JP2000135502A - Metallic lithium rolling method and equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a film of metallic lithium uniformly and accurately. SOLUTION: This equipment is equipped with first and second work rolls 16 and 18 to obtain film-like metallic lithium 14 by passing sheet-like metallic lithium 12 between them, and a lubricant applying means 50 to apply a lubricant 54 with viscosity of 10 cP or higher which does not react with the sheet-like metallic lithium 12 against the sheet-like lithium 12. The first and second work rolls 16 and 18 are made of a material superior in strength and hardness to the sheet-like metallic lithium 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for rolling metallic lithium for thinning metallic lithium.

[0002]

2. Description of the Related Art For example, lithium batteries incorporating a lithium electrode as a battery electrode have been employed for various purposes. This lithium electrode is usually manufactured by cutting (or punching) a long hoop-shaped or sheet-shaped long metal lithium foil into desired cut portions, and then fixing the strip-shaped metal lithium foil to the current collector surface. Have been.

[0003] This metal lithium foil is generally made by passing sheet-shaped metal lithium through a rolling device,
For example, it is obtained by thinning to about 30 μm. In this case, this type of rolling device is provided with a set of work rolls, and the set of work rolls rotates while pressing the plate-shaped metal lithium, thereby forming a thin film metal lithium which is a metal lithium foil. Is configured to be manufactured.

The work roll is usually formed of a metal roll. When metal lithium is rolled by this metal roll, the workability of the metal lithium causes
There is a problem that the metal lithium adheres to the metal roll.

Therefore, for example, as disclosed in Japanese Patent Publication No. 55-122, there is no reactivity with lithium,
In addition, a method of cold rolling metal lithium between smooth surfaces of a solid polymer composition having a critical surface tension of a predetermined value or less is known.

[0006]

However, in the above-mentioned prior art, a resin roll is used as a work roll for rolling metallic lithium. For this reason, it has been pointed out that the heat generated during the rolling increases the expansion of the resin roll, and the thickness of the rolled metallic lithium is not constant. In addition, the resin roll has a problem that, since the Young's modulus is considerably small, the roll is flattened and the film thickness accuracy of metallic lithium is reduced due to the orientation of the material specific to the resin. In addition, it has been pointed out that the surface of the resin roll is apt to be damaged, thereby causing breakage of metallic lithium and the like.

Therefore, a method of obtaining a sheet of metallic lithium by extrusion is considered. However, in this type of method, although a uniform thickness can be maintained when a sheet having a certain thickness is obtained, when a thin film sheet having a thickness of 100 μm or less is to be obtained, there is a problem that the yield is significantly deteriorated. It is pointed out.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a method and an apparatus for rolling metallic lithium, which can uniformly and highly accurately form a thin film of metallic lithium.

[0009]

In the method and apparatus for rolling metallic lithium according to the present invention, a lubricant having a viscosity of 10 cp or more and not reacting with the metallic lithium is applied to a metallic lithium sheet material, and then the metallic lithium is rolled. The sheet metal is passed between the first and second work rolls formed of a material having excellent strength and hardness to obtain thin-film metallic lithium.

As described above, since the lubricant is applied to the metal lithium plate material, a material capable of performing precision processing as the first and second work rolls, for example, die steel, high-speed steel, carbide or SiC ceramic is used. It becomes possible. Therefore, the metal lithium can be rolled into a thin film, and the film thickness can be maintained uniformly and with high accuracy.

As the lubricant, particularly, silicone oil or liquid paraffin is used, and the thin metal lithium may be washed with a solvent that dissolves the lubricant. This makes it possible to efficiently and smoothly obtain thin-film metallic lithium.

Further, since the first and second work rolls are each driven to rotate via two or more support rolls, the first and second work rolls surely perform the thinning treatment of metallic lithium. You.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a rolling apparatus 10 for carrying out a method for rolling metallic lithium according to an embodiment of the present invention.
FIG.

The rolling device 10 includes first and second work rolls 16 and 18 for producing a thin film metal lithium 14 by passing a sheet metal lithium 12 therebetween.
The work roll 16 has two lower support rolls 20a and 20b.
While the second work roll 18 is supported by two upper support rolls 22a and 22b. The lower support rolls 20a and 20b are rotatably supported by the first movable table 24 and are connected to a rotation drive source (not shown).

The upper support rolls 22a and 22b are rotatably supported by the second movable table 26 and are connected to a rotation drive source (not shown). This second movable base 26 is
The position of the first movable table 24 is fixed at a predetermined height while the position of the first movable table 24 is fixed at a predetermined height via a nut 30 screwed to the screw portion 28.
A constant gap is set between 8 spaces.

The first and second work rolls 16 and 18 are
It is formed of a material having higher strength and hardness than the sheet metal lithium 12. Specifically, it is made of a material that can be precision machined, such as die steel, high-speed steel, carbide, or SiC ceramics.

The rolling device 10 includes a lubricant applying means 50 disposed upstream of the first and second work rolls 16 and 18.
And a cleaning means 52 disposed downstream of the first and second work rolls 16 and 18. The lubricant applying means 50 has a viscosity of not less than 10 cp and a sheet metal lithium 1
A receiving base 56 for storing a lubricant 54 that does not react with the second base; a first lubricant applying roll 58 that is rotatable by partially immersing the lubricant in the receiving base 56; A second lubricant application roll 60 rotatably arranged opposite to the roll 58. As the lubricant 54, silicone oil or liquid paraffin is particularly used.

The cleaning means 52 includes an ultrasonic cleaner 62, in which a solvent 64 for dissolving the lubricant 54 is stored. The solvent 64 is, for example, benzene, toluene, xylene or hexane, or an ethylene, ether, acetate, or hydrocarbon solvent in addition to benzene, toluene, xylene or hexane in order to dissolve the lubricant 54 as the silicone oil or liquid paraffin. used.

The operation of the rolling apparatus 10 configured as described above will be described below in relation to the rolling method according to the present embodiment.

First, the sheet metal lithium 12 is extruded using a molding machine (not shown). The sheet metal lithium 12 obtained by the extrusion molding has a thickness of 0.1 mm.
The thickness is set in the range of 1 mm to 0.2 mm, and the plate-shaped metal lithium 12 is supplied to the rolling device 10 via a delivery mechanism (not shown).

In the rolling device 10, the upper support rolls 22a and 22b are positioned by the second movable table 26,
Lower support rolls 20a, 20b via first movable table 24
Is held at a predetermined height position. For this reason, the first work roll 16 supported by the lower support rolls 20a and 20b and the second work roll 18 supported by the upper support rolls 22a and 22b are arranged with a predetermined gap therebetween. Is done.

Next, the lower and upper support rolls 20a and 20b and the upper support rolls 22a and 22b are rotated in the directions indicated by arrows, respectively, under the action of a rotary drive source (not shown), whereby the first and second work rolls 16 and 18 are rotated. Rotates in the direction of the arrow. Here, the first and second work rolls 1
Lubricant application means 50 is arranged on the upstream side of 6, 18 and the first and second lubricant application rolls are provided on both sides of the sheet metal lithium 12 with the lubricant 54 stored in the receiving base 56. It is applied via 58,60.

The sheet metal lithium 12 coated with the lubricant 54 is pushed between the first and second work rolls 16 and 18 (see the direction of arrow A). As a result, the sheet metal lithium 12 is subjected to the rolling treatment, and the thin film metal lithium 14 is obtained. The thickness of the thin film metal lithium 14 is set in the range of 0.01 mm to 0.03 mm.

The thin-film metallic lithium 14 obtained by the first and second work rolls 16 and 18 is sent to a washing means 52 and subjected to a washing treatment in an ultrasonic washing machine 62 via a solvent 64. Therefore, after the lubricant 54 is removed from the surface of the thin film metal lithium 14, the thin film metal lithium 14 is wound integrally with the separator via a winding mechanism (not shown), for example.

In this case, in this embodiment, the first and second work rolls 16 and 18 have higher strength and hardness than the sheet metal lithium 12 and are suitable for precision processing, for example, die steel, high-speed steel, It is made of carbide or SiC ceramics. For this reason, it is excellent in precision processing properness and durability as compared with the conventional one using a resin roll, and deformation is not caused. This allows
0.01 to 0.03 mm of thin film metal lithium 14
The effect of being able to work with high precision to a constant thickness within the range described above is obtained.

At this time, the first metallic lithium 12 has
In addition, a lubricant (especially silicon oil or derived paraffin) 54 having a viscosity of 10 cp or more and not reacting with the plate-like metal lithium 12 is applied to prevent the second work rolls 16 and 18 from adhering.

Therefore, the adhesion between the sheet metal lithium 12 and the first and second work rolls 16 and 18 is reliably prevented,
There is an advantage that the thin film metal lithium 14 can be obtained efficiently. Further, the thin film metal lithium 14
The lubricant 54 applied to the surface can be automatically removed via the cleaning means 52, thereby simplifying the entire operation.

If the viscosity of the lubricant 54 is less than 10 cp, the lubricant 54 cannot effectively intervene between the surface of the sheet metal lithium 12 and the first and second work rolls 16 and 18. The viscosity of the lubricant 54 is preferably set to 10 cp or more, since the adhesion of the plate-like metal lithium 12 is caused.

[0029]

According to the method and apparatus for rolling metallic lithium according to the present invention, after a lubricant having a viscosity of 10 cp or more and not reacting with the metallic lithium is applied to the metallic lithium sheet, the metallic lithium sheet is strengthened. And a thin film of metallic lithium is obtained by passing between first and second work rolls formed of a material having excellent hardness.

[0030] For this reason, while being excellent in precision processing appropriateness and durability, the first and second work rolls that do not cause deformation can be used to obtain thin-film metallic lithium with high precision and smoothness. In operation, the metallic lithium is prevented from adhering to the first and second work rolls. This makes it possible to reliably roll the thin film of metallic lithium with a uniform thickness.

[Brief description of the drawings]

FIG. 1 is a schematic front explanatory view of a rolling apparatus for carrying out a method for rolling metallic lithium according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Rolling apparatus 12 ... Sheet metal lithium 14 ... Thin film metal lithium 16, 18 ... Working roll 50 ... Lubricant application means 52 ... Cleaning means 54 ... Lubricant 58, 60 ... Lubricant application roll 62 ... Ultrasonic cleaning machine 64 ... Solvent

Claims (7)

[Claims] 1. A step of applying a lubricant having a viscosity of 10 cp or more and not reacting with the metal lithium, to the metal lithium plate, and the step of: A step of passing between first and second work rolls formed of a material having excellent strength and hardness to make the film thinner, and a method of rolling metallic lithium. 2. The method of rolling metal lithium according to claim 1, further comprising a step of washing the thinned metal lithium with a solvent that dissolves the lubricant. 3. The method according to claim 1, wherein the lubricant is silicon oil or liquid paraffin. 4. A first and a second work roll formed of a material having strength and hardness superior to that of the metal lithium, while thinning the metal lithium by passing a metal lithium plate therebetween. And a lubricant application unit disposed upstream of the first and second work rolls and applying a lubricant having a viscosity of 10 cp or more and not reacting with the metal lithium, to the metal lithium plate material. Metallic lithium rolling equipment. 5. A rolling device according to claim 4, further comprising a washing means disposed downstream of said first and second work rolls for washing said thinned metallic lithium with a solvent capable of dissolving said lubricant. A metal lithium rolling device, comprising: 6. The rolling apparatus according to claim 4, wherein said lubricant is silicon oil or liquid paraffin. 7. The rolling device according to claim 4, wherein two or more supporting rolls are provided corresponding to the first and second work rolls, respectively, and the first and second work rolls are driven to rotate. A metal lithium rolling device, comprising: