Aluminum oxide film for new energy battery energy storage and its preparation process

Abstract

The present application discloses an aluminum oxide film for energy storage in new energy batteries and its preparation process, belonging to the field of battery materials. A preparation process for an aluminum oxide film for energy storage in new energy batteries comprises the following steps: plasma treatment of one side of the film to form a first plasma surface; vacuum evaporation of aluminum oxide on the first plasma surface to form a first aluminum oxide layer; plasma treatment of the side of the film facing away from the first aluminum oxide layer to form a second plasma surface; vacuum evaporation of aluminum oxide on the second plasma surface to form a second aluminum oxide layer, thereby obtaining an aluminum oxide film; the working gas in the plasma treatment method is a mixed gas containing argon and water vapor. The present application has the advantage of improving the comprehensive performance of the aluminum oxide film.

Description

Technical Field

[0001] The present application relates to the field of battery materials, and in particular to an aluminum oxide film for energy storage in new energy batteries and a preparation process thereof. Background Art

[0002] A current collector is a structure or component that collects current and is an essential component of lithium-ion batteries. Its function is to collect and output the current generated by the active material and to input the electrode current to the active material. This helps reduce the internal resistance of lithium-ion batteries and improve the battery's coulombic efficiency, cycle stability, and rate performance.

[0003] In the early days, current collectors in lithium-ion batteries primarily consisted of metal foils, such as copper and aluminum foil. However, these foils were known to be thick, heavy, and unsafe. With the advancement of new energy lithium-ion battery technology, the processing thickness of conventional metal foil current collectors is reaching its limit, making it difficult to meet the demands of further lithium-ion battery development.

[0004] Therefore, in recent years, composite current collectors based on polymer films have garnered widespread attention and application in the new energy industry. Composite current collectors are fabricated by applying a nanoscale metal layer to the surface of a polymer film, such as a PET-coated alumina film, to achieve a lightweight base film. However, the preparation process is still immature, and problems such as poor adhesion of the alumina layer and low barrier properties have led to reduced durability, hindering the application of alumina films in current collectors. Summary of the Invention

[0005] In order to improve the comprehensive performance of the aluminum oxide film, the present application provides an aluminum oxide film for new energy battery energy storage and a preparation process thereof.

[0006] In the first aspect, the present application provides a preparation process for an aluminum oxide film for energy storage in a new energy battery using the following technical solutions:

[0007] A preparation process for an aluminum oxide film for energy storage in a new energy battery comprises the following steps:

[0008] Plasma treatment is performed on one side of the film to form a first plasma surface;

[0009] vacuum evaporating aluminum oxide on the first plasma surface to form a first aluminum oxide layer;

[0010] performing plasma treatment on a surface of the thin film facing away from the first aluminum oxide layer to form a second plasma surface;

[0011] vacuum evaporating aluminum oxide on the second plasma surface to form a second aluminum oxide layer to obtain an aluminum oxide film;

[0012] The working gas in the plasma treatment method is a mixed gas containing argon and water vapor.

[0013] By adopting the above technical solution, vacuum evaporation is used to deposit aluminum oxide on the plasma surface of the film to form a thin aluminum oxide layer, and a double-sided plating method is used so that the aluminum oxide film can meet the requirements of the composite current collector.

[0014] Before vacuum evaporation, a plasma treatment method is used to activate and modify the film surface, introduce functional molecules or groups, and ensure the adhesion of the aluminum oxide layer to the film. Treating the film with a mixed gas plasma of argon and water vapor can significantly promote the bonding between the aluminum oxide and the film, especially for polyester film. In order to adapt to the characteristics of the mixed gas plasma treatment of argon and water vapor, compared with the traditional method of simultaneously plasma treating both sides of the film, the method of first plasma treating one side and then vapor-depositing, and then plasma treating the other side and then vapor-depositing can reduce the impact of functional group attenuation, thereby improving the overall performance of the aluminum oxide film.

[0015] Optionally, in the plasma treatment method, the working gas flow rate is 1000-1500 sccm, wherein the water vapor flow rate accounts for 5-15%.

[0016] By adopting the above technical solution, in the process of generating plasma, argon gas collides with water vapor to produce excited atoms, which etch the surface of the film and generate free radicals, introducing active functional groups. However, at the same time, water vapor combines with free radicals and affects the number of free radicals. Therefore, the flow rate of the working gas and the proportion of the water vapor flow rate are adjusted appropriately to form a surface morphology on the surface of the film suitable for the attachment of aluminum oxide.

[0017] Optionally, the output power of the plasma treatment is 900-1200W.

[0018] By adopting the above technical solution and appropriate output power, the degree of film surface etching and functional group generation can be controlled to meet the requirements of performance improvement.

[0019] Optionally, the process of vacuum evaporation of aluminum oxide includes: feeding the film into a vacuum evaporation device, evacuating the film, heating the aluminum wire at a high temperature, introducing oxygen, and forming an aluminum oxide layer on the plasma surface.

[0020] By adopting the above technical solution, the high temperature causes the aluminum wire to evaporate, combine with oxygen to form aluminum oxide, and deposit on the plasma surface of the film to form an aluminum oxide layer.

[0021] Optionally, the temperature of the heated aluminum wire is 1350-1400° C., the diameter of the aluminum wire is 1.5-2.0 mm, and the wire feeding speed of the aluminum wire is 185-230 mm / min.

[0022] By adopting the above technical solution, since the plasma surface is formed after the plasma treatment of the film, the morphology and functional group composition of the plasma surface are different from those of the ordinary film surface. Therefore, the heating state and speed of the aluminum wire are controlled, thereby controlling the cooling and deposition speed of the aluminum vapor on the film, so that the aluminum oxide can fully combine with the active plasma surface and improve the adhesion.

[0023] Optionally, in the vacuum evaporation equipment, the flow rate of the introduced oxygen is 14000-16000 sccm.

[0024] By adopting the above technical solution, the oxygen flow rate is controlled within the above range, the aluminum oxide forming process is improved, the uniformity of the aluminum oxide layer can be increased, and the quality of the aluminum oxide film can be further improved.

[0025] Optionally, in the plasma treatment method, the water vapor flow rate of the working gas accounts for 7.5-8.5%, and the output power of the plasma treatment is 1000-1050W; during the vacuum evaporation of aluminum oxide, the wire feeding speed of the aluminum wire is 205-220mm / min, and the flow rate of the oxygen introduced is 15450-15700sccm.

[0026] By adopting the above technical solution, on the one hand, the surface morphology of the plasma surface affects the interfacial bonding ability with aluminum oxide and affects the adhesion of the aluminum oxide layer. On the other hand, aluminum oxide in a properly deposited state helps to combine with the surface active functional groups of the plasma surface, thereby affecting the adhesion and uniformity of aluminum oxide, and affecting the barrier properties and other properties of the aluminum oxide film. Therefore, the surface morphology of the plasma surface and the aluminum oxide evaporation process interact and cooperate with each other. By controlling the above plasma treatment and vacuum evaporation process, the synergistic effect is enhanced, and the overall performance of the aluminum oxide film is achieved.

[0027] Optionally, the film is BOPP film or BOPET film.

[0028] Optionally, the film has a thickness of 6 μm to 8 μm.

[0029] In the second aspect, the present application provides an aluminum oxide film for energy storage in a new energy battery using the following technical solution:

[0030] An aluminum oxide film for energy storage in new energy batteries is prepared by the above-mentioned preparation process.

[0031] In summary, this application has the following beneficial effects:

[0032] 1. The present application realizes the deposition of aluminum oxide on the plasma surface of the thin film through vacuum evaporation to form a thin aluminum oxide layer, and adopts a double-sided plating method so that the aluminum oxide film can meet the requirements of the composite current collector; before vacuum evaporation, a plasma treatment method is used to activate and modify the surface of the film, introduce functional molecules or groups, and ensure the adhesion of the aluminum oxide layer to the film. The film is treated with a mixed gas plasma of argon and water vapor, which can significantly promote the bonding between aluminum oxide and the film, especially for polyester film. In order to adapt to the characteristics of the plasma treatment of a mixed gas of argon and water vapor, compared with the traditional method of simultaneously plasma treating both sides of the film, the method of first plasma treating one side and vapor-depositing, and then plasma treating the other side and vapor-depositing can reduce the impact of functional group attenuation, thereby improving the overall performance of the aluminum oxide film.

[0033] 2. The surface morphology of the plasma surface and the evaporation process of aluminum oxide interact and cooperate with each other. By controlling the plasma treatment and vacuum evaporation process, the synergistic effect is improved, and the overall performance of the aluminum oxide film is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a planar structural diagram of Example 1 of the present application.

[0035] Reference numerals:

[0036] 1. BOPET film; 2. First alumina layer; 3. Second alumina layer. DETAILED DESCRIPTION

[0037] The present application is further described in detail below.

[0038] Example 1

[0039] A preparation process for an aluminum oxide film for energy storage in a new energy battery comprises the following steps:

[0040] A BOPET film 1 having a thickness of 8 μm was taken. A surface treatment device that generates plasma by glow discharge was used to perform plasma treatment on one side of the BOPET film 1 to form a first plasma surface.

[0041] The BOPET film 1 is fed into a vacuum evaporation device, and aluminum oxide is vacuum evaporated on the first plasma surface to form a first aluminum oxide layer 2. The thickness of the first aluminum oxide layer 2 is 80±2 nm.

[0042] A plasma surface treatment device is used to perform plasma treatment on the side of the BOPET film 1 facing away from the first aluminum oxide layer 2 to form a second plasma surface.

[0043] The BOPET film 1 is fed into a vacuum evaporation device, and aluminum oxide is vacuum evaporated on the second plasma surface to form a second aluminum oxide layer 3. The thickness of the second aluminum oxide layer 3 is 80±2nm, and an aluminum oxide film is obtained. Figure 1 shown.

[0044] In the plasma treatment method, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500sccm, and the flow rate of water vapor in the working gas accounts for 5%; the output power of the plasma treatment is 900W.

[0045] The process of vacuum evaporation of aluminum oxide includes: feeding the BOPET film into the vacuum evaporation equipment, evacuating the vacuum evaporation equipment, heating the aluminum wire at a high temperature of 1350°C, the diameter of the aluminum wire is 1.5mm, the wire feeding speed of the aluminum wire is 185mm / min, and oxygen is introduced at a flow rate of 14000sccm to form an aluminum oxide layer on the plasma surface.

[0046] Example 2

[0047] A preparation process for an aluminum oxide film for energy storage in a new energy battery comprises the following steps:

[0048] A BOPET film having a thickness of 8 μm was taken and a surface treatment device that generates plasma by glow discharge was used to perform plasma treatment on one side of the film to form a first plasma surface.

[0049] The BOPET film is fed into a vacuum evaporation device, and aluminum oxide is vacuum evaporated on the first plasma surface to form a first aluminum oxide layer. The thickness of the first aluminum oxide layer is 80±2 nm.

[0050] A plasma surface treatment device is used to perform plasma treatment on the side of the BOPET film facing away from the first aluminum oxide layer to form a second plasma surface.

[0051] The BOPET film is fed into a vacuum evaporation device, and aluminum oxide is vacuum evaporated on the second plasma surface to form a second aluminum oxide layer. The thickness of the second aluminum oxide layer is 80±2 nm, thereby obtaining an aluminum oxide film.

[0052] In the plasma treatment method, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1000 sccm, and the flow rate of water vapor in the working gas accounts for 15%; the output power of the plasma treatment is 1200W.

[0053] The process of vacuum evaporation of aluminum oxide includes: feeding the BOPET film into the vacuum evaporation equipment, evacuating the vacuum evaporation equipment, heating the aluminum wire at a high temperature of 1400°C, the diameter of the aluminum wire is 2.0mm, the wire feeding speed of the aluminum wire is 230mm / min, and oxygen is introduced at a flow rate of 16000sccm to form an aluminum oxide layer on the plasma surface.

[0054] Example 3

[0055] A preparation process for an aluminum oxide film for energy storage in a new energy battery is different from that in Example 1 in the plasma treatment method.

[0056] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 11%; the output power of the plasma treatment is 900W.

[0057] Example 4

[0058] A preparation process for an aluminum oxide film for energy storage in a new energy battery is different from that in Example 1 in the plasma treatment method.

[0059] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 7.5%; the output power of the plasma treatment is 900W.

[0060] Example 5

[0061] A preparation process for an aluminum oxide film for energy storage in a new energy battery is different from that in Example 1 in the plasma treatment method.

[0062] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 5%; the output power of the plasma treatment is 1000W.

[0063] Example 6

[0064] A preparation process for an aluminum oxide film for energy storage in a new energy battery is different from that in Example 1 in the process of vacuum evaporation of aluminum oxide.

[0065] During the vacuum evaporation of aluminum oxide in this embodiment, the BOPET film is fed into the vacuum evaporation equipment, the vacuum evaporation equipment is evacuated, and the aluminum wire is heated at a high temperature of 1350°C. The diameter of the aluminum wire is 1.5 mm, and the wire feeding speed of the aluminum wire is 205 mm / min. Oxygen is introduced at a flow rate of 14000 sccm to form an aluminum oxide layer on the plasma surface.

[0066] Example 7

[0067] A preparation process for an aluminum oxide film for energy storage in a new energy battery is different from that in Example 1 in the process of vacuum evaporation of aluminum oxide.

[0068] During the vacuum evaporation of aluminum oxide in this embodiment, the BOPET film is fed into the vacuum evaporation equipment, the vacuum evaporation equipment is evacuated, and the aluminum wire is heated at a high temperature of 1350°C. The diameter of the aluminum wire is 1.5 mm, the wire feeding speed is 185 mm / min, and oxygen is introduced at a flow rate of 14800 sccm to form an aluminum oxide layer on the plasma surface.

[0069] Example 8

[0070] A preparation process for an aluminum oxide film for energy storage in new energy batteries, which differs from Example 1 in the plasma treatment method and the vacuum evaporation process of aluminum oxide.

[0071] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 7.5%; the output power of the plasma treatment is 900W.

[0072] During the vacuum evaporation of aluminum oxide in this embodiment, the BOPET film is fed into the vacuum evaporation equipment, the vacuum evaporation equipment is evacuated, and the aluminum wire is heated at a high temperature of 1350°C. The diameter of the aluminum wire is 1.5 mm, the wire feeding speed is 185 mm / min, and oxygen is introduced at a flow rate of 15450 sccm to form an aluminum oxide layer on the plasma surface.

[0073] Example 9

[0074] A preparation process for an aluminum oxide film for energy storage in new energy batteries, which differs from Example 1 in the plasma treatment method and the vacuum evaporation process of aluminum oxide.

[0075] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 11%; the output power of the plasma treatment is 1000W.

[0076] During the vacuum evaporation of aluminum oxide in this embodiment, the BOPET film is fed into the vacuum evaporation equipment, the vacuum evaporation equipment is evacuated, and the aluminum wire is heated at a high temperature of 1350°C. The diameter of the aluminum wire is 1.5 mm, and the wire feeding speed of the aluminum wire is 205 mm / min. Oxygen is introduced at a flow rate of 15450 sccm to form an aluminum oxide layer on the plasma surface.

[0077] Example 10

[0078] A preparation process for an aluminum oxide film for energy storage in new energy batteries, which differs from Example 1 in the plasma treatment method and the vacuum evaporation process of aluminum oxide.

[0079] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 7.5%; the output power of the plasma treatment is 1000W.

[0080] During the vacuum evaporation of aluminum oxide in this embodiment, the BOPET film is fed into the vacuum evaporation equipment, the vacuum evaporation equipment is evacuated, and the aluminum wire is heated at a high temperature of 1350°C. The diameter of the aluminum wire is 1.5 mm, and the wire feeding speed of the aluminum wire is 205 mm / min. Oxygen is introduced at a flow rate of 15450 sccm to form an aluminum oxide layer on the plasma surface.

[0081] Example 11

[0082] A preparation process for an aluminum oxide film for energy storage in new energy batteries, which differs from Example 1 in the plasma treatment method and the vacuum evaporation process of aluminum oxide.

[0083] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and water vapor, the flow rate of the working gas is 1500 sccm, and the flow rate of water vapor in the working gas accounts for 8.5%; the output power of the plasma treatment is 1050W.

[0084] During the vacuum evaporation of aluminum oxide in this embodiment, the BOPET film is fed into the vacuum evaporation equipment, the vacuum evaporation equipment is evacuated, and the aluminum wire is heated at a high temperature of 1350°C. The diameter of the aluminum wire is 1.5 mm, the wire feeding speed is 220 mm / min, and oxygen is introduced at a flow rate of 15700 sccm to form an aluminum oxide layer on the plasma surface.

[0085] Comparative Example 1

[0086] A preparation process for an aluminum oxide film for energy storage in a new energy battery comprises the following steps:

[0087] A BOPET film having a thickness of 8 μm was taken and placed into a vacuum evaporation device. Aluminum oxide was vacuum evaporated on the first plasma surface to form a first aluminum oxide layer having a thickness of 80±2 nm.

[0088] The BOPET film is again fed into the vacuum evaporation equipment, and aluminum oxide is vacuum evaporated on the side away from the first aluminum oxide layer to form a second aluminum oxide layer. The thickness of the second aluminum oxide layer is 80±2 nm, thereby obtaining an aluminum oxide film.

[0089] The process of vacuum evaporation of aluminum oxide includes: feeding the BOPET film into the vacuum evaporation equipment, evacuating the vacuum evaporation equipment, heating the aluminum wire at a high temperature of 1350°C, the diameter of the aluminum wire is 1.5mm, the wire feeding speed of the aluminum wire is 185mm / min, and oxygen is introduced at a flow rate of 14000sccm to form an aluminum oxide layer on the plasma surface.

[0090] Comparative Example 2

[0091] A preparation process for an aluminum oxide film for energy storage in a new energy battery is different from that in Example 1 in the plasma treatment method.

[0092] In the plasma treatment method of this embodiment, the working gas is a mixed gas composed of argon and oxygen, the flow rate of the working gas is 1500 sccm, the flow rate of water vapor in the working gas accounts for 5%; the output power of the plasma treatment is 900W.

[0093] Performance testing

[0094] Adhesion of aluminum oxide layer: Referring to QB / T 2358-1998 "Test method for heat seal strength of plastic film packaging bags", the heat seal layer of the EAA film was heat-sealed to the aluminum oxide layer of the aluminum oxide-coated film at a heat sealing temperature of 115°C, a pressure of 0.4 MPa, and a heat sealing time of 2 seconds. The aluminum oxide layer was then peeled off from the aluminum oxide-coated film using a tensile testing machine to obtain adhesion data. The results are shown in Table 1.

[0095] The aluminum oxide film was placed in an oven at 150° C. and 75% humidity for 48 hours, and then subjected to an adhesion test. The results are shown in Table 1.

[0096] Table 1

[0097]

[0098]

[0099] Barrier properties: The oxygen transmission rate and water vapor transmission rate of the aluminum oxide film were tested with reference to ASTM D-3985 and ASTM F-1249. The results are shown in Table 2.

[0100] Light transmittance: The light transmittance of the aluminum oxide film was tested according to ASTM D-1003. The results are shown in Table 2.

[0101] Table 2

[0102]

[0103] As can be seen from Tables 1 and 2, compared with Comparative Example 1 which has not undergone plasma surface treatment, Example 1 has better performance in terms of adhesion, aging resistance, barrier properties and light transmittance of the aluminum oxide layer, indicating that plasma surface treatment can activate and modify the film surface, improve the bonding strength of aluminum oxide to the film, and exhibit good adhesion fastness and coating surface condition, thereby obtaining an aluminum oxide-plated film with high durability and good comprehensive performance.

[0104] Compared with Comparative Example 2 which uses argon and oxygen as working gases, Example 1 uses argon and water vapor as working gases. The film surface modified after plasma treatment is more suitable for plating an aluminum oxide layer to meet the requirement of high stability of the aluminum oxide film.

[0105] In addition, the plasma treatment method and the parameters in the vacuum evaporation of aluminum oxide will affect the performance of the aluminum oxide film, and the influence of the parameters is mutually coordinated and restricted. Therefore, it is crucial to balance and combine the plasma treatment method and the vacuum evaporation of aluminum oxide. From the performance results of Examples 3 to 11, it can be seen that in the plasma treatment method, the water vapor flow rate of the working gas accounts for 7.5-8.5%, and the output power of the plasma treatment is 1000-1050W; in the process of vacuum evaporation of aluminum oxide, the wire feeding speed of the aluminum wire is 205-220mm / min, and the flow rate of the oxygen introduced is 15450-15700sccm. There will be a comprehensive improvement in the adhesion, aging resistance, barrier properties and light transmittance of the aluminum oxide layer, thereby improving the comprehensive performance of the aluminum oxide film.

[0106] This specific implementation manner is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the specific implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A preparation process for an aluminum oxide film for energy storage in new energy batteries, characterized in that: The following steps are involved: Plasma treatment is performed on one side of the film to activate and modify the film surface to form a first plasma surface; vacuum evaporating aluminum oxide on the first plasma surface to form a first aluminum oxide layer; performing plasma treatment on a side of the film facing away from the first aluminum oxide layer to activate and modify the film surface to form a second plasma surface; vacuum evaporating aluminum oxide on the second plasma surface to form a second aluminum oxide layer to obtain an aluminum oxide film; The working gas in the plasma treatment method is a mixed gas containing argon and water vapor; The process of vacuum evaporation of aluminum oxide includes: feeding the film into the vacuum evaporation equipment, evacuating the vacuum, heating the aluminum wire at high temperature, introducing oxygen, and forming an aluminum oxide layer on the plasma surface; In the plasma treatment method, the water vapor flow rate of the working gas accounts for 7.5~8.5%, and the output power of the plasma treatment is 1000~1050W; during the vacuum evaporation of aluminum oxide, the wire feeding speed of the aluminum wire is 205~220mm / min, and the flow rate of the oxygen introduced is 15450~15700sccm.

2. The process for preparing an aluminum oxide film for energy storage in a new energy battery according to claim 1, characterized in that: The working gas flow rate in the plasma treatment method is 1000~1500sccm.

3. The process for preparing an aluminum oxide film for energy storage in a new energy battery according to claim 1, characterized in that: The temperature of the heated aluminum wire is 1350~1400℃, and the diameter of the aluminum wire is 1.5~2.0mm.

4. The process for preparing an aluminum oxide film for energy storage in a new energy battery according to claim 1, characterized in that: The film is selected from BOPP film or BOPET film.

5. The process for preparing an aluminum oxide film for energy storage in a new energy battery according to claim 1, characterized in that: The film thickness is 6 μm to 8 μm.

6. A new energy battery energy storage aluminum oxide film, characterized by: It is prepared based on the preparation process described in any one of claims 1 to 5.

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