阅读说明：本技术 电池用镀金属膜的一次蒸镀制备方法 (One-time evaporation preparation method of metal-plated film for battery ) 是由 吴明忠 曾祥平 吴林海 于 2019-11-26 设计创作，主要内容包括：本发明涉及电池用镀金属膜的一次蒸镀制备方法,取基膜依附在冷却辊上送入真空蒸镀室内,真空蒸镀室内设有放置有金属材料的蒸发机构,当真空蒸镀室内的真空度达到设定阈值要求后,加热金属材料并使其在蒸发机构内熔融蒸发形成金属蒸汽,使得基膜浸于金属蒸汽中,即完成金属层的一次蒸镀。与现有技术相比,本发明通过将冷却辊与转向辊分别连接直流电源的两极,使得位于两者之间的基膜可以因静电吸附作用而牢牢吸附在冷却辊上,大大的提高了冷却辊与基膜之间的传热冷却效果,进而方便实现在基膜上的一次蒸镀成膜。(The invention relates to a one-time evaporation preparation method of a metal-plated film for a battery, which comprises the steps of taking a base film to attach to a cooling roller and sending the base film into a vacuum evaporation chamber, wherein the vacuum evaporation chamber is internally provided with an evaporation mechanism for placing a metal material, and after the vacuum degree in the vacuum evaporation chamber reaches the requirement of a set threshold value, heating the metal material and melting and evaporating the metal material in the evaporation mechanism to form metal steam, so that the base film is immersed in the metal steam, and the one-time evaporation of the metal layer is finished. Compared with the prior art, the cooling roller and the steering roller are respectively connected with two poles of a direct-current power supply, so that the base film between the cooling roller and the steering roller can be firmly adsorbed on the cooling roller due to electrostatic adsorption, the heat transfer cooling effect between the cooling roller and the base film is greatly improved, and further one-time evaporation film forming on the base film is conveniently realized.)

1. A one-time evaporation preparation method of a metal-plated film for a battery is characterized in that a base film is taken to be attached to a cooling roller and sent into a vacuum evaporation chamber, an evaporation mechanism with a metal material is arranged in the vacuum evaporation chamber, and after the vacuum degree in the vacuum evaporation chamber reaches a set threshold value requirement, the metal material is heated and melted and evaporated in the evaporation mechanism to form metal steam, so that the base film is immersed in the metal steam, and one-time evaporation of the metal layer is completed.

2. The method according to claim 1, wherein the cooling roller and the first turning roller disposed adjacently along the conveying direction of the base film are respectively connected to two poles of a direct current power supply.

3. The method as claimed in claim 2, wherein the voltage applied by the DC power supply is 800-1000V.

4. The one-time evaporation preparation method of a battery metallized film according to claim 1 or 2, characterized in that the base film is a nonporous base film, and the material of the base film is PET, PP or PI.

5. The method of claim 4, wherein the thickness of the base film is 3-12 μm.

6. The method of claim 1, wherein a cooling roller is provided with a cooling channel for circulating cooling liquid, and the temperature of the cooling liquid is less than or equal to-20 ℃.

7. The method of claim 1, wherein the substrate film is further subjected to a heat drying treatment at 40-80 ℃ after the surface treatment and before the substrate film is fed into the vacuum evaporation chamber.

8. The method of claim 1, wherein the degree of vacuum in the vacuum evaporation chamber is less than or equal to 9 x 10 when the metal layer is evaporated^-2Pa。

9. The method of claim 1, wherein the metal material is aluminum.

10. The method of claim 1, wherein the base film is further subjected to a surface treatment by one or more of corona treatment, electric spark treatment, plasma treatment, Ni plating, AlO plating, chemical treatment coating, and NaOH immersion treatment before being fed into the vacuum evaporation chamber through the cooling roller.

Technical Field

The invention belongs to the technical field of metal-plated battery membrane materials, and relates to a one-time evaporation preparation method of a metal-plated membrane for a battery.

Background

Currently, the anode fluid of the lithium ion battery usually adopts an aluminum foil as a carrier, but the structure using the aluminum foil as the carrier is deficient in energy density and safety. Therefore, in order to solve the above problems, a new alternative is to replace the aluminum foil with a plated metal film for a battery, in which the plated metal film for a battery is plated with aluminum on both sides of a polymer film, so that the weight and volume can be reduced to increase the energy density. Meanwhile, in the aspect of safety, the polymer plastic film is used as an intermediate, and when a high-temperature short circuit occurs, the metal film can be fused to form a broken circuit, so that the use safety of the battery is greatly improved.

Therefore, the performance of the aluminum-plated thin film for a battery directly affects the interface structure, internal resistance, and the like of the battery, and further directly affects the characteristics of the battery, such as capacity, cycle, and safety performance. The metal film with excellent performance plays an important role in improving the comprehensive performance of the battery.

There are many factors that affect the excellent performance of the film, and among them, the magnitude of the bonding strength between the metal layer and the base film is a very important factor. In addition, in order to satisfy the performance requirements of the film, it is generally necessary to deposit an aluminum plating layer or the like of a certain thickness on the surface of a polyolefin base film, for example, and it is generally required to be around 800 nm. If the aluminum plating layer with the thickness of the specification is finished by one-time evaporation, the base film is required to stay in a high-temperature vacuum evaporation chamber for a long time during the evaporation, so that the base film cannot follow up due to cooling of a cooling roller, wrinkling and deformation at high temperature are caused, and the quality of the film is seriously affected. The present invention has been made in view of the above problems.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a one-time evaporation preparation method of a metal-plated film for a battery, so that the metal layer with enough thickness is evaporated on a base film, the evaporation quality is ensured and the preparation process flow is simplified.

The purpose of the invention can be realized by the following technical scheme:

a method for preparing plated metal film for battery by one-time evaporation plating includes feeding base film into vacuum evaporation plating chamber through cooling roller, setting evaporation mechanism with metal material in vacuum evaporation plating chamber, heating metal material and fusing and evaporating in evaporation mechanism to form metal steam when vacuum degree in vacuum evaporation plating chamber reaches set threshold value requirement for making base film be immersed in metal steam to finish one-time evaporation plating of metal layer.

Further, the cooling roll and the first turning roll disposed adjacent thereto in the conveying direction of the base film are connected to both poles of a direct current power supply, respectively.

Furthermore, the voltage applied by the DC power supply is 800-1000V.

Further, the base film is a nonporous base film. The basal membrane is a PET or PP or PI membrane.

Further, the base film has a thickness of 3 to 12 μm.

Furthermore, a circulating cooling channel for introducing cooling liquid is arranged in the cooling roller, and the temperature of the introduced cooling liquid is less than or equal to-20 ℃. Further, the cooling liquid is a mixture of alcohol and hexanediol.

Further, the base film is heated and dried in the environment of 40-80 ℃ after the surface treatment and before being sent into a vacuum evaporation chamber. Through the heating and drying treatment, water vapor in the base film can be further removed, and the adhesive force of the metal layer during subsequent vacuum evaporation is improved. Meanwhile, the proper temperature in the range of 40-80 ℃ can also ensure that the base film is not curled due to overhigh temperature, and simultaneously can also ensure that the activity of molecules on the surface of the base film can be maintained when the base film enters a vacuum evaporation chamber, thereby enhancing the connection effect with metal molecules.

Furthermore, when the metal layer is evaporated, the vacuum degree in the vacuum evaporation chamber is less than or equal to 9 multiplied by 10^-2Pa。

Further, the metal material is aluminum material.

Furthermore, in the whole preparation process, the ambient temperature is not higher than 30 ℃, and the relative humidity is not higher than 60%.

Further, the surface treatment is carried out on the base film before the base film is sent into the vacuum evaporation chamber, and the surface treatment mode of the base film is one or a combination of a plurality of corona treatment, electric spark treatment, plasma treatment, Ni plating treatment, AlO plating treatment, chemical treatment coating or NaOH soaking treatment.

Furthermore, all other rollers and other components of the whole set of evaporation equipment are not communicated with each other and are subjected to insulation treatment.

The invention discovers, through research, that the main reasons that the existing evaporation mode is difficult to finish by one-time evaporation are as follows: the current metal level such as the layer of aluminizing of evaporating plating on the base film, the base film is because the tension that is located other rollers of chill roll production influences, can the tensioning attach on the chill roll surface, this kind of mode with the base film attached on the chill roll surface is because reasons such as the atress is inhomogeneous, lead to the unable complete even attached on the chill roll surface of base film very easily, make partial region produce fold arch etc. like this, when the vacuum evaporation room of process, because this partial fold bellied region can't in time be cooled off by the chill roll, and then influenced by high temperature metal (aluminium etc.) steam and cause the base film to be heated to coil and contract the fold and even partial region scalds and wear etc..

Therefore, the two poles of the direct current power supply are respectively connected with the cooling roller and the first steering roller positioned behind the cooling roller, so that two charges with different electrical properties are stored on the cooling roller and the steering rollers, the surface of the base film coated with the aluminum coating layer through vacuum evaporation plating is capable of conducting the charges on the steering rollers to the surface of the base film tightly attached to the cooling roller, and at the moment, the base film can be firmly and uniformly attached to the surface of the cooling roller due to the electrostatic adsorption effect of the charges with different electrical properties on the outer surfaces of the cooling roller and the base film.

Compared with the prior art, the invention has the following advantages:

(1) the invention adopts a direct current power supply to directly and respectively connect the cooling roller and the steering roller, and the cooling roller and the steering roller are respectively provided with different electric charges in a capacitance mode, and then the electric charges are conducted through the evaporated metal layer, so that the two sides of the part of the base film close to the cooling roller are respectively mutually attracted due to the electrostatic adsorption effect generated by the different electric charges, and the base film is firmly attached to the cooling roller and is timely cooled.

(2) Overall structure arranges simply, through adopt direct current connect respectively the chill roll with turn to the roller can, simultaneously, because all the other parts are insulation treatment, the base film also adopts insulating good membrane, can not take place the short circuit to and the charge loss on chill roll and the turn to the roller and the operation process unstability scheduling problem that produces.

(3) Through the heating drying treatment of addding the base film and getting into the vacuum evaporation room, optimize technological parameters such as ambient humidity simultaneously, improved the combination effect between metal level and the base film, guaranteed the coating by vaporization quality of metal level.

Drawings

FIG. 1 is a schematic view of the cooling roll and turning roll portion of the present invention in connection therewith;

in the figure, 1 is an evaporation mechanism, 2 is a cooling roller, and 3 is a steering roller.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In the following examples, the procedure for testing the bond strength is as follows: 1) firstly, laying an EAA film on the prepared aluminized film product; 2) hot pressing at 120 deg.C for 0.5s with a heat-sealing instrument to bond the EAA film and the aluminum-plated film; 3) and cutting the aluminum plated film into strips, pulling one side of the EAA film on a tensile testing machine, testing the tensile value for pulling the EAA film and the aluminum plated film product apart, sampling three strips each time, and averaging the obtained tensile values to obtain the bonding strength of the aluminum plated layer on the aluminum plated film product to be characterized.

The remainder, unless specifically stated, of the materials, functional elements, or processing techniques are those conventionally available in the art, or are conventional processing techniques, or are conventional functional structures in the art for performing the corresponding functions.