A metallized film

Abstract

The present invention provides a metallized film, which includes a film layer. A conductive coating is provided on the surface of the film layer. The transverse elongation rate of the film layer is greater than the longitudinal elongation rate and less than a specified multiple of the longitudinal elongation rate. By adopting a film layer in which the transverse elongation rate and the longitudinal elongation rate satisfy a corresponding relationship, the toughness of the film layer can be improved, the shrinkage degree of the film when forming the conductive coating on the film layer can be reduced, and further the adhesion between the conductive coating and the film layer can be improved, so that the conductive coating will not easily fall off. When used in a battery, especially a lithium-ion battery, the conductive stability and safety of the metallized film can be significantly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium batteries, and particularly to a metallized film. Background Art

[0002] A metallized film refers to a film with metallic properties. Due to its electrical conductivity and low mass, it is widely used in various devices, one of which is the battery field, especially the lithium-ion battery field. In the lithium-ion battery field, according to the different metals, the metallized film can be used in different parts of the battery. For example, it can be used as a negative current collector in the battery negative electrode, or as a positive current collector in the battery as the battery positive electrode.

[0003] However, when depositing metals on the existing metallized films, the adhesion is insufficient, and situations such as coating peeling are likely to occur, thereby affecting the electrical conductivity of the metallized film. Summary of the Invention

[0004] In view of the above deficiencies of the prior art, the purpose of the present invention is to provide a metallized film, aiming to improve the coating adhesion of the metallized film, and thereby improve the electrical conductivity of the metallized film.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention provides a metallized film, including a film layer, on the surface of which a conductive coating is provided. The transverse elongation rate of the film layer is greater than the longitudinal elongation rate and less than a specified multiple of the longitudinal elongation rate.

[0007] In one embodiment, if the transverse elongation rate of the film layer is A and the longitudinal elongation rate is B, then the relationship between the transverse elongation rate and the longitudinal elongation rate is: 1B < A < 3B.

[0008] In one embodiment, 10% < A < 17%, and 6% < B < 12%.

[0009] In one embodiment, the conductive coating includes a first coating and a second coating. The first coating is provided on the surface of the film layer, and the second coating is provided on the surface of the film layer;

[0010] The first coating is a metal coating made of copper metal, copper alloy, aluminum metal, aluminum alloy, titanium alloy or titanium metal, or a non-metal coating made of alumina or silicon nitride;

[0011] The second coating is a metal coating made of copper metal, aluminum metal, copper alloy or aluminum alloy.

[0012] In one embodiment, when the metallized film is transversely stretched such that the degree of deformation is within 2%, the change rate of the transverse sheet resistance before and after stretching the metallized film is within 3%.

[0013] In one embodiment, when the metallized film is longitudinally stretched such that the degree of deformation is within 5%, the change rate of the longitudinal sheet resistance before and after stretching the metallized film is within 5%.

[0014] In one embodiment, the change rate of the transverse sheet resistance of the metallized film is C1, the change rate of the longitudinal sheet resistance is C2, and the overall change rate of the sheet resistance is C. Then C = C1 / C2, and 10% <= C <= 80%.

[0015] In one embodiment, the relationship between the transverse elongation rate A and the change rate of the transverse sheet resistance C1 satisfies: 5% <= C1 / A <= 10%.

[0016] In one embodiment, the relationship between the longitudinal elongation rate B and the change rate of the longitudinal sheet resistance C2 satisfies: 0.5 <= B / C2 <= 2.

[0017] In one embodiment, the film layer is a PP film, a PET film, a PI film, or a modified film formed based on the above films. The conductive coatings are provided on both the upper and lower surfaces of the film layer, and the conductive coatings are vapor deposition coatings.

[0018] Compared with the prior art, a metallized film provided by the present invention includes a film layer. A conductive coating is provided on the surface of the film layer. The transverse elongation rate of the film layer is greater than the longitudinal elongation rate and less than a specified multiple of the longitudinal elongation rate. The inventors have found through multiple experiments that by using a film layer in which the transverse elongation rate and the longitudinal elongation rate satisfy a corresponding relationship, the toughness of the film layer can be improved, the shrinkage degree of the film when forming the conductive coating on the film layer can be reduced, and further the adhesion between the conductive coating and the film layer can be improved, so that the conductive coating will not easily fall off. When used in a battery, especially a lithium-ion battery, the conductive stability and safety of the metallized film can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings. In the drawings:

[0020] Figure 1 is a schematic diagram of the direction of the metallized film in the embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the structure of the metallized film in the embodiment of the present invention;

[0022] Figure 3 Schematic diagram of the preparation process of the metallized film in the embodiment of the present invention. Detailed implementation manners

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved in the embodiments of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, the connection can be for fixing or for circuit connection.

[0025] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0026] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality" means two or more, unless otherwise specifically defined. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of the technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0027] The present invention provides a metallized film, such as Figure 1 and Figure 2As shown, the metallized film includes a film layer 100, and a conductive coating 200 is provided on the surface of the film layer 100. Among them, the film layer 100 serves as a supporting body, and the film layer 100 is a PP film, a PET film, a PI film, or a modified film formed based on the above films. The film layer 100 has upper and lower surfaces, and the conductive coating 200 is provided on both the upper and lower surfaces. The conductive coating 200 is a vapor deposition coating. The metallized film of the present invention has a transverse direction and a longitudinal direction. The transverse direction is the width direction, and the longitudinal direction is the length direction; the transverse elongation rate of the film layer 100 is greater than the longitudinal elongation rate and less than a specified multiple of the longitudinal elongation rate. When using the film layer 100 with the above elongation rate characteristics to deposit the conductive coating 200, the toughness of the film layer 100 can be improved, the shrinkage degree of the film when forming the conductive coating 200 on the film layer 100 can be reduced, and thus the adhesion between the conductive coating 200 and the film layer 100 can be improved.

[0028] Preferably, in the metallized film provided by the present invention, the transverse elongation rate of the film layer 100 is greater than one time of the longitudinal elongation rate and less than three times of its transverse elongation rate. That is, if the transverse elongation rate is set as A and the longitudinal elongation rate is set as B, then the transverse elongation rate and the longitudinal elongation rate satisfy the following relationship: 1B < A < 3B. When the elongation rates in both directions of the film layer 100 satisfy this relationship, the adhesion between the conductive coating 200 and the film layer 100 can be improved, so that the conductive coating 200 will not easily fall off. When used in batteries, especially lithium-ion batteries, the conductive stability and safety of the metallized film can be significantly improved. Preferably, for the metallized film provided by the present invention, after infinite tests by the inventor, when 10% < A < 17% and 6% < B < 12%, the effect is the best, the adhesion effect is better, and it is more difficult to fall off.

[0029] Preferably, in the metallized film provided by the present invention, the thickness of the film layer 100 is 4 - 8 μm. If it is too thin, the film material will curl during film coating, affecting the uniformity of film coating; if it is too thick, the quality of the film material will be increased. When the thickness of the film layer 100 is 4 - 8 μm, it can be better applied to subsequent steps to ensure the quality of the metallized film.

[0030] Furthermore, in the metallized film provided by the present invention, the conductive coating 200 includes a first coating 201 and a second coating 202. The first coating 201 is disposed on the surface of the film layer 100, and the second coating 202 is disposed on the surface of the film layer 100. Specifically, the conductive coating 200 is disposed on the upper and lower surfaces of the film layer 100. Taking the upper surface as an example, when the metallized film is formed, the first coating 201 is first formed on the film layer 100 by physical vapor deposition, and then the second coating 202 is formed on the first coating 201 by physical vapor deposition. The first coating 201 can be a metal or a non-metal. When it is a metal, it can be a metal coating made of copper metal, copper alloy, aluminum metal, aluminum alloy, titanium alloy or titanium metal; when it is a non-metal, it can be a non-metal coating made of alumina or silicon nitride. The main function of the first coating 201 is to improve the adhesion between the second coating 202 and the film material. The second coating 202 is a metal, specifically a metal coating made of copper metal, aluminum metal, copper alloy or aluminum alloy. The main function of the second coating 202 is to converge the current. After the second coating 202 is formed on the film layer 100, the metallized film with good coating adhesion and not easy to fall off in the present invention can be obtained.

[0031] Preferably, the metallized film of the present application first uses magnetron sputtering vacuum coating technology to metallize the surface of the base material to form the first coating 201, ensuring that the conductivity of the material and the density and bonding force of the film layer meet certain requirements, and then thickening the copper layer by electroplating to form the second coating 202. Among them, magnetron sputtering means that the plasma generated by rare gases bombards the surface of the cathode copper target under the action of an electric field and a magnetic field, and then the molecules, atoms, ions, electrons, etc. on the surface of the target are sputtered out. The sputtered particles are shot towards the surface of the base film along a certain direction, and then a coating is formed on the surface of the base film to realize the metallization of the non-metallic material of the base film. The advantages of using this method are: 1) The sputtered atoms have high energy and the adhesion between the film and the substrate is strong; 2) The film thickness is controlled by controlling the target current, and the controllability and repeatability are good; 3) The material components of the crucible heater will not be mixed in, and the metal film layer has high purity and good quality.

[0032] Specifically, as Figure 3 shown, the metallized film of the present invention can be prepared by the following process: First, vacuum magnetron sputtering activation and vacuum magnetron sputtering copper plating (taking copper alloy as an example) are used. A PET or PP film with a thickness of 4.5 μm is used as the base film (i.e., the film layer 100), and coating is carried out in a vacuum magnetron sputtering device. By means of PVD (Physical vapor deposition), the vacuum of the equipment body and the process vacuum are controlled at certain parameters, and pure argon is introduced. Electrons are in a vacuum condition (the vacuum degree is 10 -3Pa), during the leap process, it collides with argon atoms, causing them to ionize and generate Ar+ ions and new electrons; restricted by the magnetic field on the back of the magnetron sputtering target, most electrons are confined around the magnetic field. Under the action of the electric field, Ar ions are accelerated towards the cathode target and bombard the surface of the Cu alloy target with high energy, causing the target to sputter. Among the sputtered particles, neutral target atoms or some ions are deposited on the base film to form a thin film with a thickness generally of 5 - 20 nm (the first sub - coating). Using this thin film as the base film, coating is carried out in the same way, and the formed thin film has a thickness generally of 10 - 40 nm (the second sub - coating). Here, that is to say, the first coating 201 can include the first sub - coating and the second sub - coating, and the sheet resistance of the second sub - coating is preferably below 1.5 mΩ, and then electroplating is carried out to increase the thickness. With this thickness of the first sub - coating, on the one hand, it can prevent the particles formed by sputtering from burning through the base film, that is, the thin film layer 100, and on the other hand, it can increase the heat - resistance performance of the thin film layer 100, providing a good foundation for the subsequent coating layer.

[0033] Then, the film formed with the second sub - coating is slit, and then acid plating is carried out. The specific method of acid plating is as follows: Using phosphor - copper balls as the anode, the phosphor - copper balls are placed in an anode bag made of titanium blue, and then the entire anode bag is immersed in an acidic reagent (acidic sulfuric acid solution: sulfuric acid 90 - 170 g / L, copper ions 50 - 160 g / L, chlorine ions 30 - 60 ppm). Using the metal layer on the film surface as the cathode, the film surface passes through between the lower rollers of the reagent tank solution, and the film surface is immersed in the reagent for ion migration and replacement. After obtaining electrons on the film surface, a copper layer will be formed, and the thickness of the copper deposition layer is 900 nm, and the passing speed of the film is 3 - 5 m / min. The role of acid plating is to thicken the first sub - coating, and the metal layer formed by acid plating is the second coating 202.

[0034] After acid plating, it is also necessary to carry out an anti - oxidation treatment on the film formed with the second coating 202. The specific method is as follows: Using the method of blocking air to carry out anti - oxidation on the copper deposition layer, that is, making the composite film pass through an anti - oxidation tank, and adding an antioxidant QT - 3 containing aromatic hydrocarbon compounds to the anti - oxidation tank, which can prevent copper and its alloys from corroding and discoloring. When the composite film passes through the anti - oxidation tank, a transparent semi - permeable film with a thickness of about 30 - 60 nm can be formed on the surface. Then, it is dried, slit, and packaged for shipment to obtain a metallized film that meets the customer's width requirements. Preferably, after acid plating, it is also necessary to carry out a water - washing treatment to wash off the acidic plating solution on the surface of the composite film to prevent the plating solution from contaminating the antioxidant solution in the anti - oxidation tank.

[0035] Alternatively, in another preparation process, the metallized film of the present invention can also form a first sub-coating by magnetron sputtering (with the same thickness as the previous preparation process), and then form a second sub-coating on the first sub-coating by vacuum evaporation (with the same thickness as the previous preparation process). Then, an acid plating is used to form a second coating 202 on the second sub-coating (with the same thickness as the previous preparation process). Then, the same post-treatment steps as in the previous preparation process, such as water washing, anti-oxidation, drying, and slitting, are carried out. That is, different from the previous preparation process, the second sub-coating is formed on the first sub-coating by vacuum evaporation. Vacuum evaporation is a physical vapor deposition (PVD) method, in which the metal is melted into a liquid state to form metal vapor and start to volatilize, and then the copper alloy or copper atoms in the vapor are condensed and deposited on the surface of the polymer material to grow. Adding a vacuum evaporation step after magnetron sputtering aims to increase the deposition rate. The deposition rate of vacuum evaporation is 3-4 times that of magnetron sputtering, which can quickly supplement the copper film to a suitable thickness for electroplating. The advantages are as follows: 1) Heating and melting result in a fast film formation rate and high efficiency; 2) Evaporation and adhesion do not require a high-voltage electric field, and the equipment is relatively simple and easy to operate; 3) The momentum of the atoms evaporated by vacuum heating is low, and the film thickness is uniform.

[0036] Or the present invention also adopts a one-step method for coating, that is, multiple coatings (magnetron sputtering or vacuum coating) are carried out in the same vacuum chamber to form a first coating 201 and a second coating 202, so that both the first coating 201 and the second coating 202 are coated in one vacuum chamber. Since the vacuum chamber does not need to be frequently opened and closed, this can reduce costs and improve efficiency. At the same time, since there is no need to take out the semi-finished product after coating and expose it to a non-vacuum environment, the risk of damage to the semi-finished product during transportation is reduced, and the yield rate can be improved.

[0037] Preferably, the lateral sheet resistance change rate of the metallized film in the present invention is within 3%. Specifically, the lateral sheet resistance change rate refers to the change rate of the sheet resistance when the lateral tensile deformation degree of the metallized film is within 2%. Specifically, after the metallized film is formed, the sheet resistance of the metallized film can be detected first. The detection of the sheet resistance is to measure the sheet resistance at any 3 points within 1 m² in the width direction and then take the average value. Then, a tensile machine is used to stretch the metallized film so that the lateral tensile deformation degree is within 2%, and the magnitude of the tensile force is not limited. Again, measure the sheet resistance at any 3 points within 1 m² in the width direction and then take the average value. Based on the average values of the sheet resistance before and after stretching, the lateral sheet resistance change rate of the metallized film can be calculated. Since the metallized film will be unfolded and run on various rollers in subsequent applications of lithium-ion batteries, such as welding and rolling, during the operation, the roller will apply a lateral tensile force to the metallized film. If the sheet resistance change rate is large, it will damage the coating on the metallized film, resulting in an increase in the internal resistance of the battery. Therefore, the lateral sheet resistance change rate of the metallized film in the present invention is within 3%, so that the surface conductivity of the metallized film will not be damaged in subsequent application steps, and the battery performance will not be affected.

[0038] Preferably, the longitudinal sheet resistance change rate of the metallized film in the present invention is within 5%. Specifically, the longitudinal sheet resistance change rate refers to the change rate of the sheet resistance when the longitudinal tensile deformation degree of the metallized film is within 5%. Similar to the detection method of the lateral sheet resistance change rate, after the metallized film is formed, the sheet resistance of the metallized film can be detected first. Measure the sheet resistance at any 3 points within 1 m² in the length direction and then take the average value. Then, a tensile machine is used to stretch the metallized film so that the longitudinal tensile deformation degree is within 5%, and the magnitude of the tensile force is not limited. Again, measure the sheet resistance at any 3 points within 1 m² in the length direction and then take the average value. Based on the average values of the sheet resistance before and after stretching, the longitudinal sheet resistance change rate of the metallized film can be calculated. The smaller the sheet resistance change rate, the less likely the coating is to break between the coatings during tensile deformation, and the less likely the coating is to be damaged, thereby improving the battery conductivity and safety performance.

[0039] Further, in the metallized film of the present invention, the lateral sheet resistance change rate is C1, the longitudinal sheet resistance change rate is C2, and the overall sheet resistance change rate is C. C satisfies the relationship: C = C1 / C2, and the value of C is greater than or equal to 10% and less than or equal to 80%. Because the greater the change in sheet resistance, it means that during stretching, the gap between the particles of the coating becomes larger, that is, the coating is actually damaged. Thus, under the condition that the overall sheet resistance change rate C satisfies the above conditions, the coating adhesion of the metallized film in the present invention can be improved, making the coating less likely to be damaged and improving the product strength to ensure safety.

[0040] Furthermore, for the metallized film of the present invention, the transverse elongation rate A and the transverse sheet resistance change rate C1 satisfy the following relationship: 5% <= C1 / A <= 10%. Thus, when the transverse elongation rate and the transverse sheet resistance change rate of the metallized film satisfy the above relationship, the adhesion between the conductive coating 200 and the film layer 100 in the metallized film of the present application can be improved, thereby increasing the strength and stability of the structure, preventing the coating from easily peeling off, and significantly improving the electrical conductivity of the metallized film.

[0041] Furthermore, for the metallized film of the present invention, the longitudinal elongation rate B and the longitudinal sheet resistance change rate C2 satisfy the following relationship: 0.5 <= B / C2 <= 2. Thus, when the longitudinal elongation rate and the longitudinal sheet resistance change rate of the metallized film satisfy the above relationship, when the metallized film is actually put into use, that is, in processes such as roll coating, it can prevent the coating from peeling off. Because the smaller the sheet resistance change rate, the less likely the coating is to break during tensile deformation. In this case, the longitudinal elongation rate is also smaller, and the smaller the longitudinal elongation rate, the less likely it is to shrink during coating formation, thereby improving the adhesion.

[0042] In summary, the present invention provides a metallized film including a film layer, on the surface of which a conductive coating is provided. The transverse elongation rate of the film layer is greater than the longitudinal elongation rate and less than a specified multiple of the longitudinal elongation rate. By using a film layer with a corresponding relationship between the transverse elongation rate and the longitudinal elongation rate, the present invention can improve the toughness of the film layer, reduce the shrinkage degree of the film during the formation of the conductive coating on the film layer, and further improve the adhesion between the conductive coating and the film layer, preventing the conductive coating from easily peeling off. When used in batteries, especially lithium-ion batteries, it can significantly improve the electrical conductivity stability and safety of the metallized film.

[0043] The following are the test data to prove the effect of claim 1 of the present application, as follows:

[0044] First, prepare experimental samples and comparative samples. The experimental samples are as follows: Select films with a transverse elongation rate of 10% and a longitudinal elongation rate of 9% as the film layer of test sample 1, select films with a transverse elongation rate of 13% and a longitudinal elongation rate of 7% as the film layer of test sample 2, and select films with a transverse elongation rate of 16% and a longitudinal elongation rate of 9% as the film layer of test sample 3. Then, use vacuum evaporation to form a 30-nm alumina coating on the above film layers, and in the same cavity, continue to form a 970-nm aluminum layer on the alumina coating. In this way, test samples 1, 2, and 3 are obtained.

[0045] The thin film layer of Comparative Sample 1 uses a thin film with a transverse elongation of 10% and a longitudinal elongation of 11%; the thin film layer of Comparative Sample 2 uses a thin film with a transverse elongation of 13% and a longitudinal elongation of 14%; the thin film layer of Comparative Sample 3 uses a thin film with a transverse elongation of 16% and a longitudinal elongation of 17%. Then, the above test samples are used to form a 30-nm aluminum oxide coating on the above thin film layer by vacuum evaporation. In the same cavity, a 970-nm aluminum metal layer is continuously formed on the aluminum oxide coating. In this way, Comparative Samples 1, 2, and 3 are obtained.

[0046] Then, the following method is used to test the adhesion between the coating and the thin film:

[0047] Under room temperature and atmospheric pressure conditions, use 3M double-sided tape to evenly attach the sample to a stainless steel plate, and then evenly attach the sample to be tested to the double-sided tape. The length of the sample to be tested is 120 mm and the width is 50 mm. Then, use a 500-g roller to firmly attach the sample. Then, use a 3M single-sided tape with a length of 2 cm and a width of 12.7 mm to attach it to the sample to be tested, and then use a roller to firmly attach it. Then, use a high-speed rail tensile machine to peel the conductive layer and the insulating layer of the sample to be tested. According to the data graph of the tensile force and displacement, read the maximum tensile force, divide the read value by 0.02 (unit: N), and calculate the fastness of the metal layer, that is, the adhesion F (N / m) between the current collector insulating layer and the conductive layer.

[0048]

[0049]

[0050] The above content is a further detailed description of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those skilled in the technical field to which the present invention belongs, without departing from the concept of the present invention, several equivalent substitutions or obvious modifications can be made, and as long as the performance or use is the same, it should be regarded as belonging to the protection scope of the present invention.

Claims

1. A metallized film, characterized in that: It includes a thin film layer, on the surface of which there is a conductive coating. The conductive coating is a vapor deposition coating. The transverse elongation rate of the thin film layer is greater than the longitudinal elongation rate and less than a specified multiple of the longitudinal elongation rate; If the transverse elongation rate of the thin film layer is A and the longitudinal elongation rate is B, then the relationship between the transverse elongation rate and the longitudinal elongation rate is: 1B < A < 3B, where 10% < A < 17% and 6% < B < 12%; When the metallized thin film is transversely stretched so that the degree of deformation is within 2%, the change rate of the transverse sheet resistance of the metallized thin film before and after stretching is within 3%; When the metallized thin film is longitudinally stretched so that the degree of deformation is within 5%, the change rate of the longitudinal sheet resistance of the metallized thin film before and after stretching is within 5%; If the change rate of the transverse sheet resistance of the metallized thin film is C1, the change rate of the longitudinal sheet resistance is C2, and the overall change rate of the sheet resistance is C, then C = C1 / C2, and 10% <= C <= 80% to improve the coating adhesion of the metallized thin film; The conductive coating includes a first coating and a second coating. The first coating is provided on the surface of the thin film layer, and the second coating is provided on the surface of the thin film layer; The first coating is a metal coating made of copper metal, copper alloy, aluminum metal, aluminum alloy, titanium alloy or titanium metal, or a non-metal coating made of alumina or silicon nitride; The second coating is a metal coating made of copper metal, aluminum metal, copper alloy or aluminum alloy; 2. The metallized film according to claim 1, characterized in that: The relationship between the transverse elongation rate A and the change rate of the transverse sheet resistance C1 satisfies: 5% <= C1 / A <= 10%; 3. The metallized film according to claim 1, characterized in that: The relationship between the longitudinal elongation rate B and the change rate of the longitudinal sheet resistance C2 satisfies: 0.5 <= B / C2 <= 2; 4. The metallized film according to any one of claims 1 to 3, characterized in that: The thin film layer is a PP film, a PET film, a PI film or a modified film formed based on the above films. The conductive coatings are provided on both the upper and lower surfaces of the thin film layer, and the conductive coatings are vapor deposition coatings.

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