JP2000228200A - Metal foil collector used in electrode for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a coating width accuracy of electrode active material, and also increase a production efficiency. SOLUTION: This long metal foil collector used in an electrode for a battery, is so composed that pressure-sensitive adhesive tapes having widths in the range of 2 mm or more and 100 mm or less per stripe and having 180-degree exfoliation intensity against aluminum in the range of 5 g/cm or more and 100 g/cm or less, at least to the number of one or more, are arranged in parallel in the lengthy direction. In the manufacture of an electrode for a cell in which the collector is used, an uncoated part necessary for taking out the electrode of the battery can be formed accurately, and efficient electrode production can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long metal foil current collector used for a battery electrode, and to the manufacture of a battery electrode using the current collector.

[0002]

2. Description of the Related Art At present, research and improvement of lithium ion secondary batteries as power sources for various electric devices such as personal computers, mobile phones, and video cameras are being promoted due to their high energy density. Also, lithium ion polymer secondary batteries that do not use an organic electrolyte such as lithium ion secondary batteries have been put to practical use. This lithium ion polymer secondary battery is a solid electrolyte or a gel electrolyte obtained by swelling a polymer sheet, foam, etc. with an electrolyte instead of the microporous membrane separator holding the electrolyte used in the lithium ion secondary battery. By using, a conventional lithium ion secondary battery uses a metal can as an exterior body, but on the other hand, it can be exteriorized with a polymer film, so that weight reduction, high energy density, and thinness are being realized.

[0003] Generally, an electrode used in a lithium ion secondary battery is obtained by supporting a coating liquid comprising at least an electrode active material, a binder and a dispersion solvent in a uniform thickness on a metal foil current collector and drying and solidifying the coating liquid. Is used. Therefore, as a means for increasing the production efficiency, a coating liquid is continuously applied with a uniform thickness on a wide and long metal foil current collector, and the actual solid-state electrode is dried and solidified. A method of cutting into an electrode shape was generally used. However, in the electrode thus formed, when the electrode terminal is bonded to one end thereof, the electrode active material covers the metal foil current collector, so that bonding from above will lower the bonding strength between the electrode terminal and the electrode. There was a problem.

When the electrode active material is supported only on one side of the metal foil current collector, when the electrode terminal is bonded to the exposed portion of the metal foil current collector, the bonding strength is improved, Due to the strain caused by bonding, the electrode active material on the opposite side of the exposed part of the metal foil current collector peels off, causing a short circuit due to the missing electrode active material and the conductive additive added as necessary Had occurred.

For this reason, it has been studied to use a process of cutting out the electrode active material at a portion where the electrode terminal is joined from one end on the side where the electrode terminal is joined after cutting the electrode into an actual electrode shape. In the step of stripping the substance, it takes time and effort to immerse the solvent in the part to be stripped and strip it with human hands, and the productivity cannot be said to be sufficient. In addition, a method of forming an uncoated portion that does not carry the electrode active material in advance during coating is also being studied.However, the coating apparatus becomes large-scale, or the accuracy of the uncoated portion is reduced. The problem of low is not solved.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a long metal foil current collector capable of supplying an electrode having high dimensional accuracy in an uncoated portion with high production efficiency.

[0007]

Means for Solving the Problems The inventor of the present invention has made intensive studies to solve the above problems, and as a result, has developed an adhesive tape which satisfies certain conditions in parallel with the long direction of a long metal foil current collector. Arranged, and a coating liquid containing an electrode active material as a main component is coated thereon, and the coating liquid coated on the metal foil current collector after the coating liquid is coated. Before or after drying and solidification, the adhesive tape was peeled off to increase the electrode active material coating width accuracy, and at the same time to improve the problems of conventional electrode terminal bonding, and to increase the production efficiency. .

That is, the present invention relates to: 1. An adhesive tape having a width of 2 mm or more and 100 mm or less per strip and a 180 ° peel strength with respect to aluminum of 5 g / cm or more and 100 g / cm or less, comprising at least one sheet of long metal A long metal foil current collector used for a battery electrode, wherein the metal foil current collector is arranged in parallel with a longitudinal direction of the foil current collector. 2. The long length according to 1, wherein the 180-degree peel strength of the pressure-sensitive adhesive tape against aluminum becomes 0 g / cm or more and 5 g / cm or less by being exposed to a temperature of 60 ° C. or more and 200 ° C. or less for 5 seconds or more. Metal foil current collector. 3. means for applying a coating liquid, means for supplying a long metal foil current collector to which the coating liquid is applied, and the coating applied on the metal foil current collector Means for drying and solidifying the liquid, means for winding up the metal foil current collector supporting the dried and solidified coating liquid, and 180 ° peel strength against aluminum of 5 g /
Before applying a coating liquid on the metal foil current collector, at least one piece of the adhesive tape having a width of 2 mm or more and 100 mm or less per tape is applied to the metal foil current collector. Means for arranging parallel to the longitudinal direction of the body,
After the coating liquid is applied on the long metal foil current collector on which the adhesive tape is disposed, and is applied on the long metal foil current collector on which the adhesive tape is disposed. The present invention also relates to a battery electrode manufacturing apparatus having means for peeling off the adhesive tape before or after the coating liquid is dried and solidified.

Hereinafter, the constituent requirements of the present invention will be described. The 180-degree peel strength with respect to aluminum in the present invention means that while peeling off one end of an adhesive tape stuck to sheet-like aluminum, the adhesive tape is bent at 180 degrees so that opposite sides of the adhesive surface face each other, and peeled off from the sheet. 2c while holding one end of the adhesive tape at 180 degrees
It refers to the tension when pulled at m / min. (Japanese Industrial Standard No. = K6854-1977) The long metal foil current collector used in the present invention is not particularly limited, but when used in a lithium ion secondary battery, a long metal foil for a positive electrode is used. As the current collector, metal aluminum, stainless steel, carbon, titanium, or the like can be used. Metal aluminum is preferable for workability and mass productivity. On the other hand, as the long metal foil current collector for the negative electrode, metal copper is used. , Nickel, stainless steel, carbon and the like can be used. Among them, metallic copper is preferable because of its low electric resistance.

The thickness of the long metal foil collectors for the positive and negative electrodes is generally 10 μm to 100 μm. If the thickness is less than 10 μm, the metal foil breaks during coating and the strength of the electrodes will be reduced. On the other hand, if the thickness is larger than 100 μm, the above problem is improved, but the energy density per volume and the weight energy density of the battery are undesirably reduced. Further, in order to further improve the weight energy density, it is possible to use a perforated foil or a mesh-like expanded metal.

[0011] The long metal foil current collector of the present invention has a width of 2 mm or more and 100 mm or more in parallel with the long direction.
The following adhesive tape is preferably attached, and more preferably an adhesive tape having a width of 5 mm or more and 50 mm or less is attached. If the width of the adhesive tape is less than 2 mm, it is not effective for use in joining electrode terminals,
When the width exceeds 100 mm, it is sufficient for bonding the electrode terminals, but when a battery is formed, the energy density per volume is reduced, which is not efficient. The thickness of the adhesive tape is 10μm
The thickness is generally 500 μm or less.

The adhesive strength of the pressure-sensitive adhesive tape is 180 ° peel strength to aluminum of 5 g / cm to 100 g.
/ Cm or less, more preferably 5 g
/ Cm or more and 65 g / cm or less. If it is less than 5 g / cm, the coating solution is peeled off or displaced during application, and the accuracy of the width cannot be secured. On the other hand, if it exceeds 100 g / cm, it will be difficult to peel off the adhesive tape after coating, and if it is forcibly peeled off, not only will the metal foil current collector elongate or the electrodes become fatigued, but also the metal foil current collector will be damaged. This can lead to breakage.

Further, the peel strength of the pressure-sensitive adhesive tape is preferably lowered to a range of 0 g / cm to 5 g / cm by exposing the adhesive tape to a temperature of 60 ° C. to 200 ° C. for 5 seconds or more after coating the electrode active material. . The reason why the coating liquid is applied on a long metal foil current collector and then exposed to a certain temperature range is that it is necessary to dry and remove the solvent in the coating liquid. Therefore,
The conditions for drying vary depending on the type and amount of the solvent used and the time taken for drying.
The temperature is preferably from 0 ° C to 200 ° C. If the temperature is lower than 60 ° C., the time required for drying becomes longer, and the productivity is reduced. 20
If the temperature is higher than 0 ° C., the electrode active material and the binder may be deteriorated, or the metal foil current collector may be oxidized. It is not preferable because its own thermal deterioration is considered.

Paper, acetate,
Polyvinyl chloride, polyester, polyimide and the like can be considered. The pressure-sensitive adhesive tape of the present invention may be peeled off before being dried and solidified after application of the coating liquid, but when peeled off after the drying and solidifying step, the peeling strength of the adhesive tape is increased by heating in the drying step. The effect of being able to peel easily by lowering is obtained.

The production of an electrode using a long metal foil current collector to which such an adhesive tape is adhered is a conventional problem, that is, the trouble of immersing a solvent in order to form an uncoated portion and peeling it off with a human hand. Another object of the present invention is to solve the problem of low accuracy of an uncoated portion in a method of forming an uncoated portion in advance when coating. Further, when the adhesive tape is peeled off before the coating liquid is dried and solidified, the electrode coating liquid applied on the adhesive tape can be easily collected, so that cost reduction and environmental conservation effects can be expected. .

Here, the coating liquid comprises at least an electrode active material, a binder and a solvent as described above.
Specifically, the electrode active material may be any material capable of electrochemically doping and undoping lithium ions as a positive electrode material, such as lithium cobaltate, lithium manganate, lithium nickelate, and lithium cobalt nickelate. , Lithium-vanadium composite oxide, lithium niobate, etc.
Metal chalcogenites such as titanium sulfide, lithium molybdenum sulfide, and lithium niobium selenide can be given.

On the other hand, a material which can be electrochemically doped and dedoped with lithium ions having an electrochemically lower potential than the positive electrode material is used as the negative electrode material.
For example, graphite, coke, carbon-based materials such as amorphous carbon, tin-based composite oxides, silica-based composite oxides, titanium oxide, lithium oxide solid solution of metal oxides such as iron oxide,
Ceramics such as lithium nitrogen manganese, lithium iron nitride, lithium nickel nitride, lithium copper nitride, and lithium aluminum nitride are used.

Examples of the binder material include polyvinylidene fluoride, polyvinylidene fluoride resins such as poly (hexafluoropropylene-vinylidene fluoride) copolymer and poly (chlorotrifluoroethylene-vinylidene fluoride) copolymer. Polytetrafluoroethylene,
(Hexafluoropropylene-vinylidene fluoride-
A fluoropolymer such as a (tetrafluoroethylene) copolymer, or a hydrocarbon polymer or a rubber such as a fluororubber, a styrene-butadiene copolymer, a styrene-acrylonitrile copolymer, a styrene-acrylonitrile-butadiene copolymer. Used.

The solvent may be selected from those which can be dissolved depending on the kind of the binder used, and a plasticizer or a thickener can be used in combination to adjust the viscosity. For example, when a fluorine-based resin is used for the binder, N-
Methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide and the like are selected. When using a plasticizer for the fluorine-based resin binder,
Examples include dibutyl phthalate, dioctyl phthalate, acetone, ethylene carbonate, propylene carbonate, and the like. When a water-dispersed binder is used, the viscosity of the coating liquid can be adjusted using carboxymethyl cellulose or the like.

Next, an apparatus for manufacturing a battery electrode will be described. The adhesive tape is characterized in that it is arranged in parallel to the longitudinal direction of the long metal foil current collector when applying the coating liquid, and the arrangement and peeling procedure are not particularly limited, For example, the coating is performed after arranging the adhesive tape immediately before the application of the coating liquid to the supplied long metal foil current collector, and then the coating liquid is dried and solidified after the adhesive tape is peeled off. Alternatively, it is preferable that after application, the coating liquid is dried and solidified, and then the adhesive tape is peeled off.

Specifically, the procedure is as follows. A long metal foil current collector wound in a roll is supplied, and an adhesive tape is arranged in parallel to the long direction of the long metal foil current collector. The coating liquid is applied on a long metal foil current collector on which an adhesive tape is arranged, the adhesive tape is peeled off, the coating liquid is dried and solidified, and the coating liquid is dried and solidified, thereby collecting a long metal foil current. A method of sequentially performing a step of winding a body into a roll.

Alternatively, a long metal foil current collector wound in a roll is supplied, and an adhesive tape is arranged in parallel with the longitudinal direction of the long metal foil current collector, and a coating liquid is applied to the adhesive tape. A method of sequentially performing a process of coating on a placed metal foil current collector, drying and solidifying a coating liquid, peeling off an adhesive tape, and winding a long metal foil current collector in which the coating liquid is dried and solidified into a roll shape. Is raised.

Here, the means for applying the coating liquid is a device for feeding the coating liquid at a constant rate per unit time, and a means for feeding the fed coating liquid in the width direction and length of the long metal foil current collector. The coating is performed with a device that applies a uniform thickness in the length direction. There are a pump method, a pressure feeding method, and the like for sending the coating liquid. Also,
Examples of the coating apparatus include a knife coater system, a pipe doctor system, a reverse roll system, a dip system, and a die system. The means for supplying a long metal foil current collector to which a coating liquid is applied refers to a device capable of feeding out a long metal foil current collector at a constant speed.

The means for arranging the adhesive tape is an apparatus for arranging the adhesive tape on the extended long metal foil current collector in parallel with the elongate direction so as to follow the extension speed. The means for drying and solidifying the coating liquid may be any means capable of removing the solvent contained in the coating liquid, but is preferably separated by a heat insulating material and kept in a space maintained at a certain temperature (hereinafter referred to as a drying chamber). ) In which a long metal foil current collector passes. The temperature of the drying chamber may always be constant, but two or more drying chambers having different temperature conditions may be installed depending on the type and amount of the solvent to be dried and the residence time of the long metal foil current collector in the drying chamber. Absent.

The means for peeling off the adhesive tape before or after the coating liquid applied to the long metal foil current collector on which the adhesive tape is disposed is dried and solidified is a long metal. It is a device that follows the supply speed of the foil current collector and peels off the adhesive tape before drying and solidifying the coating liquid after drying or solidifying the coating liquid after coating before winding the electrode. .

The means for winding a long metal foil current collector in which the coating liquid is dried and solidified into a roll shape means to wind the long metal foil current collector in a roll shape following the speed of the supplied long metal foil current collector. More preferably, the device is a feedback mechanism that can maintain the tension on the supply side and the winding side constant. As described above, according to the present invention, it is possible to increase the accuracy of the electrode active material coating width and increase the production efficiency. And as a further effect, the fact that the adhesive tape is peeled off before winding the electrode eliminates the need to wind an electrode in which a part of the electrode is partially raised due to the thickness of the adhesive tape, and the electrode was wound. This eliminates the occurrence of winding deviation and a gauge band, thereby further increasing the production efficiency.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described below with reference to examples. The composition of the positive electrode coating solution used in the following examples is a mixture of 100 parts by weight of lithium cobalt oxide, 5 parts by weight of graphite fine powder as a conductive auxiliary, and 3 parts by weight of polyvinylidene fluoride as a binder. A mixture obtained by adding N-methyl-2-pyrrolidone was used. At this time, the solid content was 70% by weight. Further, as a negative electrode coating liquid, a styrene-butadiene latex was prepared as a binder so as to have a solid content of 2 parts by weight with respect to 100 parts by weight of finely divided graphite fibers, and a mixture obtained by adding water as a dispersion solvent and mixing. Was. The total solid content at this time is
It was 57% by weight.

[0028]

[Example 1] A width of 100 mm, a thickness of 20 μm, and a length of 500 m
12mm wide and 45mm long on aluminum metal foil current collector
A doctor blade is used to apply a pressure-sensitive adhesive tape to an aluminum metal foil current collector having a length of 0 mm and a 180-degree peel strength against aluminum having a peel strength of 15 g / cm on a vinyl chloride base material arranged in a line in the length direction. A positive electrode coating solution is applied with a width of 70 mm, a length of 400 mm, and a thickness of 120 μm so as to cover the adhesive tape. Peeled from the body. Visual observation of the peeled surface showed no disturbance of the coating film edge, and no damage such as wrinkles was observed on the aluminum foil current collector.

Subsequently, the coating film was dried in a hot air dryer at 120 ° C. to obtain a positive electrode. The obtained positive electrode was cut into a size of 10 mm × 20 mm so that the coated portion was 10 × 10 mm and the peeled portion was 10 × 10 mm, and an electrochemical cell was assembled to perform constant current and constant voltage charge / discharge evaluation. Was. The electrode terminal of the positive electrode is 10 × 10 mm using nickel foil.
Was joined by ultrasonic welding. The electrolytic solution used was a solution in which lithium borofluoride was dissolved at a concentration of 1.0 mol / l in a 1: 1 mixture of ethylene carbonate and γ-butyrolactone, and metallic lithium was used as a counter electrode. At this time, the charge amount per gram of lithium cobalt oxide is 140
The mAh and the discharge amount were 132 mAh, which proved to be sufficiently usable as the positive electrode of the lithium ion secondary battery.

[0030]

[Example 2] width 100 mm, thickness 20 μm, length 500 m
12 mm wide, 450 mm long and 180 ° peel strength against aluminum of 8 g / c
m with a width of 70 mm so as to cover the adhesive tape using a doctor blade against a metal copper foil current collector in which an adhesive tape having an acetate film as a base material is disposed in a single line in the length direction.
A negative electrode coating liquid having a length of 400 mm and a thickness of 90 μm was applied, and the adhesive tape was peeled off from the metal copper foil current collector together with the coating liquid covering the adhesive tape before the coating liquid was dried. When the peeled surface was visually observed, there was no disturbance of the coating film edge, and no damage such as wrinkles was observed on the metal copper foil current collector.

Subsequently, the coating film was dried in a hot air dryer at a drying room temperature of 120 ° C. to obtain a negative electrode. The obtained negative electrode was coated with a coated portion of 10 × 10 mm and a peeled portion of 10 × 10 mm.
mm, and was cut into a size of 10 mm × 20 mm, assembled in the same electrochemical cell as in Example 1, and evaluated for charge and discharge at a constant current and a constant voltage. Nickel foil was used for the electrode terminal of the negative electrode, and the bonding was 10 × 10 mm as in Example 1.
Was joined by ultrasonic welding. At this time, the charge amount per gram of the pulverized graphite fiber was 320 mAh, and the discharge amount was 295 mAh, and it was found that the charge amount was sufficiently usable as the negative electrode of the lithium ion secondary battery.

[0032]

[Embodiment 3] A width of 100 mm, a thickness of 20 μm, and a length of 500 m
12mm wide and 45mm long on aluminum metal foil current collector
Aluminum metal foil on which an adhesive tape (Riba Alpha, trade name, manufactured by Nitto Denko Corporation) whose 180 degree peel strength against aluminum becomes 0 g / cm by heating at 0 mm and 100 ° C. for 10 seconds is arranged in one length direction. A positive electrode coating solution is applied to the current collector with a doctor blade with a width of 70 mm, a length of 400 mm, and a thickness of 120 μm so as to cover the adhesive tape. And dried in. After the coating film was dried and solidified, the adhesive tape and the coating film covering the adhesive tape were peeled off from the current collector to obtain a positive electrode. When the peeled surface was visually observed, there was no disturbance of the coating film edge, and no damage such as wrinkles was found on the aluminum metal foil current collector. The obtained positive electrode was coated with a coating portion of 10 × 10 mm and a peeled portion of 10 × 1.
It was cut out to a size of 10 mm × 20 mm so as to be 0 mm, and the same electrochemical cell as in Example 1 was assembled to perform charge / discharge evaluation at a constant current and a constant voltage. The electrode terminal of the positive electrode was ultrasonically welded to a 10 × 10 mm peeled portion as in Example 1.

At this time, the charge amount per gram of lithium cobalt oxide was 142 mAh, and the discharge amount was 136 mAh.
Thus, it was found that the electrode was sufficiently usable as a positive electrode of a lithium ion secondary battery.

[0034]

Embodiment 4 The means for applying the coating liquid is a three-roll reverse roll method, and the means for supplying a long metal foil current collector on which the coating liquid is applied is a roll-shaped metal foil current collector. In this method, the adhesive tape is placed on the metal foil current collector, and the means for arranging the adhesive tape is fed out while following the feeding speed of the metal foil current collector, and the coating liquid is applied. It is a method of arranging the metal foil current collector in a single row continuously in parallel with the longitudinal direction before processing, and the means for drying and solidifying the coating liquid applied on the metal foil current collector is continuous. This is a method using two drying chambers, and the means for peeling the adhesive tape covers the adhesive tape with the adhesive tape before the metal foil current collector coated with the coating liquid enters the drying chamber. This method separates the coating liquid from the metal foil current collector and winds it into a roll. Using cell electrode manufacturing apparatus comprising a system for winding into a roll while the follow the feeding speed of the means for winding the metal foil current collector the metal foil current collector.

Using this apparatus, a width of 300 mm and a thickness of 1
A 5-mm long, 300-m aluminum metal foil current collector is covered with a vinyl chloride-based pressure-sensitive adhesive tape having a width of 12 mm and a 180-degree peel strength against aluminum of 15 g / cm while covering the pressure-sensitive adhesive tape. A positive electrode coating liquid is applied at a thickness of 260 mm and a thickness of 120 μm, and before the coated aluminum metal foil current collector enters the drying chamber, the adhesive tape is coated with the coating liquid covering the adhesive tape. It was peeled off from the conductor and wound up.

The aluminum metal foil current collector in which the adhesive tape was peeled off and the strip-shaped uncoated portions were continuously formed in the longitudinal direction in parallel was passed through a drying chamber divided into two chambers, and then the positive electrode was removed. It was wound into a roll as an electrode. At this time, the line speed of the coating apparatus was 1 m per minute. The first drying room with a length of 1.8 m is 80 ° C, and the second drying room with a length of 1.8 m is 13
It was dried while being kept at 0 ° C.

When the peeled surface was visually observed, there was no disturbance of the coating film edge in the undried state immediately after the peeling, and no damage such as wrinkles was found on the aluminum metal foil current collector. Further, when the peeled surface of the coating film before being dried and wound up was visually observed, there was no disturbance of the coating film edge, and no damage such as wrinkles was found on the aluminum metal foil current collector. The electrode was continuously manufactured for 60 m, but the wound electrode did not cause any winding deviation, and no aluminum metal foil was broken and no gauge band was generated. The obtained positive electrode was coated with 10 × 10
mm, 10 mm x 10 mm so that the peeled part is 10 x 10 mm.
It was cut out to a size of 20 mm, and an electrochemical cell was assembled in the same manner as in Example 1 to evaluate the charge and discharge at a constant current and a constant voltage. At this time, the charge amount per gram of lithium cobalt oxide is
The discharge amount was 144 mAh and the discharge amount was 132 mAh, which proved that the electrode was sufficiently usable as a positive electrode of a lithium ion secondary battery.

[0038]

Example 5 Using the reverse roll type electrode manufacturing apparatus used in Example 4, the width was 300 mm, the thickness was 12 μm, and the length was 30.
While placing an adhesive tape based on acetate having a width of 12 mm and a 180-degree peel strength against aluminum of 8 g / cm on a 0 m metal copper foil current collector, the width is 260 mm and the thickness is 90 μm so as to cover the adhesive tape. Apply the negative electrode coating liquid with the metal copper foil current collector, and peel the adhesive tape from the metal copper foil current collector together with the coating liquid covering the adhesive tape before the coated metal copper foil current collector enters the drying chamber. , Wound up. The metal copper foil current collector, in which strip-shaped uncoated portions are continuously formed parallel to the long direction from which the adhesive tape has been peeled off, is passed through a drying chamber divided into two chambers, and then wound as a negative electrode. I took it.

At this time, the line speed of the apparatus is 1 / min.
m. The first drying chamber having a length of 1.8 m was dried with hot air at 80 ° C, and the second drying chamber having a length of 1.8 m was dried with hot air at 110 ° C. When the peeled surface of the adhesive tape was visually observed, there was no disturbance of the coating film edge in the undried state immediately after the peeling, and no damage such as wrinkles was found on the metal copper foil current collector. Furthermore, when the peeled surface of the adhesive tape of the electrode before being dried and wound was visually observed, there was no disturbance of the coating film edge,
No damage such as wrinkles was observed on the metal copper foil current collector. The electrode was manufactured continuously over 100 m. However, the wound electrode did not cause any winding deviation, and there was no occurrence of foil breakage of the metal copper foil current collector or generation of a gauge band. The obtained negative electrode was coated with 10 × 10
mm, 10 mm x 10 mm so that the peeled part is 10 x 10 mm.
It was cut out to a size of 20 mm, and an electrochemical cell was assembled in the same manner as in Example 1 to evaluate the charge and discharge at a constant current and a constant voltage.

At this time, the charge amount per gram of the finely divided graphite fibers was 318 mAh, and the discharge amount was 292 mAh.
It was found that the electrode was sufficiently usable as a negative electrode of a lithium ion secondary battery.

[0041]

Example 6 Using the reverse roll type electrode manufacturing apparatus used in Example 4, the width was 300 mm, the thickness was 18 μm, and the length was 30.
A 12-mm wide, 180-degree peel strength against aluminum, polyester-based pressure-sensitive adhesive tape of 63 g / cm is placed on a 0-m metal copper foil current collector, and a 260-mm-wide, 90-μm-thick film is covered to cover the pressure-sensitive adhesive tape. Apply the negative electrode coating liquid with the metal copper foil current collector, and peel the adhesive tape from the metal copper foil current collector together with the coating liquid covering the adhesive tape before the coated metal copper foil current collector enters the drying chamber. , Winding up. Visual observation of the peeled surface showed that in the undried state immediately after peeling, there was no disturbance of the coating film edge, and no damage such as wrinkles was observed on the metal copper foil current collector. Further, when the peeled surface of the coating film before being dried and wound was visually observed, there was no disturbance of the coating film edge, and no damage such as wrinkles was observed on the metal copper foil current collector. The electrode was manufactured continuously for 100 m. However, the wound electrode did not cause any winding deviation, and no breakage of the metal copper foil current collector and generation of a gauge band were observed at all.

[0042]

Example 7 The wound positive electrode of Example 4 was 9 mm
10 so that the uncoated part of width and the coated part of 98 mm width are continuous.
It was slit in a width of 7 mm and parallel to the long direction. Similarly, the negative electrode obtained in Example 5 has a 9 mm-width uncoated portion and 98
The slits were 107 mm wide and parallel to the long direction so that the coated portions having a width of mm were continuous.

On the other hand, a closed-cell foam made of a copolymer of vinylidene fluoride and hexafluoropropylene was impregnated with the electrolytic solution used in Example 1 to obtain a liquid content of 75% by weight.
Create a gel electrolyte with a width of 100 mm and a thickness of 70 μm,
The positive electrode and the negative electrode were overlapped so that the coated portions faced each other with the gel electrolyte interposed therebetween, and the non-coated portions were overlapped with each other in opposite directions. Then, lamination was performed using a roll laminator. Roll temperature during lamination is 14
0 ° C. The length of the obtained laminate in the longitudinal direction is 89 m.
m. Eight 89 mm × 116 mm laminates were alternately stacked such that metal copper foils and aluminum foils faced each other to form a unit cell. Eight pieces of aluminum foil of the uncoated part of the unit cell and nickel foil of 5 mm width and 100 μm thickness were simultaneously connected as electrode terminals using an ultrasonic welding machine. Similarly, ultrasonic welding was performed on the metal copper foil current collector portion using nickel foil as an electrode terminal.

Next, the aluminum foil forms the central layer,
The unit cell was covered with a three-layer aluminum laminate film having polypropylene as a sealant and polyester as an exterior part, and heat-sealed with a width of about 5 mm on the outer periphery so that an electrode terminal was exposed, to form a lithium ion polymer secondary battery. This lithium ion polymer secondary battery is referred to as 1A, 4.
2230mAh after 2V constant current constant voltage charging
Was obtained. When a constant current cut-off discharge of 1 A and 3 V was performed, a capacity of 1960 mAh was obtained. The average voltage at this time was 3.6 V, and it was found that the current collector according to the present invention was sufficiently usable for lithium ion polymer secondary batteries.

[0045]

[Comparative Example 1] 100 mm wide, 20 µm thick, 500 m long
12mm wide and 45mm long on aluminum metal foil current collector
Using a doctor blade, a 70 mm width is applied to an aluminum metal foil current collector on which an adhesive tape having a peel strength of 105 g / cm and a 180-degree peel strength with respect to aluminum of 0 mm is disposed using a doctor blade so as to cover the adhesive tape. 40
A positive electrode coating liquid was applied at a thickness of 0 mm and a thickness of 120 μm, and the adhesive tape was peeled off from the aluminum metal foil current collector together with the coating liquid covering the adhesive tape before the coating liquid was dried. Then, the aluminum metal foil current collector was broken and could not be used as an electrode.

[0046]

Comparative Example 2 Using the reverse roll type electrode manufacturing apparatus used in Example 4, the width was 300 mm, the thickness was 15 μm, and the length was 30.
0 m aluminum metal foil current collector, width of 12 mm, 180 degree peel strength against aluminum of 105 g / cm
While arranging an adhesive tape based on the polyester of the above, a width of 260 mm and a thickness of 90 μm are covered so as to cover the adhesive tape.
m, and before the coated aluminum metal foil current collector enters the drying chamber, the adhesive tape is removed from the aluminum metal foil current collector together with the coating solution covering the adhesive tape. Peeled and wound up.

Unlike the case of Example 4, the peeling operation was not smooth and the peeled surface was visually observed. In the undried state immediately after the peeling, a peeled surface was partially formed in the coated portion, or the peeled portion was not coated. The liquid wrapped around and a linear coating edge could not be obtained. In addition, wrinkles were generated at the portions where the aluminum metal foil current collector was exposed after peeling. Further, when the peeled surface of the coating film before being dried and wound was visually observed, a linear coating film edge could not be obtained. The aluminum metal foil current collector also remained wrinkled. Although the electrode was manufactured continuously for about 15 m, notches were formed at the edges of the peeled portion and the coated portion, and the aluminum metal foil was cut off from the notch.

[0048]

Comparative Example 3 Using the reverse roll type electrode manufacturing apparatus used in Example 4, the width was 300 mm, the thickness was 18 μm, and the length was 30.
A 12-mm-wide, 180-degree peel strength against aluminum aluminum-based polyester-based pressure-sensitive adhesive tape of 105 g / cm is placed on a 0-m metal copper foil current collector, and a 260-mm-wide thickness is applied to cover the pressure-sensitive adhesive tape. A negative electrode coating liquid is applied at 90 μm, and before the coated metal copper foil current collector enters the drying chamber, the adhesive tape is removed from the metal copper foil current collector together with the coating liquid covering the adhesive tape. Peeled and rolled up. Unlike the case of Example 4, the peeling operation was not smooth, and the peeled surface was visually observed. In the undried state immediately after the peeling, a part of the peeled surface was generated in the coated portion or the coating liquid wrapped around the peeled portion. No linear coating edge could be obtained.

Further, when the peeled surface of the coating film before being dried and wound up was visually observed, a linear coating film edge could not be obtained. Although the metal copper foil current collector did not show any damage such as wrinkles, the electrode was manufactured continuously over 30 m. Gauge band-like swelling occurred at the edge of the coated portion, and the metal copper foil current collector was cut off from that portion.

[0050]

The metal foil current collector used for the battery electrode according to the present invention enables the supply of an electrode having high dimensional accuracy in the uncoated portion of the coating liquid with high production efficiency.

Claims (3)

[Claims] 1. A strip having a width of 2 mm or more and 100 mm or less per strip and a 180 ° peel strength with respect to aluminum of 5 g.
A long metal foil used for an electrode for a battery, wherein at least one or more adhesive tapes having a length of at least one strip of at least 100 g / cm are arranged in parallel with the long direction of the long metal foil current collector. Current collector. 2. The pressure-sensitive adhesive tape according to claim 1, wherein
By exposing to a temperature of 60 ° C. or more and 200 ° C. or less for 5 seconds or more, the 80 ° peel strength is 0 g / cm or more and 5 g / c or more.
2. The long metal foil current collector according to claim 1, wherein the length is not more than m. 3. A means for applying a coating liquid, a means for supplying a long metal foil current collector to which the coating liquid is applied, and a means for applying a coating liquid on the metal foil current collector. A means for drying and solidifying the coating liquid, a means for winding the metal foil current collector carrying the dried and solidified coating liquid, and a 180 ° peel strength of 5 g / cm to 100 g / cm for aluminum. Adhesive tape, with a width of 2 mm or more and 100 mm or less per tape, at least one or more parallel to the longitudinal direction of the metal foil current collector before applying a coating liquid on the metal foil current collector And a long metal foil current collector after the coating liquid is coated on the long metal foil current collector on which the adhesive tape is arranged, and on which the adhesive tape is arranged. Means for peeling off the adhesive tape before or after the coating liquid applied on the body is dried and solidified An electrode manufacturing apparatus for a battery, comprising: