JPH07282804A - Reel winding method for lithium metal or lithium alloy thick tape - Google Patents

Abstract

PURPOSE:To enhance accuracy, workability and the like so as to increase a unit weight per reel by winding lithium metal or a lithium-aluminum alloy for flattening in a piece of reel in several or multiple rows. CONSTITUTION:A thick tape 3 made of lithium metal or a lithium alloy having a square cross section is wound in several or multiple rows in a piece of reel 2. The thick tape 3 is obtained by extruding an ingot. The thick tape 3 wound around the reel 2 is cut by a cutter 4 after winding back from the reel 2, to be molded into a coin-shaped product by a flattening jig 5, and then, is applied to a negative electrode of a lithium battery.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is used for reeling a processed product or a molded product of a lithium metal or a lithium aluminum alloy or the like, and particularly for manufacturing a product for a negative electrode of a lithium battery with improved accuracy and workability. The present invention relates to a reel winding method for a thick lithium metal or lithium alloy thick tape.

[0002]

2. Description of the Related Art Lithium metal or lithium alloys such as lithium aluminum alloys used in the manufacture of negative electrode products for lithium batteries have been used as extrusion machines for lithium metal or lithium alloy ingots when used in coin type batteries. 1 to form a tape, and the tape was wound on a reel 2 by a winding machine as shown in FIG. Then, the battery manufacturer rewinds the tape 1 from the reel 2 as shown in FIG.
The product was punched out into a coin shape and used as a negative electrode for a lithium battery.

However, with this method, the lithium metal or lithium aluminum alloy tape after punching becomes a loss, and the processing cost for this loss is incurred, which is inferior in economic efficiency.

Therefore, in consideration of economy, FIG.
As shown in (b), a thick tape 3 made by extruding lithium metal or a lithium alloy in a square cross section is wound on a reel 1 and then rewound from the reel 2 as shown in FIG. 2 (b). A method of cutting a necessary amount of the thick tape 3 with a cutter 4, crushing the thick tape 3 and immersing it with a jig 5 to form a coin type product has been studied and implemented.

Generally, when lithium metal or a lithium aluminum alloy is pressed and molded, the same volume as that of a conventional punched lithium metal or lithium alloy tape is required, and a clean circular shape is obtained after the pressing. As described above, it is required to use a thick tape having a rectangular cross section, which is narrower in width and larger in thickness than the conventional punching lithium metal or lithium alloy tape.

However, as shown in FIG.
When the thick metal tape 3 having a rectangular cross section of lithium metal or lithium alloy is wound on a reel 2 used for a conventional lithium metal or lithium alloy tape for punching,
Since the width is narrow and the thickness is large, there is a problem that the unit weight of lithium metal or lithium alloy per reel (weight of lithium metal or lithium alloy per reel) becomes small.

In general, when crushing and molding lithium metal or lithium aluminum alloy, it is necessary to have the same volume as the conventional one, and it is necessary to form a clean circular shape after crushing. It is required to use a tape having a narrower width and a larger thickness than the conventional punching lithium metal or lithium aluminum alloy.

However, when the above-mentioned lithium metal or lithium aluminum alloy is wound on a reel used for conventional punching lithium metal or lithium alloy, the width is narrow and the thickness is large, so that lithium and lithium aluminum alloy per reel are used. The weight per unit area of is reduced.

However, for the purpose of improving the productivity of battery manufacturers, it is necessary to increase the weight per unit area of lithium metal or lithium aluminum alloy per reel. In order to solve the above problem, as shown in FIG. 3 (a), it has been considered to wind the crushing lithium metal or lithium alloy into a traverse winding. However, when wound by traverse winding, the lithium metal or lithium aluminum alloy material is twisted and the accuracy of thickness and width is reduced, and the weight and volume of the lithium metal or lithium aluminum alloy after cutting may vary. .

Further, since lithium and lithium aluminum alloy have adhesiveness, when wound by traverse winding, twisted corners of lithium metal or lithium aluminum alloy adhere to each other between reels or lithium metal or lithium aluminum alloy. However, when rewinding, there is a problem that the attached portion is subjected to a force and twists, is distorted, and cannot be rewound.

[0011]

The present invention solves these problems of the prior art, improves accuracy and workability, and is used for the production of a lithium battery negative electrode product capable of increasing the unit weight per reel. It is an object of the present invention to provide a reel winding method for a thick lithium metal or lithium alloy thick tape.

[0012]

In order to solve the above problems, as a result of various studies by the present inventor, a thick metal tape having a crushing lithium metal or lithium aluminum alloy having a rectangular cross section is applied to one reel. It turns out that the problem can be solved by winding the book in multiple rows.

That is, the present invention is characterized in that a tape having a rectangular cross section of a lithium metal or a lithium alloy for a lithium battery is wound on one reel in several rows in multiple rows. It is in the reel winding method of the tape.

The present invention will be described below with reference to the drawings.

FIG. 4 (a) shows the reel winding method of the present invention. The thick tape 3 of lithium metal or lithium alloy having a square cross section has several reels on one reel 2 in multiple rows. It's rolled up. That is, as shown in FIG.
For example, it is a winding method in which the thick tape 3 is wound around one reel 2 in three rows in parallel.

The thick metal tape 3 having a rectangular cross section of lithium metal or lithium alloy used here is obtained by extruding an ingot. Although the thickness and width of the thick tape are not particularly limited, cut the thick tape,
When crushed into a product, it is necessary that both the quantity and the shape are within a range satisfying as a negative electrode of a lithium battery. A lithium aluminum alloy is preferably used as the lithium alloy used here, and the aluminum concentration thereof is preferably 900 ppm or more, more preferably 900 to 1200 ppm.

The thick metal tape 3 having a rectangular cross section of the lithium metal or lithium aluminum alloy wound on the reel 2 in this way is rewound from the reel 2 as shown in FIG. It is cut by a cutter 4 and then formed into a coin-shaped product by a crushing jig 5 and is used as a negative electrode of a lithium battery.

[0018]

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples.

Comparative Example 1 As shown in FIG. 3 (a), the core diameter is 7 cm and the collar diameter is 30.
cm, the width of the core was 5 cm, and when the extrusion thickness was 7 mm and the width of the lithium aluminum alloy with a width of about 9 mm was wound with a square thick tape, the weight per unit area was about 310 g.

Example 1 A reel of the same size as that of the comparative example was used. When three to four multi-row lithium aluminum alloys having the same extrusion size were wound in a multi-row as shown in FIG. About 930
About 1 to 2240g can be wound, the weight becomes about 3 to 4 times, the transportation cost is reduced by about 1/3 to 1/4, and the replacement frequency is also reduced by about 1/3 to 1/4. .

[0021]

As described above, the following effects can be obtained by winding several crushing lithium metal or lithium aluminum alloy on one reel in multiple rows.

1) The weight per unit area per reel becomes large, and the reel is exchanged at the time of winding and rewinding as compared with the case of winding one row of lithium metal on one reel. Frequency is reduced and workability is improved.

2) Since several single windings are wound in multiple rows, the lithium metal or the lithium aluminum alloy is not deformed by twisting when winding or rewinding, unlike the traverse winding. The accuracy is good and there is no variation in weight and volume after cutting.

3) Since several single windings are wound in multiple rows, the twisted corners of lithium and lithium aluminum alloys are reels or lithium metal or lithium alloys like traverse windings when winding or rewinding. Then, when the film is rewound, a problem is exerted on the adhered part such as twisting, distortion, and unwinding.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a conventional lithium metal or lithium alloy tape is wound on a reel and a step of manufacturing a negative electrode product for a lithium battery using the tape.

FIG. 2 is a perspective view showing a conventional thick metal tape having a rectangular cross section of lithium metal or lithium alloy wound on a reel, and a diagram showing a process of manufacturing a negative electrode product of a lithium battery using the tape.

FIG. 3 is a perspective view showing a conventional thick metal tape having a rectangular cross section of lithium metal or a lithium alloy wound on a reel, and a diagram showing a process of manufacturing a negative electrode product of a lithium battery using the tape.

FIG. 4 is a perspective view showing a state where a thick metal tape having a rectangular cross section of lithium metal or lithium alloy according to the present invention is wound on a reel, and a process showing a process for producing a negative electrode product of a lithium battery using the tape. .

[Explanation of symbols]

1: Lithium metal or lithium alloy tape, 2: Reel, 3: Thick tape with a rectangular cross section of lithium metal or lithium alloy, 4: Cutter, 5: Crushing jig.

Claims (1)

[Claims] 1. A reel of lithium metal or lithium alloy thick tape for winding a lithium metal or lithium alloy thick wall tape for a lithium battery, wherein several tapes having a rectangular cross section are wound on a reel in multiple rows. How to take.