JPWO2019111616A1 - Current collector electrode sheet, its manufacturing method, battery, and its manufacturing method - Google Patents

Abstract

By discharging the slurry containing the active material from the die head on both sides of the sheet-shaped current collector layer, the slurry is intermittently applied and dried, and the coated area and the non-applied area of the slurry are formed on the sheet-shaped current collector layer. In the process of forming the end portion of each intermittent coating region in the process of manufacturing the current collector electrode sheet by alternately forming in the winding direction, the distance between the die head and the sheet-shaped current collector layer is set in each intermittent coating region. By discharging the slurry from the die head in a state narrower than the distance between the die head and the sheet-shaped current collector layer in the step of forming the central portion of the coating region, the value of the length of the tailing portion at the end of the coating region can be increased. , A current collector electrode sheet having a thickness of 12 times or less the thickness of the single-sided active material layer after pressure compression is produced.

Description

The present invention relates to a current collector electrode sheet, a method for producing the same, a battery, and a method for producing the same.

In recent years, in light of environmental problems, interest in electric vehicles and hybrid vehicles has increased, and technical demands for higher energy density and higher capacity of secondary batteries, which are the driving sources thereof, have further increased.

Such electrodes for a secondary battery are manufactured from a current collector electrode sheet in which a slurry containing an active material is applied and dried on a strip-shaped current collector layer such as aluminum or copper. The method of applying the active material can be roughly divided into an intermittent coating method and a continuous coating method.

In the intermittent coating method, a coated region formed by applying a slurry such as an active material to a band-shaped current collector layer and a non-coated region not coated with the slurry are defined in the winding direction of the current collector layer. It is a method of forming alternately at intervals. The non-forming portions of the active material arranged at predetermined intervals are used as a portion for taking out a drawer tab for electrically connecting to an external terminal. In the method for producing a current collector electrode sheet according to the present invention, a slurry in which an active material, a conductivity-imparting agent, a binder, and a solvent, which are the main materials, are mixed or kneaded is intermittently applied to one surface of the current collector layer. After coating (hereinafter referred to as intermittent coating), the slurry is applied to both sides of the current collector layer again by intermittently coating the other surface on the opposite side of the current collector layer. Next, the current collector layer coated with slurry on both sides is pressure-molded by a compression roller. After that, the current collector is cut to a desired external size to form an electrode terminal portion on the current collector electrode sheet.

Here, a lithium-containing composite oxide is used as the positive electrode active material of the lithium ion secondary battery, and a large pressure is required when the active material layer containing such metal oxide particles as a main component is pressure-molded. And. In particular, in the positive electrode used for a secondary battery designed to have a high energy density, since it is necessary to compress the active material layer at a high density, it is often molded by applying a larger pressure in the pressure molding.

Further, the electrodes used in the secondary battery designed to have a high energy density tend to be designed so that the thickness of the current collector layer, which is a current collector, is thin.

JP-A-2002-164041

As shown in FIG. 1, when the slurry is intermittently applied to the coating end portion of the current collector electrode sheet, a trailing portion 14 of the slurry is generated at the boundary between the coating region 11 and the non-coating region 12. It's easy to do. When the strip-shaped current collector electrode sheet 10 is compression-molded by a roll press machine along the winding direction Dx of the electrode roll, if such a tailing portion 14 is present, the tailing portion 14 at the end of coating is wound in the winding direction. Since the active material layer exists only intermittently in the direction Dy perpendicular to Dx (hereinafter, also referred to as the longitudinal direction), the active material layer continuously exists in the direction Dy perpendicular to the winding direction Dx. A greater linear pressure will be applied than in the central part.

In the tailing portion 14 to which such a large linear pressure is applied, a phenomenon in which the active material particles largely bite into the metal foil 9 which is the current collector layer often occurs. Since the amount of residual meat in the foil at the portion where the active material particles bite into the metal foil 9 is extremely thin, cracks (not shown) that cause the foil to break occur. When the region where the cracks are generated is cut in the subsequent cutting step, burrs that partially fall off of the active material layer are generated on the cut surface of the sheet electrode. When the generated burrs adhere to the electrodes, they cause a short circuit during battery assembly, which causes a problem that the defective rate of the battery increases.

In order to prevent the tailing portion 14 from being generated at the coating end portion when the slurry is intermittently applied in this way, for example, Patent Document 1 describes a foil winding in the coating area to which the active material layer is applied in advance. A method of applying a fluororesin to the start and end of the taking direction Dx is presented. However, this method increases the cost for applying the fluororesin and also increases the weight and thickness of the electrode, which is a problem as a method for manufacturing an electrode used for a secondary battery designed with a high energy density. was there. Therefore, it is necessary to provide a manufacturing method that suppresses the generation of burrs and provides an electrode having a low defect rate even if only the active material layer is applied to the current collector electrode sheet.

The present invention has been made to solve the problems of the background technology as described above, and is a current collector electrode sheet capable of suppressing the generation of burrs in the cutting process without increasing the manufacturing cost, and a method for manufacturing the current collector electrode sheet. , Batteries, and methods of manufacturing them.

The current collector electrode sheet of the present invention
A current collector electrode sheet in which active materials are applied to both sides of a sheet-shaped current collector layer.
Both surfaces of the current collector layer include a coated region of the slurry and a non-coated region formed by intermittently coating and drying the slurry containing the active material.
The coated region and the non-coated region are formed alternately in the winding direction of the band-shaped current collector layer.
The value of the length of the tailing portion at the end of each of the coating regions is 12 times or less the value of the thickness of the single-sided active material layer after pressure compression.

The method for manufacturing the current collector electrode sheet of the present invention is as follows.
By discharging the slurry containing the active material from the die head on both sides of the sheet-shaped current collector layer, the slurry is intermittently applied and dried, and the coated region and the non-coated region of the slurry are applied to the current collector layer. It is a method of manufacturing a current collector electrode sheet by alternately forming it in the winding direction.
It includes a step of forming a start end portion of the coating region, a step of forming a central portion of the coating region, and a step of forming an end portion of the coating region.
In the step of forming the terminal portion, the slurry is placed in the die head in a state where the distance between the die head and the current collector layer is narrower than the distance between the die head and the current collector layer in the step of forming the central portion. Discharge from.

The second electrode current collector sheet of the present invention is
It is manufactured by using the method for manufacturing the current collector electrode sheet of the present invention.

The method for manufacturing the battery of the present invention
A step of forming a positive electrode active material layer on both sides of a sheet-shaped current collector layer to form a positive electrode current collector electrode sheet, and a process of forming a negative electrode active material layer on both sides of a sheet-shaped current collector layer to collect a negative electrode. A step of forming an electric body electrode sheet, a step of cutting the positive electrode current collector electrode sheet and the negative electrode current collector electrode sheet to predetermined sizes, and a step of forming a positive electrode and a negative electrode, respectively. A method for manufacturing a battery, comprising a step of laminating the positive electrode and the negative electrode via a separator.
Either or both of the step of forming the positive electrode current collector electrode sheet and the step of forming the negative electrode current collector electrode sheet includes each step of the method for producing the current collector electrode sheet of the present invention.

The battery of the present invention
A battery having at least a positive electrode, a negative electrode, and an electrolyte.
One or both of the positive electrode and the negative electrode include an electrode formed by cutting the current collector electrode sheet of the present invention into a predetermined size.

It should be noted that any combination of the above components and the conversion of the expression of the present invention between methods, devices, systems, recording media, computer programs and the like are also effective as aspects of the present invention.

Further, the various components of the present invention do not necessarily have to be individually independent, and a plurality of components are formed as one member, and one component is formed of a plurality of members. It may be that a certain component is a part of another component, a part of a certain component overlaps with a part of another component, and the like.

Further, although the method and the computer program of the present invention describe a plurality of procedures (or steps) in order, the order of description does not limit the order in which the plurality of procedures are executed. Therefore, when implementing the method and computer program of the present invention, the order of the plurality of procedures can be changed within a range that does not hinder the contents.

Furthermore, the methods of the present invention and the plurality of procedures (or steps) of a computer program are not limited to being executed at individually different timings. Therefore, another procedure may occur during the execution of a certain procedure, or the execution timing of the certain procedure and the execution timing of the other procedure may partially or completely overlap.

According to the present invention, there is provided a current collector electrode sheet, a method for manufacturing the same, a battery, and a method for manufacturing the current collector electrode sheet, which can suppress the generation of burrs in the cutting process of the current collector electrode sheet without increasing the manufacturing cost. Can be done.

The above-mentioned objectives and other objectives, features and advantages will be further clarified by the preferred embodiments described below and the accompanying drawings below.

It is a top view which shows the current collector electrode sheet after double-sided coating of an active material by an intermittent coating method. It is a top view which shows the current collector electrode sheet after double-sided coating in embodiment of this invention. It is a top view and a sectional view which shows the current collector electrode sheet after double-sided coating in embodiment of this invention. It is a schematic diagram which shows the outline of the slurry coating apparatus of the electrode sheet which concerns on embodiment of this invention. It is a schematic diagram which shows an example of the die coater part in the slurry coating apparatus of the electrode sheet which concerns on embodiment of this invention. It is a block diagram which shows an example of the hardware composition of the computer which realizes each apparatus of the electrode sheet manufacturing system which concerns on embodiment of this invention. It is a figure which shows typically the operation state of each apparatus in slurry coating among the manufacturing method of the electrode sheet which concerns on embodiment of this invention. It is a schematic diagram which shows the outline of the compression apparatus of the electrode sheet which concerns on embodiment of this invention. It is a schematic diagram which shows the outline of the cutting apparatus which cuts the electrode sheet which concerns on embodiment of this invention into a plurality of sheets. It is the schematic which shows an example of the structure of the battery which concerns on embodiment of this invention. It is a block diagram which shows the structural example of the manufacturing system of the current collector electrode sheet which concerns on this embodiment. It is a flowchart which shows the process of the manufacturing method of the current collector electrode sheet which concerns on this embodiment. It is a flowchart which shows an example of the processing procedure of the control program of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by a common reference numeral, and description thereof will be omitted as appropriate. Further, the figure is a schematic view and does not match the actual dimensional ratio. Further, "A to B" in the numerical range represent A or more and B or less unless otherwise specified.

<Electrodes and electrode manufacturing method>
Hereinafter, the current collector electrode sheet 10 and the method for manufacturing the current collector electrode sheet 10 according to the present embodiment will be described.
FIG. 2 is a plan view showing an example of the configuration of the current collector electrode sheet 10 according to the embodiment of the present invention.
FIG. 3A is a plan view showing a part of the current collector electrode sheet 10 after double-sided coating according to the embodiment of the present invention. FIG. 3B is a cross-sectional view of the current collector electrode sheet 10 of FIG. 3A as viewed from line I-I.

The method for manufacturing the current collector electrode sheet 10 according to the present embodiment is a method for manufacturing an electrode including a current collector layer (metal foil 9) and an electrode active material layer (coating region 11).

As described above, according to the studies by the present inventors, it has been clarified that the electrodes produced by the intermittent coating method are liable to generate burrs in the subsequent cutting step.
As a result of repeated studies based on the above findings, the present inventors have found a value of the length of the tailing portion 14 at the end 13 of the intermittently applied coating region 11 (Z in FIG. 3B). By setting the current collector electrode sheet 10 to be 12 times or less the thickness value (T in FIG. 3B) of the single-sided active material layer (coating region 11) after pressure compression, burrs in the cutting step It was found that the occurrence of can be effectively suppressed.

Further, according to the method for manufacturing the current collector electrode sheet 10 according to the present embodiment, in the step of forming the end portion of each intermittent coating region 11, the distance between the die head and the sheet-like current collector layer (metal leaf 9) is set. A method for manufacturing a current collector electrode sheet 10 in which a slurry is discharged from a die head in a state narrower than the distance between the die head and the sheet-shaped current collector layer (metal leaf 9) in the step of forming the central portion of each intermittent coating region 11. By using, the value of the length of the tailing portion 14 at the end 13 of the coating region 11 applied intermittently (Z in FIG. 3B) is the single-sided active material layer (coating region) after pressure compression. It is possible to stably obtain the current collector electrode sheet 10 which is 12 times or less the thickness value of 11) (T in FIG. 3B).

Further, according to the present embodiment, the current collector electrode for a battery includes a step of forming an active material layer on the current collector by applying a slurry to a current collector, drying it, and removing a solvent. A method of manufacturing a sheet is provided.
Further, according to the present embodiment, a battery electrode including a current collector and an active material layer provided on at least one surface of the current collector and formed of a solid content of a slurry is provided as a sheet. Will be done.

As described above, according to the method for manufacturing the current collector electrode sheet 10 according to the present embodiment, it is possible to provide an electrode in which the generation of burrs is suppressed.

Hereinafter, each step in the configuration of the current collector electrode sheet 10 and the method for manufacturing the current collector electrode sheet 10 will be described in detail.

First, each component constituting the electrode active material layer according to the present embodiment will be described.
The electrode active material layer contains an electrode active material, and if necessary, contains a binder resin, a conductive auxiliary agent, a thickener, and the like.

The electrode active material contained in the electrode active material layer according to the present embodiment is appropriately selected according to the intended use. A positive electrode active material is used when producing a positive electrode, and a negative electrode active material is used when producing a negative electrode.

The positive electrode active material is not particularly limited as long as it is a normal positive electrode active material that can be used for the positive electrode of a lithium ion battery. For example, lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-manganese composite oxide, lithium-nickel-manganese composite oxide, lithium-nickel-cobalt composite oxide, lithium-nickel-aluminum composite oxide, Transition with lithium such as lithium-nickel-cobalt-aluminum composite oxide, lithium-nickel-manganese-cobalt composite oxide, lithium-nickel-manganese-aluminum composite oxide, lithium-nickel-cobalt-manganese-aluminum composite oxide Composite oxides with metals; transition metal sulfides such as TiS ₂ , FeS, MoS ₂ ; transition metal oxides such as MnO, V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , olivine type lithium phosphorus oxides, etc. Can be mentioned.
The olivine-type lithium phosphorus oxide is, for example, at least one of the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B, Nb, and Fe. It contains elements, lithium, phosphorus, and oxygen. These compounds may be those in which some elements are partially replaced with other elements in order to improve their properties.

Among these, olivine type lithium iron phosphorus oxide, lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-manganese composite oxide, lithium-nickel-manganese composite oxide, lithium-nickel-cobalt composite oxide , Lithium-nickel-aluminum composite oxide, lithium-nickel-cobalt-aluminum composite oxide, lithium-nickel-manganese-cobalt composite oxide, lithium-nickel-manganese-aluminum composite oxide, lithium-nickel-cobalt-manganese -Aluminum composite oxide is preferred. In addition to having a high working potential, these positive electrode active materials have a large capacity and a large energy density.
As the positive electrode active material, only one kind may be used alone, or two or more kinds may be used in combination.

The negative electrode active material is not particularly limited as long as it is a normal negative electrode active material that can be used for the negative electrode of a lithium ion battery. For example, carbon materials such as natural graphite, artificial graphite, resin charcoal, carbon fiber, activated charcoal, hard carbon, and soft carbon; lithium-based metal materials such as lithium metal and lithium alloy; metal materials such as silicon and tin; polyacetylene, polyacetylene, etc. Examples thereof include conductive polymer materials such as polypyrrole. Among these, a carbon material is preferable, and a graphite material such as natural graphite or artificial graphite is particularly preferable.
The negative electrode active material may be used alone or in combination of two or more.

The average particle size of the electrode active material is preferably 1 μm or more, more preferably 2 μm or more, from the viewpoint of suppressing side reactions during charging / discharging and suppressing a decrease in charging / discharging efficiency, and from the viewpoint of input / output characteristics and electrode fabrication (electrode). From the viewpoint of surface smoothness, etc.), 100 μm or less is preferable, and 50 μm or less is more preferable. Here, the average particle size means the particle size (median diameter: D ₅₀ ) at an integrated value of 50% in the particle size distribution (volume basis) by the laser diffraction / scattering method.

The content of the electrode active material is preferably 85 parts by mass or more and 99.8 parts by mass or less when the entire electrode active material layer is taken as 100 parts by mass.

The binder resin contained in the electrode active material layer according to the present embodiment is appropriately selected according to the intended use. For example, a fluorine-based binder resin that can be dissolved in a solvent, an aqueous binder that can be dispersed in water, or the like can be used.

The fluorobinder resin is not particularly limited as long as it can be electrode-molded and has sufficient electrochemical stability, and examples thereof include polyvinylidene fluoride-based resin and fluororubber. These fluorine-based binder resins may be used alone or in combination of two or more. Among these, polyvinylidene fluoride-based resin is preferable. The fluorine-based binder resin can be used by dissolving it in a solvent such as N-methyl-pyrrolidone (NMP).

The water-based binder is not particularly limited as long as it can be electrode-molded and has sufficient electrochemical stability. For example, polytetrafluoroethylene-based resin, polyacrylic acid-based resin, styrene-butadiene rubber, etc. Polyimide-based resin and the like can be mentioned. These water-based binders may be used alone or in combination of two or more. Among these, styrene-butadiene rubber is preferable.
In the present embodiment, the aqueous binder means a binder that can be dispersed in water to form an aqueous emulsion solution.
If an aqueous binder is used, a thickener can be further used. The thickener is not particularly limited, and for example, cellulosic polymers such as carboxymethyl cellulose, methyl cellulose, and hydroxypropyl cellulose, ammonium salts and alkali metal salts thereof; polycarboxylic acid; polyethylene oxide; polyvinylpyrrolidone; sodium polyacrylate and the like. Polyacrylates; polyvinyl alcohols; and other water-soluble polymers.

The content of the binder resin is preferably 0.1 parts by mass or more and 10.0 parts by mass or less when the entire electrode active material layer is 100 parts by mass. When the content of the binder resin is within the above range, the balance between the coatability of the electrode slurry, the binding property of the binder and the battery characteristics is further excellent.
Further, when the content of the binder resin is not more than the above upper limit value, the ratio of the electrode active material is increased and the capacity per electrode mass is increased, which is preferable. When the content of the binder resin is at least the above lower limit value, electrode peeling is suppressed, which is preferable.

The conductive auxiliary agent contained in the electrode active material layer according to the present embodiment is not particularly limited as long as it improves the conductivity of the electrode, and is, for example, carbon black, ketjen black, acetylene black, natural graphite, artificial graphite. , Carbon fiber and the like. These conductive auxiliaries may be used alone or in combination of two or more.

The content of the conductive auxiliary agent is preferably 0.1 parts by mass or more and 5.0 parts by mass or less when the entire electrode active material layer is 100 parts by mass. When the content of the conductive auxiliary agent is within the above range, the balance between the coatability of the electrode slurry, the binder binding property and the battery characteristics is further excellent.
Further, when the content of the conductive auxiliary agent is not more than the above upper limit value, the ratio of the electrode active material is increased and the capacity per electrode mass is increased, which is preferable. When the content of the conductive auxiliary agent is at least the above lower limit value, the conductivity of the electrode becomes better, which is preferable.

In the electrode active material layer according to the present embodiment, when the entire electrode active material layer is 100 parts by mass, the content of the electrode active material is preferably 85 parts by mass or more and 99.8 parts by mass or less. The content of the binder resin is preferably 0.1 parts by mass or more and 10.0 parts by mass or less. The content of the conductive auxiliary agent is preferably 0.1 parts by mass or more and 5.0 parts by mass or less.
When the content of each component constituting the electrode active material layer is within the above range, the balance between the handleability of the current collector electrode sheet 10 and the battery characteristics of the obtained lithium ion battery is particularly excellent.

The density of the electrode active material layer is not particularly limited, but when the electrode active material layer is a positive electrode active material layer, for example, it is preferably 2.0 g / cm ³ or more and 4.0 g / cm ³ or less, and 2.4 g. / more preferably cm ³ or more 3.8 g / cm ³ or less, and more preferably not more than 2.8 g / cm ³ or more 3.6 g / cm ^3. Further, the electrode active when material layer of the negative electrode active material layer, for example, is preferably not more than 1.2 g / cm ³ or more ^{2.0g / cm 3, 1.3g / cm} 3 or more 1.9 g / cm ³ It is more preferably 1.4 g / cm ³ or more and 1.8 g / cm ³ or less.
It is preferable that the density of the electrode active material layer is within the above range because the discharge capacity at the time of use at a high discharge rate is improved.

Here, the higher the density of the electrode active material layer, the deeper the electrode active material particles constituting the electrode active material layer bite into the metal foil 9 which is the current collector layer, so that the thickness of the metal foil 9 of the tailing portion 14 becomes thicker. Since the metal foil 9 becomes thinner and the strength of the metal foil 9 becomes weaker, burrs tend to occur in the cutting process. However, according to the method for producing the current collector electrode sheet 10 according to the present embodiment, even if the density of the electrode active material layer is high, the generation of burrs in the cutting step can be effectively suppressed.
Therefore, the density of the positive electrode active material layer is 3.0 g / cm ³ or more from the viewpoint of further improving the energy density of the obtained lithium ion battery while effectively suppressing the generation of burrs on the current collector electrode sheet 10. It is preferably 3.2 g / cm ³ or more, more preferably 3.3 g / cm ³ or more, and the density of the negative electrode active material layer is 1.5 g / cm ³ or more. It is preferable, and it is more preferable that it is 1.6 g / cm ³ or more. Further, from a more suppressing the deterioration of the cycle characteristics at high temperatures, it is preferable that the density of the positive electrode active material layer is 4.0 g / cm ³ or less, more preferably 3.8 g / cm ³ or less, It is more preferably 3.6 g / cm ³ or less, and the density of the negative electrode active material layer is preferably 2.0 g / cm ³ or less, more preferably 1.9 g / cm ³ or less, 1 It is more preferably .8 g / cm ³ or less.

The thickness of the electrode active material layer is not particularly limited, and can be appropriately set according to desired characteristics. For example, it can be set thick from the viewpoint of energy density, and can be set thin from the viewpoint of output characteristics. The thickness of the electrode active material layer (thickness on one side) can be appropriately set in the range of 10 μm or more and 250 μm or less, preferably 20 μm or more and 200 μm or less, and more preferably 30 μm or more and 150 μm or less.

The current collector layer according to the present embodiment is not particularly limited, but aluminum, stainless steel, nickel, titanium, an alloy thereof, or the like can be used as the positive electrode current collector layer. Examples of the shape include a foil, a flat plate, a mesh, and the like. In particular, an aluminum foil can be preferably used.
Further, as the negative electrode current collector layer, copper, stainless steel, nickel, titanium or an alloy thereof can be used. Examples of the shape include a foil, a flat plate, and a mesh. In particular, copper foil can be preferably used.

The thickness of the positive electrode current collector layer is not particularly limited, but is, for example, 1 μm or more and 30 μm or less. The thickness of the negative electrode current collector layer is not particularly limited, but is, for example, 1 μm or more and 20 μm or less. Here, the thinner the metal foil 9 as the current collector layer, the stronger the strength of the metal foil 9 of the tailing portion 14. Is weakened, so that burrs tend to occur in the cutting process. However, according to the method for manufacturing the current collector electrode sheet 10 according to the present embodiment, even if the thickness of the metal foil 9 is thin, the generation of burrs in the cutting step can be effectively suppressed.
Therefore, from the viewpoint of effectively suppressing the generation of burrs on the current collector electrode sheet 10, reducing the proportion of the current collector layer in the obtained lithium ion battery, and increasing the energy density of the lithium ion battery, the positive electrode collection is performed. The thickness of the electric body layer is preferably less than 25 μm, more preferably less than 20 μm, particularly preferably less than 18 μm, and the thickness of the negative electrode current collector layer is preferably less than 15 μm, more preferably less than 12 μm, and particularly preferably less than 10 μm.

Hereinafter, among the methods for manufacturing the battery of the present invention, a detailed method for manufacturing the electrodes will be described.

First, the electrode slurry is prepared.
The electrode slurry can be prepared by mixing an electrode active material, a binder resin, a conductive auxiliary agent, and a thickener, if necessary. Since the blending ratio of the electrode active material, the binder resin, and the conductive auxiliary agent is the same as the content ratio of the electrode active material, the binder resin, and the conductive auxiliary agent in the electrode active material layer, the description thereof is omitted here.

The electrode slurry is obtained by dispersing or dissolving an electrode active material, a binder resin, a conductive auxiliary agent, and a thickener, if necessary, in a solvent.
The mixing procedure of each component is not particularly limited, but for example, the electrode slurry can be prepared by dry-mixing the electrode active material and the conductive auxiliary agent, and then adding a binder resin and a solvent and wet-mixing.
At this time, as the mixer used, a known mixer such as a ball mill or a planetary mixer can be used, and is not particularly limited.
As the solvent used for the electrode slurry, an organic solvent such as N-methyl-2-pyrrolidone (NMP) or water can be used.

In the present embodiment, the prepared slurry is, for example, 2000 mPa when measured using a B-type viscometer (Rotating viscometer manufactured by Brookfield) at 25 ° C. and a shear rate of 3.4 s- ^1. It is preferably in the range of s to 20000 mPa · s. The solid content concentration of the slurry is preferably 50% by mass to 83% by mass.

The current collector electrode sheet 10 is manufactured using the electrode slurry prepared in this manner.

FIG. 11 is a block diagram showing a configuration example of the manufacturing system 1 of the current collector electrode sheet 10 according to the present embodiment.
The manufacturing system 1 includes a slurry coating device 20, a compression device 40, and a cutting device 60. Further, a control means for controlling each device of the manufacturing system 1 may be provided. In this embodiment, the control means (sequencer) 207 (FIG. 7) described later is provided.

The slurry coating device 20, the compression device 40, and the cutting device 60 are each realized by any combination of hardware and software of the computer 100 (FIG. 6) described later. And, it is understood by those skilled in the art that there are various modifications of the realization method and the device.

Program 110 (FIG. 6) may be recorded on a recording medium readable by computer 100. The recording medium is not particularly limited, and various forms can be considered. Further, the program may be loaded from the recording medium into the memory 104 of the computer 100, or may be downloaded to the computer 100 through the network and loaded into the memory 104.

The recording medium on which the program 110 is recorded includes a medium that can be used by the non-temporary tangible computer 100, and a program code that can be read by the computer 100 is embedded in the medium. When the program 110 is executed on the computer 100, the computer 100 is made to execute the method of manufacturing the electrode sheet that realizes each device.

FIG. 12 is a flowchart showing a process of a method of manufacturing the current collector electrode sheet 10 according to the present embodiment.
The method for manufacturing the current collector electrode sheet 10 of the present embodiment includes a coating step (S1), a compression step (S5), and a cutting step (S6). The current collector electrode sheet 10 according to the present embodiment is manufactured by the manufacturing method shown in FIG. Details of each step will be described later together with a description of each device.

FIG. 4 is a schematic view showing an outline of the slurry coating device 20 for the electrode sheet according to the embodiment of the present invention.
Further, FIG. 5 is a schematic view showing an example of a die coater 21 and a die coater 22 portion of the electrode sheet slurry coating device 20 according to the embodiment of the present invention, in which the slurry is applied and intermittently coated.

First, in the coating step (S1 in FIG. 12), the metal foil 9 installed in the coating device 20 is intermittently coated with a slurry containing an active material on one surface 9a using, for example, a first die coater 21. By drying, the coating region 11 of the active material (slurry) is formed.

Using a die coater including a die head, the obtained electrode slurry is dried while being intermittently applied along the longitudinal direction of the strip-shaped metal foil 9, and at least one of the metal foils 9 is removed by removing the solvent. An electrode active material layer is intermittently formed on the surface so as to alternately repeat the coated portion and the non-coated portion.

Here, as shown in FIG. 5, the die coater 21 for intermittent coating includes the die head 200, the coating valve 201 connected to the die head 200, the pump 202, and the tank 204 for storing the slurry 203 of the active material mixture. Is provided. A relative moving means for moving the metal foil 9 relative to the die head 200 is arranged at a position facing the die head 200. In the present embodiment, the metal foil 9 which is a current collector to form the active material layer is conveyed by the rotation of the roller 27 which is an example of the relative moving means.
For example, the rotation speed of the roller 27 is controlled in the range of 10 m / min to 80 m / min.

The die head 200 is driven by a servomotor 205, which is a die head moving means, and can move closer to or away from the roller 27, and the displacement (movement amount) of the die head 200 is detected by the displacement sensor 206. The control means (sequencer) 207 controls the operation of the servomotor 205 based on the control program described later. This manufacturing apparatus may be provided with a return path for returning the slurry from the die head 200 to the tank 204, and the return path may be provided with a return valve.
When the distance (gap) between the die head 200 and the metal foil 9 in the central portion of the coating region of the active material layer (302 in FIG. 7 described later) is 100%, the transition to the end portion of the coating region (303 in FIG. 7 described later) is set. The amount of displacement (movement) of the die head 200 is preferably controlled in the range of 10% to 50%, and more preferably controlled in the range of 30% to 50%.

FIG. 6 is a block diagram showing an example of a hardware configuration of a computer 100 that realizes each device including the control means (sequencer) 207 according to the embodiment of the present invention.
The computer 100 includes a CPU (Central Processing Unit) 102, a memory 104, a program 110 including a control program that defines the operation of the servomotor 205 loaded in the memory 104, a storage 105 that stores the program 110, and I / O (Input). Output) 106 and communication interface (I / F) 107 for network connection are provided. The CPU 102 and each element are connected to each other via a bus 109, and each device such as a control means (sequencer) 207 is controlled by the CPU 102. However, the method of connecting the CPU 102 and the like to each other is not limited to the bus connection.

The CPU 102 can realize each function of each device by reading the program 110 stored in the storage 105 into the memory 104 and executing the program 110.

The program 110, which includes a control program that controls the operation of the servomotor 205, is implemented by any combination of hardware and software of the computer 100. And, it is understood by those skilled in the art that there are various modifications of the realization method and the device.

Hereinafter, a control program for controlling the operation of the servomotor 205 will be described.
In the control program according to the embodiment of the present invention, the length l in the longitudinal direction of each coating region to be applied intermittently, the rotation speed v of the roller, and the application and drying of the slurry to the current collector layer When the step (not shown) is completed, at least the average thickness T of the active material layer in the central portion of the coating region on one side of the current collector electrode sheet is set as a parameter. Then, it is input to the control means (sequencer) 207 prior to starting the process of intermittent coating. The value of each parameter may be input by the operator according to the operation screen of the control program, or may be read from the setting file stored in advance.

The control program is a die head suitable for forming the start end portion, the center portion, the end portion, and each non-applied region of each intermittently applied coating region based on each of the input parameters. The distance d between the 200 and the metal foil 9 (hereinafter, also referred to as a gap) is calculated, and is calculated from the position where the distance between the die head 200 and the metal foil 9 is adjusted, or the transport speed of the current collector 9 due to the rotation of the roller 27. , The timing for adjusting the interval d is calculated, and the servomotor 205 is operated.

FIG. 7 is a diagram for explaining the details of the coating process (S1 of FIG. 12) of the present embodiment.
FIG. 13 is a flowchart showing an example of the processing procedure of the control program of the present embodiment.
FIG. 7 shows the position of each coating region in which the gap d (gap) between the die head 200 and the metal foil 9 is intermittently formed or the coating is started by the operation of the control program according to the embodiment of the present invention. It is schematically shown that it changes depending on the elapsed time t since then.

First, the start end portion 301 of the coating region is formed (step S10). Let x _{0 be} the start position of the formation of the start end portion, and t ₀ be the start time. Then, the rotation of the roller 27 is started (step S11). The die head 200 is brought closer to the roller 27 and the metal foil 9, the gap between the die head 200 and the metal foil 9 is set to d ₁ (step S12), the coating valve 201 is opened, and the pump 202 is further adjusted to determine a predetermined value. The discharge pressure is set to (step S13). By rotating the roller 27 as it is, the metal foil 9 which is a band-shaped current collector sheet is passed directly under the discharge port of the die head 200, so that the application region of a desired length in which the slurry is continuously applied in the longitudinal direction is formed. The start end portion 301 is formed (step S10). Here, it is the end position of the start end portion 301 of the coating region, the start position of the central portion 302 of the coating region is x ₁ , and the time when the formation of the start end portion 301 is completed is t ₁ , but the start end portion 301 of the coating region is defined. Length: x ₁ − x ₀ can be appropriately determined according to the design of the battery.

Next, when the time t ₁ is reached (YES in step S14), the process proceeds to the formation of the central portion 302 of the coating region (step S20). With the coating valve 201 open, the rotation of the roller 27 causes the metal foil 9, which is a band-shaped current collector sheet, to pass directly under the discharge port of the die head 200 to form the central portion 302 of the coating region having a desired length. To do. If necessary, such as changing the thickness of the active material layer formed at the starting end portion 301 and the central portion 302, the process shifts to the formation of the central portion 302, and at the same time, the distance (gap) between the die head 200 and the metal foil 9 is increased. It may be changed to d ₂ (step S21), or the pump 202 may be adjusted to change the discharge flow rate and the discharge pressure (not shown). Here, it is the end position of the central portion 302 of the coating region, the start position of the end portion 303 of the coating region is x ₂ , and the time when the formation of the central portion 302 is completed is t ₂ , but the start end portion 301 of the coating region is defined. The combined length (x _2- x ₀ ) of the center portion 302 and the central portion 302 is preferably in the range of 88% to 93% of the total length of the total length of the start end portion, the center portion and the end portion of the coating region. .. It should be noted that the setting of a specific value within the above range should be appropriately determined according to the viscosity of the slurry used for production and the thickness of the active material layer to be formed.

Then, when it becomes time _{t 2} (YES in step S22), and proceeds to the formation of the end portions 303 of the application area (step S30). At time _{t 2} to shift to the formation of the end portions 303 of the application region, Nurikoben 201 remains open, the die head 200 and spacing of the metal foil 9 (gap) is changed from _{d 2} to _{d 3} (step S31), By the rotation of the roller 27, the metal foil 9 which is a band-shaped current collector sheet is passed directly under the discharge port of the die head 200 to form the end portion 303 of the coating region having a desired length. The distance (gap) d ₃ between the die head 200 and the current collector 9 in the formation of the terminal portion 303 of the coating region is the distance (gap) between the die head 200 and the current collector 9 in the formation of the central portion 302 of the coating region. It is preferably 50% to 70% of ₂ . Further, when shifting from the formation of the central portion 302 of the coating region to the formation of the terminal portion 303 of the coating region, it is preferable not to change the discharge flow rate or the discharge pressure by adjusting the pump 22.
This is the end position of the end portion 303 of the application area, the start position of the non-application area 12 x _3, the time at which end the formation of the end portions 303 and t _3.

In this way, the distance (gap) d ₃ between the die head 200 and the metal foil 9 in forming the end portion 303 of the coating region is set to d2, and the distance (gap) between the die head 200 and the metal foil 9 in forming the central portion 302 of the coating region is set to d ₂ . The positions (x _2- x ₀ ) for switching from the central portion 302 of the coating region to the formation of the terminal portion 303 of the coating region are set to 50% to 70%, and the start end portion 301, the central portion 302, and the terminal portion 303 of the coating region are set. The total length (x ₃ − x ₀ ) is in the range of 88% to 93%. As a result, the current collector electrode sheet 10 is obtained in which the value of the length of the tailing portion 14 at the end of the coated region is 12 times or less the value of the thickness of the single-sided active material layer after pressure compression. Can be done. Here, if the value of x _2- x ₀ is less than 88% of x _3- x ₀ , the thickness of the active material layer at the end portion 303 of the coating region may be less than the design value, which is 94% or more. Then, the length of the tail pulling portion 14 is not sufficiently shortened.

The reason why the tailing length can be kept below a certain level by controlling the coating start position of the end portion 303 and the distance (gap) between the die head and the current collector in the coating region is not necessarily clear, but the following There may be a reason.
The tailing at the final end of the coating area is caused by the dragging of the slurry because the slurry does not cut well when the application of the active material (slurry) is blocked due to the influence of the limit performance of the coating valve. is there. By making the distance (gap) d ₃ between the die head and the current collector narrower than the distance (gap) d ₂ between the die head and the current collector in the central portion, the discharge pressure increases while the coating amount decreases. The amount of slurry that contributes to dragging when the application is blocked is also reduced. Here, in order to reduce the tailing amount, the value of d ₃ is preferably not more than 90% of the value of d _2, and more preferably to less than 70% of the value of d _2. On the other hand, when d ₃ is narrowed to 50% or less of d ₂ , the discharge pressure rises too much, so that the slurry is cut off from the discharge port. Therefore, it is considered appropriate to set d ₃ to 50% to 70% of d ₂ .

Further, by setting the total length x _2- x ₀ of the start end portion and the central portion to the range of 88% to 93% of the total length x _3- x ₀ of the entire coating area, the discharge port of the die head is asymptotically set. It is considered that it is possible to reduce only the tail pulling while reducing the amount of slurry discharged from the terminal while keeping the thickness applied to the terminal portion stably equal to the thickness of the central portion.

Then, when it becomes time _{t 3} (YES in step S32), and proceeds to the formation of non-application area 12 (step S40). At time t ₃ when the process proceeds to the formation of non-application area 12, (Step S41) without ejecting the slurry from the die head 200 to close the Nurikoben 201, the metal foil 9 by the rotation of the roller 27 by a desired length transport To do. This is the end position of the non-application region 12, to _{x 4} of the starting position of the starting end 301 of the next application region, the time has been completed the formation of the non-application region 12 and _{t 4} (YES in step S42).

In the subsequent time, the formation of the start end portion 301, the center portion 302, the end portion 303, and the non-coating region 12 of the coating region is repeated in order (returning to step S12), and a large number of active material layers (coating region 11) are formed. ) Is formed. The thickness of the start end portion 301 and the central portion 302 of the active material layer coating region, the total length and width of the start end portion 301, the central portion 302, and the end portion 303 of the active material layer coating region, and the length of the non-coating region 12 are , It can be appropriately determined according to the size of the battery.

In this way, the current collector electrode sheet 10 in which the active material coating region 11 is coated on one surface 9a of the metal foil 9 which is the current collector layer is dried through a dryer 25, and then the other surface of the metal foil 9 is dried. The active material coating region 11 is formed on the surface 9b by the same method. At this time, on the other surface 9b, the start end detector 24 detects the position of the active material coating region formed on the one surface 9a. Using a die coater 22 or the like that operates by receiving the detection signal of the start end detector 24, the position corresponding to the position detected on one surface 9a is activated on the portion of the other surface 9b that is the back surface of the one surface 9a. By forming the material coating region 11, the positions of the active material coating region 11 formed on both sides of the current collector electrode sheet 10 are aligned with each other. Further, the positions of the start and end of application of the active material (slurry) are also matched on both sides of the current collector electrode sheet 10. The amount of misalignment at the beginning of application of the active material (slurry) on both sides of the current collector electrode sheet 10 is adjusted to be, for example, less than 1 mm in the winding direction Dx. The drying method is not particularly limited, but for example, a method of indirectly heating the electrode slurry from the current collector layer side or the already dried electrode active material layer side using a heating roll to dry the electrode slurry; infrared rays, far away. A method of drying the electrode slurry using electromagnetic waves such as an infrared / near-infrared heater; the electrode slurry is indirectly heated by applying hot air from the current collector layer side or the already dried electrode active material layer side to heat the electrode slurry. Examples thereof include a method of drying.

FIG. 8 is a schematic view showing an outline of the compression device 40 of the current collector electrode sheet 10 according to the embodiment of the present invention.
In the compression step (S5 of FIG. 12), in the slurry coating device 20 shown in FIG. 4, a pair of current collector electrode sheets 10 having active material coating regions 11 formed on both sides of the current collector layer are formed as shown in FIG. It is compressed by the compression roller 50 of. The current collector electrode sheet 10 is pressure-compressed when passing through the gaps between the pair of compression rollers 50, and is wound in the winding direction Dx.
In this compression step, even if the direction of flow through the current collector electrode sheet 10, that is, the winding direction Dx is set from the coating end side to the coating start end side, the direction from the coating start end side to the coating end side is conversely. It may be set as.

In the compression step, the compression device 40 appropriately sets the load applied to the central portion of the coating region 11 of the metal foil 9 which is the current collector layer on which the active material layer is formed, according to the desired density of the electrodes. It can be, for example, pressurized to 0.2 to 3 ton / cm. The size of the compression roll is not particularly limited, but for example, a roll having a radius r of 250 mm to 375 mm can be used.

In this compression step, in the conventional method, the tailing portion 14 is compressed more than the central portion of the coating region, and a phenomenon that the active material particles bite into the current collector layer often occurs. Since the amount of residual meat in the current collector layer at the portion where the active material particles bite into the current collector layer is extremely thin, cracks that cause the foil to break are likely to occur (not shown). On the other hand, in the current collector electrode sheet formed by the method shown in the present embodiment of the present invention, cracks do not occur in the tailing portion 14 even in the compression step. The reason for this is not always clear, but the following reasons can be considered. Since the active material layer exists only intermittently in the direction Dy perpendicular to the winding direction Dx in the tailing portion 14 formed by the conventional method, the active material layer is continuous in the direction Dy perpendicular to the winding direction Dx. A greater linear pressure will be applied than in the central portion of the coating area that exists. On the other hand, in the method shown in the present embodiment of the present invention, the length of the tailing portion 14 is sufficiently short, and the active material layer is substantially continuously present in the tailing portion 14 in the direction Dy. Therefore, it is considered that the linear pressure is almost the same between the coating central portion and the tailing portion 14, and the active material particles are suppressed from biting into the current collector layer, so that cracks in the foil do not occur.

FIG. 9 is a schematic view showing an outline of the cutting device 60 according to each embodiment of the present invention.
The cutting device 60 cuts the current collector electrode sheet 10 into a plurality of sheets. The cutting device 60 includes a first cutting blade 61, a second cutting blade 62, two backup rollers 63, and a pair of guide rollers 64.

A plurality of electrodes can be obtained by cutting the current collector electrode sheet 10 to a predetermined size. The method of cutting out the electrode from the current collector electrode sheet 10 is not particularly limited, but for example, it is cut in parallel with the longitudinal direction of the current collector electrode sheet 10 (cut along the winding direction cut line 17 in FIG. 1). A method of cutting out a plurality of electrodes having a predetermined width can be mentioned. Further, an electrode for a battery can be obtained by punching to a predetermined size according to the application. Here, the method for cutting the current collector electrode sheet 10 is not particularly limited, and the current collector electrode sheet 10 can be cut using, for example, a blade made of metal or the like.

In this cutting step (S6 of FIG. 12), in the conventional method, burrs are generated from the place where the crack is generated in the band base portion during the compression step, but the method shown in the present embodiment of the present invention is used. When used, no cracks are generated in the foil, so no burrs are observed.

This completes the electrodes of the battery of the present invention. Subsequently, a method of manufacturing a battery using the manufactured electrodes will be described.
<Battery>
FIG. 10 is a schematic view showing an example of the configuration of the stacked battery 150 according to the embodiment of the present invention.
The battery according to the present embodiment includes the current collector electrode sheet 10 according to the present embodiment. Hereinafter, the case where the battery according to the present embodiment is a laminated battery 150 of a lithium ion battery will be described as a typical example.
The laminated battery 150 includes a battery element in which a positive electrode 121 and a negative electrode 126 are alternately laminated in a plurality of layers via a separator 120, and these battery elements are a flexible film together with an electrolytic solution (not shown). It is stored in a container consisting of 140. The positive electrode terminal 131 and the negative electrode terminal 136 are electrically connected to the battery element, and a part or all of the positive electrode terminal 131 and the negative electrode terminal 136 are drawn out to the outside of the flexible film 140. ..

The positive electrode 121 is provided with a positive electrode active material coated portion (positive electrode active material layer 122) and a non-coated region on the front and back surfaces of the positive electrode current collector layer 123, and the negative electrode 126 is provided with front and back surfaces of the negative electrode current collector layer 128. Is provided with a coated portion of the negative electrode active material (negative electrode active material layer 127) and a non-coated region.

To connect the non-coated region of the positive electrode active material in the positive electrode current collector layer 123 to the positive electrode terminal 131 as the positive electrode tab 130, and to connect the non-coated region of the negative electrode active material in the negative electrode current collector layer 128 to the negative electrode terminal 136. The negative electrode tab 125 of the above.
The positive electrode tabs 130 are grouped on the positive electrode terminal 131 and connected to each other by ultrasonic welding or the like together with the positive electrode terminal 131, and the negative electrode tabs 125 are grouped on the negative electrode terminal 136 and connected to each other by ultrasonic welding or the like together with the negative electrode terminal 136. Will be done. Then, one end of the positive electrode terminal 131 is pulled out to the outside of the flexible film 140, and one end of the negative electrode terminal 136 is also pulled out to the outside of the flexible film 140.

An insulating member can be formed at the boundary portion 124 between the coated portion (coated region 11) (positive electrode active material layer 122) of the positive electrode active material and the non-coated region 12, if necessary, and the insulating member is the boundary portion 124. Not only that, it can be formed near the boundary between the positive electrode tab 130 and the positive electrode active material.

Similarly, an insulating member can be formed at the boundary portion 129 between the coated portion (negative electrode active material layer 127) of the negative electrode active material and the non-coated region, and the boundary between both the negative electrode tab 125 and the negative electrode active material can be formed as needed. It can be formed near the part.

Usually, the external dimensions of the negative electrode active material layer 127 are larger than the external dimensions of the positive electrode active material layer 122 and smaller than the external dimensions of the separator 120.

(Non-aqueous electrolyte solution containing lithium salt)
The non-aqueous electrolytic solution containing a lithium salt used in the present embodiment can be appropriately selected from known ones according to the type of electrode active material, the use of the lithium ion battery, and the like.

Specific examples of the lithium salt, for _{example, LiClO 4, LiBF 6, LiPF} 6, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10, LiAlC l4, LiCl, LiBr, LiB (C ₂ H ₅ ) ₄ , CF ₃ SO ₃ Li, CH ₃ SO ₃ Li, LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, lithium lower fatty acid carboxylate and the like can be mentioned.

The solvent for dissolving the lithium salt is not particularly limited as long as it is usually used as a liquid for dissolving an electrolyte, and is not particularly limited as long as it is usually used as a liquid for dissolving an electrolyte, such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), and dimethyl carbonate. Carbonates such as (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), vinylene carbonate (VC); lactones such as γ-butyrolactone and γ-valerolactone; trimethoxymethane , 1,2-Dimethoxyethane, diethyl ether, tetrahydrofuran, 2-methyl tetrahydrofuran and other ethers; dimethyl sulfoxide and other sulfoxides; 1,3-dioxolane, 4-methyl-1,3-dioxolane and other oxolanes; acetonitrile , Nitrogen-containing solvents such as nitromethane, formamide, dimethylformamide; organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, ethyl propionate; phosphate triesters and diglimes; triglimes; Sulfolans such as sulfolane and methyl sulfolane; oxazolidinones such as 3-methyl-2-oxazolidinone; sulton species such as 1,3-propane sulton, 1,4-butane sulton and nafta sulton can be mentioned. These may be used individually by 1 type, or may be used in combination of 2 or more type.

(container)
In the present embodiment, a known member can be used for the container, and it is preferable to use the flexible film 140 from the viewpoint of reducing the weight of the battery. As the flexible film 140, a film in which resin layers are provided on the front and back surfaces of a metal layer as a base material can be used. As the metal layer, one having a barrier property such as preventing leakage of an electrolytic solution and invasion of water from the outside can be selected, and aluminum, stainless steel, or the like can be used. A heat-sealing resin layer such as modified polyolefin is provided on at least one surface of the metal layer, and the heat-sealing resin layers of the flexible film 140 are opposed to each other via the battery element to form the battery element. The exterior body is formed by heat-sealing the periphery of the storage portion. A resin layer such as a nylon film or a polyester film can be provided on the surface of the exterior body, which is the surface opposite to the surface on which the heat-sealing resin layer is formed.

(Terminal)
In the present embodiment, the positive electrode terminal 131 may be made of aluminum or an aluminum alloy, and the negative electrode terminal 136 may be made of copper or a copper alloy or nickel-plated thereto. Each terminal is pulled out to the outside of the container, and a heat-sealing resin can be provided in advance at a portion of each terminal located at a portion where the periphery of the exterior body is heat-welded.

(Insulation member)
When the insulating member is formed at the boundary portion 124 and 129 of the coated portion and the non-coated region of the active material, polyimide, glass fiber, polyester, polypropylene or those containing these in the composition can be used. An insulating member can be formed by applying heat to these members to weld them to the boundary portions 124 and 129, or by applying a gel-like resin to the boundary portions 124 and 129 and drying them.

(Separator)
The separator 120 according to the present embodiment preferably includes a resin layer containing a heat-resistant resin as a main component.
Here, the resin layer is formed of a heat-resistant resin as a main component. Here, the "main component" means that the ratio in the resin layer is 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more, and 100% by mass. It means that it may be.
The resin layer constituting the separator 120 according to the present embodiment may be a single layer or two or more types of layers.

Examples of the heat-resistant resin forming the resin layer include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, poly-m-phenylene terephthalate, poly-p-phenylene isophthalate, polycarbonate, polyester carbonate, aliphatic polyamide, and all. Aromatic polyamide, semi-aromatic polyamide, total aromatic polyester, polyphenylene sulfide, polyparaphenylene benzobisoxazole, polyimide, polyarylate, polyetherimide, polyamideimide, polyacetal, polyether ether ketone, polysulfone, polyether sulfone, One or more selected from a fluororesin, a polyether nitrile, a modified polyphenylene ether and the like can be mentioned.

Among these, from the viewpoint of excellent balance of heat resistance, mechanical strength, elasticity, price, etc., polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, aliphatic polyamide, total aromatic polyamide, semi-aromatic polyamide and total fragrance. One or more selected from group polyesters are preferred, and one or more selected from polyethylene terephthalates, polybutylene terephthalates, aliphatic polyamides, total aromatic polyamides and semi-aromatic polyamides are more preferred, polyethylene terephthalates and One or more selected from the total aromatic polyamide is more preferable, and polyethylene terephthalate is more preferable.

The resin layer constituting the separator 120 according to the present embodiment is preferably a porous resin layer. As a result, when an abnormal current is generated in the lithium ion battery and the temperature of the battery rises, the micropores in the porous resin layer can be blocked to block the current flow, and thermal runaway of the battery can be avoided. be able to.

From the viewpoint of the balance between mechanical strength and lithium ion conductivity, the porosity of the porous resin layer is preferably 20% or more and 80% or less, more preferably 30% or more and 70% or less, and 40% or more and 60% or less. Is particularly preferable.
The vacancy rate can be calculated from the following formula.
ε = {1-Ws / (ds · ts)} × 100
Here, ε: pore ratio (%), Ws: basis weight (g / m ² ), ds: true density (g / cm ³ ), ts: film thickness (μm).

The planar shape of the separator 120 according to the present embodiment is not particularly limited, and can be appropriately selected according to the shape of the electrode or the current collector, and can be, for example, a rectangle.

The thickness of the separator 120 according to the present embodiment is preferably 5 μm or more and 50 μm or less from the viewpoint of the balance between mechanical strength and lithium ion conductivity.

As described above, according to the present embodiment, the battery can be manufactured by using the current collector electrode sheet 10 manufactured by the manufacturing method of the above embodiment.
According to the method for manufacturing an electrode of the present invention, a collection occurs when an active material layer is formed on a thin current collector such as a current collector layer, dried, compressed, and cut to produce an electrode. It is possible to assemble an electrochemical device such as a battery in which the occurrence of burrs on an electric body is suppressed, and it is possible to provide an electrochemical device such as a battery having good characteristics.

Although the embodiments of the present invention have been described above with reference to the drawings, these are examples of the present invention, and various configurations other than the above can be adopted.
Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.

Hereinafter, specific examples will be described in more detail.
(Example 1)
As a positive electrode active material, 50% cumulative diameter determined from the particle size distribution measurement value _{(D 50)} is 8 [mu] m, also 90% cumulative diameter _{(D 90)} is _{12μm, Li (Ni 0.6 Co 0.2} Mn 0. ₂ ) N-methylpyrrolidone is added to a mixture of O ₂ having a mass of 94.8%, a graphite material as a conductive auxiliary material having a mass of 2.5%, and polyvinylidene fluoride as a binder having a mass of 2.7%. The mixture was mixed to prepare a positive electrode slurry. The viscosity of the completed slurry was measured using a B-type viscometer (Rotating viscometer manufactured by Brookfield) at 25 ° C. and a shear rate of 3.4 s ^-1 , and found to be 4850 mPa · s. The solid content concentration of the slurry was 66% by mass.

The total length l of the coating area including the start end, the center, and the end is 222 mm, the rotation speed v of the roller is 30 m / min, and the distance (gap) d between the die head and the metal foil at the start 301 and the center 302. ₂ was set to 130 μm, the total length x _2- x ₀ of the start end portion 301 and the center portion 302 was set to 202 mm, and the distance (gap) d ₃ between the die head and the metal foil at the end portion 303 was set to 80 μm. Then, by discharging the slurry from the die head so that the coating amount is 23.5 mg / cm ² , it moves on the backup roller 26 on the strip-shaped aluminum foil current collector foil surface (9a, 9b) having a thickness of 12 μm. The coated region 11 and the non-coated region 12 were intermittently coated so as to be alternately formed in the winding direction Dx of the foil 9.

Further, the slurry containing the active material and the like applied to the aluminum foil 9 was dried and solidified by a drying furnace (dryer 25) subsequently installed. Further, with respect to the back surface 9b coated with the slurry in the coating step, the start end of the coating region 11 coated on the front surface 9a is detected, and the deviation of the start end of the coating region 11 on the back surface 9b is controlled to be 1 mm or less. , The slurry was applied and dried and solidified in the same manner to obtain a current collector electrode sheet 10 in which the slurry was applied to both surfaces of the aluminum foil 9. In the slurry coating step, the length of the coating region 11 was adjusted to be 2 mm or less in the same aluminum foil roll. A part of the obtained current collector electrode sheet 10 was extracted, and the maximum length of the tailing portion measured was 0.5 mm.

Next, using a pressure compression device 40 provided with a compression roller 50 having a roll radius of 250 mm, which is a pair of upper and lower two, the current collector electrode sheet 10 to which the slurry is intermittently applied is subjected to the above. The gap width was set so as to pass between the compression rollers and the winding tension was 230 N, and pressure compression was performed by moving on the backup roller 51 at a rotation speed of 60 m / min. At this time, the compression pressure is adjusted so that the linear pressure on the coating area of the active material slurry is 1.8 t / cm, the gap between the vertical compression rollers 50 is 0.4 mm on average, and the roller compression pressure is 19 MPa on average. It became. A part of the obtained current collector electrode sheet 10 was extracted, and the average thickness of the single-sided active material layer was 65 μm, and the film thickness was constant up to the end of coating. Further, using a visual inspection machine attached to the compression device 40, it was confirmed that there was no slurry adhered to the non-coated region 12.

Subsequently, using a cutting device 60 provided with a shear blade 61 at the top and a gang blade 62 at the bottom, the current collector electrode sheet 10 pressurized and compressed above is passed between the blades, and the winding tension is constant. The cutting was performed by moving the backup roller 63 at a constant speed. A part of the obtained cutting sheet was extracted, and the presence or absence of burrs from the tailing portion after the cutting process was confirmed.

The obtained evaluation results are shown in Table 1.

塗布領域終端部の膜厚不足、非塗布領域へのスラリの付着、およびバリの発生は、それぞれ１０検体観察し、発生が１検体でもあった場合を発生とした。

Insufficient film thickness at the end of the coated area, adhesion of slurry to the non-coated area, and occurrence of burrs were observed in 10 samples each, and the occurrence was assumed to occur even in 1 sample.

(Examples 2 to 6, Comparative Examples 1 to 6)
The same as in Example 1 except that the distance (gap) d ₃ between the die head and the metal foil at the end portion and the total length x _2- x ₀ of the start end portion and the center portion were changed to the values shown in Table 1. The coated area 11 and the non-coated area 12 are intermittently applied on the surface of the strip-shaped aluminum foil collecting foil so as to be alternately formed in the winding direction Dx of the foil, and the maximum length of the tailing portion is measured and applied. The presence or absence of insufficient film thickness at the end of the coated region after drying, the presence or absence of slurry adhering to the non-coated region, and the presence or absence of burrs from the tailing portion after the cutting step were confirmed. The results obtained are shown in Table 1.

Although the present invention has been described above with reference to the embodiments and examples, the present invention is not limited to the above embodiments and examples. Various changes that can be understood by those skilled in the art can be made within the scope of the present invention in terms of the structure and details of the present invention.

Hereinafter, an example of the reference form will be added.
1. 1. A current collector electrode sheet in which active materials are applied to both sides of a sheet-shaped current collector layer.
Both surfaces of the current collector layer include a coated region of the slurry and a non-coated region formed by intermittently coating and drying the slurry containing the active material.
The coated region and the non-coated region are formed alternately in the winding direction of the band-shaped current collector layer.
A current collector electrode sheet in which the value of the length of the tailing portion at the end of each of the coating regions is 12 times or less the value of the thickness of the single-sided active material layer after pressure compression.
2. 2. By discharging the slurry containing the active material from the die head on both sides of the sheet-shaped current collector layer, the slurry is intermittently applied and dried, and the coated region and the non-coated region of the slurry are applied to the current collector layer. It is a method of manufacturing a current collector electrode sheet by alternately forming it in the winding direction.
It includes a step of forming a start end portion of the coating region, a step of forming a central portion of the coating region, and a step of forming an end portion of the coating region.
In the step of forming the terminal portion, the slurry is placed in the die head in a state where the distance between the die head and the current collector layer is narrower than the distance between the die head and the current collector layer in the step of forming the central portion. A method for manufacturing a current collector electrode sheet to be discharged from.
3. 3. 2. 2. In the method for manufacturing a current collector electrode sheet described in 1.
The distance between the die head and the current collector layer in the step of forming the end portion of the coating region is 50, which is the distance between the die head and the current collector layer in the step of forming the central portion of the coating region. % Or more and 90% or less, a method for manufacturing a current collector electrode sheet.
4. 3. 3. In the method for manufacturing a current collector electrode sheet described in 1.
The distance between the die head and the current collector layer in the step of forming the end portion of the coating region is 50, which is the distance between the die head and the current collector layer in the step of forming the central portion of the coating region. % Or more and 70% or less, a method for manufacturing a current collector electrode sheet.
5. 2. 2. To 4. In the method for manufacturing a current collector electrode sheet according to any one of the above.
From the step of forming the central portion of the coating region when the coating is completed up to a point having a length of 88% to 93% of the total length of the coating region in each coating region formed by intermittently applying the slurry. A method for manufacturing a current collector electrode sheet, which comprises narrowing the distance between the die head and the current collector layer in order to shift to the step of forming the end portion of the coating region.
6. 2. 2. To 5. In the method for manufacturing a current collector electrode sheet according to any one of the above.
A method for manufacturing a current collector electrode sheet, wherein the distance between the die head and the current collector layer is changed by moving the die head.
7. 2. 2. To 6. A current collector electrode sheet manufactured by using the method for manufacturing a current collector electrode sheet according to any one of the above.
8. A step of forming a positive electrode active material layer on both sides of a sheet-shaped current collector layer to form a positive electrode current collector electrode sheet, and a process of forming a negative electrode active material layer on both sides of a sheet-shaped current collector layer to collect a negative electrode. A step of forming an electric body electrode sheet, a step of cutting the positive electrode current collector electrode sheet and the negative electrode current collector electrode sheet to predetermined sizes, and a step of forming a positive electrode and a negative electrode, respectively. A method for manufacturing a battery, comprising a step of laminating the positive electrode and the negative electrode via a separator.
One or both of the step of forming the positive electrode current collector electrode sheet and the step of forming the negative electrode current collector electrode sheet are 2. To 6. A method for manufacturing a battery, which comprises each step of the method for manufacturing a current collector electrode sheet according to any one of the above.
9. A battery having at least a positive electrode, a negative electrode, and an electrolyte.
Either or both of the positive electrode and the negative electrode are 1. Or 7. A battery including an electrode formed by cutting a current collector electrode sheet according to the above item into a predetermined size.

This application claims priority on the basis of Japanese application Japanese Patent Application No. 2017-234647 filed on December 6, 2017, and incorporates all of its disclosures herein.

Claims (9)

A current collector electrode sheet in which active materials are applied to both sides of a sheet-shaped current collector layer.
Both surfaces of the current collector layer include a coated region of the slurry and a non-coated region formed by intermittently coating and drying the slurry containing the active material.
The coated region and the non-coated region are formed alternately in the winding direction of the band-shaped current collector layer.
A current collector electrode sheet in which the value of the length of the tailing portion at the end of each of the coating regions is 12 times or less the value of the thickness of the single-sided active material layer after pressure compression. By discharging the slurry containing the active material from the die head on both sides of the sheet-shaped current collector layer, the slurry is intermittently applied and dried, and the coated region and the non-coated region of the slurry are applied to the current collector layer. It is a method of manufacturing a current collector electrode sheet by alternately forming it in the winding direction.
It includes a step of forming a start end portion of the coating region, a step of forming a central portion of the coating region, and a step of forming an end portion of the coating region.
In the step of forming the terminal portion, the slurry is placed in the die head in a state where the distance between the die head and the current collector layer is narrower than the distance between the die head and the current collector layer in the step of forming the central portion. A method for manufacturing a current collector electrode sheet to be discharged from. In the method for manufacturing a current collector electrode sheet according to claim 2.
The distance between the die head and the current collector layer in the step of forming the end portion of the coating region is 50, which is the distance between the die head and the current collector layer in the step of forming the central portion of the coating region. % Or more and 90% or less, a method for manufacturing a current collector electrode sheet. In the method for manufacturing a current collector electrode sheet according to claim 3.
The distance between the die head and the current collector layer in the step of forming the end portion of the coating region is 50, which is the distance between the die head and the current collector layer in the step of forming the central portion of the coating region. % Or more and 70% or less, a method for manufacturing a current collector electrode sheet. In the method for manufacturing a current collector electrode sheet according to any one of claims 2 to 4.
From the step of forming the central portion of the coating region when the coating is completed up to a point having a length of 88% to 93% of the total length of the coating region in each coating region formed by intermittently applying the slurry. A method for manufacturing a current collector electrode sheet, which comprises narrowing the distance between the die head and the current collector layer in order to shift to the step of forming the end portion of the coating region. In the method for manufacturing a current collector electrode sheet according to any one of claims 2 to 5.
A method for manufacturing a current collector electrode sheet, wherein the distance between the die head and the current collector layer is changed by moving the die head. A current collector electrode sheet manufactured by using the method for manufacturing a current collector electrode sheet according to any one of claims 2 to 6. A step of forming a positive electrode active material layer on both sides of a sheet-shaped current collector layer to form a positive electrode current collector electrode sheet, and a process of forming a negative electrode active material layer on both sides of a sheet-shaped current collector layer to collect a negative electrode. A step of forming an electric body electrode sheet, a step of cutting the positive electrode current collector electrode sheet and the negative electrode current collector electrode sheet to predetermined sizes, and a step of forming a positive electrode and a negative electrode, respectively. A method for manufacturing a battery, comprising a step of laminating the positive electrode and the negative electrode via a separator.
The step of forming the positive electrode current collector electrode sheet and / or both of the steps of forming the negative electrode current collector electrode sheet of the current collector electrode sheet according to any one of claims 2 to 6. A method of manufacturing a battery, including each step of the manufacturing method. A battery having at least a positive electrode, a negative electrode, and an electrolyte.
A battery including an electrode in which either or both of the positive electrode and the negative electrode are formed by cutting the current collector electrode sheet according to claim 1 or 7 into a predetermined size.

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