JPH1012222A - Belt-like metallic foil for battery electrode and continuous supply method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and continuously supply belt-like metallic foil for a battery electrode. SOLUTION: In the case of performing continuous supply of belt-like metallic foil for a battery electrode by this method so as to continuously supply the belt like metallic foil for a battery electrode by adhering a starting end part of the belt-like metallic foil for a battery electrode supplied later to a tail end part of the belt like metallic foil for a battery electrode supplied previously by an adhesive tape 7, the free end on the downstream side more than the adhesive tape 7 is adhered by an adhesive tape 9 arranged on the downstream side more than the adhesive tape 7 of a starting end part of the belt-like metallic foil for a battery electrode supplied later, and the belt-like metallic foil for a battery electrode is continuously supplied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip-shaped metal foil for a battery electrode and a method for continuously supplying the same, and more particularly, to a method for continuously connecting a positive electrode of a lithium ion battery in which a lithium composite oxide is coated on both sides of a strip-shaped aluminum foil. The present invention relates to a band-shaped metal foil for a battery electrode used for continuous production of a negative electrode of a lithium-ion battery in which carbon is applied to both sides of a band-shaped copper foil, and a continuous supply method thereof.

[0002]

2. Description of the Related Art Batteries are roughly classified into primary batteries and secondary batteries. The former primary battery has its life when discharged, but the latter secondary battery can be used many times by being charged even if it is discharged.

[0003] There are several types of the latter secondary batteries, specifically, for example, a lead storage battery, a nickel cadmium battery, a nickel hydride battery, and a lithium ion battery. This lithium-ion battery has a higher energy density and power density per volume than other secondary batteries, and the lithium in the battery exists in an ionic state and has a high level of safety. In recent years, demand has been increasing as a source.

FIG. 5 is an overall structural view of a lithium ion battery. In this battery 50, carbon 52 as an anode active material is applied to both surfaces of a copper foil 51 as a strip-shaped anode current collector,
A negative electrode 53 formed by drying and cooling, a band-shaped separator 80, and a lithium composite oxide 5 as a positive electrode mixture are formed on both surfaces of an aluminum foil 54 having a thickness of several tens of μm, which is a band-shaped positive electrode current collector.
5 is applied, dried and cooled, and the wound positive electrode 56 is layered and wound into a battery can 58 on which an insulating plate 57 is mounted.
After the positive and negative electrode leads 59 and 60 are connected, an electrolytic solution is injected into the battery can 58, the battery can 58 is caulked via the gasket 61, and the battery lid 63 on which the safety valve device 62 is mounted is fixed. It was completed. The negative electrode 53 and the positive electrode 56 are formed not continuously for one battery but for many batteries. That is, for example, when forming the negative electrode 53, first, a film-like copper foil (raw material) wound in a roll shape having a width of about 600 mm is sent out, and is wound through a carbon coating step, a drying step, and a cooling step. Can be The winding speed at this time is generally 15 to 100 m / min, and the tension is controlled to about 30 kg / mm. Next, the rolled copper foil to which carbon has been applied is sent out and moved to a cutting step, and cut into a predetermined size of a cell to be a battery. Each of the cut pieces becomes the negative electrode 53.

By the way, a film-shaped copper foil (raw material) wound in a roll shape is wound about 1,500 m. The starting ends of the film-shaped copper foil (next raw material) wound around are connected and continuously supplied. As a joining method, the same method as that for continuously producing magnetic tapes is employed. That is, by automatically operating the pressure roll and bonding the starting end of the film copper foil to be supplied later to the terminal end of the previously supplied film copper foil with an adhesive tape, the film copper foil is formed. It was supplied continuously.

FIG. 6 is a schematic view of a film-like copper foil (later raw material) wound in a roll shape to be supplied later. At the starting end of the film-shaped copper foil wound into a roll, an adhesive tape 65 having an adhesive surface facing upward is provided, and at the leading end thereof, a temporary fixing for preventing the roll itself from being unraveled. Tape 66 is provided at three places.

[0007]

However, according to the above-mentioned conventional method for continuously supplying a film-like copper foil, the film-like copper foil is connected to the preceding film-like copper foil while passing through a number of rotating guide rolls. Wrinkles and knuckles were formed at the joints, and this often caused instantaneous tearing of the film-shaped copper foil.

FIG. 7 is an explanatory diagram when wrinkles are formed on the above-mentioned copper foil film. As shown in this figure, the adhesive tape 65 is used to automatically attach the first film-shaped copper foil and the second film-shaped copper foil.
When they are joined together, the end of the end portion of the film-like copper foil becomes a free end, so that the film-like copper foil is wrinkled while passing through a number of rotating guide rolls, and is torn.
Therefore, automatic continuous feeding is not performed, and when the previous film-like copper foil approaches the end, the line is stopped, and the end of the previous film-like copper foil is manually stopped without using a crimping roll. In order to prevent the terminal from becoming a free end, the end of the film-shaped copper foil was joined to the start of the film-shaped copper foil, and then the supply of the film-shaped copper foil was restarted. Therefore, productivity did not increase.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and provides a belt-shaped metal foil for a battery electrode capable of automatically and continuously supplying the band-shaped metal foil for a battery electrode, and a method for continuously supplying the same. The purpose is to provide.

[0010]

In order to achieve the above object, according to the present invention, the starting end of the battery electrode strip metal foil supplied later is connected to the terminal end of the battery electrode strip metal foil supplied earlier. In a continuous supply method of a battery-electrode band-shaped metal foil for continuously supplying a battery-electrode band-shaped metal foil by bonding with an adhesive tape, the terminal portion of the previously supplied battery-electrode band-shaped metal foil is supplied. The free end on the downstream side of the adhesive tape is adhered by an adhesive tape provided downstream of the adhesive tape at the start end of the band-shaped metal foil for a battery electrode to be supplied later to continuously supply the band-shaped metal foil for a battery electrode. The present invention provides a method for continuously supplying a strip-shaped metal foil for a battery electrode.

Further, in the present invention, an adhesive tape for adhering an end portion of the previously supplied battery electrode band-shaped metal foil to a starting end portion of a battery electrode band-shaped metal foil to be supplied later, and a downstream side of the adhesive tape. And an adhesive tape for adhering a free end downstream of the adhesive tape at the terminal end of the previously supplied battery electrode band-shaped metal foil provided on the side of the battery electrode. I will provide a.

According to the above-mentioned battery electrode band-shaped metal foil and its continuous supply method, the terminal end of the battery electrode band-shaped metal foil supplied first is bonded to the start end of the battery electrode band-shaped metal foil supplied later. After bonding with a tape, the free end on the downstream side is further bonded with a bonding tape. This bonding can be automatically performed with a pressure roll, and the end of the end portion of the battery electrode strip metal foil supplied earlier is fixed and does not become a free end. As a result, the battery electrode strip metal foil is consequently formed. Can be automatically and continuously supplied.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view showing an entire apparatus for carrying out a method for continuously supplying a strip-shaped metal foil for a battery electrode according to the present invention. In this figure, a cooling step and a cutting step in the above-described electrode manufacturing step of the lithium ion battery are omitted. Also, the manufacturing process of the negative electrode will be described, and the description will be omitted because the positive electrode is formed in the same manner.

This device comprises an unwinding section 1, a prefeed (PF) section 2, and a head section 3. Unwinding part 1
In the above, a film-like copper foil (first raw material) A wound in a roll shape to be supplied first is sent out via a rotation guide roll 3 and a dancer roll 4. The film-shaped copper foil A sent out is controlled in tension by a dancer roll 5 or the like in a pre-feed section 2 and then, while being guided by a rotary guide roll 6 in a head section 3, carbon as a negative electrode active material is applied to both surfaces thereof. You. Then, it is dried with a dryer. Film-shaped copper foil wound into a roll to be supplied first (the original web)
Next to A, a film-like copper foil (later raw material) B wound in a roll shape to be supplied later is prepared.

FIG. 2 is a schematic view of a film-shaped copper foil B wound in a roll shape to be supplied later. At the beginning of the film-shaped copper foil B wound in the form of a roll, an adhesive tape 7 having an adhesive surface facing upward is provided, and the tip of the adhesive tape 7 prevents the roll itself from being unraveled. Temporary fixing tapes 8 are provided at three places. Further, a double-sided adhesive tape 9 is provided at the center and three places on both sides thereof at a position one winding delay downstream of the position where the adhesive tape 7 is provided.

FIG. 3 is an explanatory diagram showing the positional relationship between the double-sided adhesive tape and the adhesive tape. As shown in this figure, since the double-sided adhesive tape 9 is located at a position facing the adhesive tape 7, a release paper 10 is interposed between the two so that they are not bonded.

Further, the unwinding section 1 has a film-like copper foil A supplied first and a film-like copper foil B supplied later.
And a cutter 12 that cuts off the terminal end of the film-like copper foil A that has been supplied first and coated with carbon after the connection. As described above, the press roll 11 has the same configuration as that used when continuously producing magnetic tapes.

When the film-like copper foil A supplied first and coated with carbon approaches the end, the film-like copper foil B wound in a roll to be supplied later at the same rotation speed is rotated, The press roll 11 descends, and the terminal end of the film copper foil A supplied earlier and the start end of the film copper foil B supplied later are pressed into contact with each other. The terminal end is adhered to the starting end of the film-like copper foil B to be supplied later with the adhesive tape 7, and the free end downstream thereof is also adhered with the double-sided adhesive tape 9. These bondings can be performed automatically by the pressure roll 11.

FIG. 4 shows a film-like copper foil A previously supplied.
It is a schematic side view which shows the state at the time of bonding of the film-form copper foil B supplied later. In this way, since the terminal end of the film-like copper foil A supplied earlier is fixed by the adhesive tape 7 and the double-sided adhesive tape 9 on the downstream side, the film-like copper foils A and B are fixed.
No wrinkles or odors are generated even if the two are continuously supplied. The film-like copper foil A previously supplied as described above
By bonding the film-shaped copper foil B to be supplied later, the film-shaped copper foil for a negative electrode of a lithium ion battery can be automatically and continuously supplied. The roll-shaped film-shaped copper foil coated with carbon, dried, cooled and wound up in this way is cut into a large number of cells having predetermined dimensions.

[0020]

The width of the adhesive tape 7 on the upstream side is the same as that of the film-like copper foil for a negative electrode of a lithium ion battery, for example, 600 mm, and is provided at one position, and the length thereof is 30 mm.
The width of the double-sided adhesive tape 9 on the downstream side is smaller than the width of the negative electrode film-shaped copper foil, for example, 10 mm.
Preferably, at least three places are provided at the center and both ends in the width direction, and the length is preferably about 10 mm. The upstream adhesive tape 7 has a thickness of 0.5 mm or more and a tensile strength of 20 kN.
g / mm ² or more, and the double-sided adhesive tape 9 on the downstream side.
Is preferably 1.0 mm or more in thickness and 10 kg / mm ² or more in tensile strength.

In the case where the continuous supply is automatically performed in the above preferable state, the time required for the connection by hand (for example, 364 minutes per day) is longer than that in the related art in which the line is stopped and connected by hand and then the supply is restarted. The operating rate improved as much as it disappeared. In addition, compared to the conventional technique of connecting by hand, additional work time is reduced (for example, 21 minutes per day), and high productivity can be realized. In the above embodiment, the band-shaped metal foil for a battery electrode, particularly, the film-shaped copper foil for a negative electrode of a lithium ion battery has been described.However, the present technology can be applied to other secondary batteries, and a polyester film can be used. Etc. can be applied. In the above embodiment, the adhesive tape on the downstream side of the adhesive tape 7 is the double-sided adhesive tape 9, but a normal single-sided tape is provided with the adhesive surface facing upward, and the surface opposite to the adhesive surface is supplied later by the adhesive. May be bonded to the film-like copper foil B.

[0022]

As described above, according to the present invention, at the end of the previously supplied band-shaped metal foil for battery electrode,
The starting end of the battery electrode band-shaped metal foil to be supplied later is automatically adhered with an adhesive tape, and the free end downstream of the adhesive tape at the terminal portion of the battery electrode band-shaped metal foil supplied earlier is further removed. Since the battery electrode band-shaped metal foil is supplied automatically by an adhesive tape provided downstream of the adhesive tape at the start end of the battery electrode band-shaped metal foil to be supplied, the battery electrode band-shaped metal foil is continuously supplied. The foil can be continuously supplied without causing wrinkles or ole. Thereby, the starting end of the battery electrode band-shaped metal foil to be supplied later, at the terminal end portion of the battery electrode band-shaped metal foil supplied earlier,
The productivity can be improved by automatically and continuously supplying as compared with the above-described conventional technique in which the line is stopped and the supply is restarted again after manually bonding with the adhesive tape.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an entire apparatus for carrying out a method for continuously supplying a strip-shaped metal foil for a battery electrode according to the present invention.

FIG. 2 is a schematic view of a film-shaped copper foil B wound in a roll shape to be supplied later, which is a band-shaped metal foil for a battery electrode according to the present invention.

FIG. 3 is an explanatory diagram showing a positional relationship between a double-sided adhesive tape and an adhesive tape provided on a film-shaped copper foil B wound in a roll shape in FIG. 2;

FIG. 4 is a schematic side view showing a state in which a film-like copper foil A supplied first and a film-like copper foil B supplied later are bonded in FIG.

FIG. 5 is an overall structural diagram of a lithium ion battery.

FIG. 6 is a schematic view of a conventional film-shaped copper foil wound into a roll to be supplied afterward.

FIG. 7 is an explanatory diagram when a wrinkle occurs in the film-like copper foil in the conventional continuous supply method.

[Explanation of symbols]

1: unwinding part, 2: pre-feed part, 3: head part,
4,5: dancer roll, 6: rotating guide roll, 7:
Adhesive tape, 8: Temporary fixing tape, 9: Double-sided adhesive tape, 10: Release paper, 11: Compression roll, 12: Cutter

Claims (4)

[Claims] 1. A battery electrode strip-shaped metal foil, which is supplied first, is bonded to the terminal end of the battery electrode strip-shaped metal foil supplied later with an adhesive tape, so that the battery electrode strip-shaped metal foil is bonded. In the method for continuously supplying a continuously supplied battery electrode band-shaped metal foil, the battery electrode to be supplied after the free end of the terminal portion of the previously supplied battery electrode band-shaped metal foil downstream of the adhesive tape is supplied. A method of continuously supplying a band-shaped metal foil for a battery electrode, wherein the band-shaped metal foil for a battery electrode is continuously supplied by bonding with a bonding tape provided downstream of the adhesive tape at the start end of the band-shaped metal foil for a battery electrode. . 2. An adhesive tape for adhering an end portion of a previously supplied battery electrode band-shaped metal foil to a start end portion of a battery electrode band-shaped metal foil to be supplied later; An adhesive tape for adhering a free end downstream of the adhesive tape at the end of the previously supplied battery electrode metal foil, the adhesive tape being provided with a battery electrode. 3. The adhesive tape on the upstream side has the same width as the band-shaped metal foil for a battery electrode and is provided at one location, and has a length of 30 mm or more, and the adhesive tape on the downstream side is
The band-shaped metal foil for a battery electrode according to claim 2, wherein the width is smaller than the width of the band-shaped metal foil for a battery electrode, and is provided at least at three places at the center and both ends in the width direction. 4. The adhesive tape on the upstream side has a thickness of 0.5 mm or more and a tensile strength of 20 kg /
and mm ² or more, the adhesive tape on the downstream side, the thickness is not more 1.0mm or more, the tensile strength 10kg
/ Mm ² or more and to strip the metal foil for a battery electrode according to claim 2, characterized in that the.