive heating; a plurality of evaporation boats are arranged in a double-row staggered manner to form an evaporation source, and a metal thickening layer is respectively coated on the upper and lower surfaces of the base film at one time based on the heated above-mentioned metal raw material to obtain the base material.

[0015] In some embodiments of the present invention, in the above-mentioned step S4, a coating layer is provided on the surface of the above-mentioned slit roll material after slitting. The coating layer includes graphene and a bonding adhesive. The bonding adhesive is provided between the above-mentioned slit roll material and the above-mentioned graphene, and the thickness of the coating layer is 20 - 100 nm.

[0016] In some embodiments of the present invention, the above-mentioned polymer film raw material is made of PET, PP or PI.

[0017] In some embodiments of the present invention, the above-mentioned pre-coating layer is a metal film or a metal oxide film.

[0018] In some embodiments of the present invention, the thickness of the above-mentioned pre-coating layer is 20 - 200 nm.

[0019] In some embodiments of the present invention, the sum of the thicknesses of the above-mentioned pre-coating layer and the metal thickening layer is 1 μm.

[0020] According to the second aspect of the embodiments of the present invention, a composite current collector preparation device is provided, including:

[0021] A baking component, used for baking the polymer film raw material to obtain a base film;

[0022] A coating component, used for adding a pre-coating layer on the surface of the above-mentioned base film through pre-coating, and performing coating treatment on the side of the above-mentioned pre-coating layer away from the above-mentioned base film to coat a metal thickening layer to obtain a base material;

[0023] The slitting component is used to wind the above-mentioned base material to obtain a wound material. After the winding of the above-mentioned wound material is completed, the whole roll of the above-mentioned wound material is slit by a slitter to obtain slit materials;

[0024] The modification component is used to perform surface modification on the above-mentioned slit materials after slitting to obtain a composite current collector.

[0025] The technical solution provided in the embodiment of the present invention has at least the following technical effects or advantages:

[0026] The method for preparing the composite current collector in the embodiment of the present invention uses a single evaporation coating process for coating. The process is simple, the coating efficiency is high, the film forming quality is high, and the one-time coating on both sides improves the coating efficiency. At the same time, the use of inductive heating for pre-coating can improve the interfacial bonding force, ensuring both the coating efficiency and the coating quality.

[0027] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 It is a schematic flow chart of a method for preparing a composite current collector provided by an embodiment of the present invention;

[0030] Figure 2 It is a schematic cross-sectional view of the prepared composite current collector;

[0031] Figure 3 It is a reference schematic diagram of an inductive heating evaporation coating device;

[0032] Figure 4 It is a reference schematic diagram of a dual evaporation source coating device;

[0033] Figure 5 It is a schematic diagram of the principle structure of a device for preparing a composite current collector provided by an embodiment of the present invention.

[0034] Description of the reference numerals:

[0035] 1. Base film; 2. Pre-coated layer; 3. Metal thickening layer; 4. Coating layer; 11. First evaporation source; 12. First coating roller; 21. Second evaporation source; 22. Third evaporation source; 23. First wire feeding mechanism; 24. Second wire feeding mechanism; 25. Second coating roller; 26. Third coating roller; 27. Evaporation boat; 100. Baking assembly; 200. Coating assembly; 300. Slitting assembly; 400. Modifying assembly. Detailed implementation manners

[0036] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0037] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0038] In the context of the present disclosure, when a layer / component is referred to as being "on" another layer / component, the layer / component can be directly on the other layer / component, or there can be an intermediate layer / component between them. Additionally, if a layer / component is "on" another layer / component in one orientation, then when the orientation is reversed, the layer / component can be "under" the other layer / component. In the context of the present disclosure, similar or identical components may be denoted by the same or similar reference numerals.

[0039] To better understand the above technical solutions, the above technical solutions will be described in detail below in conjunction with specific implementation manners. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solutions of the present invention, rather than limitations on the technical solutions of the present invention. Without conflict, the technical features in the embodiments of the present invention and the embodiments can be combined with each other.

[0040] Figure 1 It is a schematic flow chart of a method for preparing a composite current collector provided by an embodiment of the present invention. Figure 2 It is a schematic cross-sectional view of the prepared composite current collector. Combining Figure 1-2 As shown, the method for preparing the composite current collector includes the following steps:

[0041] S1. Bake the polymer thin film raw material to obtain the base film 1;

[0042] In the embodiment of the present invention, the polymer thin film raw material is made of materials such as PET, PP, or PI.

[0043] In the above S1 step, in the embodiment of the present invention, the polymer thin film raw material is placed in an oven for baking treatment. The baking time is 12 h, and the baking temperature is 30 - 120 °C. The base film 1 after baking is left standing for 24 h to release the internal thermal stress.

[0044] S2. A pre - plating layer 2 is added on the surface of the base film 1 through pre - plating treatment, and a metal thickening layer 3 is plated on the side of the pre - plating layer 2 away from the base film 1 to obtain a base material.

[0045] In the above S2 step, in the embodiment of the present invention, an evaporation source is composed of multiple graphite crucibles. The upper and lower surfaces of the base film 1 are respectively pre - plated through an induction heating method by a vacuum coating machine, so that a pre - plating layer 2 is respectively added on the surface of the base film 1. The purpose of pre - plating is to improve the interfacial bonding force between the metal thickening layer 3 and the base film 1.

[0046] Combined Figure 3 As shown, it is a reference schematic diagram of an induction heating evaporation coating equipment. In the embodiment of the present invention, the pre - plating equipment is an induction heating evaporation coating equipment, including an evaporation source (the first evaporation source 11) composed of 11 graphite crucibles and a first coating roller 12. The base film 1 is wound on the first coating roller 12, and the heating method is induction heating; this heating method has obvious advantages, with stable temperature and not easy to splash. During the coating process, since the pre - plating layer 2 to be plated is relatively thin and the evaporation rate is large using the crucible as the evaporation source, the coating speed can reach more than 200 m / min. Normally, the coating speed of this equipment can be arbitrarily selected between 50 - 350 m / min. The volume of the configured crucible can support continuous coating of more than 10,000 meters, maintaining high coating efficiency.

[0047] In the above S2 step, in the embodiment of the present invention, the base film 1 pre - plated with the pre - plating layer 2 is placed on the unwind roller of the induction vacuum evaporation coating equipment; the metal raw material is fed into the crucible by wire feeding, and the metal raw material is heated by resistive heating; multiple evaporation boats 27 are arranged in a double - row staggered manner to form an evaporation source, and based on the heated metal raw material, the upper and lower surfaces of the base film 1 are coated at one time, respectively plating a metal thickening layer 3 to obtain a base material. According to different requirements, the thickness of the metal thickening layer 3 can also be increased. The metal thickening layer 3 is related to multiple physical properties, such as sheet resistance, tensile properties, interfacial bonding force, and density, etc. The metal thickening layer 3 has relatively high requirements for the purity of the raw material, requiring the purity to be greater than 99.9%.

[0048] Combined Figure 4As shown, it is a reference schematic diagram of a dual-evaporation-source evaporation coating device. In the embodiments of the present invention, the device for coating treatment is a dual-evaporation-source evaporation coating device, which includes two evaporation sources (i.e., the second evaporation source 21 and the third evaporation source 22), two wire feeding mechanisms (i.e., the first wire feeding mechanism 23 and the second wire feeding mechanism 24), and two coating rollers (i.e., the second coating roller 25 and the third coating roller 26). Evaporation boats 27 are arranged in a staggered manner on both evaporation sources. The characteristic of this device is that it uses the wire feeding method for feeding, and the heating is by resistive heating. It has two evaporation sources and coating rollers. The evaporation source is composed of multiple evaporation boats 27 arranged in a double-row staggered manner, which can coat the front and back sides of the base film 1 at one time, achieving the effect of one-time film formation. The dual-evaporation-source one-time double-sided film formation can avoid excessive damage to the base film 1 caused by high temperature, and the physical properties of the coated foil are better. During the coating process, the speed can reach up to 18 m / min at most, and the coating efficiency is relatively high. The coating roller is equipped with a cold roller and a bias system, which can not only reduce the damage to the base film 1 caused by high temperature, but also make the adhesion between the base film 1 and the coating roller higher. The direction of the coating roller can be adjusted according to requirements, and the dual-evaporation source is used for one-time single-sided coating to improve the density of the film layer. The double-row staggered arrangement of the evaporation boats 27 can further improve the coating density.

[0049] In the embodiments of the present invention, the pre-coating layer 2 is a metal thin film or a metal oxide thin film; the thickness of the pre-coating layer 2 is 20 - 200 nm; the sum of the thicknesses of the pre-coating layer 2 and the metal thickening layer 3 is 1 μm.

[0050] S3. The base material is wound to obtain a wound material. After the winding of the wound material is completed, the whole roll of the wound material is cut by a slitter to obtain a slit wound material;

[0051] In the above step S3, in the embodiments of the present invention, after the winding of the wound material is completed, the whole roll of the wound material is placed on the slitter for cutting. During the cutting process, the edges need to be trimmed, and the width of the trimming is determined according to the coating situation. The remaining material after trimming is cut according to the required size. Special attention should be paid to the configuration of the blade and tension during the slitting of the composite current collector to avoid cutting burrs.

[0052] S4. The slit wound material after slitting is subjected to surface modification treatment to obtain a composite current collector.

[0053] In the above step S4, in the embodiments of the present invention, a coating layer 4 is provided on the surface of the slit wound material after slitting. The coating layer 4 includes graphene and a binder. The binder is arranged between the slit wound material and graphene. The thickness of the coating layer 4 is 20 - 100 nm. The coating layer 4 is used to reduce the internal resistance of the battery, protect the current collector from being eroded by the electrolyte, and can improve the overall performance of the battery and extend the service life of the battery.

[0054] For example, in the embodiment of the present invention, an oven is used to bake the polymer film raw material for 12 hours at a baking temperature of 100 °C to obtain the base film 1; the baked base film 1 is left standing for 24 hours; the entire roll of base film 1 is placed on the unwinding roller of an inductive vacuum evaporation coating device, and copper particles or aluminum particles are filled in the crucible for pre-coating treatment. The appropriate unwinding tension, coating tension, and winding tension are adjusted. After the vacuum degree reaches 5×10⁻³ or lower, heating and pre-coating are carried out. The coating speed is adjusted to 200 - 220 m / min, and the coating thickness is 50 nm; after the pre-coating is completed, resistive vacuum evaporation is used for thickening. Coating treatment is carried out on the outer side of the pre-coated layer 2, and a metal thickening layer 3 is respectively coated on both sides to obtain the base material. During the unwinding process, the plasma system is adjusted to make the foil surface have a certain roughness to obtain better adhesion. The appropriate coating speed and wire feeding speed are adjusted to thicken both sides to 1000 nm in one-time film formation; after the thickening is completed, slitting and rewinding are carried out, slitting is carried out according to the required width, and at the same time, the edges are trimmed; when the slitting is completed, surface carbon coating is carried out. The slurry is doped with a certain proportion of binder to improve the adhesion between the slurry and the foil surface, and the thickness of the carbon coating is 60 nm.

[0055] Among them, the baked base film 1 is aluminized using a resistive heating vacuum evaporation coating device, and the aluminizing thickness is 6 μm on one side. Double evaporation sources are used for single-sided coating simultaneously, and the evaporation coating is carried out in 3 times. A bias power supply can be added in the second and third times to adjust the adhesion between the base film 1 and the roller surface. Each time the tension needs to be readjusted. After the aluminizing is completed, copper plating is carried out using inductive vacuum evaporation. The copper plating thickness is 200 nm, and the copper plating is carried out in two times, with a single copper plating thickness of 100 nm.

[0056] The method for preparing the composite current collector in the embodiment of the present invention uses a single evaporation coating process for coating. The process is simple, the coating efficiency is high, and the film formation quality is high. The double evaporation source evaporation coating device can reduce the damage to the base film 1 caused by high temperature. One-time coating on both the front and back sides improves the coating efficiency. At the same time, using an inductive heating evaporation coating device for pre-coating can improve the interfacial adhesion, ensuring both the coating efficiency and the coating quality.

[0057] On the basis of the above embodiments, as an implementation of the above Figure 1 shown method, the present invention provides an embodiment of a composite current collector preparation device. This device embodiment corresponds to the Figure 1 shown method embodiment. This device can be specifically applied to various electronic devices. Referring to Figure 5 shown, the above composite current collector preparation device includes:

[0058] A baking assembly 100 for baking the polymer film raw material to obtain the base film 1;

[0059] The coating component 200 is used to add a pre - coating layer 2 to the surface of the base film 1 through pre - coating treatment, and then perform coating treatment on the side of the pre - coating layer 2 away from the base film 1 to deposit a metal thickening layer 3 to obtain a base material;

[0060] The slitting component 300 is used to wind the base material to obtain a wound material. After the winding of the wound material is completed, the whole wound material is slit on a slitter to obtain slit materials;

[0061] The modification component 400 is used to perform surface modification on the slit materials after slitting to obtain a composite current collector.

[0062] The composite current collector preparation device described in the embodiments of the present invention can execute the composite current collector preparation method provided in the above - mentioned embodiments. The composite current collector preparation device has the corresponding functional steps and beneficial effects of the composite current collector preparation method described in the above - mentioned embodiments. For details, please refer to the embodiments of the composite current collector preparation method. The embodiments of the present invention will not be elaborated herein.

[0063] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of the present invention can be practiced without these specific details. In some instances, well - known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0064] Similarly, it should be understood that, in order to streamline the present disclosure and assist in understanding one or more of the various inventive aspects, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected by the claims, the inventive aspects lie in less than all the features of the single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate embodiment of the present invention.

[0065] It should be noted that the above - mentioned embodiments illustrate the present invention rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims.

Claims

1. A method for preparing a composite current collector, characterized in that: The following steps are involved: S1, baking the polymer film raw material to obtain a base film; S2, adding a pre-plating layer by pre-plating treatment on the surface of the base film, and performing a coating treatment on the side of the pre-plating layer away from the base film to plate a metal thickening layer to obtain a base material; S3, rolling up the base material to obtain a coiled material, and after the coiled material is rolled up, cutting the whole coiled material through a slitting machine to obtain split coils; S4, performing surface modification treatment on the cut coil material to obtain a composite current collector.

2. The method for preparing a composite current collector according to claim 1, characterized in that: In the step S1, the polymer film raw material is placed in an oven for baking. The baking time is 12 hours and the baking temperature is 30-120°C.

3. The method for preparing a composite current collector according to claim 1, characterized in that: In the step S2, a plurality of graphite crucibles are used to form an evaporation source, and the upper and lower surfaces of the base film are pre-plated by a vacuum coating machine in an induction heating manner, so that a pre-plating layer is added to the surface of the base film.

4. The method for preparing a composite current collector according to claim 1, characterized in that: In the S2 step, the pre-plated base film with a pre-plated layer is placed on a unwinding roller of an induction vacuum evaporation device; the metal raw material is fed into a crucible by wire feeding, and the metal raw material is heated by resistive heating; a plurality of evaporation boats are arranged in double rows in a staggered manner to form an evaporation source, and a metal thickening layer is plated on the upper surface and the lower surface of the base film respectively based on the heated metal raw material at one time to obtain the base material.

5. The method for preparing a composite current collector according to claim 1, characterized in that: In the step S4, a coating layer is provided on the surface of the slit coil material, the coating layer comprises graphene and adhesive, the adhesive is provided between the slit coil material and the graphene, and the thickness of the coating layer is 20 to 100 nm.

6. The method for preparing a composite current collector according to claim 1, characterized in that: The polymer film raw material is PET, PP or PI.

7. The method for preparing a composite current collector according to claim 1, characterized in that: The pre-plating layer is a metal film or a metal oxide film.

8. The method for preparing a composite current collector according to claim 1, characterized in that: The thickness of the pre-plating layer is 20-200 nm.

9. The method for preparing a composite current collector according to claim 1, characterized in that: The sum of the thickness of the pre-plating layer and the metal thickening layer is 1 um.

10. A composite current collector preparation device, applied to the composite current collector preparation method according to any one of claims 1 to 9, characterized in that: include: A baking component is used to bake the polymer film raw material to obtain a base film; A coating component is used to add a pre-plating layer by pre-plating on the surface of the base film, and to plate a metal thickening layer on the side of the pre-plating layer away from the base film to obtain a base material; A slitting assembly is used to roll up the base material to obtain a coiled material, and after the coiled material is rolled up, the whole coiled material is cut by a slitting machine to obtain split coils; The modification component is used to perform surface modification treatment on the coiled material after slitting to obtain a composite current collector.

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