Conductive film, pole piece, energy storage device and electric equipment

Abstract

The utility model discloses a conductive film, a pole piece, an energy storage device and electric equipment, the conductive film comprises a base material layer, a conductive main body layer and an isolation layer, along a first direction, the base material layer comprises a first surface and a second surface; the conductive main body layer comprises a first metal layer and a second metal layer, the first metal layer is arranged on the first surface, and the second metal layer is arranged on the second surface; the isolation layer is arranged on the surface, away from the substrate layer, of at least one of the first metal layer and the second metal layer; wherein the isolating layer comprises a structural layer with a melting point lower than that of the conductive main body layer. The problem that the metal layers on the surfaces of the two sides of the base film are easily adhered to each other is solved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular, to a conductive film, a pole piece, an energy storage device, and an electrical device. Background Art

[0002] Currently, the preparation processes of composite current collector materials generally include the following methods:

[0003] 1) Adopting a coating method such as vacuum magnetron sputtering or thermal evaporation to deposit a metal layer (such as a copper layer Cu) on the surface of a polymer base film, thereby obtaining a composite current collector in one step.

[0004] 2) Adopting a two-step forming method of vacuum magnetron sputtering or thermal evaporation + electroplating with water to deposit a copper layer on the surface of a polymer base film to obtain a composite current collector.

[0005] 3) Adopting a three-step forming method of magnetron sputtering coating + thermal evaporation coating + electroplating with water to deposit a copper layer on the surface of a polymer base film to obtain a composite current collector.

[0006] After the coating is completed, the obtained composite current collector needs to be wound in a roll-to-roll manner. In the wound film roll, the metal layers on both surfaces of the base film are prone to adhesion to each other, resulting in adhesion failure of the film layer during the unwinding process of the film roll and causing delamination defects, that is, local or sporadic peeling of the copper layer on the surface of the base film. Utility Model Content

[0007] The main purpose of the present application is to provide a conductive film, a pole piece, an energy storage device, and an electrical device to solve the problem that the metal layers on both surfaces of the base film are prone to adhesion to each other mentioned in the background art.

[0008] According to one aspect of the present application, a conductive film is provided, including:

[0009] A substrate layer, along a first direction, the substrate layer includes a first surface and a second surface;

[0010] A conductive main body layer, the conductive main body layer includes a first metal layer and a second metal layer, the first metal layer is disposed on the first surface, and the second metal layer is disposed on the second surface;

[0011] An isolation layer, the isolation layer is disposed on at least one of the surfaces of the first metal layer and the second metal layer away from the substrate layer, and the isolation layer is used to isolate the first metal layer and the second metal layer in the wound conductive film;

[0012] Wherein, the isolation layer includes a structural layer with a melting point lower than that of the conductive main body layer.

[0013] Further, the isolation layer includes a structural layer with a melting point not higher than 800 °C.

[0014] Further, the isolation layer includes a single-metal layer, and the single-metal layer includes at least one of a zinc layer, a tin layer, a lead layer, an antimony layer, a cadmium layer, a silver layer, a magnesium layer, and a lithium layer; and / or, the alloy-metal layer includes at least one of a zinc alloy layer, a tin alloy layer, a lead alloy layer, a magnesium alloy layer, a cadmium alloy layer, and an antimony alloy layer.

[0015] Further, the isolation layer further includes at least one of a lead oxide layer, an antimony oxide layer, a cadmium oxide layer, and a boron oxide layer.

[0016] Further, along the first direction, the thickness of the isolation layer is not less than 0.2 nm and not greater than 40 nm.

[0017] Further, both the first metal layer and the second metal layer include a copper layer or an aluminum layer; and / or,

[0018] The substrate layer includes at least one of a polypropylene layer, a polyethylene terephthalate layer, a polyethylene layer, a polyamide layer, a polyimide layer, a polyphenylene ether layer, a polyvinyl chloride layer, an ABS plastic layer, a poly(p-phenyleneterephthalamide) layer, a polyoxymethylene layer, a polytetrafluoroethylene layer, a polyvinylidene fluoride layer, a polycarbonate layer, a polyvinyl alcohol layer, a polyethylene glycol layer, and a cellulose layer.

[0019] Further, the conductive main body layer further includes:

[0020] An adhesion-enhancing layer, which is disposed between the conductive main body layer and the substrate layer.

[0021] Further, the isolation layer further includes a structural layer with an electrode potential less than that of the first metal layer and the second metal layer.

[0022] Further, the conductive main body layer further includes:

[0023] A metal thickening layer, which is disposed on the surface of at least one side of the conductive film;

[0024] and / or, along the first direction, the total thickness of one side of the conductive film is between 700 nm and 1600 nm.

[0025] Further, before the isolation layer is disposed on the conductive film, the conductive film has a first sheet resistance, and after the isolation layer is disposed on the conductive film, the conductive film has a second sheet resistance, and the second sheet resistance is increased by 3% to 300% compared with the first sheet resistance.

[0026] According to another aspect of the present application, a pole piece is provided, and the pole piece includes a current collector, and the current collector includes the conductive film described above.

[0027] According to another aspect of the present application, a energy storage device is provided, and the energy storage device includes the electrode tab described above.

[0028] According to another aspect of the present application, an electrical equipment is provided, and the electrical equipment includes the energy storage device described above.

[0029] According to another aspect of the present application, a method for preparing a conductive film is provided. The method for preparing a conductive film is used to prepare the conductive film described above, and the method includes:

[0030] Preparing a first metal layer and a second metal layer on a first surface and a second surface of a substrate layer by using a first preparation process;

[0031] Preparing a separation layer with a melting point lower than that of the first metal layer and the second metal layer on a surface of at least one of the first metal layer and the second metal layer away from the substrate layer by using a second preparation process.

[0032] Further, the first preparation process and the second preparation process include a vacuum magnetron sputtering coating process or a thermal evaporation coating process.

[0033] For the conductive film provided by the present application, since a separation layer is provided on a surface of the first metal layer facing away from the substrate layer or a surface of the second metal layer facing away from the substrate layer, thus, when the conductive film is wound up, the first metal layer and the second metal layer can be separated by the separation layer, so that the first metal layer and the second metal layer will not stick to each other. When the wound-up conductive film is unwound, the first metal layer or the second metal layer will not peel off from the substrate layer, that is, no delamination defect will appear on the surface of the conductive film, and the finished product quality of the conductive film is improved. Moreover, since the melting point of the separation layer is lower than that of the conductive main body layer, thus, the target of the separation layer can be heated and evaporated by using the waste heat generated during the deposition of the first metal layer and the second metal layer. The evaporation deposition of the separation layer can be realized without adding an evaporation source, reducing the preparation cost of the conductive film and the energy consumption generated during the preparation process of the conductive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present application, and constitute a part of the present application. The schematic embodiments of the present application and the descriptions thereof are used to explain the present application, and do not constitute an improper limitation to the present application. In the drawings:

[0035] Figure 1 is a schematic structural diagram of the conductive film disclosed in the present application;

[0036] Figure 2 is a schematic flow diagram of the method for preparing the conductive film disclosed in the present application.

[0037] Among them, the above-mentioned drawings include the following reference numerals:

[0038] 10. Substrate layer; 11. First surface; 12. Second surface; 20. First metal layer; 30. Second metal layer; 40. Isolation layer; 50. Adhesion enhancement layer. Detailed implementation manners

[0039] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The following will detail this application with reference to the drawings and in combination with the embodiments.

[0040] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary embodiments according to this application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or their combinations.

[0041] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of this application. At the same time, it should be understood that, for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0042] During the preparation of the current current collector, after evaporating or magnetron sputtering a metal layer on both sides of the substrate layer 10, it is sometimes necessary to enter a hydroplating device to thicken the metal layer. Before the current collector enters the hydroplating device, the current collector needs to be wound and then unwound to the hydroplating device. However, during the winding and unwinding of the current collector, the metal layers on both sides of the substrate layer 10 will stick together, easily causing the metal layer to peel off from the substrate layer 10. The essence of this situation is that the interfacial bonding force F1 between the metal layer and the polymer base film is less than the bonding force F2 between the metal layers on both sides of the wound polymer substrate (such as between copper films), resulting in the phenomenon of film layer peeling. In response to this, to solve the problem that the metal layers on both sides of the surface of the substrate layer 10 are prone to sticking to each other, the first embodiment of the present utility model provides a conductive film, which includes a substrate layer 10, a conductive main body layer, and an isolation layer 40.

[0043] Please refer to Figure 1 , along the first direction, the substrate layer 10 includes a first surface 11 and a second surface 12. The first direction is the thickness direction of the substrate layer 10, that is Figure 1 the direction indicated by the arrow X shown. The conductive main body layer includes a first metal layer 20 and a second metal layer 30. The first metal layer 20 is disposed on the first surface 11, and the second metal layer 30 is disposed on the second surface 12. The isolation layer 40 is disposed on the surface of at least one of the first metal layer 20 and the second metal layer 30 away from the substrate layer 10. The isolation layer 40 is used to isolate the first metal layer 20 and the second metal layer 30 in the wound conductive film. Thus, when the conductive film is wound, the isolation layer 40 can isolate the first metal layer 20 and the second metal layer 30. During the unwinding process of the conductive film, since the first metal layer 20 and the second metal layer 30 do not stick to each other, not only is it easy to pull and unwind the conductive film, but also there will be no delamination defect on the surface of the conductive film.

[0044] Among them, the isolation layer 40 includes a structural layer with a melting point lower than that of the conductive main body layer. Thus, the target of the isolation layer can be heated and evaporated by using the waste heat generated during the plating of the first metal layer and the second metal layer. On the basis of not requiring an additional evaporation source, the evaporation plating of the isolation layer can be realized, reducing the preparation cost of the conductive film and the energy consumption generated during the preparation process of the conductive film.

[0045] Moreover, the conductive film in this embodiment has a first sheet resistance before the isolation layer 40 is provided, and a second sheet resistance after the isolation layer 40 is provided. The second sheet resistance increases by 3% to 300% compared with the first sheet resistance. Within this range, it can ensure that the sheet resistance of the conductive film provided with the isolation layer 40 does not increase too much, thereby ensuring the overall conductive performance of the conductive film finished product after electroplating thickening. Moreover, after the isolation layer 40 remains in the conductive film finished product, it will not cause damage to the energy storage device.

[0046] Specifically, the sheet resistance of the second party in this embodiment increases by 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 22%, 25%, 26%, 27%, 29%, 30%, 32%, 34%, 36%, 38%, 40%, 41%, 45%, 50%, 60%, 70%, 80%, 90%, 100%, 110%, 120%, 130%, 140%, 150%, 160%, 170%, 180%, 190%, 200%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, 290%, 300%, etc. compared with the first party. Preferably, the sheet resistance of the second party in this embodiment increases by 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 23%, 28%, 32%, 36%, 40%, 43%, 46%, 50%, etc. compared with the first party. A further optimized range is that the sheet resistance of the second party increases by 3%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 23%, 28%, 30%, etc. compared with the first party. Within this range, the sheet resistance of the conductive film increases very little or hardly at all after the isolation layer 40 is provided. For example, when the first sheet resistance is 1000 mΩ, if the second sheet resistance increases by 3%, the second sheet resistance is 1030 mΩ; if the second sheet resistance increases by 10%, the second sheet resistance is 1100 mΩ; if the second sheet resistance increases by 20%, the second sheet resistance is 1200 mΩ, etc. It can be seen that the overall sheet resistance of the conductive film increases less, and the conductive film provided with the isolation layer 40 can be directly transferred to the hydroplating process for electroplating thickening until the thickness of the conductive film reaches the use requirement to obtain the conductive film finished product. Since the provided isolation layer 40 has little influence on the sheet resistance of the conductive film, the conductivity of the conductive film finished product can meet the use requirement. When the conductive film finished product is used as the current collector of an energy storage device such as a battery, the isolation layer 40 will not cause damage to the battery. Moreover, due to the presence of the isolation layer 40, the first metal layer 20 and the second metal layer 30 of the conductive film during winding can be isolated, preventing the first metal layer 20 and the second metal layer 30 from sticking to each other. When the wound conductive film is unwound later, a small traction force can be applied to the conductive film for unwinding, and there will be no delamination defect on the unwound conductive film, ensuring the quality of the conductive film.

[0047] It can be seen that in this embodiment, since the isolation layer 40 is provided on the surface of the first metal layer 20 facing away from the base material layer 10 or the surface of the second metal layer 30 facing away from the base material layer 10, when the conductive film is wound, the first metal layer 20 and the second metal layer 30 can be isolated by the isolation layer 40, so that the first metal layer 20 and the second metal layer 30 will not stick to each other. When the wound conductive film is unwound, the first metal layer 20 or the second metal layer 30 will not peel off from the base material layer 10, that is, no delamination defect will appear on the surface of the conductive film, improving the finished product quality of the conductive film. Moreover, since the melting point of the isolation layer 40 is lower than that of the conductive main body layer, the target of the isolation layer 40 can be heated and evaporated by using the waste heat generated during the plating of the first metal layer 20 and the second metal layer 30, and the evaporation plating of the isolation layer 40 can be realized without adding an evaporation source, reducing the energy consumption generated during the preparation process of the conductive film. Furthermore, when the conductive film is used as a current collector of an energy storage device (such as a lithium battery), the isolation layer 40 in the conductive film will not damage the energy storage device.

[0048] The isolation layer 40 provided in this embodiment includes a third metal layer or a non-metal layer whose material is different from that of the conductive main body layer. That is, the material of the isolation layer 40 is different from both the first metal layer 20 and the second metal layer 30. Therefore, the existence of the isolation layer 40 can reduce the adhesion force between the first metal layer 20 and the second metal layer 30, so that the first metal layer 20 and the second metal layer 30 will not stick to each other. Thus, the isolation layer 40 can isolate the first metal layer 20 and the second metal layer 30, preventing delamination defects from occurring on the conductive film due to the adhesion between the first metal layer 20 and the second metal layer 30, such as the phenomenon of partial or sporadic peeling of the first metal layer 20 and the second metal layer 30 on the conductive film.

[0049] In the actual process of preparing the conductive film, the first metal layer 20 and the second metal layer 30 can be plated on the first surface 11 and the second surface 12 of the base material layer 10 by means of vacuum magnetron sputtering coating or thermal evaporation coating. The isolation layer 40 can also be plated on the surface of the first metal layer 20 facing away from the base material layer 10 or the surface of the second metal layer 30 facing away from the base film layer by means of thermal evaporation coating. When the isolation layer 40 includes a non-metal layer, the non-metal layer may specifically include a metal oxide layer, such as at least one of a lead oxide layer, an antimony oxide layer, a cadmium oxide layer, and a boron oxide layer. When the isolation layer 40 selects a structure layer such as a lead oxide layer, an antimony oxide layer, a cadmium oxide layer, or a boron oxide layer, for example, when the conductive main body layer includes a copper layer, since the melting points of the lead oxide layer, the antimony oxide layer, the cadmium oxide layer, and the boron oxide layer are relatively low, the evaporation plating of the isolation layer can be realized by using the waste heat generated during the heating and evaporation of the copper target for obtaining the copper layer. Among them, the material price of the boron oxide layer is relatively low, and the selection of the boron oxide layer can also reduce the production cost of the conductive film.

[0050] Along the first direction, the thickness of the isolation layer 40 is not less than 0.2 nm and not greater than 40 nm. The isolation layer 40 within this thickness range not only has a good isolation effect on the first metal layer 20 and the second metal layer 30 on opposite sides of the conductive film to prevent adhesion between the first metal layer 20 and the second metal layer 30, but also enables the conductive film to have good electrical conductivity, such that the increase in the sheet resistance of the second side of the conductive film after setting the isolation layer 40 relative to the first sheet resistance is between 3% and 300%. While ensuring the electroplating effect of the conductive film, the isolation layer 40 will not damage the backend application products such as batteries. The specific thickness of the isolation layer 40 may include one of 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.7 nm, 0.8 nm, 1 nm, 1.1 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.7 nm, 1.8 nm, 2 nm, 2.2 nm, 2.4 nm, 2.5 nm, 2.7 nm, 2.8 nm, 2.9 nm, 3 nm, 3.2 nm, 3.5 nm, 3.7 nm, 3.8 nm, 4 nm, 4.1 nm, 4.3 nm, 4.6 nm, 4.8 nm, 5 nm, 5.2 nm, 5.3 nm, 5.5 nm, 5.7 nm, 5.9 nm, 6 nm, 6.3 nm, 6.4 nm, 6.5 nm, 6.7 nm, 6.9 nm, 7 nm, 7.3 nm, 7.5 nm, 7.7 nm, 7.9 nm, 8 nm, 8.1 nm, 8.3 nm, 8.4 nm, 8.6 nm, 8.8 nm, 9 nm, 9.2 nm, 9.5 nm, 9.6 nm, 9.8 nm, 10 nm, 10.5 nm, 11 nm, 11.5 nm, 12 nm, 12.5 nm, 13 nm, 15 nm, 18 nm, 19 nm, 20 nm, 22 nm, 23 nm, 25 nm, 27 nm, 28 nm, 30 nm, 31 nm, 32 nm, 33 nm, 35 nm, 37 nm, 38 nm, 40 nm, etc.

[0051] Since the isolation layer 40 in this embodiment includes a structural layer with a melting point lower than that of the conductive main body layer, the energy consumption generated in the process of depositing the conductive film can be greatly reduced. For example, when depositing the isolation layer 40 by thermal evaporation coating, the waste heat generated during the deposition of the first metal layer 20 and the second metal layer 30 by thermal evaporation coating can be used to heat and evaporate the target material of the isolation layer 40, so as to deposit the isolation layer 40 on the surface of the first metal layer 20 or the second metal layer 30. Therefore, the evaporation deposition of the isolation layer 40 can be realized without adding an evaporation source, reducing the energy consumption generated in the process of preparing the conductive film. At the same time, due to the low melting point of the isolation layer 40, the target material of the isolation layer 40 can be quickly melted and evaporated or sputtered on the first metal layer 20 or the second metal layer 30, and the isolation layer 40 is also convenient for quickly condensing and fixing on the surface of the first metal layer 20 or the second metal layer 30, which can reduce the preparation time of the isolation layer 40 in this embodiment to a certain extent and improve the production efficiency of the conductive film in this embodiment.

[0052] Preferably, the isolation layer 40 in this embodiment includes a structural layer with a melting point not higher than 800 °C. For example, the isolation layer 40 specifically includes structural layers with melting points of 800 °C, 769 °C, 700 °C, 660 °C, 651 °C, 630 °C, 600 °C, 500 °C, 419 °C, 400 °C, 450 °C, 328 °C, 321 °C, 300 °C, 232 °C, 200 °C, 100 °C, etc. Thus, when heating and evaporating the target material of the conductive main body layer by using existing coating equipment (such as evaporation coating equipment), the temperature generated is often relatively high. For example, when both the first metal layer 20 and the second metal layer 30 of the conductive main body layer are copper layers with a melting point higher than that of the isolation layer 40, if an effective copper film layer is to be deposited, the heating temperature of the copper material should reach at least 1100 °C and above. Therefore, when using the waste heat generated by heating and evaporating the conductive main body layer to heat and evaporate the target material of the isolation layer 40, it can ensure that the target material of the isolation layer 40 can be fully heated and evaporated, reducing energy consumption, and enabling the target material of the isolation layer 40 to be quickly melted and deposited on the first metal layer 20 or the second metal layer 30. And the isolation layer 40 is more convenient for quickly condensing and fixing on the surface of the first metal layer 20 or the second metal layer 30, improving the production efficiency of the conductive film.

[0053] When the isolation layer 40 may include a third metal layer, the third metal layer specifically includes at least one of a single-element metal layer and an alloy metal layer. The single-element metal layer includes at least one of a zinc layer, a tin layer, a lead layer, an antimony layer, a cadmium layer, a silver layer, an aluminum layer, a magnesium layer, and a lithium layer. The alloy metal layer includes at least one of a zinc alloy layer, a tin alloy layer, an aluminum alloy layer, a lead alloy layer, a magnesium alloy layer, a cadmium alloy layer, and an antimony alloy layer. The aluminum alloy layer includes at least one of an aluminum-magnesium alloy layer, an aluminum-cadmium alloy layer, an aluminum-copper alloy layer, an aluminum-zinc alloy layer, and an aluminum-tin alloy layer, etc. The lead alloy layer includes at least one of a lead-tin alloy layer, a lead-antimony alloy layer, a lead-copper alloy layer, a lead-cadmium alloy layer, and a lead-silver alloy layer, etc. The magnesium alloy layer includes at least one of a magnesium-aluminum alloy layer, a magnesium-manganese alloy layer, and a magnesium-zinc alloy layer, etc. The cadmium alloy layer includes at least one of a cadmium-zinc alloy, a cadmium-magnesium alloy, and a cadmium-aluminum alloy, etc. The antimony alloy layer includes at least one of an antimony-tin alloy layer, an antimony-lead alloy layer, and an antimony-copper alloy layer, etc.

[0054] Preferably, the single-element metal layer may include at least one of a zinc layer and a tin layer. The alloy metal layer includes at least one of a zinc alloy layer and a tin alloy layer. The zinc alloy layer may include at least one of a zinc-aluminum alloy layer, a zinc-copper alloy layer, and a zinc-magnesium alloy layer, etc. The tin alloy layer includes at least one of a tin-zinc alloy layer, a tin-silver alloy layer, and a tin-lead alloy layer, etc.

[0055] In this embodiment, the zinc layer and the tin layer are preferred for the single-element metal layer. When the isolation layer 40 is preferably a zinc layer, since zinc (Zn) can achieve efficient sputtering deposition in magnetron sputtering because it has a good sputtering response to argon ions and a high sputtering rate, a thin film can be formed on the first metal layer 20 or the second metal layer 30 relatively quickly. The zinc thin film prepared by the magnetron sputtering method usually has excellent density and purity, and good film-forming uniformity, which is beneficial to improving the conductivity, mechanical properties, and chemical stability of the thin film. The melting point of zinc is relatively low (419.5 °C), and it has good evaporation performance under suitable evaporation conditions, and can be quickly converted into vapor and deposited as a thin film after condensation. It can be seen that whether it is magnetron sputtering or evaporation coating process, zinc shows good deposition performance and application prospects, especially in new energy batteries, thin film electronic devices, optical coating, and anti-corrosion coatings, etc., and the further optimized conditions are more excellent in the way of evaporation coating.

[0056] When the isolation layer 40 is preferably a tin layer, since the sputtering rate of tin (Sn) is relatively fast compared to some high melting point metals, a uniform thin film layer can be formed within a reasonable sputtering time. Since the melting point of tin is relatively low (about 232 °C), the tin layer can be deposited by utilizing the waste heat generated during the plating of the conductive main body layer, thereby reducing the energy consumption of the coating equipment. Moreover, the heat generated during the magnetron sputtering process will not cause excessive thermal load on many sensitive substrates, allowing the thin film deposition to be completed at a lower temperature and reducing the potential damage to the substrate material. Magnetron sputtering can precisely control the chemical composition of the tin thin film. Tin (Sn) has strong evaporation performance at an appropriate temperature, capable of forming a continuous and uniform vapor flow, and depositing a continuous and thickness-controlled thin film. In short, whether it is magnetron sputtering or evaporation coating, as a soft metal, tin is easy to be plated on the first metal layer 20 and the second metal layer 30 due to its good deposition performance, thin film quality, and process controllability when preparing thin film materials.

[0057] The electrode potential of the isolation layer 40 in this embodiment is less than the electrode potentials of the first metal layer 20 and the second metal layer 30. Thus, while isolating the first metal layer 20 and the second metal layer 30 by using the isolation layer 40, it can also play a role in cathodic protection for the first metal layer 20 and / or the second metal layer 30. This is because when the conductive film encounters corrosive media such as water and oxygen in the air during transportation or storage, a micro-battery will be formed with the elemental metal layer as the negative electrode and the first metal layer 20 and / or the second metal layer 30 as the positive electrode. The elemental metal layer (i.e., the isolation layer 40) at the negative electrode part of the micro-battery is more likely to release electrons and be oxidized to form metal ions than the first metal layer 20 and / or the second metal layer 30 as the positive electrode. When the first metal layer 20 and / or the second metal layer 30 may release electrons, since they will receive the electrons transferred from the isolation layer 40 as the negative electrode, the rate of releasing electrons is reduced or even the oxidized part is restored, so that the first metal layer 20 and / or the second metal layer 30 is cathodically protected, ensuring that the conductive film containing the isolation layer 40 is not easily corroded during transportation and storage.

[0058] When the isolation layer 40 provided in this embodiment includes a non-metal layer with a melting point lower than that of the conductive main body layer, the non-metal layer may include one of an alumina layer and a boron oxide layer (chemical formula: B2O3). Among them, B2O3 has strong thermal stability, and the vapor pressure of B2O3 can increase significantly with the increase of temperature, which is conducive to forming a stable vapor flow during vacuum evaporation or magnetron sputtering. During the evaporation or magnetron sputtering process, B2O3 can maintain a high purity. The vacuum environment reduces the chance of B2O3 reacting with impurities in the air, which helps to generate a pure and uniform borate film. In addition, the melting point of B2O3 is relatively low (about 450°C) and it is easy to evaporate under appropriate heating conditions. That is to say, in this embodiment, the waste heat generated by the coating equipment that heats and evaporates the target of the conductive main body layer can be used to realize the evaporation coating of the B2O3 target, reducing the energy consumption generated by the existing coating equipment. Moreover, the high volatility of B2O3 means that a high vapor pressure can be obtained at a lower evaporation temperature, which is conducive to further reducing the energy consumption during the evaporation process and reducing the thermal stress on the substrate and equipment. In addition, the low melting point is also conducive to alternate evaporation with other high melting point materials in the preparation of multi-layer structures, avoiding an increase in process complexity caused by too large a temperature difference. During the actual preparation of the isolation layer 40, the thickness and composition distribution of the boron oxide layer can be precisely controlled by controlling the temperature of the evaporation source, the evaporation rate, and the distance between the substrate and the evaporation source, etc., so as to isolate the first metal layer 20 and the second metal layer 30 during the winding process of the conductive film and prevent delamination of the conductive film.

[0059] Along the first direction, the thickness of the boron oxide layer is not less than 0.2 nm and not greater than 40 nm. Thus, while achieving the anti-sticking effect through the boron oxide layer within this thickness range, the increase in the sheet resistance of the second side of the conductive film device after the boron oxide layer is not too large, that is, the sheet resistance of the second side increases by 5% to 300% compared to the first side resistance, ensuring the conductivity of the conductive film. The thickness of the boron oxide layer may include one of 0.2 nm, 0.3 nm, 0.4 nm, 0.5 nm, 0.7 nm, 0.8 nm, 1 nm, 1.1 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.7 nm, 1.8 nm, 2 nm, 2.2 nm, 2.4 nm, 2.5 nm, 2.7 nm, 2.8 nm, 2.9 nm, 3 nm, 3.2 nm, 3.5 nm, 3.7 nm, 3.8 nm, 4 nm, 4.1 nm, 4.3 nm, 4.6 nm, 4.8 nm, 5 nm, 5.2 nm, 5.3 nm, 5.5 nm, 5.7 nm, 5.9 nm, 6 nm, 6.3 nm, 6.4 nm, 6.5 nm, 6.7 nm, 6.9 nm, 7 nm, 7.3 nm, 7.5 nm, 7.7 nm, 7.9 nm, 8 nm, 8.1 nm, 8.3 nm, 8.4 nm, 8.6 nm, 8.8 nm, 9 nm, 9.2 nm, 9.5 nm, 9.6 nm, 9.8 nm, 10 nm, 10.5 nm, 11 nm, 11.5 nm, 12 nm, 12.5 nm, 13 nm, 15 nm, 18 nm, 19 nm, 20 nm, 21 nm, 23 nm, 25 nm, 28 nm, 30 nm, 32 nm, 34 nm, 35 nm, 36 nm, 37 nm, 39 nm, 40 nm, etc.

[0060] In this embodiment, both the first metal layer 20 and the second metal layer 30 include copper layers. Copper has extremely high electrical conductivity, second only to silver. When the conductive film is used as a current collector, copper can effectively transmit and collect the current generated by the electrode material, reduce resistance, and improve the charge and discharge efficiency and overall performance of the battery. Copper has sufficient ductility and flexibility, and is easy to be processed into foil materials to meet the requirements of different battery manufacturing processes such as winding and stacking. It ensures good contact and firm combination between the current collector and the electrode active material. In addition, compared with other precious metals with similar electrical conductivity, the price of copper is more reasonable. Using a conductive film including a copper layer as a current collector in large-scale battery production can greatly reduce costs.

[0061] Among them, when both the first metal layer 20 and the second metal layer 30 include copper layers, the isolation layer 40 in this embodiment can preferably be a zinc layer or a zinc alloy layer. The zinc layer itself has a certain electrical conductivity and is not likely to increase the sheet resistance of the conductive film. Moreover, since zinc and copper can form a brass structure in a certain proportion and brass has good electrical conductivity, plating a zinc layer on the surface of the copper layer will not only not make the sheet resistance of the conductive film larger, but also enable the conductive film to obtain good electrical conductivity. Moreover, when the first metal layer 20 and the second metal layer 30 include copper layers, since the electrode potential of copper is +0.337V. If the isolation layer 40 is a tin layer (Sn) or a zinc layer (Zn), the electrode potential of Sn is -0.136V, and the electrode potential of Zn is -0.763V. The electrode potentials of tin and zinc are both less than that of copper. Since the isolation layer 40 remains in the conductive film, the copper layer will be cathodically protected by the isolation layer 40, thereby preventing the main layer of the conductive film from being oxidized and corroded, which reduces the electrical conductivity of the conductive film. Moreover, even if the isolation layer 40 is oxidized and corroded due to contact with a corrosive medium, since the material of the oxidized and corroded isolation layer 40 is different from that of the copper layer, it can still play an anti-sticking effect.

[0062] Certainly, in other embodiments of the present invention, the first metal layer 20 and the second metal layer 30 can also be aluminum layers, etc. As long as it is other deformation methods under the concept of the present invention, they are all within the protection scope of the present invention.

[0063] In this embodiment, an isolation layer with a low melting point structure can be plated on both opposite sides of the conductive film. For example, a ZnCu alloy can be plated on one side of the conductive film, and an SnCu alloy can be plated on the other side, etc.

[0064] The substrate layer 10 in this embodiment includes at least one of a polypropylene layer, a polyethylene terephthalate layer, a polyethylene layer, a polyamide layer, a polyimide layer, a polyphenylene ether layer, a polyvinyl chloride layer, an ABS plastic layer, a poly(p-phenylene terephthalamide) layer, a polyoxymethylene layer, a polytetrafluoroethylene layer, a polyvinylidene fluoride layer, a polycarbonate layer, a polyvinyl alcohol layer, a polyethylene glycol layer, and a cellulose layer. That is to say, different material combinations can be selected as the base material of the substrate layer 10 in this embodiment. Among them, the polypropylene layer has chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties, and good high-abrasion processing properties. The polyethylene terephthalate layer has excellent physical and mechanical properties in a relatively wide temperature range and excellent electrical insulation. The polyethylene layer has excellent low-temperature resistance and chemical stability. The polyamide layer has good wear resistance and strong structural strength. The polyimide layer can withstand extremely low temperatures and has excellent mechanical properties and high radiation resistance. The polyphenylene ether layer has the advantages of high heat resistance, good flame retardancy, and high strength. The polyvinyl chloride layer has good mechanical properties and excellent dielectric properties. The ABS plastic layer has good chemical corrosion resistance and heat resistance. The poly(p-phenylene terephthalamide) layer has high heat resistance and chemical corrosion resistance. The polyoxymethylene layer has high mechanical properties and excellent electrical insulation. The polytetrafluoroethylene layer has the characteristics of being acid and alkali resistant, resistant to various organic solvents, and high temperature resistant. The polyvinylidene fluoride layer has good chemical resistance, weather resistance, and ultraviolet radiation resistance. The polycarbonate layer has good mechanical properties and good impact resistance. The polyvinyl alcohol layer has high strength. The polyethylene glycol layer has good acid and alkali resistance. The cellulose layer has a strong polar effect.

[0065] Furthermore, the substrate layer 10 in this embodiment selects a polypropylene layer. The reason is that the polypropylene layer has a strong corrosion resistance. Only carbon-carbon bonds exist in its molecular chain. Except for being eroded by concentrated sulfuric acid and concentrated nitric acid, the polypropylene layer can adapt to various other chemical reagents and has relatively stable chemical properties. Especially when the conductive film in the present utility model is used as a current collector in a battery, selecting a polypropylene layer is not easily corroded by the electrolyte, thereby being able to extend the battery life.

[0066] The conductive main body layer provided in this embodiment further includes an adhesion enhancing layer 50, and the adhesion enhancing layer 50 is disposed between the conductive main body layer and the substrate layer 10. Specifically, the adhesion enhancing layer 50 is disposed between the first metal layer 20 and the substrate layer 10, and between the second metal layer 30 and the substrate layer 10. The adhesion enhancing layer 50 can improve the adhesion of the first metal layer 20 and the second metal layer 30 to the substrate layer 10, that is, enhance the interfacial bonding force F1 between the metal layer and the substrate layer 10, so that the interfacial bonding force F1 between the metal layer and the substrate layer 10 is greater than the bonding force F2 between the first metal layer 20 and the second metal layer 30, and prevent the film layer on one side of the conductive film from being pulled off by the other side. Coupled with the fact that the first metal layer 20 and the second metal layer 30 are separated by the isolation layer 40, the bonding force F2 is greatly weakened, making the adhesion between the first metal layer 20 and the second metal layer 30 during the process of unrolling the conductive film smaller, and preventing the first metal layer 20 and the second metal layer 30 from sticking to each other.

[0067] In this embodiment, the isolation layer 40 actually provides a substance between the first metal layer 20 and the second metal layer 30 to form a transition interface at the interface of the first metal layer 20 and the second metal layer 30 of the same original material. The isolation layer 40 has different interfacial characteristics from the first metal layer 20 or the second metal layer 30, and prevents the first metal layer 20 and the third metal layer 30 from directly contacting, ultimately solving the problem of mucosal adhesion.

[0068] The adhesion enhancing layer 50 in this embodiment may include any one of a copper alloy layer, a nickel alloy layer, a titanium alloy layer, an aluminum alloy layer, an aluminum oxide layer, a silicon nitride layer, a silicon carbide layer, a polyethylene glycol layer, etc.

[0069] When the conductive main body layer further includes a metal thickening layer, the metal thickening layer is disposed on the surface of at least one side of the conductive film. For example, when the conductive film is the first metal layer 20 / adhesion enhancing layer 50 / substrate layer 10 / adhesion enhancing layer 50 / second metal layer 30 / isolation layer 40, the metal thickening layer can be disposed on the surface of the first metal layer 20 and / or the isolation layer 40 to make the thickness of the conductive film finished product meet the usage requirements.

[0070] Along the first direction, at least one side of the conductive film is thickened by water electroplating. The total thickness of the conductive film on one side after thickening is between 700nm and 1600nm. The total thickness of the conductive film on one side is the total thickness of all the coatings on one side of the substrate layer 10. If one side of the substrate layer 10 has an adhesion enhancing layer 50, a first metal layer 20 and an isolation layer 40, the total thickness of the conductive film on one side is the thickness of the adhesion enhancing layer 50 + the thickness of the first metal layer 20 + the thickness of the isolation layer 40. The thickness of a single side of the conductive film may specifically include one of 700nm, 730nm, 740nm, 760nm, 780nm, 800nm, 830nm, 850nm, 870nm, 900nm, 910nm, 930nm, 950nm, 970nm, 980nm, 1000nm, 1100nm, 1150nm, 1180nm, 1200nm, 1250nm, 1300nm, 1350nm, 1400nm, 1450nm, 1500nm, 1550nm, 1580nm, 1600nm and the like.

[0071] In this embodiment, the total mass of elements in the coatings on both sides of the substrate layer 10 along the first direction is a first value, the total mass of elements in the isolation layer 40 is a second value, and the percentage between the second value and the first value is between 0.0006% and 2.5%. The percentage between the second value and the first value may specifically include: 0.0006%, 0.0008%, 0.001%, 0.003%, 0.005%, 0.007%, 0.009%, 0.01%, 0.013%, 0.015%, 0.018%, 0.02%, 0.03%, 0.05%, 0.08%, 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.21%, 0.23%, 0.25%, 0.3%, 0.4%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.1%, 2.3%, 2.4%, 2.5% and the like. The isolation layer 40 having the above-mentioned total element mass can not only effectively isolate the first metal layer 20 and the second metal layer 30, but also reduce the influence of the isolation layer 40 on the conductive properties of the conductive film, thereby avoiding the reduction of the conductivity of the conductive film due to the isolation layer 40 being too thick, or the failure to achieve the anti-sticking effect due to the isolation layer 40 being too little, thereby improving the quality of the finished conductive film.

[0072] In this embodiment, the first value and the second value detected in the conductive film can be specifically obtained by EDS, XPS or ICP. EDS is the abbreviation of Energy Dispersive Spectrometer. EDS is used to analyze the types and contents of elemental components in the microregions of materials, and is used in conjunction with scanning electron microscopes and transmission electron microscopes. The analysis results of EDS will contain data such as percentages (atomic %) and elemental ratios (i.e., mass ratios, weight %). Inductively coupled plasma (ICP) is a spectral light source used for atomic emission spectroscopy, which can detect the presence, content, and properties of elements. In this embodiment, ICP is used to detect the coatings on both sides of the substrate layer 10 including the isolation layer 40 to obtain the content of the elements in the isolation layer 40 in the overall coating. The percentage content obtained by its inspection is the mass ratio of metal elements or equivalent metal elements. For example, when the isolation layer 40 in special cases is a film layer structure such as a boron oxide layer or a cadmium oxide layer, the mass of boron element and the mass of cadmium element are equivalently measured. XPS is the abbreviation of X-ray Photoelectron Spectroscopy. XPS is a surface analysis method. In this embodiment, XPS can be used to detect the content of isolation particles on the surface of the first metal layer 20 and / or the second metal layer 30.

[0073] Specifically, in this embodiment, ICP is used to detect the first value and the second value in the conductive film, and the percentage between the second value and the first value is detected to be between 0.0006% and 2.5%. Specifically, since a metal thickening layer is usually plated on the outermost surface of the conductive film (such as plating a metal thickening layer on the surfaces of the first metal layer 20 and the second metal layer 30), the coating thickness of the conductive film can meet the usage requirements.

[0074] In an embodiment of the present invention, when the isolation layer 40 includes a zinc layer, before plating the metal thickening layer on the conductive film, the percentage between the second value and the first value is between 0.005% and 2.5%. At this time, the percentage between the second value and the first value may include one of 0.05%, 0.08%, 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.21%, 0.23%, 0.25%, 0.3%, 0.4%, 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.1%, 2.3%, 2.4%, 2.5%, etc.

[0075] After depositing a metal thickening layer on the conductive film, the percentage between the second value and the first value is between 0.0006% and 0.25%. At this time, the percentage between the second value and the first value may include one of 0.0006%, 0.0008%, 0.001%, 0.003%, 0.005%, 0.007%, 0.009%, 0.01%, 0.013%, 0.015%, 0.018%, 0.02%, 0.03%, 0.05%, 0.08%, 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.21%, 0.23%, 0.25%, etc.

[0076] Specifically, when the ICP is used to detect the first value and the second value in this embodiment, the metal elements inside are inspected. When the isolation layer 40 includes a boron oxide layer, the detected second value is the total mass of boron elements. At this time, the first value includes not only the total mass of metal elements in the first metal layer 20, the second metal layer 30, and the adhesion enhancement layer 50, but also the total mass of boron elements.

[0077] In this embodiment, when the isolation layer 40 includes a metal oxide layer, such as at least one of a lead oxide layer, an antimony oxide layer, and a cadmium oxide layer (CdO). At this time, the first value includes not only the total mass of metal elements in the first metal layer 20, the second metal layer 30, and the adhesion enhancement layer 50, but also the total mass of metal elements in the metal oxide particles (such as the total mass of cadmium elements), and the second value is specifically the total mass of metal elements in the metal oxide particles (such as the total mass of cadmium elements).

[0078] The adhesion situation or the mucosal situation on the opposite sides of the conductive film is specifically manifested as the presence or absence of light-transmitting points and the number of light-transmitting points when observing the surface of the conductive film after unwinding the wound conductive film. The method for measuring the mucosal tension of the film rolls of different conductive films in this embodiment is as follows: When the roll lengths of the film rolls of different conductive films are certain, for example, when unwinding a film roll of a conductive film with a width of 1600 mm, the film roll of the conductive film is set on the unwinding shaft, and after pulling the film horizontally, the distribution of light-transmitting points on the conductive film is observed. The so-called light-transmitting points are the light-transmitting phenomena generated at the falling-off positions after the film layer adheres, causing partial or sporadic peeling off of the first metal layer 20 and / or the second metal layer 30. That is, the fewer the light-transmitting points, the less likely the conductive film is to have a mucosal situation. To verify the anti-adhesion situation on the opposite sides of the conductive film after setting the isolation layer 40, after the mucosal tests are carried out on the conductive film without the isolation layer 40 and the conductive film with different thicknesses of the isolation layer 40, the test results of the film pulling tests on different conductive films are shown in the following table (the A side and the B side in the following table represent the opposite sides of the conductive film):

[0079]

[0080] Table 1

[0081] As can be seen from Table 1, since the isolation layer 40 is not provided in the conductive film 1, after the mucosal tensile strength of the conductive film 1 is measured, it is found that the number of light-transmitting points per unit area is as high as 857. Compared with the conductive film 1 without the isolation layer 40, the number of light-transmitting points of the conductive films 2 to 8 with the isolation layer 40 is significantly reduced. It can be seen that after the isolation layer 40 is provided on the conductive film, it is not easy for the metal layers on the opposite surfaces of the conductive film to adhere to each other, greatly reducing the situation of local or sporadic peeling of the copper layer on the surface of the base film and improving the finished product quality of the conductive film.

[0082] As can be seen from Table 1, the thickness of the isolation layer 40 provided in the conductive film 2 is 40 nm, and the thicknesses of the isolation layers 40 provided in the conductive films 3 to 8 are all less than that of the isolation layer 40 in the conductive film 2. After the mucosal tensile strength of the conductive film 2 is measured, it is found that the number of light-transmitting points per unit area is only 1, which is less than that of the conductive films 3 to 8. It can be seen that when the thickness of the isolation layer 40 is relatively thick, it is less likely for the opposite sides of the conductive film to produce a mucosal phenomenon.

[0083] As can be seen from Table 1, the thickness of the isolation layer 40 in the conductive film 4 is the smallest, only 0.2 nm. Although the number of light-transmitting points per unit area is much smaller than that of the conductive film 1, compared with the conductive films 2 to 3 and the conductive films 5 to 8, the number of light-transmitting points per unit area is relatively large. Therefore, the thicker the thickness of the isolation layer 40, the less likely it is for the opposite sides of the conductive film to produce a mucosal phenomenon.

[0084] As can be seen from Table 1, the thicknesses of the isolation layers 40 provided in the conductive films 5 and 6 are the same, but the conductive film 5 is provided with a zinc layer (Zn layer), and the conductive film 6 is provided with a boron oxide layer. It can be seen that when the conductive film is provided with a zinc layer, the anti-mucosal effect is more significant than when it is provided with a boron oxide layer on the opposite sides.

[0085] The second embodiment of the present invention provides a pole piece, which includes a current collector. The current collector includes a conductive film. For the specific structure of the conductive film, please refer to the content provided in the first embodiment of the present invention, and details will not be repeated here. Moreover, since the technical effects of the current collector have been described in detail in the first embodiment of the present invention, details will not be repeated here.

[0086] The third embodiment of the present invention provides an energy storage device, which includes but is not limited to a battery, a battery pack, etc. The energy storage device includes a pole piece. Therefore, the energy storage device includes all the technical effects of the above current collector. Since the technical effects of the current collector have been described in detail above, details will not be repeated here.

[0087] The fourth embodiment of the present utility model provides an electrical device, which includes but is not limited to a computer, an electric vehicle, etc. The electrical device includes the energy storage device provided in the third embodiment. Therefore, the electrical device includes all the technical effects of the above-mentioned energy storage device, conductive film, and electrode sheet. Since the technical effects of the energy storage device, conductive film, and electrode sheet have been described in detail above, they will not be elaborated here.

[0088] The fifth embodiment of the present utility model provides a method for preparing a conductive film. The method for preparing a conductive film is used to prepare the conductive film provided in the first embodiment of the present utility model. Please refer to Figure 2 , and the method includes the following steps:

[0089] Step S1: Use a first preparation process to prepare a first metal layer 20 and a second metal layer 30 on the first surface 11 and the second surface 12 of the substrate layer 10.

[0090] In this step S1, the first preparation process can be a thermal evaporation coating process or a vacuum magnetron sputtering coating process. The equipment for performing the thermal evaporation coating process and the equipment for the vacuum magnetron sputtering coating process are the equipment for thermal evaporation coating or vacuum magnetron sputtering on the market at present, and will not be specifically introduced in this embodiment. The substrate layer 10 is selected from at least one of a polypropylene layer, a polyethylene terephthalate layer, a polyethylene layer, a polyamide layer, a polyimide layer, a polyphenylene ether layer, a polyvinyl chloride layer, an ABS plastic layer, a poly(p-phenylene terephthalamide) layer, a polyoxymethylene layer, a polytetrafluoroethylene layer, a polyvinylidene fluoride layer, a polycarbonate layer, a polyvinyl alcohol layer, a polyethylene glycol layer, and a cellulose layer.

[0091] When actually performing step S1, first make the substrate layer 10 enter a vacuum magnetron sputtering coating equipment or a thermal evaporation coating equipment, and then after plating a first metal layer 20 and a second metal layer 30 with a certain thickness on the substrate layer 10, perform step S2. The first metal layer 20 and the second metal layer 30 in this embodiment can be copper layers or other metal layers (such as aluminum layers). Before plating the first metal layer 20 and the second metal layer 30 on the substrate layer 10, a bonding strength enhancing layer 50 can also be plated on the surface of the substrate layer 10 first, so as to improve the interfacial bonding strength between the first metal layer 20 and the second metal layer 30 and the substrate layer 10 after plating the first metal layer 20 and the second metal layer 30 on the bonding strength enhancing layer 50.

[0092] Step S2: Use a second preparation process to prepare an isolation layer 40 with a melting point lower than that of the first metal layer 20 and the second metal layer 30 on the surface of at least one of the first metal layer 20 and the second metal layer 30 away from the substrate layer 10.

[0093] In this step S2, the second preparation process can be a thermal evaporation coating process or a vacuum magnetron sputtering coating process. The equipment for performing the thermal evaporation coating process and the equipment for the vacuum magnetron sputtering coating process are the equipment for thermal evaporation coating or vacuum magnetron sputtering on the market currently, and will not be specifically introduced in this embodiment.

[0094] When actually performing step S2, first, the conductive film coated with the first metal layer 20 and the second metal layer 30 is introduced into a vacuum magnetron sputtering coating equipment or a thermal evaporation coating equipment, and then an isolation layer 40 is coated on the surface of the first metal layer 20 or the second metal layer 30.

[0095] In the above steps, in this embodiment, the first sheet resistance of the conductive film after obtaining the first metal layer 20 and the second metal layer 30 on the substrate layer 10 can also be detected, and the second sheet resistance of the conductive film after obtaining the isolation layer 40 can be detected to determine whether the second sheet resistance is increased by 3% to 300% compared with the first sheet resistance. If so, a metal thickening layer is prepared on the surface of the isolation layer 40 by using a third preparation process, so that the thickness of the conductive film finished product meets the use requirements.

[0096] When the isolation layer 40 prepared in this embodiment includes a structural layer with a melting point lower than that of the conductive main body layer, when the first preparation process is a thermal evaporation coating process, the second preparation process is also preferably a thermal evaporation coating process. Thus, the heat generated when evaporating and coating the first metal layer 20 and the second metal layer 30 by the thermal evaporation coating process can be used to heat and evaporate the target material of the isolation layer 40, so as to prepare the isolation layer 40 on the surface of the first metal layer 20 or the second metal layer 30, reduce the energy consumption and production cost in the process of preparing the conductive film, and improve the production efficiency of the conductive film.

[0097] For the sake of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations for the spatial relative descriptions used here are made.

[0098] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings. Therefore, it should not be construed as a limitation on the protection scope of this application.

[0099] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A conductive film, characterized in that: include: A substrate layer (10), wherein along a first direction, the substrate layer (10) comprises a first surface (11) and a second surface (12); A conductive main layer, the conductive main layer comprising a first metal layer (20) and a second metal layer (30), the first metal layer (20) being arranged on the first surface (11), and the second metal layer (30) being arranged on the second surface (12); an isolation layer (40), the isolation layer (40) being disposed on a surface of at least one of the first metal layer (20) and the second metal layer (30) that is away from the substrate layer (10); Wherein, the isolation layer (40) comprises a structural layer having a melting point lower than that of the conductive main layer.

2. The conductive film according to claim 1, characterized in that The isolation layer (40) comprises a structural layer having a melting point not higher than 800°C.

3. The conductive film according to claim 1, characterized in that The isolation layer (40) comprises a single metal layer, and the single metal layer comprises at least one of a zinc layer, a tin layer, a lead layer, an antimony layer, a cadmium layer, a silver layer, a magnesium layer, and a lithium layer.

4. The conductive film according to claim 1, characterized in that The isolation layer (40) further comprises at least one of a lead oxide layer, an antimony oxide layer, a cadmium oxide layer, and a boron oxide layer.

5. The conductive film according to any one of claims 1 to 4, characterized in that: Along the first direction, the thickness of the isolation layer (40) is not less than 0.2 nm and not more than 40 nm.

6. The conductive film according to any one of claims 1 to 4, characterized in that: The first metal layer (20) and the second metal layer (30) both comprise a copper layer or an aluminum layer; and / or, The substrate layer (10) comprises at least one of a polypropylene layer, a polyethylene terephthalate layer, a polyethylene layer, a polyamide layer, a polyimide layer, a polyphenylene ether layer, a polyvinyl chloride layer, an ABS plastic layer, a poly(p-phenylene terephthalamide) layer, a polyoxymethylene layer, a polytetrafluoroethylene layer, a polyvinylidene fluoride layer, a polycarbonate layer, a polyvinyl alcohol layer, a polyethylene glycol layer and a cellulose layer.

7. The conductive film according to claim 6, characterized in that The conductive body layer further comprises: An adhesion enhancing layer (50), wherein the adhesion enhancing layer (50) is disposed between the conductive main body layer and the substrate layer (10).

8. The conductive film according to any one of claims 1 to 4 and 7, characterized in that: The isolation layer also includes a structural layer having an electrode potential lower than that of the first metal layer (20) and the second metal layer (30).

9. The conductive film according to any one of claims 1 to 4 or 7, characterized in that: The conductive body layer further comprises: A metal thickening layer, the metal thickening layer is disposed on a surface of at least one side of the conductive film; And / or, along the first direction, the total thickness of a single side of the conductive film is between 700 nm and 1600 nm.

10. The conductive film according to any one of claims 1 to 4 or 7, characterized in that: The conductive film has a first square resistance before the isolation layer (40) is provided, and has a second square resistance after the isolation layer (40) is provided, and the second square resistance is increased by 3% to 300% compared with the first square resistance.

11. A pole piece, characterized in that: The pole piece includes a current collector, and the current collector includes the conductive film according to any one of claims 1 to 10.

12. An energy storage device, characterized in that: The energy storage device comprises the pole piece according to claim 11.

13. An electrical equipment, characterized in that: The electrical equipment includes the energy storage device according to claim 12.

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