Conductive film and pole piece

Abstract

The utility model discloses a kind of conductive film and pole piece, and conductive film includes substrate layer, conductive layer and heat insulation protective layer, along the thickness direction of substrate layer, substrate layer includes first surface and second surface;Conductive layer is set to at least one of first surface and second surface two;Along the thickness direction of substrate layer, heat insulation protective layer is set between conductive layer and substrate layer, and heat insulation protective layer is used to reduce the heat radiation that substrate layer is received when depositing conductive layer.The utility model solves the problem that substrate film is prone to thermal deformation in the process of plating conductive layer on the surface of macromolecular base film.

Description

Technical Field

[0001] This application relates to the field of conductive thin film production technology, and more specifically, to a conductive film and electrode. Background Technology

[0002] The conductive film obtained by depositing a conductive layer (or metal layer) on the surface of a polymer base film can be used as a current collector in lithium-ion batteries. In order to increase the deposition rate of the conductive layer on the surface of the polymer base film, the number of film deposition cycles can be reduced.

[0003] To reduce the number of coating passes, some organizations use common industry methods such as wire feeding + first evaporation boat evaporation coating or first crucible particles + electrode heating to deposit a conductive layer of approximately 1µm thickness on the surface of the base film in a single pass. However, this coating method is prone to thermal deformation of the base film during the deposition of the conductive layer. While this method results in a high deposition rate, it is also susceptible to stress mismatch, leading to a decrease in the performance of the conductive film. Utility Model Content

[0004] The main objective of this application is to provide a conductive film and electrode to solve the problem mentioned in the background art where the base film is prone to thermal deformation during the process of depositing a conductive layer on the surface of a polymer base film.

[0005] According to a first aspect of this application, a conductive film is provided, comprising:

[0006] A substrate layer, along the thickness direction of the substrate layer, includes a first surface and a second surface;

[0007] A conductive layer is disposed on at least one of the first surface and the second surface;

[0008] A heat-insulating protective layer is disposed between the conductive layer and the substrate layer along the thickness direction of the substrate layer. The heat-insulating protective layer is used to reduce the thermal radiation received by the substrate layer during the deposition of the conductive layer.

[0009] Furthermore, the heat insulation layer includes an infrared radiation resistant layer, which is a structural layer obtained by depositing infrared radiation resistant particles on the surface of the substrate layer.

[0010] Furthermore, along the thickness direction of the substrate layer, the thickness of the infrared radiation-resistant layer is not less than 30 nm and not more than 100 nm; and / or,

[0011] The infrared reflectivity of the anti-infrared radiation layer for infrared radiation with wavelengths within a predetermined range is not less than 80%, and the predetermined range is not less than 1200nm and not greater than 2500nm.

[0012] Furthermore, the infrared radiation resistant layer includes one of the following: an aluminum layer, a copper layer, a nickel layer, a chromium layer, a zinc layer, a tin layer, and a silver layer; and / or,

[0013] The conductive layer includes at least one of an aluminum layer, a copper layer, a zinc layer, a tin layer, and a silver layer.

[0014] Furthermore, the heat insulation layer includes a structural layer with the same metal material as the conductive layer; and / or,

[0015] Along the thickness direction of the substrate layer, the thickness of the conductive layer is not less than 750 nm and not greater than 1500 nm; and / or,

[0016] The conductive layer may be a single-layer structure or a multi-layer structure, and the conductive layer in a multi-layer structure may have at least two layers.

[0017] Furthermore, when the conductive layer is a multilayer structure, the thickness difference between two adjacent film layers in the conductive layer is no greater than 100 nm along the thickness direction of the substrate layer.

[0018] Furthermore, the heat insulation layer includes a first metal particle, and the conductive layer includes a second metal particle, wherein the first metal particle is a metal particle with the same metal element as the second metal particle.

[0019] Furthermore, it also includes:

[0020] A surface modification layer is disposed between the substrate layer and the thermal insulation layer along the thickness direction of the substrate layer. The surface modification layer is used to increase the bonding force between the thermal insulation layer and the substrate layer.

[0021] Furthermore, along the thickness direction of the substrate layer, the thickness of the surface modification layer is not less than 10 nm and not more than 40 nm; and / or,

[0022] The surface modification layer includes at least one of a metal compound layer and a first metal layer. The metal compound layer includes at least one of a metal oxide layer, a metal nitride layer, and a metal oxynitride layer. The first metal layer includes at least one of a titanium layer, a nickel layer, a chromium layer, a nickel-chromium alloy layer, an aluminum layer, a copper layer, and a silicon layer.

[0023] According to a second aspect of this application, an electrode is also provided, the electrode comprising the conductive film provided in the first aspect of this application.

[0024] In this application, since a heat-insulating protective layer is provided between the conductive layer and the substrate layer of the conductive film, the heat-insulating protective layer needs to be deposited on the surface of the substrate layer before the conductive layer is prepared. During the preparation of the conductive layer, the heat-insulating protective layer can reduce the heat radiation received by the substrate layer during the deposition of the conductive layer, allowing the temperature of the substrate layer to be maintained at a lower level, thereby preventing damage and deformation caused by direct exposure to excessive heat radiation. Secondly, it can also prevent interface peeling or cracking between the substrate layer and the conductive layer due to a mismatch in their coefficients of thermal expansion, improving the overall structural stability and reliability of the conductive film product. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the structure of a conductive film provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of a conductive film provided in another embodiment of the present invention;

[0028] Figure 3 A schematic flowchart illustrating a method for preparing a conductive film according to another embodiment of the present invention;

[0029] Figure 4 for Figure 3 A flowchart illustrating step S1;

[0030] Figure 5 This is a schematic diagram of the coating equipment used in one embodiment when a heat insulation protective layer is deposited based on a suspension coating method.

[0031] Figure 6 This is a schematic diagram of the coating equipment used in one embodiment when a heat insulation protective layer is coated using a roller coating method.

[0032] Figure 7 This is a schematic diagram of the coating equipment used in one embodiment when a surface modification layer is deposited using a suspension coating method.

[0033] Figure 8 This is a schematic diagram of the coating equipment used in one embodiment when a surface modification layer is deposited using a roller coating method.

[0034] Figure 9 This is a schematic diagram of the coating equipment used in one embodiment when a conductive layer is deposited using a roller coating method.

[0035] Figure 10This is a diagram showing the reflection of infrared light at various wavelengths by an aluminum layer with a thickness of 30nm in one embodiment.

[0036] Figure 11 This is a diagram showing the reflection of infrared light at various wavelengths by an aluminum layer with a thickness of 70 nm in one embodiment.

[0037] Figure 12 This is a diagram showing the reflection of infrared light at various wavelengths by an aluminum layer with a thickness of 100 nm in one embodiment.

[0038] Figure 13 A schematic diagram showing the porosity of the conductive film obtained after depositing a conductive layer directly on the surface of a substrate layer;

[0039] Figure 14 A schematic diagram showing the porosity of a conductive film obtained by depositing a thermal insulation protective layer on the surface of a substrate layer followed by a conductive layer.

[0040] Figure 15 A diagram showing the appearance of a conductive film without a heat insulation layer.

[0041] Figure 16 A diagram showing the appearance of a conductive film with a heat-insulating protective layer.

[0042] Figure 17 A surface morphology diagram of a conductive film without a heat insulation protective layer;

[0043] Figure 18 A surface morphology diagram of a conductive film with a heat-insulating protective layer;

[0044] Figure 19 This is a schematic diagram for tension detection of a conductive film;

[0045] Figure 20 This is a schematic diagram showing the deformation of a conductive film without a heat insulation layer.

[0046] Figure 21 This is a schematic diagram showing the deformation of a conductive film with a heat-insulating protective layer.

[0047] The above figures include the following reference numerals:

[0048] 10. Substrate layer; 11. First surface; 12. Second surface; 20. Conductive layer; 30. Heat insulation layer; 31. Infrared radiation resistant layer; 40. Surface modification layer; 50. Coating equipment; 51. First evaporation boat; 52. First cold roller; 53. Second cold roller; 54. Second evaporation boat; 55. Third cold roller; 56. Fourth cold roller; 57. Third evaporation boat; 58. Fifth cold roller; 60. Tension roller assembly; 70. Measuring probe. Detailed Implementation

[0049] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0050] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0051] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0052] Currently, during the deposition of the conductive layer 20 on the surface of the polymer substrate layer 10, the substrate layer 10 is prone to thermal deformation. Due to factors such as thermal deformation, the conductive film products obtained by one-time deposition are prone to stress mismatch, leading to a decline in the performance of the conductive film products. In response, the inventors of this utility model, through in-depth research, have discovered that the main reason for the above problems is that: in the direct deposition of a relatively thick conductive film layer of about 1µm on the surface of a polymer substrate with virtually no resistance to thermal shock, firstly, the polymer substrate will be directly exposed to the thermal radiation of the evaporating heat source during the deposition process, causing thermal deformation of the substrate, i.e., the direct deposition of a relatively thick conductive film layer results in thermal stress problems. Secondly, when a conductive film layer of about 1µm thickness is directly deposited on the substrate surface, the phase transition from gaseous metal to solid metal also releases a large amount of heat. Due to the poor thermal conductivity of the substrate, it is also prone to deformation, ultimately affecting the deposition effect of the conductive film layer.

[0053] To address the aforementioned problems, the first embodiment of this utility model provides a conductive film, please refer to [link to relevant documentation]. Figures 1 to 2 The conductive film includes a substrate layer 10, a conductive layer 20, and a heat-insulating protective layer 30. Along the thickness direction of the substrate layer 10 (e.g., ... Figure 1 (In the direction indicated by the middle arrow X), the substrate layer 10 includes a first surface 11 and a second surface 12. The conductive layer 20 is disposed on at least one of the first surface 11 and the second surface 12.

[0054] Along the thickness direction of the substrate layer 10, a heat-insulating protective layer 30 is disposed between the conductive layer 20 and the substrate layer 10. The heat-insulating protective layer 30 is used to reduce the heat radiation received by the substrate layer 10 during the deposition of the conductive layer 20. In other words, during the fabrication of the conductive layer 20, because the heat-insulating protective layer 30 is disposed on the surface of the substrate layer 10, the heat-insulating protective layer 30 can prevent the heat source used to fabricate the conductive layer 20 from directly baking the substrate layer 10, reducing the amount of heat radiation received by the substrate layer 10, thus keeping the substrate layer 10 at a lower temperature level and preventing thermal deformation. Figure 15 A morphological diagram of the conductive film for which the heat insulation protective layer 30 is provided is shown. Figure 15 The conductive film in the middle exhibits significant thermal deformation and cross-bubbling. For example... Figure 16 As shown, the conductive film with the heat insulation protective layer 30 is relatively... Figure 15 The others are flatter and show no obvious deformation.

[0055] As can be seen, in this embodiment, since a heat-insulating protective layer 30 is provided between the conductive layer 20 and the substrate layer 10 of the conductive film, the heat-insulating protective layer 30 needs to be deposited on the surface of the substrate layer 10 before the conductive layer 20 is prepared. Therefore, during the preparation of the conductive layer 20, the heat-insulating protective layer 30 can reduce the heat radiation received by the substrate layer 10 during the deposition of the conductive layer 20, allowing the temperature of the substrate layer 10 to be maintained at a lower level, thereby preventing damage and deformation caused by direct exposure to excessive heat radiation. Secondly, it can also prevent interface peeling or cracking between the substrate layer 10 and the conductive layer 20 due to a mismatch in their coefficients of thermal expansion, improving the overall stability and reliability of the conductive film product.

[0056] The thermal insulation layer 30 in this embodiment may include a thermal conductivity barrier layer, which is a structural layer obtained by depositing particles with a thermal conductivity lower than a predetermined value on the surface of the substrate layer 10. Thermal conductivity, also known as the thermal conductivity coefficient, represents the amount of heat that a unit area of ​​material can conduct per unit time under a unit temperature difference. The unit is typically watts per meter (W / m·K). A thermal conductivity lower than a predetermined value, such as a thermal conductivity coefficient lower than 70 W / m·K, effectively reduces the heat radiation from the heat source conducted to the substrate layer 10, thus preventing heat transfer and thermal deformation of the substrate layer 10 due to overheating. Specifically, the thermal conductivity barrier layer may include at least one of the following: a lead layer (thermal conductivity approximately 35 W / m·K), a titanium layer (thermal conductivity 21.9 W / m·K), an iron-nickel alloy layer (thermal conductivity 11 W / m·K), a silicon oxide layer (1.4 W / m·K), a silicon nitride layer (28 W / m·K), or boron nitride (2 W / m·K). The lead layer not only has low thermal conductivity but also good corrosion resistance. It provides radiation shielding and heat insulation for the substrate layer 10 to prevent thermal deformation of the substrate layer 10, while also improving the structural stability of the conductive film product.

[0057] In this embodiment, the heat insulation layer 30 includes an infrared radiation resistant layer 31, which is a structural layer obtained by depositing infrared radiation resistant particles on the surface of the substrate layer 10. Infrared radiation is the primary way that conductive films and heat sources transfer heat to the substrate layer 10, especially in the high-temperature environment of evaporative coating.

[0058] Therefore, this embodiment first applies an infrared radiation-resistant layer 31 to the surface of the substrate layer 10 to reflect or absorb most of the infrared thermal radiation, directly reducing the heat transferred to the substrate layer 10 from the source of heat generation, thereby significantly reducing the temperature rise of the substrate layer 10 and further reducing the risk of thermal deformation. Simultaneously, the infrared radiation-resistant layer 31 also forms a thermal insulation barrier on the surface of the substrate layer 10, reducing heat transfer into the substrate layer 10, making the temperature distribution of the substrate layer 10 more uniform, reducing thermal stress caused by excessive temperature gradients, and thus reducing thermal deformation. Secondly, the infrared radiation-resistant layer 31 typically has good high-temperature stability, maintaining its structural and performance stability in high-temperature environments and continuously providing thermal insulation. Furthermore, because the infrared radiation-resistant layer 31 can effectively reflect or absorb infrared radiation, it reduces the direct effect of heat on the substrate layer 10, thereby reducing the thermal load on the substrate layer 10, delaying aging and performance degradation, further reducing the possibility of thermal deformation, and improving the service life and reliability of the substrate layer 10, making it particularly suitable for high-temperature or strong infrared radiation environments.

[0059] While existing technologies also seek to improve the deformation problem of the substrate layer 10 by enhancing the adhesion between the polymer substrate layer 10 and the cooling roller, such as through ceramic electrostatic adsorption, there are still many issues to be resolved in terms of cost and performance. This invention, by adding an infrared radiation-resistant layer 31 with heat radiation resistance to the substrate layer 10, gives the substrate layer 10 stronger resistance to deformation. Even if the substrate layer 10 experiences poor contact with the roller at a certain moment during the coating process, the infrared radiation-resistant layer 31 reflects a large amount of infrared heat radiation, reducing the temperature of the film itself, thereby improving its thermal deformation resistance and improving the appearance quality of the final product.

[0060] In this embodiment, the thickness of the thermal insulation layer 30 is less than the thickness of the conductive layer 20 along the thickness direction of the substrate layer 10. As a result, the thermal insulation layer 30 deposited on the substrate layer 10 has better density. During the process of depositing the conductive layer 20 on the surface of the thermal insulation layer 30 with better density, more crystal nucleus growth sites will be generated during the deposition process of the conductive layer 20, so that the finally deposited conductive layer 20 can have higher density. The higher the density, the better its electrical performance, and the more firmly the conductive layer 20 and the substrate layer 10 are bonded.

[0061] Along the thickness direction of the substrate layer 10, the thickness of the infrared radiation-resistant layer 31 is not less than 30 nm and not more than 100 nm. When the thickness of the infrared radiation-resistant layer 31 is within the above range, it can be ensured that the infrared radiation-resistant layer 31 can reflect most of the infrared thermal radiation. Moreover, since the infrared radiation-resistant layer 31 within the thickness range can be formed by a single thermal evaporation process, not only is the production efficiency high, but the substrate layer 10 is also subjected to less baking during the deposition of the infrared radiation-resistant layer 31 on the surface of the substrate layer 10, further reducing the risk of the substrate layer 10 being deformed by baking during this period. At the same time, when the infrared radiation-resistant layer 31 is within the above thickness range, more crystal nucleus growth sites can be generated during the deposition of the conductive layer 20, so that the finally deposited conductive layer 20 can have higher density. The higher the density, the better its electrical performance, and the stronger the bond between the conductive layer 20 and the substrate layer 10.

[0062] The thickness of the infrared radiation-resistant layer 31 may specifically include one of the following: 30nm, 33nm, 35nm, 37nm, 40nm, 41nm, 42nm, 45nm, 46nm, 48nm, 49nm, 50nm, 51nm, 53nm, 54nm, 57nm, 58nm, 60nm, 62nm, 64nm, 65nm, 68nm, 69nm, 70nm, 72nm, 74nm, 76nm, 78nm, 80nm, 81nm, 83nm, 85nm, 87nm, 89nm, 90nm, 91nm, 93nm, 95nm, 97nm, 99nm, and 100nm, or any other thickness value between 30nm and 100nm.

[0063] In this embodiment, the infrared reflectivity of the anti-infrared radiation layer 31 for infrared rays with wavelengths within a predetermined range is not less than 70%, and the predetermined range is not less than 1200 nm and not greater than 2500 nm. The infrared rays generated by the evaporation source (such as the evaporation boat or crucible used in the thermal evaporation process for depositing the conductive layer 20) during the deposition of the conductive layer 20 are essentially within the aforementioned predetermined range. Therefore, the infrared rays generated during the preparation of the conductive layer 20 are accurately reflected by the anti-infrared radiation layer 31, resulting in more precise and effective protection of the substrate layer 10.

[0064] In this embodiment, the reflectivity of the anti-infrared radiation layer 31 includes one of the following: 70%, 73%, 75%, 77.5%, 80%, 81%, 82%, 82.6%, 84%, 85%, 86%, 88%, 90%, 90.5%, 91%, 92%, 93%, 95%, 97%, 98%, 99%, 99.8%, or any other percentage value not less than 80%. During the fabrication of the conductive layer 20, the wavelength of the infrared radiation emitted by the thermal radiation may specifically include 1200nm, 1250nm, 1260nm, 1275nm, 1280nm, 1298nm, 1300nm, 1320nm, 1350nm, 1380nm, 1400nm, 1430nm, 1450nm, 1470nm, 1500nm, 1520nm, 1540nm, 1570nm, 1590nm, 1600nm, 1620nm, 16 One of the following: 40nm, 1670nm, 1700nm, 1710nm, 1730nm, 1780nm, 1800nm, 1840nm, 1870nm, 1900nm, 1940nm, 1980nm, 1994nm, 2000nm, 2010nm, 2050nm, 2100nm, 2140nm, 2200nm, 2300nm, 2500nm, or any other value between 1200nm and 2500nm.

[0065] At the same time, such as Figure 13 As shown, if a large number of metal atoms are deposited directly on the surface of the substrate layer 10 or the surface of the surface modification layer 40 to form the conductive layer 20 within a unit time, the density of the large number of crystal nuclei formed by the metal atoms constituting the conductive layer 20 is low. Therefore, the growth of the conductive layer 20 near the surface of the substrate layer 10 or the surface of the surface modification layer 40 is prone to problems such as insufficient density and many pores, which can also lead to a significant impact on the electrical performance of the conductive layer 20.

[0066] To further improve the electrical performance of the conductive layer 20, in this embodiment, the heat insulation layer 30 is preferably a structural layer with the same metal material as the conductive layer 20. For example, if the conductive layer 20 is an aluminum layer, the heat insulation layer 30 is preferably an aluminum layer. Therefore, in this embodiment, during the deposition of the conductive layer 20 on the heat insulation layer 30 (e.g., an aluminum layer) with the same metal material as the conductive layer 20, the atoms forming the conductive layer 20 (e.g., aluminum atoms) easily form high-density crystal nuclei on the homogeneous surface of the heat insulation layer 30. Figure 14 As shown, the competitive growth of high-density polycrystalline nuclei can reduce the number of pores, thereby enhancing the density of the conductive layer 20 and reducing the impact of the number of pores on the electrical properties of the conductive film. Figure 13 and Figure 14 This shows the number of pores within the same size range observed under a scanning electron microscope at 30,000x magnification for different conductive films.

[0067] In this embodiment, the infrared radiation resistant layer 31 includes one of an aluminum layer, a copper layer, a nickel layer, a chromium layer, a zinc layer, a tin layer, and a silver layer. Preferably, the infrared radiation resistant layer 31 in this embodiment is an aluminum layer, which is inexpensive and possesses not only good infrared radiation resistance but also a suitable thermal conductivity (237 W / m·K). Before preparing the conductive layer 20, aluminum layers can be prepared on both the first surface 11 and the second surface 12 of the substrate layer 10. Therefore, the step of depositing the conductive layer 20 on the surface of the aluminum layer away from the substrate layer 10 using a thermal evaporation process in this embodiment specifically includes: based on a roll-to-roll coating method, when the substrate layer 10 is unwound above the third evaporation boat 57 and the surface of the substrate layer 10 facing away from the third evaporation boat 57 is attached to the surface of the fifth cold roller, the filament is thermally evaporated by the third evaporation boat 57 (or the molten metal can be continuously supplied to the third evaporation boat 57 for thermal evaporation to obtain the conductive layer 20), so that the generated evaporation particles are deposited on the surface of the aluminum layer to form the conductive layer 20. During this process, since the substrate layer 10 is attached to the surface of the fifth cold roller, the aluminum layer can better conduct the heat released when the evaporating particles change from a gaseous phase to a solid phase to the fifth cold roller, thereby further preventing the substrate layer 10 from thermal deformation due to the heat generated when the conductive layer 20 is deposited.

[0068] like Figures 10 to 12 As shown, when the infrared radiation resistant layer 31 includes an aluminum layer, Figure 10 The reflection of infrared light at various wavelengths by an aluminum layer with a thickness of 30 nm is shown. Figure 11 The reflection of infrared light at various wavelengths by an aluminum layer with a thickness of 70 nm is shown. Figure 12 The reflection of infrared light at various wavelengths by an aluminum layer with a thickness of 100 nm is shown. From Figures 10 to 12 It is evident that the aluminum layer of the aforementioned thickness has an infrared reflectivity of over 80%, meeting the infrared resistance requirements when the conductive layer 20 is plated, and ensuring the structural stability of the substrate layer 10.

[0069] When the infrared radiation resistant layer 31 includes a zinc layer, if the thickness of the zinc layer is 100 nm, the near-infrared (NIR) reflectivity of the zinc layer reaches 70%, and the mid-infrared (MIR) reflectivity is 85%. Please refer to Table 1, which also lists the infrared radiation resistance (i.e., reflectivity) of several other types of infrared radiation resistant layers 31 with corresponding thicknesses.

[0070]

[0071] Table 1

[0072] The conductive layer 20 in this embodiment includes at least one of an aluminum layer, a copper layer, a zinc layer, a tin layer, and a silver layer. The preferred material for the conductive layer 20 is an aluminum layer or a copper layer, so that the conductive film product can meet the production and usage requirements of most battery products.

[0073] Along the thickness direction of the substrate layer 10, the thickness of the conductive layer 20 is not less than 750 nm and not more than 1500 nm. The conductive layer 20 within this thickness range can be deposited in a single step using a thermal evaporation process, ensuring that the conductive film possesses the required conductivity while also improving the production efficiency of the conductive film. Moreover, since fewer deposition steps are required for the conductive layer 20 within this thickness range (e.g., one deposition, two depositions, three depositions), the impact of heat generated by the evaporation source on the substrate layer 10 is further reduced. The thickness of the conductive layer 20 may specifically include one of 750 nm, 760 nm, 780 nm, 800 nm, 840 nm, 870 nm, 890 nm, 900 nm, 950 nm, 970 nm, 1000 nm, 1100 nm, 1200 nm, and 1500 nm, or any other thickness value between 750 nm and 1500 nm.

[0074] The conductive layer 20 in this embodiment includes a single-layer structure or a multi-layer structure. The multi-layer conductive layer 20 has at least two layers. When the conductive layer 20 is a single-layer structure, it means that in this embodiment, it can be deposited in a single step on the heat insulation layer 30 using a thermal evaporation process. When the conductive layer 20 is a multi-layer structure, such as a two-layer or three-layer structure (not more than four layers, thus avoiding reduced production efficiency due to excessive deposition steps), since the total thickness of the conductive layer 20 is fixed (i.e., not less than 750 nm and not more than 1500 nm), the thickness of each single-layer structure in the conductive layer 20 will be smaller. Depositing smaller thickness layers each time to ultimately obtain the required thickness of the conductive layer 20 improves the density of the conductive film.

[0075] In this embodiment, when the conductive film is cross-sectionally cut and polished and then tested and observed using a scanning electron microscope, the total number of coating layers observable on one side of the substrate layer 10 is no less than two. For example, if the anti-infrared radiation layer 31 is a single layer and the conductive layer 20 is a multi-layer structure, a first interface (the boundary between the anti-infrared radiation layer 31 and the conductive layer 20) can be observed within any thickness of not less than 40 nm and not more than 100 nm from the surface of the substrate layer 10. Then, one or two second interfaces can be observed within any thickness of not less than 750 nm and not more than 1500 nm from the anti-infrared radiation layer 31. That is, the second interface is the boundary between different film layers in the conductive layer 20. For example, if the conductive layer 20 has two film layers, there is one second interface; if the conductive layer 20 has three film layers, there are two second interfaces. When the conductive layer 20 has a single-layer structure, the number of second interfaces is zero. In other words, the conductive layer 20 with a thickness of not less than 750 nm and not more than 1500 nm can be a thin film deposition under the same spatial and temporal conditions in terms of physical morphology, or it can be formed by separate two or three depositions.

[0076] When the conductive layer 20 has a multilayer structure, the thickness difference between two adjacent layers in the conductive layer 20 along the thickness direction of the substrate layer 10 is no greater than 100 nm. In other words, in this embodiment, when the conductive layer 20 is obtained by at least two depositions using a thermal evaporation process, the thickness difference between the next deposited layer and the previous deposited layer is kept to no more than 100 nm. This reduces the thickness difference between different layers in the conductive layer 20, preventing current concentration or excessively high local resistance due to thickness differences. It also allows the conductive layer 20 to provide a more stable electron transport path, reducing electron scattering and thus lowering the overall resistivity. Furthermore, it helps reduce grain boundaries and void defects, increasing the density of the conductive layer 20, thereby improving carrier mobility and conductivity. When the thickness difference is within the aforementioned range, the interfaces between different layers are smoother, and the bonding force between layers is stronger, preventing defects such as interlayer peeling and cracks, and improving the mechanical strength and durability of the conductive layer 20.

[0077] The thickness difference between two adjacent film layers in the conductive layer 20 may include one of 100nm, 98nm, 95nm, 90nm, 87nm, 86nm, 83nm, 80nm, 79nm, 75nm, 71nm, 68nm, 65nm, 60nm, and 50nm, or any other value not greater than 100nm. This embodiment does not impose a unique limitation on this.

[0078] In this embodiment, the heat-insulating protective layer 30 includes first metal particles, and the conductive layer 20 includes second metal particles. The first metal particles are metal particles with the same metal element as the second metal particles. This allows for a better lattice matching between the conductive layer 20 and the heat-insulating protective layer 30, reducing lattice mismatch and loss at their interface, and facilitating the formation of a smooth, continuous interface, thus promoting the uniform and dense growth of the conductive layer 20. It also strengthens the bond between the heat-insulating protective layer 30 and the conductive layer 20, reducing the risk of delamination.

[0079] like Figure 2 As shown, the conductive film provided in this embodiment also includes a surface modification layer 40. Along the thickness direction of the substrate layer 10, the surface modification layer 40 is disposed between the substrate layer 10 and the heat insulation layer 30. The surface modification layer 40 is used to increase the adhesion between the heat insulation layer 30 and the substrate layer 10. Thus, by using the surface modification layer 40, the adhesion between the heat insulation layer 30 and the substrate layer 10 is increased, allowing the heat insulation layer 30 to adhere better to the substrate layer 10, preventing peeling of the heat insulation layer 30, and thereby providing stability and reliability to the overall structure of the conductive film.

[0080] Along the thickness direction of the substrate layer 10, the thickness of the surface modification layer 40 is not less than 10 nm and not more than 40 nm. When the thickness of the surface modification layer 40 is within this range, the bonding force between the heat insulation layer 30 and the substrate layer 10 will not be too weak due to the thickness being too small, nor will the substrate layer 10 be subjected to a large thermal impact during the deposition of the surface modification layer 40 due to the thickness being too large. That is, the substrate layer 10 is subjected to less baking during the deposition of the surface modification layer 40, and the substrate layer 10 is not prone to thermal deformation.

[0081] The thickness of the surface modification layer 40 includes one of the following: 10nm, 11nm, 13nm, 15nm, 16nm, 18nm, 20nm, 21nm, 24nm, 27nm, 28nm, 30nm, 32nm, 34nm, 35nm, 37nm, 9nm, and 40nm, or any other thickness value between 10nm and 40nm.

[0082] In this embodiment, the surface modification layer 40 includes at least one of a metal compound layer and a first metal layer. The metal compound layer includes at least one of a metal oxide layer, a metal nitride layer, and a metal oxide nitride layer, such as TiOx, TiNx, CrOxNy, SiOxNy, TiOxNy, etc. (where x and y are stoichiometric coefficients). The target material is a metal or semiconductor material, which is sputtered and deposited in an atmosphere containing oxygen and nitrogen. The sputtering deposition method can be magnetron sputtering. Another metal oxide material, specifically aluminum oxide, is formed by the combination of metal evaporation with oxygen in an oxygen atmosphere, making deposition convenient and efficient. The first metal layer includes at least one of a titanium layer, a nickel layer, a chromium layer, a nickel-chromium alloy layer, an aluminum layer, a copper layer, and a silicon layer. The metal oxide layer may include at least one of a titanium oxide layer, a chromium oxide layer, an aluminum oxide layer, a copper oxide layer, and a silicon oxide layer. The metal nitride layer may include at least one of a titanium nitride layer, a chromium nitride layer, an aluminum nitride layer, a copper nitride layer, and a silicon nitride layer.

[0083] As can be seen from the above, the heat-insulating protective layer 30 provided on the surface of the substrate layer 10 in this embodiment can block heat radiation, thereby reducing the amount of heat radiation received by the substrate layer 10, keeping the substrate layer 10 at a lower temperature level, and preventing thermal deformation of the substrate layer 10. Secondly, the heat-insulating protective layer 30 can also promote the formation of more crystal nucleus growth sites during the deposition of the conductive layer 20, resulting in a more compact conductive layer 20 and thus better electrical performance of the conductive film product.

[0084] When the heat insulation protective layer 30 includes an infrared radiation resistant layer 31, since the infrared radiation resistant layer 31 has an infrared reflection function, during the preparation process of depositing the conductive layer 20 on the infrared radiation resistant layer 31, it can directly reflect infrared thermal radiation, thereby avoiding the substrate layer 10 from being baked or deformed by infrared thermal radiation, and avoiding the problem of insufficient adhesion between the conductive layer 20 and the substrate layer 10 caused by the thermal stress of the conductive layer 20.

[0085] The thickness of the infrared radiation-resistant layer 31 is not less than 30 nm and not more than 100 nm. This thickness of the infrared radiation-resistant layer 31 can have good infrared reflection capability in the corresponding infrared thermal radiation blackbody radiation temperature range. Its reflectivity of infrared thermal radiation in the wavelength range of not less than 1200 nm and not more than 2500 nm is more than 70%, thereby accurately reflecting the thermal radiation generated during the preparation of the conductive layer 20, and providing better, more precise and effective protection for the substrate layer 10.

[0086] The conductive film with the heat-insulating protective layer 30 obtained in this embodiment is designated as Product 1, and the conductive film without the heat-insulating protective layer 30 is designated as Comparative Example 1. When the thickness and structure of the conductive layer 20 are the same in Product 1 and Comparative Example 1, the conductivity of Product 1 is ≥20% higher than that of Comparative Example 1. That is, Product 1 has lower resistance, resulting in less resistance and lower resistance during electron transport in the conductive film. This allows the conductive film of Product 1 to effectively conduct current and reduce energy loss. The conductive film of Product 1 also has a stronger current-carrying capacity and is less prone to overheating or damage due to excessive current.

[0087] Secondly, the rate of change in tensile resistance of Product 1 improved by 50% (i.e., a 5% stretching deformation of the conductive film in Comparative Example 1 resulted in a 3.5% increase in average surface resistance, while a 5% stretching deformation of the conductive film in Product 1 resulted in a 1.3% increase in its average surface resistance). In this embodiment, both Product 1 and Comparative Example 1 were tested using an optical microscope under the same conditions (500x magnification). The results showed that... Figure 17 As shown, the surface irregularities of the conductive film in Comparative Example 1 ( Figure 17 The black dots (i.e., bumps and depressions) are obvious defects. Even conductive films using positive circumferential evaporation coating and with only a heat insulation protective layer 30 have many bump and depression defects on their surface. For example... Figure 18 As shown, the surface of the conductive film of Product 1 shows almost no black bumps. The more bumps there are, the more likely the film will break during the rolling process in cell production, thus affecting the yield. Clearly, Product 1 obtained in this embodiment does not have this problem, and the conductive film quality is better.

[0088] To better verify the product quality of the conductive film obtained in this embodiment, this embodiment compares conductive film products with heat insulation protective layers 30 of different thicknesses (such as the products shown in Examples 1 to 8 in Tables 2 and 3 below) with conductive films without heat insulation protective layers 30 in Comparative Examples 1, 2, and 3. The specific comparison results are shown in Tables 2 and 3 below:

[0089]

[0090] Table 2

[0091] Regarding the data on surface deformation quality, resistivity, and bump defects in Table 2: First, the absolute values ​​of the surface deformation quality, resistivity, and bump defects of Comparative Example 1 are all considered as 100%. The relative percentage values ​​of the absolute values ​​of Comparative Examples 2, 3, and Examples 1 to 8 are obtained by comparing them with the absolute value of Comparative Example 1. The smaller the percentage value of the above parameters such as surface deformation quality, resistivity, and bump defects relative to Comparative Example 1, the better the performance.

[0092] As shown in Table 2, Comparative Example 1 and Comparative Example 2 are similar in that neither has a heat insulation protective layer 30. The difference is that Comparative Example 2 also has a surface modification layer 40 on the surface of the substrate layer. Comparative Example 3 differs from Comparative Examples 1 and 2 in that Comparative Examples 1 and 2 use a wire feeding + evaporation boat mode for coating, while Comparative Example 3 uses a crucible thermal evaporation method for coating. It is normal for different coating methods, equipment power, and equipment types to have certain differences in coating speed. The above represents the approximate range of the process.

[0093] The difference between Examples 1 to 8 and Comparative Examples 1 and 2 lies in the inclusion of a heat-insulating protective layer 30. Example 1 does not include a surface modification layer 40, while Examples 2 to 8 do. Surface deformation quality reflects the wrinkling and deformation of the conductive film's appearance (e.g., ...). Figure 15 and Figure 16 (As shown in Table 2). Therefore, it can be seen from Table 2 that the conductive film products in the three comparative examples without the heat insulation protective layer 30 have higher surface deformation quality parameters, with visible wrinkles and more pronounced bump defects. For example... Figure 17 As shown. In Examples 1 to 8, the surface deformation quality parameters (i.e., percentage values) are smaller, the surface is smoother, and the defects such as bumps and depressions are less noticeable, resulting in a smoother surface. Figure 18 As shown.

[0094]

[0095] Table 3

[0096] Explanation of the performance parameters and significance of interface density (porosity) and tensile strength: Interface density (porosity) refers to the porosity observable within the same interface length range at the interface between the polymer substrate layer 10 and the conductive layer 20 under a scanning electron microscope at 30,000x magnification. A smaller percentage value for the ratio of other comparative examples and embodiments to Comparative Example 1 indicates a more significant improvement. Tensile resilience expresses the rate of change in sheet resistance of the conductive film before and after being stretched by 5%, usually expressed as a percentage. A larger percentage indicates poorer performance in this aspect. Tensile strength is the tensile resistance of the surface conductive film; a higher absolute strength indicates better performance. For tensile strength, a larger percentage ratio of Comparative Examples 2 and 3, and Examples 1 to 8 relative to Comparative Example 1 indicates better performance. For interface density, a smaller percentage ratio of Comparative Examples 2 and 3, and Examples 1 to 8 relative to Comparative Example 1 indicates better performance.

[0097] The performance results in Tables 2 and 3 represent only relative trends (or average relative trends) under each condition. Due to the unique characteristics of the composite current collector of the polymer substrate layer 10 and its manufacturing process environment, it is entirely possible that the performance of a certain local area in Comparative Example 1 may achieve the same effect as the embodiment. However, in terms of the overall quality trend, the embodiment is still superior. In comparison, adding a heat insulation layer 30 using crucible thermal evaporation can achieve better results. Similarly, for the wire feeding + evaporation boat evaporation coating method, we can infer that adding a heat insulation layer 30 can also improve the effect.

[0098] As can be seen from Table 3, Comparative Examples 1 and 2 have poor density, while Examples 1 to 8 have better density. Furthermore, Examples 1 to 8 have higher tensile strength, better ductility, and better tensile resistance to deformation, making them less prone to breakage or deformation, and exhibiting better structural stability and reliability of the conductive film.

[0099] The absolute values ​​of the surface deformation quality parameter in Table 2 were obtained using tension testing. Figure 19 As shown, the tension detection system mainly consists of three parts: 1) tension roller assembly 60, 2) measuring probe 70, and 3) the conductive film being measured. The tension roller assembly 60 is a system composed of a series of rollers, the main purpose of which is to provide a certain tension to the conductive film. At the same time, the tension roller assembly 60 can support the width direction of the conductive film to be on the same parallel line as the horizontal movement direction of the measuring probe 70 located above and below the conductive film.

[0100] Figure 19 The length direction (indicated by arrow Y) and width direction (indicated by arrow Z) of the conductive film are also marked. The tension on the conductive film originates from the stretching of its length by the tension roller assembly 60. When the conductive film is subjected to a certain tension, it is straightened or flattened. Then, the upper and lower measuring probes 70 move along the width direction of the conductive film. The function of the measuring probes 70 is to measure the relative distance between a certain positioning position of the conductive film and a certain reference height. Thus, by measuring a series of position, film displacement height, and other data, a schematic diagram of the horizontal condition of the conductive film can be drawn (i.e., a schematic diagram of the tension test report, such as...). Figure 20 and Figure 21 As shown in the figure, this serves as a criterion for judging the deformation quality of the conductive film surface.

[0101] like Figure 20 As shown (this figure corresponds to the conductive film in Comparative Example 1 or Comparative Example 2), the height difference between the top and bottom of the conductive film is ~10mm (highest value - lowest value). Figure 20 The edge on the left side is more severely deformed. Due to the overall deformation, there is another noticeable deformation at around 140mm.

[0102] like Figure 21 As shown, the height difference between the upper and lower parts of the conductive film is ~0.55mm (highest value - lowest value), which can be regarded as a quantification of the surface deformation quality. Figure 20 The diagram shows the deformation of the conductive film corresponding to any of the improved embodiments 1 to 8.

[0103] In conclusion, along the thickness direction of the substrate layer 10, one side of the conductive film product obtained in this embodiment can have the following structure: a surface-modified layer of 10 / 20nm polymer substrate layer, a heat-insulating protective layer of 40 / 70nm, and a conductive layer 20 of 30 / 930nm. Alternatively, it can be: a surface-modified layer of 10 / 20nm polymer substrate layer, a heat-insulating protective layer of 40 / 70nm, a conductive layer 20 of 30 / 450nm, and a conductive layer 20 of 480nm. The conductive film product with the above structure has a smooth and flat surface and a highly dense internal structure.

[0104] The second embodiment of this utility model also provides a method for preparing a conductive film. This method is used to prepare the conductive film provided in the first embodiment of this utility model. For the specific structure of the conductive film, please refer to the content provided in the first embodiment. This embodiment will not repeat the details here.

[0105] like Figure 3 As shown, the method for preparing the conductive film provided in this embodiment includes the following steps:

[0106] Step S1: During the process of controlling the substrate layer 10 to travel at the first film-moving speed, a heat insulation protective layer 30 is deposited on the surface of the substrate layer 10 using a thermal evaporation process. The first film-moving speed is not less than 150m / min and not more than 500m / min.

[0107] Overall, the wire feeding + evaporation boat coating method can be preferentially used to quickly deposit the heat insulation protective layer 30. Based on the fact that traditional equipment systems can generally deposit a film thickness of about 60 nm at a speed of 300 m / min, the coating speed is set at 150 m / min and 500 m / min in combination with the expected thickness of the heat insulation protective layer 30 of this utility model. Such a high speed is relatively less affected by the heat baking effect on the substrate layer 10 compared with the coating speed of 20 m / min or 30 m / min for conductive film layers. In addition, the amount of latent heat of phase change released by the deposited metal film layer is also very small. Therefore, the above-mentioned coating speed setting can avoid the negative impact of heat baking while taking into account the needs of the film layer.

[0108] In this embodiment, a thermal insulation protective layer 30 of the required thickness can be deposited on the surface of the substrate layer 10 in a single step using a thermal evaporation process at a first film-laying speed. Therefore, during the deposition of the thermal insulation protective layer 30 onto the substrate layer 10, the baking of the substrate layer 10 is reduced, minimizing the negative impact of deformation caused by baking and ensuring the structural stability of the substrate layer 10 before the conductive layer 20 is deposited. The first film-laying speed may include one of the following: 150 m / min, 160 m / min, 170 m / min, 190 m / min, 200 m / min, 230 m / min, 250 m / min, 280 m / min, 300 m / min, 310 m / min, 350 m / min, 400 m / min, 420 m / min, 450 m / min, 470 m / min, 500 m / min, or any other speed value between 150 m / min and 500 m / min.

[0109] Preferably, the first film-laying speed is 350 m / min or 200 m / min, meaning that during the deposition of the heat-insulating protective layer 30, the film-laying speed of the substrate layer 10 reaches several hundred meters per minute, further ensuring that the substrate layer 10 is subjected to less baking. At the same time, since the portion of the heat-insulating protective layer 30 already deposited on the substrate layer 10 can immediately exert its heat-insulating effect during the deposition process, the risk of thermal deformation of the substrate layer 10 is reduced.

[0110] Step S2: A conductive layer 20 is deposited on the surface of the heat-insulating protective layer 30 away from the substrate layer 10 using the first preparation process. During step S2, the heat-insulating protective layer 30 reduces the heat radiation received by the substrate layer 10 during the deposition of the conductive layer 20, allowing the temperature of the substrate layer 10 to be maintained at a lower level, thereby preventing damage and deformation caused by direct exposure to excessive heat radiation. Furthermore, it also prevents interface peeling or cracking between the substrate layer 10 and the conductive layer 20 due to a mismatch in their coefficients of thermal expansion, improving the overall stability and reliability of the conductive film product.

[0111] like Figure 4 and Figure 5 As shown, step S1, which involves depositing a heat-insulating protective layer 30 on the surface of the substrate layer 10 using a thermal evaporation process, includes:

[0112] Step S11: Based on the suspension coating method, when the substrate layer 10 is unwound above the first evaporation boat 51 and the portion of the substrate layer 10 relative to the first evaporation boat 51 is suspended, the filament material conveyed by the first evaporation boat 51 is thermally evaporated, so that the generated evaporation particles are deposited on the surface of the substrate layer 10 near the first evaporation boat 51 to form a heat insulation protective layer 30. Wherein, when the heat insulation protective layer 30 includes an infrared radiation resistant layer 31, the filament material conveyed to the first evaporation boat 51 is an infrared radiation resistant filament material (such as one of aluminum wire, copper wire, zinc wire, tin wire, or silver wire).

[0113] Step S12: The portion of the substrate layer 10 that has left the first evaporation boat 51 is moved to the first cooling roller 52 and attached to the surface of the first cooling roller 52 for cooling. The first cooling roller 52 is along the traveling direction of the substrate layer 10 (e.g., ...). Figure 5 (The direction indicated by the middle arrow Y) is a cold roller disposed on the front side of the first evaporation boat 51. That is to say, in this embodiment, after the heat insulation protective layer 30 is obtained by vapor deposition on the surface of the substrate layer 10, the substrate layer 10 can be cooled and dissipated by the first cold roller 52, thereby reducing the temperature of the substrate layer 10 to a lower level. When the subsequent conductive layer 20 is deposited, the substrate layer 10 will be less likely to generate a high temperature rise and cause thermal deformation.

[0114] like Figure 6 As shown, in step S1, the step of depositing the heat-insulating protective layer 30 on the surface of the substrate layer 10 using a thermal evaporation process further includes:

[0115] Based on the roller coating method, when the substrate layer 10 is unwound above the first evaporation boat 51 and the surface of the substrate layer 10 facing away from the first evaporation boat 51 is attached to the surface of the second cold roller 53, the filament material conveyed by the first evaporation boat 51 is thermally evaporated so that the generated evaporation particles are deposited on the surface of the substrate layer 10 close to the first evaporation boat 51 to form a heat insulation protective layer 30.

[0116] Therefore, in this embodiment, during the deposition of the heat insulation protective layer 30 on the surface of the substrate layer 10, the substrate layer 10 can be cooled and dissipated in real time by the second cold roller 53, thereby further ensuring that the substrate layer 10 will not undergo thermal deformation during the deposition of the heat insulation protective layer 30.

[0117] Of course, this embodiment can also be based on the roll coating method, where the substrate layer 10 is unrolled above the first crucible so that the first crucible thermally evaporates the metal particles required to form the heat insulation protective layer 30, and the evaporated particles generated by thermal evaporation are deposited on the surface of the substrate layer 10 to form the heat insulation protective layer 30.

[0118] Meanwhile, the heat insulation protective layer 30 includes an infrared radiation resistant layer 31, and the infrared radiation resistant layer 31 includes a second metal layer with a thermal conductivity of not less than 80 W / m·K. The second metal layer can preferably be one or more of magnesium, aluminum, and copper layers. Since the second metal layer has already been deposited on the surface of the substrate layer 10 away from the first evaporation boat 51, when the infrared radiation resistant layer 31 is obtained by thermally evaporating the filament through the second evaporation boat 54 and depositing it on the surface of the substrate layer 10 near the second evaporation boat 54, the heat of the substrate layer 10 can be transferred to the second cold roller 53 more efficiently due to the better thermal conductivity of the second metal layer, thereby further reducing the risk of thermal deformation of the substrate layer 10 during the deposition of the heat insulation protective layer 30.

[0119] The thermal conductivity of the infrared radiation resistant layer 31 may include 80 W / m·K, 90 W / m·K, 150 W / m·K, 160 W / m·K, 237 W / m·K, 360 W / m·K, 386 W / m·K, 401 W / m·K, etc.

[0120] In step S1, the step of depositing the heat-insulating protective layer 30 on the surface of the substrate layer 10 using a thermal evaporation process further includes:

[0121] The substrate layer 10 is unrolled above the first crucible, so that the evaporation particles generated by the thermal evaporation of the raw material in the first crucible are deposited on the surface of the substrate layer 10 near the first crucible to form a heat-insulating protective layer 30. In other words, in this embodiment, in addition to forming the heat-insulating protective layer 30 on the substrate layer 10 using a suspension coating method and / or a roll coating method, the heat-insulating protective layer 30 can also be obtained by thermally evaporating the raw material (such as aluminum particles, copper particles, nickel particles, chromium particles, zinc particles, tin particles, etc.) in the first crucible. Regardless of the thermal evaporation method, the baking of the substrate layer 10 is reduced during the deposition of the heat-insulating protective layer 30 on the substrate layer 10, reducing the negative impact of deformation caused by baking and ensuring the structural stability of the substrate layer 10 before the conductive layer 20 is deposited.

[0122] Before depositing the heat-insulating protective layer 30 on the surface of the substrate layer 10 using a thermal evaporation process, the preparation method provided in this embodiment further includes:

[0123] During the process of controlling the substrate layer 10 to travel at a second film-moving speed, a surface-modified layer 40 is deposited on the surface of the substrate layer 10 using a second preparation process. The second preparation process includes at least one of thermal evaporation and magnetron sputtering processes. The second film-moving speed is not less than 200 m / min and not more than 600 m / min. Specifically, the second film-moving speed may include one of the following: 200 m / min, 210 m / min, 230 m / min, 250 m / min, 280 m / min, 300 m / min, 310 m / min, 350 m / min, 370 m / min, 400 m / min, 420 m / min, 450 m / min, 480 m / min, 500 m / min, 510 m / min, 530 m / min, 560 m / min, 580 m / min, and 600 m / min, or any other speed value between 200 m / min and 600 m / min.

[0124] Therefore, since the second film-forming speed is not less than 200 m / min during the deposition of the surface modification layer 40 in this embodiment, the substrate layer 10 will be subjected to relatively less baking during the deposition of the surface modification layer 40 onto the substrate layer 10 (especially under thermal evaporation processes), and the substrate layer 10 is less prone to thermal deformation. Moreover, when the second film-forming speed is within the above-mentioned range, it can also ensure that the required thickness (e.g., not less than 10 nm and not more than 40 nm) of the surface modification layer 40 is obtained in one deposition, improving the production efficiency of conductive films while further ensuring that the substrate layer 10 is not subjected to excessive baking, and the risk of the substrate layer 10 being baked and deformed is smaller.

[0125] like Figures 7 to 8 As shown, when the second preparation process in this embodiment includes a thermal evaporation process, the step of depositing a surface modified layer 40 on the surface of the substrate layer 10 using the second preparation process includes:

[0126] Based on the suspension coating method, when the substrate layer 10 is unwound above the second evaporation boat 54 and the portion of the substrate layer 10 relative to the second evaporation boat 54 is suspended, the filament material is thermally evaporated by the second evaporation boat 54, so that the generated evaporation particles are deposited on the surface of the substrate layer 10 near the second evaporation boat 54 to form a surface modification layer 40.

[0127] The portion of the substrate layer 10 that leaves the second evaporation boat 54 travels to the third cold roller 55 and adheres to its surface for cooling. The third cold roller 55 is a cold roller positioned in front of the second evaporation boat 54 along the traveling direction of the substrate layer 10. And / or,

[0128] Based on the roller coating method, when the substrate layer 10 is unwound above the second evaporation boat 54 and the surface of the substrate layer 10 facing away from the second evaporation boat 54 is attached to the surface of the fourth cold roller 56, the conveyed filament is thermally evaporated by the second evaporation boat 54, so that the generated evaporation particles are deposited on the surface of the substrate layer 10 near the second evaporation boat 54 to form a surface modified layer 40; and / or,

[0129] The substrate layer 10 is unwound and rolled above the second crucible so that the evaporation particles generated by the thermal evaporation of the raw material by the second crucible are deposited on the surface of the substrate layer 10 near the second crucible to form a surface modification layer 40.

[0130] In other words, this embodiment can deposit the surface modified layer 40 by conveying filaments (such as nickel wire, chromium wire, aluminum wire, titanium wire, etc.) to the second evaporation boat 54 for thermal evaporation, based on a suspension coating method and / or a roll coating method. Alternatively, the surface modified layer 40 can be deposited on the surface of the substrate layer 10 by using a second crucible to thermally evaporate raw materials (such as nickel particles, chromium particles, aluminum particles, titanium particles, etc.). Regardless of the aforementioned evaporation coating method, this embodiment ensures that the substrate layer 10 is not prone to thermal deformation during the process of obtaining the surface modified layer 40. At the same time, since the substrate layer 10 is cooled and dissipated by the third cold roller 55 and the fourth cold roller 56 during the process of obtaining the surface modified layer 40 based on the suspension coating method and / or the roll coating method, the temperature of the substrate layer 10 is kept at a lower level, and the risk of thermal deformation of the substrate layer 10 during subsequent coating processes will be lower.

[0131] Furthermore, the second preparation process in this embodiment may also include magnetron sputtering, thereby depositing a surface-modified layer 40 on the surface of the substrate layer 10 by magnetron sputtering. For example, the metal target (such as titanium target, nickel target, chromium target, nickel-chromium alloy target, aluminum target, or copper target) required for depositing the surface-modified layer 40 is placed in the vacuum chamber of the magnetron sputtering coating equipment 50, and an atmosphere such as Ar (argon) + O2 (oxygen), Ar + N2 (nitrogen), or Ar + O2 + N2 is introduced into the vacuum chamber to carry out the relevant reaction to obtain the surface-modified layer 40. Since the temperature generated by the magnetron sputtering process (such as room temperature to several hundred degrees Celsius) is relatively lower than the temperature generated by the thermal evaporation process (up to thousands of degrees Celsius, such as between 1000°C and 2000°C), it is possible to ensure that the substrate layer 10 is not prone to thermal deformation without controlling the substrate layer 10 to travel at the second film-moving speed.

[0132] The first preparation process in this embodiment also includes a thermal evaporation process. Therefore, the step of depositing the conductive layer 20 on the surface of the heat-insulating protective layer 30 away from the substrate layer 10 using the first preparation process includes:

[0133] During the process of controlling the substrate layer 10 to travel at a third film-laying speed, a conductive layer 20 is deposited on the surface of the heat insulation protective layer 30 using a thermal evaporation process. The third film-laying speed is not less than 10 m / min and not more than 35 m / min. Therefore, in this embodiment, at the third film-laying speed, a conductive layer 20 of the required thickness (e.g., not less than 750 nm and not more than 1500 nm) can be deposited on the surface of the heat insulation protective layer 30 in a single deposition using the thermal evaporation process. During this process, the heat insulation protective layer 30 can reduce the thermal radiation received by the substrate layer 10 during the deposition of the conductive layer 20. For example, the infrared radiation is directly reflected by the anti-infrared radiation layer 31, allowing the temperature of the substrate layer 10 to be maintained at a lower level, thereby preventing damage and deformation caused by direct exposure to excessive thermal radiation. Furthermore, it can prevent interface peeling or cracking between the substrate layer 10 and the conductive layer 20 due to a mismatch in thermal expansion coefficients, improving the overall stability and reliability of the conductive film product.

[0134] The third film-moving speed may be one of 10 m / min, 11 m / min, 13 m / min, 15 m / min, 17 m / min, 18 m / min, 20 m / min, 21 m / min, 23 m / min, 24 m / min, 26 m / min, 27 m / min, 29 m / min, 30 m / min, 31 m / min, or 35 m / min, or any other speed value between 10 m / min and 35 m / min.

[0135] In this embodiment, the heat insulation layer 30 includes an infrared radiation resistant layer 31. The infrared radiation resistant layer 31 includes a second metal layer with a thermal conductivity of not less than 80 W / m·K. This second metal layer may include one or more of the following: a magnesium layer, an aluminum layer, and a copper layer. Figure 9 As shown, the steps for depositing a conductive layer 20 on the surface of the heat insulation protective layer 30 using a thermal evaporation process include:

[0136] After the second metal layer is deposited on both opposite sides of the substrate layer 10 along its thickness direction, based on the roll-to-roll coating method, the substrate layer 10 is unwound above the third evaporation boat 57 and attached to the surface of the fifth cold roller 58 with the surface of the substrate layer 10 facing away from the third evaporation boat 57. The filament material is then thermally evaporated by the third evaporation boat 57, causing the generated evaporation particles to deposit on the surface of the second metal layer to form a conductive layer 20. Alternatively, in this embodiment, the substrate layer 10 can also be unwound above the crucible, allowing the evaporation particles generated by the crucible's thermal evaporation of the raw material to deposit on the surface of the second metal layer near the crucible to form a conductive layer 20.

[0137] Therefore, during the deposition of the conductive layer 20, since the substrate layer 10 is always in contact with the surface of the fifth cold roller 58, the substrate layer 10 can be cooled down by the fifth cold roller 58. At the same time, since the thermal conductivity of the second metal layer in contact with the fifth cold roller 58 is not less than 237, such as an aluminum layer or a copper layer, the second metal layer will more efficiently conduct the temperature of the substrate layer 10 to the fifth cold roller 58, thereby further improving the cooling efficiency of the fifth cold roller 58 on the substrate layer 10, making the probability of thermal deformation of the substrate layer 10 smaller, and further ensuring the stability and reliability of the overall structure of the conductive film after the conductive layer 20 is deposited.

[0138] Of course, in this embodiment, the conductive layer 20 can also be deposited on the surface of the heat insulation layer 30 by thermally evaporating the evaporation particles required for depositing the conductive layer 20 in a crucible, and the substrate layer 10 can be controlled to travel at a third film-moving speed, thereby depositing the conductive layer 20 of the required thickness (e.g., not less than 750 nm and not more than 1500 nm) on the surface of the heat insulation layer 30 in one step. In this process, since the heat insulation layer 30 can reduce the heat radiation received by the substrate layer 10 during the deposition of the conductive layer 20, such as by directly reflecting the infrared rays in the heat radiation through the infrared radiation-resistant layer 31, the temperature of the substrate layer 10 can be maintained at a low level, thereby avoiding damage and deformation of the substrate layer 10 due to direct exposure to a large amount of heat radiation. Secondly, it can also prevent interface peeling or cracking between the substrate layer 10 and the conductive layer 20 due to the mismatch of thermal expansion coefficients, thereby improving the overall structural stability and reliability of the conductive film product.

[0139] In this embodiment Figures 5 to 9 The parts other than the evaporation boat and the cold roller are the unwinding roller, the conveying roller, and the rewinding roller of the coating equipment 50. The coating equipment 50 for depositing different coating layers (such as surface modification layer 40, conductive layer 20, and heat insulation protective layer 30) can be a single piece of equipment or different pieces of equipment. This can be adapted to meet actual production needs, and this embodiment does not impose a unique limitation.

[0140] The substrate layer 10 in this embodiment may include at least one of the following: 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 polyoxymethylene layer, a polytetrafluoroethylene layer, a polyvinylidene fluoride layer, a polycarbonate layer, a polyvinyl alcohol layer, a polyethylene glycol layer, and a cellulose layer.

[0141] Based on the above preparation method, in a specific embodiment of this utility model, the preparation process of the conductive film may include:

[0142] The substrate layer 10 is fed into the coating equipment 50 at a second film-coating speed (i.e., not less than 200 m / min and not more than 600 m / min). The coating process involves wire feeding and a second evaporation boat 54. A certain amount of oxygen atmosphere is introduced into the vacuum chamber of the coating equipment 50. The evaporation particles generated after the thermal evaporation of the wire by the second evaporation boat 54 form a surface modification layer 40 (such as an alumina layer) of not less than 10 nm and not more than 40 nm on the surface of the substrate layer 10. This coating method can employ either vacuum suspension coating or roller coating.

[0143] Furthermore, after the surface modification layer 40 is deposited, a similar deposition method to that used for the surface modification layer 40 is employed, except that the oxygen atmosphere is stopped from being introduced into the vacuum chamber (i.e., evaporation in a metallic state). While the substrate layer 10 is controlled to travel at a first film-moving speed (not less than 100 m / min and not more than 400 m / min), an infrared radiation resistant layer 31 (an aluminum layer in this embodiment) is deposited on the surface of the surface modification layer 40 away from the substrate layer 10. Optimization can be achieved by using a speed of 350 nm / min to deposit an infrared radiation resistant layer 31 with a thickness of 70 nm. The infrared radiation resistant layer 31 can be deposited using a metal particle + evaporation crucible method, where the first film-moving speed can be controlled to reach 200 m / min.

[0144] Furthermore, a conductive layer 20 is deposited on the surface of the infrared radiation-resistant layer 31 away from the substrate layer 10. Thermal evaporation deposition is performed using a wire feeding + third evaporation boat 57 method, or a combination of metal particles + evaporation crucible method. The substrate layer 10 is controlled to move at a third film-moving speed (not less than 10 m / min and not more than 35 m / min). Finally, a conductive layer 20 with a thickness of not less than 750 nm and not more than 1500 nm is deposited on the surface of the infrared radiation-resistant layer 31.

[0145] In other words, in this embodiment, the same heat-evaporating metal particles or wires can be used for the surface modification layer 40, the heat insulation layer 30, and the conductive layer 20 during deposition. Therefore, after placing the metal particles or wires in the vacuum chamber of the coating equipment 50, the atmosphere required for depositing the surface modification layer 40 (such as the oxygen atmosphere mentioned above) can be introduced into the vacuum chamber. After the surface modification layer 40 is deposited, the atmosphere is stopped from being introduced into the vacuum chamber, and the substrate layer 10 is unwound into the vacuum chamber at a first film-winding speed for the deposition of the heat insulation layer 30 (such as the anti-infrared radiation layer 31). After the heat insulation layer 30 is deposited, the substrate layer 10 is unwound into the vacuum chamber at a third film-winding speed for the deposition of the conductive layer 20. The above deposition process is efficient and convenient, and ensures that the substrate layer 10 is not prone to thermal deformation during the deposition of each layer, resulting in a higher quality conductive film.

[0146] In existing technologies, when a conductive layer 20 of approximately 1000 nm is deposited on the surface of a substrate layer 10 in a single process, the interface between the conductive layer 20 and the substrate layer 10 may experience significant expansion of the polymer material due to the heat generated by the substrate layer 10 during deposition. This results in considerable thermal stress, leading to a decrease in film performance.

[0147] In comparison, the infrared radiation-resistant layer 31 deposited in this embodiment, with a thickness of not less than 40 nm and not more than 100 nm, is exactly the thickness of a single deposition in a traditional evaporation boat (wire feeding) coating process. The initial film-drawing speed at this stage is very high, reaching up to 300 m / min (while existing equipment systems deposit 1000 nm in a single pass at a speed of approximately 20 m / min). Under these coating conditions, the thermal damage to the substrate layer 10 from the baking effect is minimal. The infrared radiation-resistant layer 31 (such as an aluminum layer) with a thickness of not less than 40 nm and not more than 100 nm can be deposited on the substrate layer 10 or a substrate layer 10 with a surface modification layer 40, such as aluminum oxide, with almost no thermal expansion. That is, the thermal stress between the infrared radiation-resistant layer 31 and the substrate layer 10 or the substrate layer 10 with the surface modification layer 40 is very small. After laying this foundation, it is easier to deposit the conductive layer 20 for subsequent thickening (the thickness of the conductive layer 20 is not less than 750nm and not more than 1500nm). The deposition speed (third film speed) of the conductive layer 20 is relatively low. Firstly, it can efficiently deposit the conductive layer 20 in fewer passes (e.g., one, two, or three). Secondly, during the deposition of the conductive layer 20, the presence of the infrared radiation-resistant layer 31, which reflects infrared heat radiation while also having good thermal conductivity, allows the heat source of the heat radiation to be directly reflected while the heat of the substrate layer 10 is transferred to the cold roller in real time. Therefore, during the deposition of the conductive layer 20, the thermal expansion deformation of the substrate layer 10 (mainly the plastic base film) can be significantly improved, and the thermal stress between the conductive layer 20 and the infrared radiation-resistant layer 31 can also be improved. Therefore, in this embodiment, the substrate layer 10 of the conductive film will always be in a state of no or low thermal stress during processing, meeting the demand for stress-free film deposition in the vacuum coating industry.

[0148] Furthermore, in this embodiment, when both the first surface 11 and the second surface 12 of the substrate layer 10 are coated with an anti-infrared radiation layer 31, it also has the advantage of heat conduction and heat dissipation, enabling the heat of the substrate layer 10 to be transferred to the cold roller in a timely manner. The opposing side of the conductive layer 20 during deposition is in close contact with the cold roller, meaning the other side also has an anti-infrared radiation layer 31, which promotes heat conduction between the substrate layer 10 and the cold roller and allows the localized heat of the substrate layer 10 to be diffused over a large area, thus reducing the risk of thermal deformation of the substrate layer 10.

[0149] The third embodiment of this utility model also provides an electrode sheet, which includes a conductive film prepared by a method for preparing a conductive film. The method for preparing the conductive film is described in the second embodiment of this utility model, and will not be repeated here. Alternatively, the electrode sheet in this embodiment includes the conductive film provided in the first embodiment of this utility model. The specific structure of the conductive film is described in the first embodiment of this utility model, and will not be repeated here.

[0150] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0151] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0152] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A conductive film, characterized in that, include: The substrate layer (10) includes a first surface (11) and a second surface (12) along the thickness direction of the substrate layer (10); A conductive layer (20) is disposed on at least one of the first surface (11) and the second surface (12); A heat insulation protective layer (30) is disposed between the conductive layer (20) and the substrate layer (10) along the thickness direction of the substrate layer (10). The heat insulation protective layer (30) is used to reduce the heat radiation received by the substrate layer (10) when the conductive layer (20) is deposited.

2. The conductive film according to claim 1, characterized in that, The heat insulation protective layer (30) includes an infrared radiation resistant layer (31), which is a structural layer obtained by depositing infrared radiation resistant particles on the surface of the substrate layer (10).

3. The conductive film according to claim 2, characterized in that, Along the thickness direction of the substrate layer (10), the thickness of the infrared radiation-resistant layer (31) is not less than 30 nm and not greater than 100 nm; and / or, The infrared reflectivity of the anti-infrared radiation layer (31) for infrared rays with wavelengths within a predetermined range in thermal radiation is not less than 70%, and the predetermined range is not less than 1200 nm and not greater than 2500 nm.

4. The conductive film according to claim 2, characterized in that, The infrared radiation resistant layer (31) includes one of the following: an aluminum layer, a copper layer, a nickel layer, a chromium layer, a zinc layer, a tin layer, and a silver layer; and / or, The conductive layer (20) includes at least one of an aluminum layer, a copper layer, a zinc layer, a tin layer, and a silver layer.

5. The conductive film according to any one of claims 1 to 4, characterized in that, The heat insulation layer (30) comprises a structural layer with the same metal material as the conductive layer (20); and / or, Along the thickness direction of the substrate layer (10), the thickness of the conductive layer (20) is not less than 750 nm and not greater than 1500 nm; and / or, The conductive layer (20) includes a single-layer structure or a multi-layer structure, and the conductive layer (20) of the multi-layer structure includes at least two layers.

6. The conductive film according to claim 5, characterized in that, When the conductive layer (20) is a multilayer structure, the thickness difference between two adjacent film layers in the conductive layer (20) along the thickness direction of the substrate layer (10) is not greater than 100nm.

7. The conductive film according to any one of claims 1 to 4, characterized in that, The heat insulation layer (30) includes a first metal particle, and the conductive layer (20) includes a second metal particle. The first metal particle is a metal particle with the same metal element as the second metal particle.

8. The conductive film according to any one of claims 1 to 4, characterized in that, Also includes: A surface modification layer (40) is disposed between the substrate layer (10) and the heat insulation layer (30) along the thickness direction of the substrate layer (10). The surface modification layer (40) is used to increase the bonding force between the heat insulation layer (30) and the substrate layer (10).

9. The conductive film according to claim 8, characterized in that, Along the thickness direction of the substrate layer (10), the thickness of the surface modification layer (40) is not less than 10 nm and not greater than 40 nm; and / or, The surface modification layer (40) includes at least one of a metal compound layer and a first metal layer. The metal compound layer includes at least one of a metal oxide layer, a metal nitride layer, and a metal oxynitride layer. The first metal layer includes at least one of a titanium layer, a nickel layer, a chromium layer, a nickel-chromium alloy layer, an aluminum layer, a copper layer, and a silicon layer.

10. An electrode sheet, characterized in that, The electrode comprises the conductive film according to any one of claims 1 to 9.

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