JPH02190482A - Production of thin lithium film - Google Patents

Abstract

PURPOSE:To continuously mass-produce the thin Li film having good workability and dimensional precision with good reproducibility by utilizing the perforated structure of a screen material, passing metallic Li, etc., through the perforation, and stucking the metals, etc., on a support of metal, etc. CONSTITUTION:The metallic Li 8, etc., are pressed on the support 1 of metal, etc., through the opening 4a of the cylindrical screen material 4 having the thickness corresponding to the desired film thickness, and stucked on the support. In this case, the metallic Li 8, etc., screen material 4, support 1, etc., are heated and respectively held at a specified temp. In addition, the support 1 is preferably rolled out from a roller 2 by the forced rotation of driving rollers 5 and 6 opposed to each other, and supplied into the gap between the screen material 4 and the roller 5. Namely, the metallic Li 8, etc., are supplied onto the screen material 4 from a supply port 9, introduced into the opening 4a under specified pressure, and further pressed by a spatula 10 to stuck a desired amt. of the metallic Li 8, etc., on the surface of the support 1 in the thickness controlled by the thickness of the screen material 4. The product is continuously transferred by the rollers 5 and 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to so-called lithium metals, which can be used for example in lithium electrodes, etc., and which are made of metal lithium, lithium alloys, and metal lithium mixed with foreign substances (hereinafter collectively referred to as lithium metals). This invention relates to a method for producing a lithium thin film.

[Prior Art] Conventional methods for producing lithium thin films include methods such as extrusion and rolling. For example, Japanese Patent Publication No. 55-122 discloses a method for manufacturing a relatively thin lithium strip of about 40 microns by cold rolling lithium metal between the surfaces of a solid polymer composition to reduce its thickness. Tokuko Showa 5
No. 5-41841 discloses a method of rolling a metal foil by passing it together with a plastic belt through a gap between a pair of rollers.

[Problems to be Solved by the Invention] However, conventional manufacturing methods such as rolling and extrusion can yield very thin lithium films of, for example, 100μ or less, but because they are processed by rolling, extrusion, etc., there are problems inherent to lithium metals. It is extremely difficult to handle, especially when manufacturing lithium batteries, as it is affected by various mechanical properties and is easily deformed during processing, and easily breaks due to insufficient tensile strength. It had drawbacks such as interfering with sex.

An object of the present invention is to provide a method for manufacturing a lithium thin film that takes into account the mechanical properties inherent to lithium metals, has good workability, and can be obtained at a low cost with accurate dimensions.

[Means for Solving the Problems] As a result of intensive studies to achieve the above objectives, we developed a method for producing lithium thin films using screen materials.

In other words, screen materials such as wire mesh, expanded metal, punched metal, etc. have certain openings, and the openings are kept open by a frame with a certain thickness surrounding them. . Therefore, if a configuration is adopted in which lithium metal is forced into the opening and is deposited on the metal support through the opening, the thickness of the lithium thin film can be controlled by the thickness of the screen material without rolling. I can do it,
It is also possible to provide a uniform thickness. Furthermore, since the film is simply deposited rather than rolled with film thickness taken into consideration, the above-mentioned handling disadvantages due to the physical and mechanical properties inherent to lithium metals can be avoided as much as possible.

The present invention focuses on the structural characteristics of this type of screen material, uses a screen material whose thickness corresponds to the thickness of the desired lithium thin film, and supplies lithium metals into the openings of the screen material. A method was adopted in which a lithium thin film was produced by pressing and adhering it onto a holder made of metal or the like through an opening.

Since lithium metals are passed through the openings in the screen material, the temperature of the lithium metals itself must be controlled as appropriate, such as by heating or removing heat, to ensure a certain level of fluidity, and the temperature of the screen material, holder, etc. must also be controlled. It is desirable to do so.

By the way, since the present invention is a method of adhering lithium metals by pressing them onto a metal holder through the openings of a screen material having a thickness corresponding to the desired film thickness, this method can be used as a continuous production method for lithium thin films. It can also be adopted as

For example, there is a method of using a cylindrical screen material as the screen material. In other words, a cylindrical screen material is arranged opposite to a drive roller, a holding body such as metal is continuously fed between the drive roller and the cylindrical screen material, and as the drive roller and screen material rotate, the cylindrical screen This is a method of supplying lithium metals from inside the material and depositing the lithium metals on the holder of the metals.

Moreover, a plate-shaped material can also be used as the screen material. In this case, create a plate-shaped screen material of the desired thickness, place it on the base facing each other,
During this time, a holding body such as a metal is continuously fed, and the lithium metal is pushed horizontally on the screen material while being pressed downward, and the lithium metal is attached to the holding body such as the metal. It's a method.

In any case, the lithium metal adheres to the holder at least within the height of the entire screen material, so by selecting a thin screen material, a lithium thin film with an extremely small thickness can be easily obtained.

In both methods, if necessary, a supply container is used as a means of supplying lithium metals, and a spatula is used to follow the supply of lithium metals and slide it horizontally on the screen material while applying pressure. do. It is preferable.

By the way, the screen material only needs to have a certain thickness and have openings.
Punched metal or the like can be used as appropriate, but a screen material that can be freely selected to be thick or thin and has excellent shape stability from the viewpoint of holding the openings is desirable. Note that the shape, size, etc. of the apertures of the screen material can also be controlled by appropriately setting the aperture conditions such as the shape and size of the apertures of the screen material.

In addition, by appropriately controlling the temperature of the lithium metal, the screen material, and the holding body, we can utilize the viscosity of the lithium metal on the holding body and the solidification temperature due to cooling to produce lithium thin films with angular cross-sections and smooth surfaces. Continuous composition forms can also be obtained. Furthermore, in order to obtain a lithium thin film with a very smooth surface, a rolling process may be added after using the screen material. In addition, if you mask the screen material while leaving the desired shape, you can create a circular shape on the holding body.
Lithium thin films of arbitrary shapes, such as rectangular or star-shaped, can also be obtained.

In addition to metals, metallized substances and organic substances can also be used as the holder for metals, such as battery outer can materials, battery separators (in the case of organic films), peelable carriers, solid electrolytes, etc. Can be used as a holder. In addition, when manufacturing a lithium thin film continuously as described below, it is preferable to continuously feed the lithium film in the form of a so-called strip of metal or the like.

[Function] The present invention utilizes the aperture structure of the screen material and has a structure in which lithium metals are deposited on a metal holder through the apertures, so the thickness of the metal thin film can be controlled by the thickness of the screen material. Moreover, it can have a uniform thickness, and since it is not rolled, the work is not restricted by the inherent mechanical properties such as deformation and tensile strength of lithium metals, so it is easy to handle and work. Therefore, workability, especially in assembling lithium batteries, is greatly improved.

There are other methods for attaching lithium metals to the holder, such as vapor deposition in a vacuum, electrochemical deposition methods such as plating, and welding methods used in ceramics, etc., but all are necessary. The heat and electrical energy involved is large, and there is some distance between the lithium metal and the holder to which it is to be attached, so there is a possibility that the lithium metal may change in quality due to the influence of the working environment before it adheres to the holder. is high, and there is a lot of raw material loss. Furthermore, if a device for preserving the working environment to prevent such deterioration is adopted, the device itself will be large-scale, which is not desirable in terms of product cost. In this regard, since the present invention is a method of directly attaching lithium metals to the support, evaporation and scattering of lithium metals is extremely low, energy costs are low, and continuity of reproducibility can be ensured. Lithium thin films with very accurate dimensions and shapes can be obtained at low cost. .

[Example] Next, a method for manufacturing a lithium thin film according to the present invention will be described with reference to the drawings.

Figures 1 and 2 are schematic diagrams showing a continuous manufacturing method using a cylindrical screen material, in which 1 is a holder made of strip-shaped metal, etc.; , the other end is wound with a roll 3.

In the middle of transporting the holding body 1, a cylindrical screen material 4 and a driving roller 5 are placed which are vertically opposed to each other as shown in the figure, and the strip-shaped holding body 1 is fed between the screen material 4 and the driving roller 5. be provided. The cylindrical screen material 4 is
As shown in FIG. 2, it is slightly narrower than the drive roller 5 in the width direction, and is pressed together from the inside by the upper drive roller 6 at one side end, and the upper drive roller 6 and the drive roller 5 By forced rotation with
The feeding of the holder 1 and the rotational movement of the cylindrical screen material 4 are applied simultaneously. Reference numeral 7 denotes a supply container for lithium metals 8 installed outside the screen material 4. A supply path is inserted into the screen material 4, and lithium metals 8 are supplied to the surface of the screen material 4 from the lithium supply port 9 at the end. be done. As shown in FIG. 2, the screen material 4 of this embodiment has an opening 4a at an intermediate position in the width direction, and masked closed holes 4b are arranged on both sides of the opening 4a. Therefore, the lithium supply port 9 is connected to this opening 4a.
The structure is such that lithium metals are directly supplied onto the holder 1 from the opening 4a so as to match the width dimension of the holder 1. Reference numeral 10 denotes a spatula that applies pressure on the screen material and feeds the supplied lithium metals into the openings 4a. Hera 10
Since the screen material 4 of this embodiment is forced to rotate, it is of a fixed type. Note that when the lithium metals 8 are supplied onto the screen material 4 and deposited on the holder 1, the lithium metals are heated, heat removed, etc. from the supply container 7 to the supply port 9 in order to ensure constant fluidity. The temperature is appropriately controlled, and the temperature of the screen material 4, holder 1, etc. is also controlled.

Therefore, when using a cylindrical screen material, the drive roller 5
By the forced rotation of the upper drive roller 6, the holding body 1 made of metal or the like is unwound from the unwinding roller 2 and is fed into the gap between the cylindrical screen material 4 and the driving roller 5. circle·
Since there is a supply port 9 for lithium metals supplied from the outside inside the cylindrical screen material 4, lithium metals 8 are supplied onto the cylindrical screen material 4 from the supply port 9. The lithium metals 8 supplied onto the screen material 4 are supplied into the openings 4a of the screen 4 with a constant pressure,
It is further pressed by the spatula 10 which is in a fixed state. A desired amount of the pressed lithium metals 8, which is regulated by the thickness of the screen material 4, adheres to the surface of the holder 1, and is continuously transported by the drive roller 5 and the upper drive roller 6.

FIG. 3 is a schematic diagram showing a continuous manufacturing method when a plate-shaped screen material is used, and is an explanatory diagram of another embodiment according to the present invention.

In the figure, reference numerals 1, 8, and 10 indicate a holder, lithium metals, and a spatula as in the previous embodiment.

11 is a plate-shaped screen material, 12 is a frame that holds the screen material 11 on its outer periphery, and 13 is a supply container that supplies lithium metals 8 directly onto the screen material 11. As shown, the screen material 11 is arranged on a base 14 so as to be movable up and down, and the holder 1, which is unwound as a strip from one end and wound up at the other end, is fed into the gap therebetween.

Note that the temperature of the lithium metals 8, the supply container 13, the frame 12, the holder 1, the screen material 1↓, and the spatula 10 is controlled by heating or cooling.

Therefore, lithium metals 8 are directly supplied from the supply container onto the screen material 11 onto the holder 1 which is continuously fed into the gap between the base 14 and the screen material 11, and is kept pressed downward. Slide it horizontally as shown in Figure 4,
Further, the spatula 10 is slid laterally on the screen material 11 while applying the same pressure, thereby depositing lithium metals onto the holder 1 through the openings 11a of the screen material.

In addition, FIG. 5 shows lithium metals 8, screen material 11,
By controlling the temperature of the holder 1,
A schematic cross-sectional view showing the adhesion state of a lithium thin film with an angular cross-sectional shape obtained by utilizing the viscosity of the lithium metals and the solidification temperature due to cooling. Figure 6 shows the adhesion state of a lithium thin film with a smooth surface. FIG.

[Effects of the Invention] As described above, the present invention utilizes the structural characteristics of the screen material to adhere the screen material onto the holding body through the screen material, so there is no possibility of deformation or
It is possible to continuously produce large quantities of homogeneous, ultra-thin lithium thin films with accurate dimensions without tearing or wasting raw materials with good reproducibility. Therefore, it is extremely easy to handle, has good workability, and is economical. Moreover, since the shape, size, etc. can be adjusted as appropriate by masking, temperature control, etc., it has an especially remarkable effect that has never been seen before in this technical field.

[Brief explanation of the drawing]

Figures 1 and 2 are front and side schematic diagrams showing the continuous manufacturing method using cylindrical screen material, and Figure 3 is a schematic diagram showing the continuous manufacturing method using plate-shaped screen material. Figure 4 is an enlarged schematic view of the same essential parts, Figure 5 is a schematic cross-sectional view showing the state of adhesion of a lithium thin film with an angular cross-sectional shape, and Figure 6 is a schematic view showing the state of adhesion of a lithium thin film with a smooth surface. FIG. 1... Holder 4.11... Screen material 4a, lla... Opening part

Claims (3)

[Claims] (1) A method for producing a lithium thin film, which comprises pressing and adhering lithium metal onto a holder made of metal or the like through the openings of a screen material having a thickness corresponding to the desired film thickness. (2) Continuously feed a holding body such as metal between the opposing drive roller and cylindrical screen material, and as the drive roller and screen material rotate, lithium metals are supplied from inside the cylindrical screen material. 2. The method for producing a lithium thin film according to claim 1, wherein lithium metals are deposited on a support such as the metal. (3) A plate-shaped screen material is applied from above the base onto a holding body such as metal that is continuously fed onto the base, and lithium metal is pressed against the screen material in the lateral direction. 2. The method for producing a lithium thin film according to claim 1, wherein the lithium metal is deposited on the holder of the metal by sliding the lithium thin film on the lithium thin film.