Aluminum-plastic film, preparation method thereof, battery and electric device

Abstract

The application relates to the technical field of battery packaging, in particular to an aluminum-plastic film, a preparation method thereof, a battery and an electric device. The aluminum-plastic film comprises an aluminum layer, at least part of the surface of the aluminum layer is provided with a passivation layer, and the porosity of the passivation layer is less than or equal to 10%. The aluminum-plastic film is stable in insulation performance at high temperatures and can be used for the packaging of solid-state batteries.

Description

Technical Field

[0001] This invention relates to the field of battery packaging technology, specifically to an aluminum-plastic film and its preparation method, a battery, and electrical equipment. Background Technology

[0002] Solid-state batteries, due to their high energy density, high safety, and long cycle life, are considered one of the core technologies for next-generation power batteries and are widely used in applications with extremely high requirements for energy density and thermal stability, such as new energy vehicles, energy storage systems, and aerospace. In the packaging process of solid-state batteries, aluminum-plastic film, as the outer packaging material, is typically composed of multiple layers of plastic coatings (such as nylon, polypropylene PP, etc.) bonded to an aluminum layer using adhesives. However, this technology has the following drawbacks:

[0003] Solid-state batteries must withstand higher restraint forces during charging and discharging (i.e., the pressure between the battery cell and the aluminum-plastic film inside the battery) and must pass a 200°C hot box test (far exceeding the 130°C standard for liquid batteries). Under the influence of restraint forces, the PP and other plastic layers are prone to stretching and thinning, leading to a decrease in their insulation performance. In addition, the molecular chain structure of PP and other plastic layers often changes at high temperatures, and at even higher temperatures, some plastic layers may melt, causing the aluminum layer to come into direct contact with the electrode core, inducing a high-temperature short circuit between the positive and negative electrodes through the aluminum-plastic film.

[0004] Therefore, it is of great significance to develop an aluminum-plastic film with high strength and stable insulation properties suitable for solid-state batteries. Summary of the Invention

[0005] The aluminum-plastic film provided by this invention has stable insulation performance at high temperatures and does not cause stretching or leakage problems, making it suitable for packaging solid-state batteries.

[0006] The method for preparing aluminum-plastic film provided by this invention can prepare the above-mentioned aluminum-plastic film with stable insulation performance at high temperature.

[0007] The battery provided by this invention is less prone to short circuits.

[0008] The electrical equipment provided by this invention is less prone to short circuits and has high safety.

[0009] The aluminum-plastic film provided by the present invention includes an aluminum layer, wherein at least a portion of the surface of the aluminum layer is provided with a passivation layer, and the porosity of the passivation layer is ≤10%.

[0010] The passivation layer of the aluminum-plastic film described above has a thickness of 100nm-100μm, preferably 200nm-50μm.

[0011] The aluminum-plastic film described above has an aluminum layer thickness of 20μm-120μm.

[0012] In the aluminum-plastic film described above, the passivation layer is an aluminum oxide passivation layer.

[0013] The aluminum-plastic film described above includes an aluminum oxide passivation layer comprising α-Al2O3.

[0014] In the aluminum-plastic film described above, a fixing layer is further provided on the side of the passivation layer away from the aluminum layer, and the fixing layer includes plastic.

[0015] The present invention also provides a method for preparing the above-mentioned aluminum-plastic film, comprising the following steps:

[0016] The aluminum foil is subjected to anodic micro-arc oxidation and oxygen plasma treatment in sequence to form a passivation layer, thereby obtaining the aluminum-plastic film.

[0017] According to the preparation method described above, during the anodic micro-arc oxidation treatment, the pulse voltage is 50 V-800 V, the pulse frequency is 50 Hz-1000 Hz, the time is 0.1 h-6 h, the electrolyte includes sodium silicate 5 g / L-20 g / L, sodium phosphate 2 g / L-10 g / L, potassium hydroxide 1 g / L-5 g / L, pH value is 10-13, and electrolyte temperature is 15-40℃.

[0018] According to the preparation method described above, the electrolyte also includes 1 g / L-15 g / L of Y2O3 nanoparticles, wherein the particle size of the Y2O3 nanoparticles is 20 nm-100 nm;

[0019] According to the preparation method described above, during the oxygen plasma treatment, the power is 50 W-1000 W, the temperature is 100℃-400℃, an oxygen-containing mixed gas is introduced into the vacuum chamber and the pressure of the vacuum chamber is maintained at 10Pa-200Pa, and the treatment time is 0.05h-1h, wherein the volume fraction of oxygen in the oxygen-containing mixed gas is 20%-80%.

[0020] According to the preparation method described above, the aluminum foil after oxygen plasma treatment is further subjected to heat treatment at a temperature of 300℃-500℃ for a time of 0.5h-2h.

[0021] The preparation method described above further includes the step of setting a fixing layer on the surface of the passivation layer.

[0022] The present invention also provides a battery comprising the aluminum-plastic film described above or the aluminum-plastic film prepared by the above preparation method.

[0023] The battery described above is a solid-state battery.

[0024] The present invention also provides an electrical device comprising the aluminum-plastic film described above, the aluminum-plastic film prepared by the above preparation method, or the battery described above.

[0025] The aluminum-plastic film provided by this invention, by setting a passivation layer with a porosity of ≤10% on the aluminum-plastic film, can ensure that its insulation resistance remains relatively stable at high temperatures. Compared with traditional high-temperature resistant aluminum-plastic films that include a plastic coating, this aluminum-plastic film does not require a high-temperature plastic coating for bonding, and has better stability under high temperature and high pressure conditions. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0027] Figure 1 This is a microscopic morphology diagram of the surface of the aluminum foil in Embodiment 1 of the present invention after anodic micro-arc oxidation treatment. Detailed Implementation

[0028] To enable those skilled in the art to better understand the solutions of this invention, the following provides a further detailed description of this application. The specific embodiments listed below are merely descriptions of the principles and features of this invention; the examples are only for explaining the invention and are not intended to limit its scope. Based on the embodiments of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the scope of protection of this invention.

[0029] Due to the problems with the plastic layer in traditional aluminum-plastic films, some technologies have attempted to replace the plastic coating by applying an alumina film to the aluminum layer surface. However, alumina films are generally formed on the aluminum layer surface using anodizing technology with an electrolyte, resulting in a dense alumina film. Alumina films have high porosity and low insulation resistance, especially at high temperatures where the insulation resistance drops significantly. Furthermore, they are prone to cracking or peeling under high-voltage restraint and high-temperature conditions during thermal chamber testing, failing to meet the high-temperature and long-term high-voltage operating requirements of solid-state batteries.

[0030] Based on this, the present invention provides an aluminum-plastic film, which includes an aluminum layer, and at least a portion of the surface of the aluminum layer is provided with a passivation layer, wherein the porosity of the passivation layer is ≤10%.

[0031] This invention provides a passivation layer on an aluminum layer. The passivation layer has high high-temperature resistance. By controlling its porosity to ≤10%, it can ensure that its insulation resistance remains relatively stable at high temperatures and improve its strength, making it less prone to cracking.

[0032] In this invention, the porosity of the passivation layer can be obtained by the BET method. Specifically, the aluminum-plastic film can be tested directly, or the plastic layer on the surface can be removed by high-temperature heating before testing.

[0033] In some embodiments, the porosity is 1%-10%. When the porosity is greater than or equal to 1%, production costs can be reduced. When the porosity is ≤10%, better strength and insulation performance can be guaranteed.

[0034] In some embodiments, the thickness of the passivation layer is 100nm-100μm. Specifically, the thickness of the passivation layer can be 100nm, 200nm, 300nm, 500nm, 800nm, 1μm, 10μm, 50μm, 100μm, or any value between any two of the above.

[0035] When the thickness of the passivation layer is 100nm or more, it can ensure that there are enough passivation layers to perform the insulation effect and prevent the passivation layer from being broken down by high voltage. When the thickness of the passivation layer is 100μm or less, the cost can be reduced.

[0036] The thickness of the passivation layer can be detected by SEM. Specifically, the aluminum-plastic film is made into a 1cm×1cm cross section and then detected by scanning electron microscopy (SEM).

[0037] In some embodiments, the thickness of the aluminum layer is 20 μm-120 μm. Specifically, the thickness of the aluminum layer can be 20 μm, 40 μm, 60 μm, 80 μm, 100 μm, 120 μm, or any value between any two of the above.

[0038] When the aluminum layer thickness is greater than or equal to 20μm, it can effectively block the penetration of water vapor, oxygen, etc., providing good isolation and protection for the battery cell. When the aluminum layer thickness is less than or equal to 120μm, it can ensure that the aluminum-plastic film has good flexibility, avoiding difficulties in processing and forming, as well as problems such as easy cracking due to internal stress.

[0039] In some embodiments, the passivation layer is an alumina passivation layer. The alumina passivation layer can be formed by directly electrochemically treating the aluminum layer, resulting in a tighter bond between the passivation layer and the aluminum layer, making it less prone to detachment and exhibiting better stability.

[0040] In some embodiments, the alumina passivation layer includes α-Al2O3, which has higher hardness and stability than γ-Al2O3. When the alumina passivation layer includes α-Al2O3, the aluminum-plastic film has better strength and high-temperature stability.

[0041] In some embodiments, a fixing layer is further provided on the side of the passivation layer away from the aluminum layer. The fixing layer includes plastic and is located outside the passivation layer to protect the passivation layer and prevent it from falling off.

[0042] In some embodiments, the method for preparing the above-mentioned aluminum-plastic film includes the following steps:

[0043] The aluminum foil is subjected to anodic micro-arc oxidation and oxygen plasma treatment in sequence to form a passivation layer, thus obtaining an aluminum-plastic film.

[0044] The method for preparing aluminum-plastic film provided by the present invention directly generates a passivation layer on the surface of aluminum foil through a synergistic process of anodic micro-arc oxidation and oxygen plasma treatment. The operation is simple and the porosity of the generated passivation layer can reach 10% or less, with high strength and good insulation performance, which can better meet the application requirements of solid-state batteries.

[0045] In some embodiments, the pulse voltage during anodic micro-arc oxidation is 50V-800V, the pulse frequency is 50Hz-1000Hz, the treatment time is 0.1h-6h, the electrolyte temperature is 15℃-40℃, and the electrolyte is an alkaline electrolyte of silicate-phosphate composite system, comprising sodium silicate 5g / L-20g / L, sodium phosphate 2g / L-10g / L, potassium hydroxide 1g / L-5g / L, and a pH value of 10-13.

[0046] Specifically, the pulse voltage can be 50V, 100V, 200V, 300V, 400V, 500V, 600V, 700V, 800V, or any value between any two of the above. The pulse frequency can be 50Hz, 100Hz, 200Hz, 300Hz, 400Hz, 500Hz, 600Hz, 700Hz, 800Hz, 900Hz, 1000Hz, or any value between any two of the above. The processing time can be 0.1h, 1h, 2h, 3h, 4h, 5h, 6h, or any value between any two of the above. The electrolyte temperature can be 15℃, 20℃, 30℃, 40℃, or any value between any two of the above. The concentration of sodium silicate in the electrolyte can be 5 g / L, 10 g / L, 15 g / L, 20 g / L, or any value between any two of the above; the concentration of sodium phosphate can be 2 g / L, 4 g / L, 6 g / L, 8 g / L, 10 g / L, or any value between any two of the above; and the concentration of potassium hydroxide can be 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, or any value between any two of the above.

[0047] Under these conditions, the thickness of the passivation film generated after anodic micro-arc oxidation can be guaranteed to be between 100 nm and 100 μm. This passivation film has a porous and loose structure containing a large number of micron- or submicron-sized pores.

[0048] Preferably, the electrolyte also includes 1g / L-15g / L of Y2O3 nanoparticles (particle size 20-100nm), which can improve the stability of the passivation layer.

[0049] In some embodiments, the pulse voltage during anodic micro-arc oxidation is 50 V-600 V, the duration is 0.2 h-4 h, and the electrolyte is an alkaline electrolyte of a silicate-phosphate composite system, comprising 5 g / L-20 g / L sodium silicate, 2 g / L-10 g / L sodium phosphate, 1 g / L-5 g / L potassium hydroxide, and a pH value of 10-13. Under these conditions, the thickness of the passivation film formed after anodic micro-arc oxidation can be guaranteed to be between 200 nm and 50 μm.

[0050] In some embodiments, during oxygen plasma treatment, the power is 50W-1000W, the temperature is 100℃-400℃, an oxygen-containing mixed gas is introduced into the vacuum chamber and the vacuum chamber pressure is maintained at 10Pa-200Pa, and the treatment time is 0.05h-1h. The volume fraction of oxygen in the oxygen-containing mixed gas is 20%-80%. Oxygen plasma treatment can repair micropores formed by anodic micro-arc oxidation, significantly reducing porosity. Under these conditions, the porosity of the passivation film can be reduced to below 10%, forming a passivation layer with a porosity ≤10%.

[0051] Specifically, the power can be 50W, 100W, 300W, 500W, 800W, 1000W, or any value between any two of the above; the temperature can be 100℃, 200℃, 300℃, 400℃, or any value between any two of the above; the vacuum chamber pressure can be 10Pa, 100Pa, 200Pa, or any value between any two of the above; and the volume fraction of oxygen in the oxygen-containing gas mixture can be 20%, 40%, 60%, 80%, or any value between any two of the above.

[0052] In some embodiments, the aluminum foil after oxygen plasma treatment is further treated at 300°C-500°C for 0.5h-2h. This heat treatment can promote the transformation of γ-Al2O3 to the more stable α-Al2O3, thereby further improving the hardness and stability of the passivation layer.

[0053] In some embodiments, the method further includes the step of attaching a fixing layer to the surface of the passivation layer. Attaching a fixing layer to the surface of the passivation layer can further prevent the passivation layer from detaching.

[0054] Specifically, a fixed layer containing plastic can be formed by spin-coating molten plastic onto the surface of the passivation layer and allowing it to cool and solidify.

[0055] The present invention also provides a battery comprising the aluminum-plastic film described above or the aluminum-plastic film prepared by the above-described preparation method. Specifically, the battery comprises a battery cell and an aluminum-plastic film, wherein the aluminum-plastic film covers the battery cell.

[0056] The battery can be a liquid battery or a solid-state battery, preferably a solid-state battery. There are no restrictions on the type of solid-state battery; it can be a lithium-ion solid-state battery, a sodium-ion solid-state battery, or a potassium-ion solid-state battery.

[0057] The present invention also provides an electrical device comprising the aluminum-plastic film described above, the aluminum-plastic film prepared by the above preparation method, or the battery described above.

[0058] The electrical equipment of the present invention can be conventional electrical equipment in the art, such as power equipment (e.g., electric vehicles, electric cars), automobile chassis, electronic equipment (e.g., mobile phones, tablets, laptops, digital cameras, etc.), wearable devices (e.g., watches, bracelets, VR glasses, etc.), energy storage power stations, etc., and there are no particular limitations.

[0059] The technical solution of this application will be further explained below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise specified, all reagents used are commercially available or obtained through public channels.

[0060] Example 1

[0061] This embodiment provides an aluminum-plastic film, including an aluminum layer, and a passivation layer (specifically an Al2O3 passivation layer) is disposed on the surface of the aluminum layer, the porosity of the passivation layer being 8%.

[0062] The aluminum layer has a thickness of 59.7 μm, the passivation layer has a thickness of 300 nm, and the aluminum oxide passivation layer includes α-Al2O3.

[0063] The aluminum-plastic film is prepared by the following method:

[0064] Step 1: Clean the surface of the aluminum foil (60μm thick) to remove surface impurities and obtain the pretreated aluminum foil.

[0065] Step 2: Using the pretreated aluminum foil as the anode, and the silicate-phosphate composite system as the alkaline electrolyte, anodic micro-arc oxidation is performed using a pulsed power supply. After treatment, the foil is removed, cleaned, and dried. The pulse voltage for anodic micro-arc oxidation is 100V, the pulse frequency is 100Hz, and the time is 0.2h. The electrolyte of the silicate-phosphate composite system includes 11g / L sodium silicate, 5g / L sodium phosphate, 3g / L potassium hydroxide, and 8g / L Y₂O₃ nanoparticles (50nm particle size), with a pH of 12.

[0066] The passivation layer was detected using the BET method, and its porosity was 28%. The surface microstructure was observed using a scanning electron microscope (SEM), as shown below. Figure 1 As shown.

[0067] Step 3: Place the aluminum foil treated in Step 2 into the vacuum chamber of the plasma treatment equipment and evacuate it. Then, introduce a mixture of oxygen and argon gas (oxygen volume fraction of 30%) into the vacuum chamber, adjust the pressure of the vacuum chamber to 100 Pa, control the power to 100 W, and the temperature to 200 °C, and perform oxygen plasma treatment for 0.15 h to form a passivation layer.

[0068] Step 4: Place the aluminum foil treated in step 3 at 400℃ for 1 hour to obtain aluminum-plastic film.

[0069] The passivation layer was measured using SEM and its thickness was 300 nm.

[0070] Example 2

[0071] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 59.5 μm, the thickness of the passivation layer is 500 nm, and the porosity is 6%.

[0072] The preparation method differs from that in Example 1 in that:

[0073] In step 2, the pulse voltage is 100V, the pulse frequency is 100Hz, the treatment time is 0.25h, and the electrolyte of the silicate-phosphate composite system includes 5g / L sodium silicate, 10g / L sodium phosphate, 1g / L potassium hydroxide, 15g / L Y2O3 nanoparticles (particle size of 50nm), and pH value of 10.8.

[0074] In step 3, the power of the oxygen plasma treatment is 150W, the volume fraction of oxygen in the mixed gas is 20%, the temperature is 100℃, and the time is 0.15h.

[0075] Step 4: Heat treatment at 300℃ for 2 hours.

[0076] Example 3

[0077] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 59.35 μm, the thickness of the passivation layer is 650 nm, and the porosity is 2%.

[0078] The preparation method differs from that in Example 1 in that:

[0079] In step 2, the pulse voltage is 100V, the pulse frequency is 100Hz, the processing time is 0.33h, and the electrolyte of the silicate-phosphate composite system includes 20g / L sodium silicate, 2g / L sodium phosphate, 5g / L potassium hydroxide, 1g / L Y2O3 nanoparticles (particle size of 50nm), and pH value of 13.

[0080] In step 3, the power during oxygen plasma treatment is 200W;

[0081] Step 4: Heat treatment at 500℃ for 0.5 hours.

[0082] Example 4

[0083] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 59.8 μm, the thickness of the passivation layer is 200 nm, and the porosity is 7.5%.

[0084] The preparation method differs from that in Example 1 in that:

[0085] In step 2, the pulse voltage is 50V, the pulse frequency is 50Hz, and the processing time is 0.2h; the electrolyte of the silicate-phosphate composite system includes 11g / L sodium silicate, 5g / L sodium phosphate, 3g / L potassium hydroxide, and a pH value of 11.5.

[0086] In step 3, the power is 110W and the time is 0.2h.

[0087] Example 5

[0088] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 35 μm, the thickness of the passivation layer is 25 μm, and the porosity is 1%.

[0089] The preparation method differs from that in Example 1 in that:

[0090] In step 2, the pulse voltage is 600V, the pulse frequency is 600Hz, and the processing time is 3h.

[0091] In step 3, the power is 800W and the time is 1 hour.

[0092] Example 6

[0093] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 10 μm, the thickness of the passivation layer is 50 μm, and the porosity is 10%.

[0094] The preparation method differs from that in Example 1 in that:

[0095] In step 2, the pulse voltage is 600V, the pulse frequency is 800Hz, and the processing time is 3.8h.

[0096] In step 3, the power is 200W and the time is 0.1h.

[0097] Example 7

[0098] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 59.9 μm, the thickness of the passivation layer is 100 nm, and the porosity is 7%.

[0099] The preparation method differs from that in Example 1 in that:

[0100] In step 2, the pulse voltage is 50V, the pulse frequency is 50Hz, and the processing time is 0.1h.

[0101] In step 3, the power is 100W and the pressure is 200Pa.

[0102] Example 8

[0103] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 20 μm, the thickness of the passivation layer is 100 μm, and the porosity is 3%.

[0104] The preparation method differs from that in Example 1 in that:

[0105] In step 1, the thickness of the aluminum foil is 120 μm;

[0106] In step 2, the pulse voltage is 800V, the pulse frequency is 1000Hz, and the processing time is 6h.

[0107] In step 3, the power is 500W, the volume fraction of oxygen in the oxygen-containing gas mixture is 80%, the time is 1 hour, and the temperature is 400℃.

[0108] Example 9

[0109] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 20 μm, the thickness of the passivation layer is 0.35 μm, and the porosity is 7.8%.

[0110] The preparation method differs from that in Example 1 in that:

[0111] The aluminum foil used in step 1 has a thickness of 20.35 μm.

[0112] Example 10

[0113] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the thickness of the aluminum layer is 120 μm, the thickness of the passivation layer is 0.28 μm, and the porosity is 8.3%.

[0114] The preparation method differs from that in Example 1 in that:

[0115] The aluminum foil used in step 1 has a thickness of 120.28 μm.

[0116] Example 11

[0117] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that the aluminum oxide in the aluminum oxide passivation layer is γ-Al2O3 with a porosity of 8%.

[0118] The preparation method differs from that in Example 1 in that step 4 is not included.

[0119] Example 12

[0120] This embodiment provides an aluminum-plastic film, which differs from Embodiment 1 in that it further includes a fixing layer, which is PET and has a thickness of 20μm.

[0121] The preparation method differs from that in Example 1 in that:

[0122] It also includes step 5, where PET plastic is melted and then coated onto the passivation layer surface of the aluminum foil after heat treatment in step 4, and after curing, an aluminum-plastic film is obtained.

[0123] Comparative Example 1

[0124] This comparative example provides an aluminum-plastic film that differs from Example 1 in that the thickness of the aluminum layer is 59.72 μm, the thickness of the passivation layer is 280 nm, and the porosity is 28%.

[0125] The difference between its preparation method and that of Example 1 is that step 3 is missing.

[0126] Comparative Example 2

[0127] This comparative example provides an aluminum-plastic film that differs from Example 1 in that the thickness of the aluminum layer is 59.97 μm, the thickness of the passivation layer is 30 nm, and the porosity is 3%.

[0128] The difference between its preparation method and that of Example 1 is that step 2 is missing.

[0129] Comparative Example 3

[0130] This comparative example provides an aluminum-plastic film comprising a polypropylene layer, an aluminum layer, a nylon layer, and a PET layer stacked sequentially. The polypropylene layer has a thickness of 15 μm, the aluminum layer has a thickness of 60 μm, the nylon layer has a thickness of 15 μm, and the PET layer has a thickness of 20 μm. All layers are bonded together using a polyethylene-based adhesive.

[0131] Performance testing:

[0132] The high and low temperature impedance and breakdown voltage of the aluminum-plastic film in the above embodiments and comparative examples were tested. The specific testing methods are as follows, and the test results are shown in Table 1 below.

[0133] Porosity of the passivation layer: Detected using the BET method.

[0134] High and low temperature impedance: Tests were conducted at room temperature (25±3℃) and 200℃ using a heating plate, an insulation withstand voltage tester, and a thermocouple. Specifically, the aluminum-plastic film was placed stably on the heating plate, the test end of the aluminum-plastic film was connected to the insulation withstand voltage tester, and the thermocouple was tightly attached to the surface of the aluminum-plastic film for temperature monitoring. After the temperature stabilized, the impedance value of the insulation withstand voltage tester was recorded.

[0135] Table 1

[0136]

[0137] As can be seen from the above results, the aluminum-plastic film in Examples 1-12 has good insulation performance at both room temperature and high temperature (200℃), and the insulation performance retention rate at high temperature is significantly better than that of the comparative example. This shows that the aluminum-plastic film provided by the present invention can still maintain high insulation performance at high temperature and the insulation performance is stable.

[0138] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to what has been described above. Various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. An aluminum-plastic film, characterized in that, It includes an aluminum layer, at least a portion of the surface of which is provided with a passivation layer, the porosity of which is ≤10%.

2. The aluminum-plastic film according to claim 1, characterized in that, The thickness of the passivation layer is 100nm-100μm, preferably 200nm-50μm; And / or, the thickness of the aluminum layer is 20μm-120μm.

3. The aluminum-plastic film according to claim 1 or 2, characterized in that, The passivation layer is an aluminum oxide passivation layer; Preferably, the alumina passivation layer comprises α-Al2O3.

4. The aluminum-plastic film according to any one of claims 1-3, characterized in that, A fixing layer, comprising plastic, is also provided on the side of the passivation layer away from the aluminum layer.

5. A method for preparing the aluminum-plastic film according to any one of claims 1-4, characterized in that, Includes the following steps: The aluminum foil is subjected to anodic micro-arc oxidation and oxygen plasma treatment in sequence to form a passivation layer, thereby obtaining the aluminum-plastic film.

6. The preparation method according to claim 5, characterized in that, During the anodic micro-arc oxidation treatment, the pulse voltage is 50 V-800 V, the pulse frequency is 50 Hz-1000 Hz, the time is 0.1 h-6 h, the electrolyte includes sodium silicate 5 g / L-20 g / L, sodium phosphate 2 g / L-10 g / L, potassium hydroxide 1 g / L-5 g / L, pH value is 10-13, and electrolyte temperature is 15-40 ℃. Preferably, the electrolyte further includes 1g / L-15g / L of Y2O3 nanoparticles, wherein the particle size of the Y2O3 nanoparticles is 20nm-100nm; And / or, during the oxygen plasma treatment, the power is 50 W-1000 W, the temperature is 100℃-400℃, an oxygen-containing mixed gas is introduced into the vacuum chamber and the pressure of the vacuum chamber is maintained at 10Pa-200Pa, and the treatment time is 0.05h-1h, wherein the volume fraction of oxygen in the oxygen-containing mixed gas is 20%-80%.

7. The preparation method according to claim 5 or 6, characterized in that, The aluminum foil treated with oxygen plasma is then subjected to heat treatment at a temperature of 300℃-500℃ for a time of 0.5h-2h.

8. The preparation method according to any one of claims 5-7, characterized in that, Also includes: The step of setting a fixing layer on the surface of the passivation layer.

9. A battery, characterized in that, Includes the aluminum-plastic film according to any one of claims 1-5 or the aluminum-plastic film prepared by the preparation method according to any one of claims 6-8; Preferably, the battery is a solid-state battery.

10. An electrical appliance, characterized in that, Includes the aluminum-plastic film according to any one of claims 1-5, or the aluminum-plastic film prepared by the preparation method according to any one of claims 6-8, or the battery according to claim 9.

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