JP2019145378A - Compressing device, current collector electrode sheet manufacturing method, current collector electrode sheet, and battery - Google Patents

Abstract

To suppress a decrease in the yield of an electrode manufactured thereafter by powder generated from the electrode.SOLUTION: A compressing device 40 for manufacturing a collector electrode sheet for compressing and processing a sheet-like electrode material (electrode sheet 10) includes a pair of rolls 41 in which the respective rotating shafts 43 are substantially horizontal, and arranged at substantially the same height, and a powder removing mechanism 70 that causes an electrode sheet 10 to pass from below to above between the pair of rolls 41, and provided above the pair of rolls 41.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a compression device, a method for producing a current collector electrode sheet using the compression device, a current collector electrode sheet produced using the compression device, and a battery produced from the current collector electrode sheet. .

  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, have further increased.

  Such an electrode for a secondary battery is produced from an electrode sheet obtained by applying and drying a slurry containing an active material on a strip-shaped metal foil such as aluminum or copper. The application method of the active material can be roughly classified into an intermittent coating method and a continuous coating method.

In FIG. 9, the collector electrode sheet manufactured by an intermittent coating system is shown.
In the intermittent coating method, an application region 11 formed by applying a slurry such as an active material to a strip-shaped metal foil 9 and a non-application region 12 where no slurry is applied are arranged in a predetermined direction in the longitudinal direction Dx of the metal foil 9. This is a method of alternately forming at intervals. The non-formation parts of the active material arranged at a predetermined interval are used as a part for taking out a drawer tab for electrical connection with an external terminal.

  As shown in FIG. 10, in the method for producing an electrode sheet related to the present invention, a slurry obtained by mixing or kneading a main material, an active material, a conductivity-imparting agent, a binder, and a solvent, is formed on one surface of a metal foil 9. After intermittent application (hereinafter referred to as intermittent application), the other surface on the opposite side of the metal foil 9 is again intermittently applied, and slurry is applied to both sides of the metal foil 9 (step). S1). Next, the metal foil 9 coated with slurry on both sides is pressure-molded by the compression roller 50 of FIG. 11 (step S3). Then, it cut | disconnects to a desired external dimension as a collector (step S5), and formed the electrode terminal part in the collector electrode sheet.

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

  Moreover, the electrode used for the secondary battery designed to have a high energy density tends to be designed with a thin metal foil as a current collector.

  Patent Documents 2 and 3 also describe production of an electrode including a step of compressing and adhering composite particle powder and active material (electrode active material, auxiliary powder, adhesive) to a current collector sheet by roll rolling. A method is described. Thus, in the method of compressing by roll rolling, a part of the active material may peel off and adhere to the roll surface. Therefore, in Patent Document 4, when an electrode sheet having an active material coated on both surfaces of a metal foil is compressed while being conveyed in a horizontal direction between a pair of press rolls, the active material adhered as a foreign matter to the roll surface. A configuration is described in which a portion of the layer is removed without contact. Specifically, gas is blown out from the gas outlet to blow off foreign matter on the roll surface, and further, the foreign matter peeled from the roll surface is sucked by the suction duct.

JP 2012-216465 A JP 2013-77559 A JP 2017-91987 JP, 2006-184559, A

  However, in the cited document 4, since the electrode sheet is conveyed in the horizontal direction, the active material partially peeled off from the sheet by rolling may adhere to the upper surface of the sheet before being sucked. For example, in the case of an electrode sheet on which an active material is intermittently applied, there is a possibility that the active material spills and adheres to a non-application region where the active material does not exist.

  An object of the present invention is to prevent the yield of electrodes manufactured thereafter from being lowered by the powder generated from the electrodes.

  Each aspect of the present invention employs the following configurations in order to solve the above-described problems.

The first aspect relates to a compression device. The compression device according to the first aspect is a compression device for producing a collector electrode sheet for compressing a sheet-like electrode material,
A pair of rolls in which each rotation axis is substantially horizontal and arranged at substantially the same height;
The sheet-like electrode material is passed between the pair of rolls from below to above, and a powder removing mechanism is provided above the pair of rolls.

A 2nd side surface is related with the manufacturing method of a collector electrode sheet. The method of manufacturing the collector electrode sheet according to the second aspect is as follows:
Including a compression step of compressing the current collector electrode sheet in the thickness direction by passing the current collector electrode sheet having the active material applied on both surfaces of the sheet-like metal foil between a pair of rolls;
In the pair of rolls, each rotation axis is substantially horizontal, arranged at substantially the same height,
In the compression step, a compression device is
When the sheet-like electrode material is passed through the pair of rolls from below to above, removing the powder using a powder removing mechanism provided above the pair of rolls.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  The various components of the present invention do not necessarily have to be independent of each other. A plurality of components are formed as a single member, and a single 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, or the like.

  Moreover, although the several procedure is described in order in the method and computer program of this invention, the order of the description does not limit the order which performs a several procedure. For this reason, when the method and computer program of the present invention are implemented, the order of the plurality of procedures can be changed within a range that does not hinder the contents.

  Furthermore, the plurality of procedures of the method and the computer program of the present invention are not limited to being executed at different timings. For this reason, another procedure may occur during the execution of a certain procedure, or some or all of the execution timing of a certain procedure and the execution timing of another procedure may overlap.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that the yield of the electrode manufactured after that with the powder which arises from an electrode falls.

It is a side surface which shows the outline | summary of a structure of the compression apparatus of the collector electrode sheet which concerns on embodiment of this invention. It is a schematic diagram which shows an example of a structure of the powder removal mechanism of the compression apparatus of this embodiment. It is a schematic diagram which shows an example of a structure of the powder removal mechanism of the compression apparatus of this embodiment. It is a schematic diagram which shows an example of a structure of the compression apparatus of this embodiment. It is a schematic diagram which shows an example of a structure of the powder removal mechanism of the compression apparatus of this embodiment. It is a block diagram which shows the structural example of the manufacturing system of the electrode sheet which concerns on embodiment of this invention. It is a block diagram which shows an example of the hardware constitutions of the computer which implement | achieves each apparatus of the manufacturing system of the electrode sheet which concerns on embodiment of this invention. It is a flowchart which shows an example of the process of the manufacturing method of the collector electrode sheet which concerns on embodiment of this invention. It is a partial top view which shows the collector electrode sheet after double-sided application of an active material. It is the schematic which shows an example of a structure of the battery which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

  First, the electrode sheet 10 compressed in the compression process (step 3 of FIG. 8) of the manufacturing method of the collector electrode sheet which concerns on embodiment of this invention by the compression apparatus which concerns on embodiment of this invention is demonstrated. FIG. 9 is a partial plan view showing the current collector electrode sheet 10 after applying both sides of the active material in step S1 of FIG.

  The electrode sheet 10 has a configuration in which an application region 11 and a non-application region 12 of a slurry such as an active material are intermittently formed in the longitudinal direction Dx on both surfaces of a strip-shaped metal foil 9. In addition, in the electrode sheet 10 of this invention, an active material layer is not limited to what is formed by apply | coating intermittently. The active material layer may be formed by, for example, continuous stripe coating in addition to intermittent coating.

  Here, although the electrode produced from the electrode sheet 10 which concerns on this embodiment is not specifically limited, For example, they are electrodes (positive electrode or negative electrode) for lithium ion batteries, such as a lithium ion primary battery and a lithium ion secondary battery.

  Hereinafter, the configuration of the electrode will be described in detail.

First, each component which comprises the electrode active material layer which forms the application | coating area | region 11 of the slurry which concerns on this embodiment is demonstrated.
The electrode active material layer includes an electrode active material, and includes a binder resin, a conductive additive, a thickener, and the like as necessary. In the present embodiment, for example, a lithium metal composite oxide can be used as the electrode active material.

  The electrode active material contained in the electrode active material layer according to the present embodiment is appropriately selected according to the application. 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, 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, etc. Composite oxides with metals; transition metal sulfides such as TiS ₂ , FeS, and MoS ₂ ; transition metal oxides such as MnO, V ₂ O ₅ , V ₆ O ₁₃ , and TiO ₂ , olivine type lithium phosphorous oxide, etc. Can be mentioned.
The olivine-type lithium phosphorus oxide is, for example, at least one member selected from 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. In order to improve the characteristics of these compounds, some elements may be partially substituted with other elements.

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 complex oxide is preferable. These positive electrode active materials have a high working potential, a large capacity, and a large energy density.
A positive electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type.

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, natural graphite, artificial graphite, resin carbon, carbon fiber, activated carbon, hard carbon, soft carbon and other carbon materials; lithium metal materials such as lithium metal and lithium alloy; metal materials such as silicon and tin; polyacene, polyacetylene, Examples thereof include conductive polymer materials such as polypyrrole. Among these, carbon materials are preferable, and graphite materials such as natural graphite and artificial graphite are particularly preferable.
A negative electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type.

  The average particle diameter 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 charge / discharge and suppressing the decrease in charge / discharge efficiency, and the viewpoint of input / output characteristics and electrode production (electrode From the viewpoint of surface smoothness and the like, it is preferably 100 μm or less, and more preferably 50 μm or less. Here, the average particle diameter means a particle diameter (median diameter: D50) at an integrated value of 50% in a particle size distribution (volume basis) by a 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 100 parts by mass.

  The binder resin contained in the electrode active material layer according to this embodiment is appropriately selected according to the application. 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 fluorine-based binder resin is not particularly limited as long as electrode molding is possible and it has sufficient electrochemical stability, and examples thereof include polyvinylidene fluoride-based resins and fluorine rubber. These fluorine-based binder resins may be used alone or in combination of two or more. Among these, a polyvinylidene fluoride resin is preferable. The fluorine-based binder resin can be used after being dissolved in a solvent such as N-methyl-pyrrolidone (NMP).

The water-based binder can be formed into an electrode and is not particularly limited as long as it has sufficient electrochemical stability. For example, a polytetrafluoroethylene resin, a polyacrylic acid resin, a styrene / butadiene rubber, Examples include polyimide resins. These aqueous 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 refers to a binder that can be dispersed in water to form an aqueous emulsion solution.
When an aqueous binder is used, a thickener can be further used. Although it does not specifically limit as a thickener, For example, cellulosic polymers, such as carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, and these ammonium salts, and alkali metal salts; Polycarboxylic acid; Polyethylene oxide; Polyvinylpyrrolidone; Sodium polyacrylate etc. And water-soluble polymers such as polyvinyl acrylate, polyvinyl alcohol, and the like.

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 of electrode slurry coating properties, binder binding properties, and battery characteristics is further improved.
Moreover, it is preferable that the content of the binder resin is not more than the above upper limit value because the ratio of the electrode active material is increased and the capacity per electrode mass is increased. It is preferable for the content of the binder resin to be not less than the above lower limit value because electrode peeling is suppressed.

  The conductive auxiliary agent contained in the electrode active material layer according to this embodiment is not particularly limited as long as it improves the conductivity of the electrode. For example, carbon black, ketjen black, acetylene black, natural graphite, artificial graphite And carbon fiber. These conductive aids 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 assistant is within the above range, the balance of electrode slurry coating property, binder binding property, and battery characteristics is further improved.
Moreover, it is preferable that the content of the conductive assistant is not more than the above upper limit value because the ratio of the electrode active material is increased and the capacity per electrode mass is increased. It is preferable that the content of the conductive auxiliary is not less than the above lower limit value because the conductivity of the electrode becomes better.

In the electrode active material layer according to this 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. Further, 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 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 lithium ion battery electrode 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 preferably 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 Or less, 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 be within the above range because the discharge capacity at the time of use at a high discharge rate is improved.

  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 (single-sided thickness) of the electrode active material layer can be appropriately set, for example, in the range of 10 μm to 250 μm, preferably 20 μm to 200 μm, and more preferably 30 μm to 150 μm.

Although it does not specifically limit as a collector layer (metal foil 9) which concerns on this embodiment, Aluminum, stainless steel, nickel, titanium, or these alloys etc. can be used as a positive electrode collector layer. Examples of the shape include a foil, a flat plate, and a mesh. In particular, an aluminum foil can be suitably used.
As the negative electrode current collector layer, copper, stainless steel, nickel, titanium, or an alloy thereof can be used. Examples of the shape include foil, flat plate, and mesh. In particular, a copper foil can be suitably used.

  Although the thickness of a positive electrode electrical power collector layer is not specifically limited, For example, they are 1 micrometer or more and 30 micrometers or less. Moreover, although the thickness of a negative electrode collector layer is not specifically limited, For example, they are 1 micrometer or more and 20 micrometers or less.

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

  As a method for applying the electrode slurry onto the current collector layer, generally known methods can be used. Examples thereof include a reverse roll method, a direct roll method, a doctor blade method, a knife method, an extrusion method, a curtain method, a gravure method, a bar method, a dip method, and a squeeze method. Among these, the doctor blade method, the knife method, and the extrusion method are preferable in that a favorable surface state of the coating layer can be obtained in accordance with the physical properties such as the viscosity of the electrode slurry and the drying property.

  The method for drying the electrode slurry coated on the current collector layer is not particularly limited. For example, the electrode slurry is indirectly heated from the current collector layer side or the already dried electrode active material layer side using a heating roll. , A method of drying the electrode slurry; a method of drying the electrode slurry using an electromagnetic wave such as an infrared, far-infrared or near-infrared heater; an electrode by applying hot air from the current collector layer side or the already dried electrode active material layer side Examples include a method of indirectly heating the slurry and drying the electrode slurry.

FIG. 6 is a block diagram illustrating a configuration example of the manufacturing system 1 of the electrode sheet 10 according to the embodiment of the present invention.
The manufacturing system 1 includes a slurry application device 20, a compression device 40, and a cutting device 60. Furthermore, you may provide the control apparatus (not shown) which controls each apparatus of the manufacturing system 1. FIG.

FIG. 7 is a block diagram showing an example of a hardware configuration of a computer that implements each device of the electrode sheet manufacturing system according to the embodiment of the present invention.
Each of the slurry application device 20, the compression device 40, and the cutting device 60 is realized by at least one computer 100. The computer 100 includes a CPU (Central Processing Unit) 102, a memory 104, a program 110 for realizing each device loaded in the memory 104, a storage 105 for storing the program 110, an I / O (Input Output) 106, and a network connection Communication interface (I / F) 107. The CPU 102 and each element are connected to each other via a bus 109, and the entire computer 100 is controlled by the CPU 102. However, the method of connecting the CPUs 102 and the like is not limited to bus connection. However, the connection means is not limited to a bus.

  Each function of each device can be realized by the CPU 102 reading the program 110 stored in the storage 105 into the memory 104 and executing it.

  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. It will be understood by those skilled in the art that there are various modifications to the implementation method and apparatus.

  The program 110 may be recorded on a recording medium readable by the 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 for recording the program 110 includes a medium that can be used by the non-transitory tangible computer 100, and 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 caused to execute a manufacturing method of the electrode sheet 10 that realizes each device.

  The manufacturing method of the electrode sheet 10 according to the embodiment of the present invention includes the application step (S1), the compression step (S3), and the cutting step (S5) as described with reference to FIG. The current collector electrode sheet 10 according to the embodiment of the present invention is manufactured by the manufacturing method shown in FIG. 8 including the compression step (S3) using the compression device 40 of FIG.

  In the example of FIG. 8, each process is performed in the order of the coating process (S1), the compression process (S3), and the cutting process (S5). In other examples, the coating process (S1) and the cutting process (S5). Each step may be executed in the order of the compression step (S3). In the cutting step (S5), the electrode sheet 10 is cut to a predetermined width while the electrode sheet 10 is conveyed in the longitudinal direction of the electrode sheet 10.

Drawing 1 is a mimetic diagram showing an outline of compression device 40 of electrode sheet 10 concerning an embodiment of the present invention.
The electrode sheet 10 in which the active material application region 11 and the non-application region 12 are formed on both surfaces of the metal foil 9 in FIG. 9 is compressed by a pair of compression rolls 41 as shown in FIG. The electrode sheet 10 is compressed when passing through the gap between the pair of compression rolls 41 and is conveyed in the conveyance direction Dt.

  The compression device 40 includes a pair of compression rolls 41 in which the respective rotation shafts 43 are substantially horizontal and arranged at substantially the same height, and a sheet-like electrode material (electrode sheet 10) between the pair of compression rolls 41. Each has a conveying means (not shown) for conveying from below to above.

  In the method of manufacturing a collector electrode sheet of the present invention, in the compression step of step S3 in FIG. 8, the compression device 40 conveys the electrode sheet 10 between the pair of compression rolls 41 from below to above.

  Although a conveyance means is not specifically limited, it is a pair of backup rollers 51 provided vertically, and pulls the electrode sheet 10 wound around one electrode sheet roll while winding it around the other roll. And the powder removal mechanism 70 provided above a pair of roll 41 is provided. In addition, since the electrode sheet 10 pinched | interposed by rotation of a pair of compression roll 41 is conveyed toward upper direction from the downward direction, a pair of compression roll 41 also serves as the function of a conveyance means.

  Due to the insufficient binding force of the active material in the coating region 11 formed on the electrode sheet 10, the active material powder may fall off the electrode sheet 10 after being pressed by the compression roll 41. Then, the dropped powder is transferred to the compression roll 41 and gives a dent to the surface of the compression roll 41. And the unevenness | corrugation of the surface of the compression roll 41 may generate | occur | produce an unevenness | corrugation also on the electrode sheet 10 surface after rolling. Therefore, in the present embodiment, the powder removal mechanism 70 is used to remove the powder that falls off the electrode sheet 10 and is transferred to the surface of the compression roll 41.

  Various configurations of the powder removal mechanism 70 are conceivable and are exemplified below. Moreover, each structure can also be combined suitably.

(Configuration example 1)
FIG. 2 is a schematic diagram showing an outline of a configuration example 1 of the powder removal mechanism 70 of FIG. FIG. 2A is a front view seen from the α direction in FIG. FIG. 2B is a cross-sectional view of the line II in FIG. 2A as viewed from the center of the roll 41 toward the side end.

  In this example, the powder removal mechanism 70 is a suction device 71 that sucks powder provided at both ends of both sides of the sheet on the exit side of the electrode sheet 10 that passes between a pair of rolls.

  The suction device 71 is a dust collector that sucks the active material powder that falls off the electrode sheet 10 and adheres to the surface of the compression roll 41 with a predetermined air volume.

  In the present invention, since the electrode sheet 10 passes between the pair of compression rolls 41 from below to above, the dropped powder adheres to the surface of the compression roll 41 without entering between the compression rolls 41 and is compressed. The roll 41 moves in the direction away from the electrode sheet 10 by the rotation. Therefore, the suction device 71 is provided above the compression roll 41, that is, on the carry-out side of the electrode sheet 10, thereby sucking and collecting the powder that falls off the electrode sheet 10 and emerges upward.

  Although FIG. 2 shows an example in which two hood-type suction nozzles are provided at both ends of each compression roll 41, the present invention is not limited to this. It is good also as a structure which provided the slit-shaped suction nozzle extended above the compression roll 41 along the rotating shaft 43 direction of each compression roll 41, respectively.

(Configuration example 2)
FIG. 3 is a schematic diagram showing an outline of a configuration example 2 of the powder removal mechanism 70 of FIG. FIG. 3A is a front view seen from the α direction in FIG. 3B is a cross-sectional view of the line II-II in FIG. 3A as viewed from the outer side of the roll 41 toward the center.

  In this example, the powder removal mechanism 70 is an air blow device 72 that blows off the powder by wind pressure, which is provided at both ends of both sides of the sheet on the exit side of the electrode sheet 10 passing between a pair of rolls.

  The air blowing device 72 blows off the active material powder that falls off the electrode sheet 10 and adheres to the surface of the compression roll 41 with a predetermined air volume. In FIG. 3A, air is ejected from the vicinity of the center of the compression roll 41 toward both ends and the rotation direction of the compression roll 41. Thereby, the powder which has come out above the compression roll 41 can be blown off in the rotation direction of the compression roll 41 or the material side end direction.

  In another example, air is jetted in the direction of the rotation axis 43 of the compression roll 41 from one side end of the compression roll 41 toward the other side end, so that the surface of the compression roll 41 is moved to the other side end side. The powder that falls off may be blown off.

(Configuration example 3)
FIG. 4 is a schematic diagram showing an outline of a configuration example 3 of the powder removal mechanism 70 of FIG. FIG. 4A is a front view seen from the α direction in FIG. 4B is a cross-sectional view of the line III-III in FIG. 4A as viewed from the center of the roll 41 toward the outer side.

  In this example, the powder removing mechanism 70 is a rotating brush 73 that removes powder and is provided at both ends of both sides of the sheet on the exit side of the electrode sheet 10 that passes between a pair of rolls. The rotating brush 73 has a rotating shaft 74 that is substantially parallel to the rotating shaft 43 of the compression roll 41, and reversely rotates with the compression roll 41 to remove powder.

  The rotary brush 73 preferably extends in a range that exceeds the length of the compression roll 41 in the direction of the rotation axis 43 and can remove the powder on the entire surface of the compression roll 41.

  The rotating brush 73 of Configuration Example 3 may be provided in combination with the suction device 71 of Configuration Example 1 or the air blow device 72 of Configuration Example 2. The powder discharged from the surface of the compression roll 41 by the rotary brush 73 can be sucked by the suction device 71 or blown off by the air blow device 72, and the powder can be removed more reliably.

  As described above, according to the compression device 40 of the present embodiment, the electrode sheet 10 on which the active material is intermittently applied between the two compression rolls 41 arranged at substantially the same height is directed from below to above. Therefore, the powder of the active material that has fallen off from the electrode sheet 10 that has passed through the compression roll 41 after pressurization comes out upward without being inserted between the pair of compression rolls 41. And since it is set as the structure which provided the powder removal mechanism 70 above the compression roll 41, the powder which comes out above the compression roll 41 can be removed.

  As described above, according to the compression device 40 of the present embodiment, since the powder generated above the compression roll 41 can be removed by the powder removal mechanism 70, transfer to the compression roll 41 is prevented, and the surface of the compression roll 41 is hit. The generation of traces can also be prevented. Furthermore, it can suppress that the yield of the electrode produced using the electrode sheet 10 manufactured in this way falls.

(Second Embodiment)
FIG. 5 is a schematic diagram illustrating an example of the configuration of the compression device 40 of the present embodiment. FIG. 5A is a front view seen from the α direction of FIG. FIG.5 (b) is sectional drawing seen toward the side end direction from the center of the roll 41 about line IV-IV of Fig.5 (a). The compression apparatus 40 of this embodiment is the same as that of the said embodiment except the point further including the means to receive the substance which falls from an electrode material (electrode sheet 10).

  In the embodiment described above, the powder removing mechanism 70 of the compression roll 41 is assumed on the assumption that the powder dropped from the electrode sheet 10 rolled by the compression roll 41 comes out above the compression roll 41 as the electrode sheet 10 is transferred. It was provided above. In the present embodiment, the compression device 40 further includes means (a saucer 80) that is provided below the compression roll 41 and receives a substance that falls off the electrode material (electrode sheet 10).

  The tray 80 is provided below each compression roll 41. The tray 80 has a rectangular bottom surface with a width exceeding the length of the rotation axis 43 of the compression roll 41 and a diameter of the compression roll 41, and an outer periphery of the bottom surface having a predetermined height so that the dropped material does not slide off the tray 80. And provided side walls.

  The configuration of this embodiment is preferably provided together with the powder removal mechanism 70 of the above embodiment. That is, it is preferable that the powder generated above the compression roll 41 is removed by the powder removing mechanism 70 and the powder dropped below the compression roll 41 is captured and collected by the tray 80.

  The installation position of the tray 80 is preferably such that the tray 80 is separated from the lower end of the compression roll 41. Furthermore, it is preferable that the tray 80 is spaced apart from the electrode sheet 10 so as not to come into contact with both surfaces.

  As described above, according to the present embodiment, the same effects as those of the above-described embodiment can be obtained, and further, the powder that has fallen below the compression roll 41 can also be collected.

As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.
Further, the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within a scope that can achieve the object of the present invention are included in the present invention.

For example, a battery can be manufactured using the electrode sheet 10 manufactured by the manufacturing method of the said embodiment.
The electrode manufacturing method of the present invention is an electrode produced during a compression step when an active material layer is formed on a current collector such as a metal foil, and the electrode is produced through a step of compression and cutting after drying (FIG. 8). The surface of the electrode sheet 10 after rolling due to the transfer of the active material powder that has fallen off from the sheet 10 to the compression roll 41 and the occurrence of dents on the compression roll 41, and the unevenness of the dents on the surface of the compression roll 41. In addition, it is possible to assemble an electrochemical device such as a battery in which defects due to unevenness that occur are suppressed, and to provide an electrochemical device such as a battery with good characteristics.

FIG. 10 is a schematic diagram showing an example of the configuration of the battery 150 according to the embodiment of the present invention.
The battery according to this embodiment includes an electrode produced from the electrode sheet 10 described in the above embodiment. Hereinafter, the battery according to the present embodiment will be described as a representative example in which the battery is a stacked battery 150 of a lithium ion battery.
The laminated battery 150 includes a battery element in which a plurality of positive electrodes 121 and negative electrodes 126 are alternately stacked via separators 120, and these battery elements together with an electrolyte (not shown) are flexible films. It is stored in a container made of 140. A positive electrode terminal 131 and a 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 of the flexible film 140. .

  The positive electrode 121 is provided with a positive electrode active material coating portion (positive electrode active material layer 122) and an uncoated portion 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. In addition, a negative electrode active material coating portion (negative electrode active material layer 127) and an uncoated portion are provided.

In order to connect the non-coated portion of the positive electrode active material in the positive electrode current collector layer 123 to the positive electrode terminal 131 and connect the non-coated portion of the negative electrode active material in the negative electrode current collector layer 128 to the negative electrode terminal 136. Negative electrode tab 125.
The positive electrode tabs 130 are grouped together on the positive electrode terminal 131 and connected to each other together with the positive electrode terminal 131 by ultrasonic welding or the like, and the negative electrode tabs 125 are grouped together on the negative electrode terminal 136 and together with the negative electrode terminal 136 are connected to each other by ultrasonic welding or the like. Is done. In addition, one end of the positive electrode terminal 131 is drawn out of the flexible film 140, and one end of the negative electrode terminal 136 is also drawn out of the flexible film 140.

  An insulating member can be formed on the boundary portion 124 between the coated portion of the positive electrode active material (coated region 11) (positive electrode active material layer 122) and the uncoated portion (non-coated region 12) as necessary. The member can be formed not only at the boundary portion 124 but also near the boundary portion of both the positive electrode tab 130 and the positive electrode active material.

  Similarly, an insulating member can be formed on the boundary portion 129 between the negative electrode active material application portion (negative electrode active material layer 127) and the non-application portion as necessary, and the boundary between the negative electrode tab 125 and the negative electrode active material. It can be formed near the part.

  Usually, the outer dimension of the negative electrode active material layer 127 is larger than the outer dimension of the positive electrode active material layer 122 and smaller than the outer dimension of the separator 120.

(Non-aqueous electrolyte containing lithium salt)
The nonaqueous electrolytic solution containing a lithium salt used in the present embodiment can be appropriately selected from known ones according to the type of the 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, LiAlCl 4, 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, and a lower fatty acid lithium carboxylate.

  The solvent for dissolving the lithium salt is not particularly limited as long as it is usually used as a liquid for dissolving the electrolyte. Ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), carbonates such as methyl ethyl carbonate (MEC), vinylene carbonate (VC); lactones such as γ-butyrolactone and γ-valerolactone; trimethoxymethane 1,2-dimethoxyethane, diethyl ether, tetrahydrofuran, ethers such as 2-methyltetrahydrofuran; Sulfoxides such as dimethyl sulfoxide; 1,3-dioxolane, 4-methyl-1,3-dioxolane Oxolanes such as: nitrogen-containing solvents such as acetonitrile, nitromethane, formamide, and dimethylformamide; organic acid esters such as methyl formate, methyl acetate, ethyl acetate, butyl acetate, methyl propionate, and ethyl propionate; Diglymes; triglymes; sulfolanes such as sulfolane and methylsulfolane; oxazolidinones such as 3-methyl-2-oxazolidinone; sultones such as 1,3-propane sultone, 1,4-butane sultone and naphtha sultone. These may be used individually by 1 type, and 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 the flexible film 140 is preferably used from the viewpoint of reducing the weight of the battery. As the flexible film 140, a film in which a resin layer is provided on the front and back surfaces of a metal layer serving as a substrate can be used. As the metal layer, a metal layer having a barrier property such as preventing leakage of the electrolytic solution or entry of moisture from the outside can be selected, and aluminum, stainless steel, or the like can be used. A heat-fusible resin layer such as a modified polyolefin is provided on at least one surface of the metal layer, and the heat-fusible resin layers of the flexible film 140 are opposed to each other with the battery element interposed therebetween. An exterior body is formed by heat-sealing the periphery of the portion to be stored. A resin layer such as a nylon film or a polyester film can be provided on the surface of the exterior body that is the surface opposite to the surface on which the heat-fusible resin layer is formed.

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

(Insulating material)
In the case where the insulating member is formed at the boundary portions 124 and 129 between the application portion and the non-application portion of the active material, polyimide, glass fiber, polyester, polypropylene, or those containing these in the configuration can be used. The insulating member can be formed by applying heat to these members and fusing them to the boundary portions 124 and 129, or applying and drying a gel-like resin on the boundary portions 124 and 129.

(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 you may.
The resin layer constituting the separator 120 according to this 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, all Aromatic polyamide, semi-aromatic polyamide, wholly aromatic polyester, polyphenylene sulfide, polyparaphenylene benzobisoxazole, polyimide, polyarylate, polyetherimide, polyamideimide, polyacetal, polyetheretherketone, polysulfone, polyethersulfone, One type or two or more types selected from fluorine-based resins, polyether nitriles, modified polyphenylene ethers and the like can be mentioned.

  Among these, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, aliphatic polyamide, wholly aromatic polyamide, semi-aromatic polyamide, and wholly aromatic from the viewpoint of excellent balance of heat resistance, mechanical strength, stretchability, price, etc. One or two or more types selected from group polyesters are preferred, one or more types selected from polyethylene terephthalate, polybutylene terephthalate, aliphatic polyamide, wholly aromatic polyamide and semi-aromatic polyamide are more preferred, polyethylene terephthalate and One or more kinds selected from wholly aromatic polyamides are more preferred, and polyethylene terephthalate is more preferred.

  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, thereby avoiding thermal runaway of the battery. be able to.

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 more preferably 40% or more and 60% or less from the viewpoint of the balance between mechanical strength and lithium ion conductivity. Is particularly preferred.
The porosity can be obtained from the following formula.
ε = {1-Ws / (ds · t)} × 100
Here, ε: porosity (%), Ws: basis weight (g / m 2), ds: true density (g / cm 3), t: 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, rectangular.

  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, a battery can be manufactured using the electrode sheet 10 manufactured by the manufacturing method of the above embodiment.
According to the electrode sheet 10 of the present invention, when an active material layer is formed on a current collector such as a metal foil by intermittent application, and the electrode is manufactured through a step of compression and cutting after drying (FIG. 8), the compression step Due to the transfer of the active material powder dropped from the electrode sheet 10 to the compression roll 41 and the occurrence of the dents on the compression roll 41, and the unevenness of the dents on the surface of the compression roll 41, the electrode after rolling Batteries with good characteristics, etc. can be assembled by suppressing the defects due to the irregularities that also occur on the surface of the sheet 10 or assembling electrochemical devices such as batteries that prevent the use of electrode sheets with irregularities on the surface. It is possible to provide an electrochemical device. Thereby, it is suppressed that the yield of the electrode manufactured is reduced.

  While the present invention has been described 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 to the configuration and details of the present invention within the scope of the present invention.

A part or all of the above embodiments can be described as in the following supplementary notes, but is not limited thereto.
1. A compression device for producing a collector electrode sheet for compressing a sheet-like electrode material,
A pair of rolls in which each rotation axis is substantially horizontal and arranged at substantially the same height;
A compression apparatus comprising: a powder removing mechanism provided above the pair of rolls while allowing the sheet-like electrode material to pass between the pair of rolls from below to above.
2. 1. In the compression apparatus described in
The powder removing mechanism is provided on both sides of the sheet on the exit side of the sheet of electrode material that passes between the pair of rolls, suction means for sucking powder, means for blowing off the powder by wind pressure, And a rotary brush having a rotation axis substantially parallel to the rotation axis of the roll and rotating the roll reversely to wipe the powder.
3. 1. Or 2. In the compression apparatus described in
Furthermore, a compression apparatus provided with a means for receiving a substance that drops from the electrode material, which is provided below the roll.
4). 1. To 3. In the compression device according to any one of the above,
The sheet-like electrode material has an application region where a slurry containing an active material is applied on both sides of a sheet-like metal foil, and a non-application region where the slurry is not applied intermittently in the longitudinal direction of the metal foil. A compression device that is formed alternately.
5. Including a compression step of compressing the current collector electrode sheet in the thickness direction by passing the current collector electrode sheet having the active material applied on both surfaces of the sheet-like metal foil between a pair of rolls;
In the pair of rolls, each rotation axis is substantially horizontal, arranged at substantially the same height,
In the compression step, a compression device is
A collector electrode that removes powder using a powder removal mechanism provided above the pair of rolls when the sheet-like electrode material is passed between the pair of rolls from below to above. Sheet manufacturing method.
6). 5. In the method for producing a collector electrode sheet described in
In the current collector electrode sheet, an application region in which a slurry containing the active material is applied to both surfaces of the metal foil and a non-application region in which the slurry is not applied are intermittently alternately in the longitudinal direction of the metal foil. The manufacturing method of the collector electrode sheet formed.
7). 5. Or 6. In the method for producing a collector electrode sheet described in
On the exit side of the sheet of electrode material passing between the pair of rolls, suction means for sucking powder, means for blowing off the powder by wind pressure, and rotating shaft of the roll, provided on both ends of the sheet A current collector electrode sheet that removes powder using the powder removal mechanism that includes at least one of a rotating brush that has a rotation axis substantially parallel to the roll and that rotates in reverse with the roll to pay the powder. Manufacturing method.
8). 5. To 7. In the compression device according to any one of the above,
Furthermore, the manufacturing method of the collector electrode sheet which receives the substance which falls from the said electrode material using the means provided under the said roll.
9. 1. To 4. A current collector electrode sheet that is compressed using the compression device according to any one of the above.
10. 9. In the collector electrode sheet described in
In the current collector electrode sheet, an application region in which a slurry containing an active material is applied to both surfaces of a sheet-like metal foil and a non-application region in which the slurry is not applied are intermittently alternated in the longitudinal direction of the metal foil. A current collector electrode sheet that is formed into a compact and then compressed using the compression device.
11. 10. A battery manufactured using the current collector electrode sheet described in 1.

DESCRIPTION OF SYMBOLS 1 Manufacturing system 9 Metal foil 10 Electrode sheet | seat 11 Application | coating area | region 12 Non-application | coating area | region 20 Slurry application | coating apparatus 40 Compression apparatus 41 Compression roll 43 Rotating shaft 51 Backup roll 60 Cutting apparatus 70 Powder removal mechanism 71 Suction apparatus 72 Air blow apparatus 73 Rotating brush 74 Rotation Shaft 80 Pan 100 Computer 102 CPU
104 memory 105 storage 109 bus 110 program 120 separator 121 positive electrode 122 positive electrode active material layer 123 positive electrode current collector layer 124 boundary 125 negative electrode tab 126 negative electrode 127 negative electrode active material layer 128 negative electrode current collector layer 129 boundary 130 positive electrode tab 131 positive electrode Terminal 136 Negative electrode terminal 140 Flexible film 150 Battery

Claims (9)

A compression device for producing a collector electrode sheet for compressing a sheet-like electrode material,
A pair of rolls in which each rotation axis is substantially horizontal and arranged at substantially the same height;
A compression apparatus comprising: a powder removing mechanism provided above the pair of rolls while allowing the sheet-like electrode material to pass between the pair of rolls from below to above. The compression device according to claim 1.
The powder removing mechanism is provided on both sides of the sheet on the exit side of the sheet of electrode material that passes between the pair of rolls, suction means for sucking powder, means for blowing off the powder by wind pressure, And a rotary brush having a rotation axis substantially parallel to the rotation axis of the roll and rotating the roll reversely to wipe the powder. The compression apparatus according to claim 1 or 2,
Furthermore, a compression apparatus provided with a means for receiving a substance that drops from the electrode material, which is provided below the roll. The compression device according to any one of claims 1 to 3,
The sheet-like electrode material has an application region where a slurry containing an active material is applied on both sides of a sheet-like metal foil, and a non-application region where the slurry is not applied intermittently in the longitudinal direction of the metal foil. A compression device that is formed alternately. Including a compression step of compressing the current collector electrode sheet in the thickness direction by passing the current collector electrode sheet having the active material applied on both surfaces of the sheet-like metal foil between a pair of rolls;
In the pair of rolls, each rotation axis is substantially horizontal, arranged at substantially the same height,
In the compression step, a compression device is
A collector electrode that removes powder using a powder removal mechanism provided above the pair of rolls when the sheet-like electrode material is passed between the pair of rolls from below to above. Sheet manufacturing method. In the manufacturing method of the collector electrode sheet according to claim 5,
In the current collector electrode sheet, an application region in which a slurry containing the active material is applied to both surfaces of the metal foil and a non-application region in which the slurry is not applied are intermittently alternately in the longitudinal direction of the metal foil. The manufacturing method of the collector electrode sheet formed.   The collector electrode sheet which is compressed using the compression apparatus as described in any one of Claim 1 to 4. In the collector electrode sheet according to claim 7,
In the current collector electrode sheet, an application region in which a slurry containing an active material is applied to both surfaces of a sheet-like metal foil and a non-application region in which the slurry is not applied are intermittently alternated in the longitudinal direction of the metal foil. A current collector electrode sheet that is formed into a compact and then compressed using the compression device.   A battery manufactured using the current collector electrode sheet according to claim 8.

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