Device and method for manufacturing electrode for battery

Abstract

To keep a volume of an electrode composition in a hopper of an electrode composition supplying device.SOLUTION: A device for manufacturing an electrode for a battery comprises: a conveyance part for conveying a belt-like base material film; a supply part for keeping an electrode composition containing an active material in a hopper, and supplying the electrode composition to the conveyed base material film; a rotation member made of a porous material at least on its surface; and a casing covering the rotation member. The device comprises a rotary feeder for supplying the electrode composition into the hopper by injecting gas from a surface of the rotation member while conveying the electrode composition held in a pocket which is a gap between the rotation member and the casing by rotating the rotation member.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an apparatus and a method for manufacturing a battery electrode. [Background technology]

[0002] Lithium ion batteries are high-capacity secondary batteries that have been used in various applications in recent years. An electrode of a lithium ion battery is composed of an active material layer, a current collector layer, a separator, and a frame that encapsulates the active material layer (see, for example, Patent Document 1). The active material layer in a lithium ion battery can be formed, for example, by supplying an electrode composition to a strip-shaped substrate film and compressing it with a roll press or the like.

[0003] The electrode composition is supplied to the base film by, for example, an electrode composition supplying device equipped with a hopper. That is, the electrode composition supplying device can appropriately supply the electrode composition held in the hopper to the base film. Here, in order to stabilize the supply of the electrode composition to the base film, it is preferable to maintain the bulk of the electrode composition in the hopper within a predetermined range. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6633866 [Patent Document 2] JP 2016-155657 A Summary of the Invention [Problem to be solved by the invention]

[0005] In order to maintain the bulk of the electrode composition in the hopper of the electrode composition supplying device, it is considered to supply the electrode composition in a fixed amount into the hopper by a rotary feeder. However, the electrode composition has a property of sticking when pressure is applied, and may get stuck in the pocket of the rotary feeder. In this case, the electrode composition stuck in the pocket is not discharged from the rotary feeder, and the bulk of the electrode composition in the hopper of the electrode composition supplying device may not be maintained.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a battery electrode manufacturing apparatus and a battery electrode manufacturing method that can maintain the volume of electrode composition in the hopper of an electrode composition supply device. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the battery electrode manufacturing apparatus of the present invention comprises a conveying section that conveys a strip-shaped base film, a supplying section that holds an electrode composition containing an active material in a hopper and supplies the electrode composition to the conveyed base film, a rotating member having at least a porous surface, and a casing that covers the rotating member, and by rotating the rotating member, the electrode composition held in a pocket that is the gap between the rotating member and the casing is conveyed while gas is ejected from the surface of the rotating member, thereby supplying the electrode composition into the hopper. Effect of the Invention

[0008] According to the battery electrode manufacturing apparatus and battery electrode manufacturing method of the present invention, the bulk of the electrode composition in the hopper of the electrode composition supplying device can be maintained. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view of a single cell of a battery produced using an apparatus for producing a battery electrode according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram of a battery electrode manufacturing apparatus according to an embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of an electrode composition supplying device according to an embodiment. [Figure 4] FIG. 4 is a side view of the rotary feeder according to the embodiment. [Diagram 5] FIG. 5 is a perspective view of the rotary feeder according to the embodiment. [Figure 6A] FIG. 6A is a diagram for explaining a plate-shaped member according to an embodiment. [Figure 6B] FIG. 6B is a diagram for explaining a rotating member according to the embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of a configuration of a rotary feeder according to an embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of a configuration of a rotary feeder according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings used in the following description may show characteristic parts in an enlarged scale for the purpose of emphasizing the characteristic parts, and the dimensional ratios of each component may not be the same as the actual ones. Also, for the same purpose, some parts may be omitted in the drawings.

[0011] <Battery pack (secondary battery)> The battery electrode manufacturing apparatus and battery electrode manufacturing method of the embodiment are applied to, for example, the manufacture of lithium ion batteries. Lithium ion batteries are used in the form of a modularized battery assembly formed by combining a plurality of lithium ion single batteries (also referred to as single cells or battery cells), or in the form of a battery pack formed by combining a plurality of such battery assemblies and adjusting the voltage and capacity. An example of a lithium ion secondary battery is shown below, but the type of secondary battery according to the present invention is not limited to a lithium ion secondary battery and includes other secondary batteries.

[0012] <Single cell (battery cell)> 1 is a schematic cross-sectional view of a unit cell 10. The above-mentioned battery pack can be produced by combining a plurality of unit cells 10. For example, the unit cell 10 has a positive electrode 20a and a negative electrode 20b as two electrodes 20 (battery electrodes), and a separator 30.

[0013] The separator 30 is disposed between the positive electrode 20a and the negative electrode 20b. In the assembled battery, the multiple single cells 10 are stacked with the positive electrodes 20a and the negative electrodes 20b facing in the same direction.

[0014] The separator 30 holds an electrolyte. Thus, the separator 30 functions as an electrolyte layer. The separator 30 is disposed between the electrode active material layers 22 of the positive electrode 20a and the negative electrode 20b, and prevents them from contacting each other. Thus, the separator 30 functions as a partition wall between the positive electrode 20a and the negative electrode 20b.

[0015] Examples of the electrolyte held in the separator 30 include an electrolytic solution or a gel polymer electrolyte. By using these electrolytes, high lithium ion conductivity is ensured. Examples of the form of the separator include a porous sheet separator made of a polymer or fiber that absorbs and holds the electrolyte, a nonwoven fabric separator, and the like.

[0016] The positive electrode 20a and the negative electrode 20b each have a current collector 21, an electrode active material layer 22, and a frame 35. The electrode active material layer 22 and the current collector 21 are arranged in this order from the separator 30 side. The frame 35 is frame-shaped (annular). The frame 35 surrounds the periphery of the electrode active material layer 22. The frame 35 of the positive electrode 20a and the frame 35 of the negative electrode 20b are welded to each other and integrated. In the following description, when the electrode active material layers 22 of the positive electrode 20a and the negative electrode 20b are to be distinguished from each other, they are called the positive electrode active material layer 22a and the negative electrode active material layer 22b, respectively.

[0017] <Specific examples of positive electrode current collectors> As the positive electrode current collector constituting the positive electrode current collector layer 21a, a current collector used in a known lithium ion cell can be used, for example, a known metal current collector and a resin current collector composed of a conductive material and a resin (such as the resin current collectors described in JP 2012-150905 A and WO 2015 / 005116 A, etc.) can be used. From the viewpoint of battery characteristics, etc., the positive electrode current collector constituting the positive electrode current collector layer 21a is preferably a resin current collector.

[0018] Examples of the metal current collector include one or more metal materials selected from the group consisting of copper, aluminum, titanium, nickel, tantalum, niobium, hafnium, zirconium, zinc, tungsten, bismuth, antimony, alloys containing one or more of these metals, and stainless steel alloys. These metal materials may be used in the form of a thin plate or metal foil. In addition, the above metal materials may be formed on the surface of a substrate made of a material other than the above metal materials by a method such as sputtering, electrodeposition, or coating, and used as the metal current collector.

[0019] The resin collector preferably contains a conductive filler and a matrix resin. Examples of the matrix resin include, but are not limited to, polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), etc. The conductive filler is not particularly limited as long as it is selected from materials having electrical conductivity. The conductive filler may be a conductive fiber having a fibrous shape.

[0020] The resin current collector may contain other components (such as a dispersant, a crosslinking accelerator, a crosslinking agent, a colorant, an ultraviolet absorber, and a plasticizer) in addition to the matrix resin and the conductive filler. A plurality of resin current collectors may be laminated, or a resin current collector and a metal foil may be laminated.

[0021] The thickness of the positive electrode collector layer 21a is not particularly limited, but is preferably 5 to 150 μm. When a plurality of resin collectors are laminated to be used as the positive electrode collector layer 21a, the total thickness after lamination is preferably 5 to 150 μm. The positive electrode collector layer 21a can be obtained, for example, by melt-kneading a matrix resin, a conductive filler, and an optional filler dispersant to obtain a conductive resin composition, and molding the conductive resin composition into a film by a known method.

[0022] <Specific examples of positive electrode active materials> The positive electrode active material layer 22a is preferably a non-binding mixture containing a positive electrode active material. Here, the non-binding means that the position of the positive electrode active material in the positive electrode active material layer is not fixed, and the positive electrode active materials are not irreversibly fixed to each other and to the current collector. When the positive electrode active material layer 22a is a non-binding material, the positive electrode active materials are not irreversibly fixed to each other, so that the interface between the positive electrode active materials can be separated without mechanically destroying it, and even if stress is applied to the positive electrode active material layer 22a, the positive electrode active material moves, so that destruction of the positive electrode active material layer 22a can be prevented, which is preferable. The positive electrode active material layer 22a that is a non-binding material can be obtained by, for example, making the positive electrode active material layer 22a into a positive electrode active material layer 22a that contains a positive electrode active material and an electrolyte but does not contain a binder. In this specification, the binder means a chemical agent that cannot reversibly fix the positive electrode active materials to each other or to the positive electrode active material and the current collector, and examples of such binders include known solvent-dried binders for lithium ion batteries such as starch, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose, polyvinylpyrrolidone, tetrafluoroethylene, styrene-butadiene rubber, polyethylene, and polypropylene. These binders are used by dissolving or dispersing them in a solvent, and by volatilizing or distilling off the solvent, the surface becomes solidified without showing any adhesiveness, and therefore cannot reversibly fix the positive electrode active materials to each other or to the positive electrode active material and the current collector.

[0023] Examples of the positive electrode active material include, but are not limited to, composite oxides of lithium and transition metals, composite oxides containing two types of transition metal elements, and composite oxides containing three or more types of metal elements.

[0024] The positive electrode active material may be a coated positive electrode active material having at least a part of its surface coated with a coating material containing a polymer compound. When the positive electrode active material is coated with the coating material, the volume change of the positive electrode is mitigated, and the expansion of the positive electrode can be suppressed.

[0025] As the polymer compound constituting the coating material, those described as active material coating resins in JP 2017-054703 A and WO 2015 / 005117 A, for example, can be suitably used.

[0026] The coating material may contain a conductive agent, which may be the same as the conductive filler contained in the positive electrode current collector layer 21a.

[0027] The positive electrode active material layer 22a may contain an adhesive resin. For example, the adhesive resin may be a resin for coating a non-aqueous secondary battery active material described in JP 2017-054703 A in which a small amount of organic solvent is mixed to adjust the glass transition temperature to room temperature or lower, and a resin described as an adhesive in JP 10-255805 A. The adhesive resin means a resin that does not solidify even when the solvent component is evaporated and dried, and has adhesiveness (the property of adhering by applying a slight pressure without using water, solvent, heat, etc.). On the other hand, the solution-drying type electrode binder used as a binder means a material that dries and solidifies by evaporating the solvent component, thereby firmly adhering and fixing the active materials to each other. Therefore, the above-mentioned binder (solution-drying type electrode binder) and the adhesive resin are different materials.

[0028] The positive electrode active material layer 22a may contain an electrolytic solution containing an electrolyte and a non-aqueous solvent. As the electrolyte, a substance used in a known electrolytic solution can be used. As the non-aqueous solvent, a substance used in a known electrolytic solution (e.g., phosphoric acid ester, nitrile compound, and mixtures thereof) can be used. For example, a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC), or a mixture of ethylene carbonate (EC) and propylene carbonate (PC) can be used.

[0029] The positive electrode active material layer 22a may contain a conductive assistant, which may be a conductive material similar to the conductive filler contained in the positive electrode current collector layer 21a.

[0030] The thickness of the positive electrode active material layer 22a is not particularly limited, but from the viewpoint of battery performance, it is preferably 300 to 750 μm, and more preferably 350 to 600 μm.

[0031] In an embodiment, the positive electrode composition supplied to form the positive electrode active material layer 22a is a wet powder containing a positive electrode active material and a non-aqueous electrolyte solution. The wet powder is more preferably in a pendular or funicular state.

[0032] The proportion of the nonaqueous electrolyte in the wet powder is not particularly limited, but in order to achieve a pendular or funicular state, in the case of a positive electrode, it is desirable that the proportion of the nonaqueous electrolyte be 0.5 to 30% by weight of the entire wet powder.

[0033] <Specific examples of negative electrode current collectors> The negative electrode current collector constituting the negative electrode current collector layer 21b may be appropriately selected from the same configuration as that described for the positive electrode current collector, and may be obtained by the same method. From the viewpoint of battery characteristics, the negative electrode current collector layer 21b is preferably a resin current collector. The thickness of the negative electrode current collector layer 21b is not particularly limited, but is preferably 5 to 150 μm.

[0034] <Specific examples of negative electrode active materials> The negative electrode active material layer 22b is preferably a non-binding material of a mixture containing a negative electrode active material. The reason why the negative electrode active material layer is preferably a non-binding material and the method for obtaining the non-binding negative electrode active material layer 22b are the same as the reason why the positive electrode active material layer 22a is preferably a non-binding material and the method for obtaining the non-binding positive electrode active material layer 22a.

[0035] As the negative electrode active material, for example, a carbon-based material, a silicon-based material, or a mixture thereof can be used, but is not particularly limited.

[0036] The negative electrode active material may be a coated negative electrode active material having at least a part of its surface coated with a coating material containing a polymer compound. When the negative electrode active material is coated with the coating material, the volume change of the negative electrode is mitigated, and the expansion of the negative electrode can be suppressed.

[0037] As the coating material, the same coating material as that constituting the coated positive electrode active material can be suitably used.

[0038] The negative electrode active material layer 22b contains an electrolytic solution containing an electrolyte and a non-aqueous solvent. The composition of the electrolytic solution may be the same as that of the electrolytic solution contained in the positive electrode active material layer 22a.

[0039] The negative electrode active material layer 22b may contain a conductive additive, which may be a conductive material similar to the conductive filler contained in the positive electrode active material layer 22a.

[0040] The negative electrode active material layer 22b may contain an adhesive resin, which may be the same as the adhesive resin that is an optional component of the positive electrode active material layer 22a.

[0041] The thickness of the negative electrode active material layer 22b is not particularly limited, but from the viewpoint of battery performance, it is preferably 450 to 900 μm, and more preferably 500 to 750 μm.

[0042] In an embodiment, the negative electrode composition supplied to form the negative electrode active material layer 22b is a wet powder containing a negative electrode active material and a non-aqueous electrolyte solution. The wet powder is more preferably in a pendular or funicular state.

[0043] The proportion of the nonaqueous electrolyte in the wet powder is not particularly limited, but in order to achieve a pendular or funicular state, in the case of a negative electrode, it is desirable that the proportion of the nonaqueous electrolyte be 0.20 to 40% by weight of the entire wet powder.

[0044] <Specific examples of separators> Examples of the electrolyte held in the separator 30 include an electrolytic solution and a gel polymer electrolyte. By using these electrolytes, high lithium ion conductivity is ensured in the separator 30. Examples of the form of the separator 30 include, but are not limited to, a porous film made of polyethylene or polypropylene.

[0045] <Examples of frame bodies> The frame 35 is not particularly limited as long as it is a material that is durable against the electrolyte, but for example, a polymer material is preferable, and a thermoplastic polymer material is more preferable. The material constituting the frame 35 may be any material that has insulation properties, sealing properties (liquid-tightness), heat resistance under the battery operating temperature, etc., and a resin material is preferably used. More specifically, the frame 35 may be, for example, an epoxy resin, a polyolefin resin, a polyurethane resin, or a polyvinylidene fluoride resin, and the like, and an epoxy resin is preferable because it is highly durable and easy to handle.

[0046] <Battery electrode manufacturing device and battery electrode manufacturing method> Next, a battery electrode manufacturing apparatus and a battery electrode manufacturing method (hereinafter, abbreviated as manufacturing method) of this embodiment will be described. For example, in the battery electrode manufacturing apparatus and the battery electrode manufacturing method, the positive electrode 20a and the negative electrode 20b are first manufactured. The manufacturing method of the positive electrode 20a and the manufacturing method of the negative electrode 20b mainly differ in the electrode active material contained in the electrode active material layer 22. Here, as the manufacturing method of the electrode 20, the manufacturing methods of the positive electrode 20a and the negative electrode 20b will be collectively described.

[0047] 2 is a schematic diagram of a battery electrode manufacturing apparatus 1000. For example, the battery electrode manufacturing apparatus 1000 includes a chamber 100, a conveying device 200, a rotary feeder 300, an electrode composition supplying device 400, a pressing device 500, and a frame supplying device 600. The conveying device 200 is an example of a conveying section. The electrode composition supplying device 400 is an example of a supplying section. In the following, a case where the strip-shaped base film is a strip-shaped current collector 21B will be described as an example.

[0048] The chamber 100 is a room whose interior can be kept at a reduced pressure lower than atmospheric pressure. The interior of the chamber 100 is reduced to a pressure lower than atmospheric pressure by a decompression pump (not shown). The standard atmospheric pressure is about 1013 hPa (about 101 kPa).

[0049] For example, the current collector roll 21R is disposed outside the chamber 100, and the strip-shaped current collector 21B drawn from the current collector roll 21R is transported into the chamber 100 through a slit. Hereinafter, the strip-shaped current collector 21B may be referred to as the current collector 21B. The current collector 21B is the current collector 21 before it is cut into a predetermined shape. The current collector 21B is transported at a predetermined speed along the transport direction Da. In the following description, the direction in which the current collector 21B is transported is referred to as the downstream side Da1, and the opposite direction is referred to as the upstream side Da2. The external space of the chamber 100 in which the current collector roll 21R is disposed may be at normal pressure, or may be reduced in pressure by a chamber different from the chamber 100.

[0050] 2, the upper side in the vertical direction Db is designated as Db1, and the lower side in the vertical direction Db is designated as Db2. The direction perpendicular to the transport direction Da and the vertical direction Db corresponds to the width direction of the current collector 21B and the electrode composition 22c placed on the current collector 21B.

[0051] The conveying device 200 conveys the current collector 21B to the downstream side Da1 in the conveying direction Da. For example, the conveying device 200 is a belt conveyor that supports the current collector 21B from below. After the electrode composition supplying device 400 described below supplies the electrode composition 22c, the conveying device 200 conveys the current collector 21B carrying the electrode composition 22c. After the frame supplying device 600 described below supplies the frame 35, the conveying device 200 conveys the frame 35 and the current collector 21B carrying the electrode composition 22c.

[0052] The rotary feeder 300 supplies the electrode composition 22c into a hopper provided in the electrode composition supplying device 400, and the electrode composition supplying device 400 supplies the electrode composition 22c held in the hopper to the conveyed current collector 21B. A specific configuration of the rotary feeder 300 will be described later.

[0053] An example of the configuration of the electrode composition supplying device 400 is shown in Fig. 3. The electrode composition supplying device 400 in Fig. 3 includes an electrode composition supplying unit 410, a fixing member 420, and a shutter 430. In the electrode composition supplying device 400, the electrode composition 22c is held in the space between the electrode composition supplying unit 410 and the fixing member 420, and the electrode composition 22c is supplied to the current collector 21B by controlling the operation of the electrode composition supplying unit 410 and the shutter 430. That is, in Fig. 3, the electrode composition supplying unit 410 and the fixing member 420 form a hopper, and the electrode composition supplying device 400 supplies the electrode composition 22c held in the hopper to the current collector 21B being transported.

[0054] More specifically, the electrode composition supply unit 410 is composed of an electrode composition supply drive belt 411, a drive roller 412, and a drive roller 413. The fixed member 420 is, for example, a metal wall surface. The drive roller 412 and the drive roller 413 rotate in the direction indicated by the arrow in FIG. 3, so that the surface of the electrode composition supply drive belt 411 that is in contact with the electrode composition 22c moves downward. This allows the electrode composition supply unit 410 to discharge the electrode composition 22c from the opening below the hopper and supply it to the current collector 21B. In addition, by stopping the rotation of the drive roller 412 and the drive roller 413 and closing the opening below the hopper with the shutter 430, the supply of the electrode composition 22c to the current collector 21B can be stopped. In this way, by controlling the supply and stop of the electrode composition 22c, the electrode composition 22c can be intermittently supplied to the current collector 21B as shown in FIG. 2.

[0055] 3 is merely an example, and the specific configuration of the electrode composition supplying device 400 can be changed as appropriate. For example, the shutter 430 may be omitted. Also, for example, an electrode composition supplying unit similar to the electrode composition supplying unit 410 may be provided instead of the fixing member 420. Also, for example, a fixing member similar to the fixing member 420 may be provided instead of the electrode composition supplying unit 410. That is, the hopper of the electrode composition supplying device 400 may have some or all of its inner walls movable, or all of its inner walls fixed.

[0056] Here, it is preferable that the bulk of the electrode composition 22c in the hopper of the electrode composition supply device 400 is maintained within a certain range. That is, if the bulk of the electrode composition 22c in the hopper becomes too low, the electrode composition 22c becomes difficult to discharge from the hopper, and the supply amount of the electrode composition 22c to the current collector 21B may become unstable. Also, if the bulk of the electrode composition 22c in the hopper becomes too high, pressure is applied to the electrode composition 22c, causing it to solidify in the hopper, and the electrode composition 22c may not be discharged from the hopper.

[0057] In order to maintain the bulk of the electrode composition 22c in the hopper of the electrode composition supplying device 400, the rotary feeder 300 supplies the electrode composition 22c in a fixed amount to the hopper of the electrode composition supplying device 400. In particular, the rotary feeder 300 prevents the electrode composition 22c from getting stuck in the rotary feeder 300 by a configuration described below with reference to the drawings. Thus, the rotary feeder 300 stabilizes the supply of the electrode composition 22c to the hopper of the electrode composition supplying device 400 and maintains the bulk of the electrode composition 22c in the hopper.

[0058] 4 and 5 show an example of the configuration of rotary feeder 300. Fig. 4 is a side view of rotary feeder 300, and Fig. 5 is a perspective view of rotary feeder 300. For example, rotary feeder 300 is composed of a casing 310, plate-shaped members 321 and 322, a rotating member 330, hoses 341 and 342, and a shaft 360.

[0059] The casing 310 is a member that covers the outside of the rotary feeder 300. For the sake of explanation, the casing 310 is omitted in FIGS. 4 and 5. In addition, in the perspective view of FIG. 5, the rotary feeder 300 is shown partially disassembled in order to illustrate each component included in the rotary feeder 300. The Z direction shown in FIGS. 4 and 5 is a direction parallel to the rotation axis of the rotating member 330. The Z direction is, for example, a direction perpendicular to the conveying direction Da and the vertical direction Db shown in FIG. 2. In this case, the X direction corresponds to the conveying direction Da.

[0060] Although shown in an exploded state in Fig. 5, the plate-shaped members 321, 322, and the rotating member 330 operate integrally. Specifically, when the rotary feeder 300 operates, the plate-shaped members 321, 322, and the rotating member 330 rotate integrally on a rotation axis parallel to the Z direction. As shown in Fig. 4, the plate-shaped members 321 and 322 are disposed on both ends of the rotating member 330 in the Z direction. The plate-shaped members 321 and 322 are, for example, flange plates having a larger diameter in a direction perpendicular to the rotation axis than the rotating member 330.

[0061] The shaft 360 is a rod-shaped member that rotatably supports the plate-shaped member 321, the plate-shaped member 322, and the rotating member 330. Here, an air vent is provided inside the shaft 360 to pass the gas flowing in from the hose 341 and the hose 342. For example, the air vent in the shaft 360 is provided in a portion on the shaft 360 that is outside the positions on the shaft 360 along the Z direction where the plate-shaped member 321 and the plate-shaped member 322 are provided. As another example, the air vent in the shaft 360 is provided throughout the shaft 360. That is, the shaft 360 may be a pipe-shaped member through which an air vent penetrates in the Z direction. When the shaft 360 is a pipe-shaped member, one of the hose 341 and the hose 342 can be omitted.

[0062] The plate-shaped members 321 and 322 are made of a non-porous material. Although the specific material of the plate-shaped members 321 and 322 is not limited, for example, aluminum, stainless steel, or the like can be used. Furthermore, the plate-shaped members 321 and 322 are provided with vents for passing gas that has flowed in through the vent in the shaft 360. For example, the gas that has flowed in from the hoses 341 and 342 is discharged to the vent in the plate-shaped member 321 through the vent in the shaft 360.

[0063] The vents of the plate-shaped member 321 and the plate-shaped member 322 will be specifically described with reference to FIG. 6A. For example, the vent of the plate-shaped member 321 is a groove provided on one side of the plate-shaped member 321. Also, for example, the vent of the plate-shaped member 321 is a cavity provided inside the plate-shaped member 321. More specifically, the plate-shaped member 321 shown in FIG. 6A is a disk-shaped member having a hole in the center for passing the shaft 360. As shown by dotted lines in FIG. 6A, the plate-shaped member 321 is provided with 12 vents that spread radially from the center (the position of the shaft 360). The gas that flows in from the shaft 360 is branched into 12 by these 12 vents. Although not shown, the plate-shaped member 322 is also provided with 12 vents.

[0064] Rotating member 330 has, for example, a columnar shape (dodecanal) with a dodecagonal base disposed at both ends in the Z direction. Furthermore, rotating member 330 has a through hole near the surface as shown in Fig. 5. The through hole of rotating member 330 is a hole connecting the bottom surfaces at both ends of the dodecagonal prism, and is an air vent for passing gas flowing in from plate-like member 321 and plate-like member 322.

[0065] The rotating member 330 is partially or entirely made of a porous material. For example, only the portion of the rotating member 330 near the surface on the side surface side may be made of a porous material. For example, only the portion of the rotating member 330 outside the through hole when viewed from the center of rotation (the position of the shaft 360) may be made of a porous material. The portion of the rotating member 330 made of a porous material is also referred to as a porous portion. There is no limitation on the specific material of the porous member, but porous ceramics, porous metal, and porous carbon can be used as examples.

[0066] More specifically, as shown in FIG. 6B, twelve through holes are provided in the rotating member 330 at positions corresponding to the twelve vents provided in the plate-shaped members 321 and 322. For example, the plate-shaped member 321 is provided with the vent 321a shown in FIG. 6A, and the vent 321a is connected to the through hole 330a provided in the rotating member 330. Then, the gas flowing in from the hose 341 and the hose 342 passes through the vent of the shaft 360, the vent of the plate-shaped members 321 and 322, and the through hole of the rotating member 330 in this order, and further passes through the porous portion of the rotating member 330, and is ejected from the surface of the rotating member 330 as shown by the arrow in FIG. 5. This causes the electrode composition 22c to hover (prevent adhesion) relative to the rotating member 330.

[0067] A series of processes from when the electrode composition 22c is introduced into the rotary feeder 300 until the electrode composition 22c is supplied to the electrode composition supplying device 400 will be described. First, although not shown in Figs. 4 and 5, the rotary feeder 300 includes a casing 310 shown in Fig. 6B. The casing 310 has openings on the upper and lower sides in the vertical direction Db. The electrode composition 22c is introduced from the upper opening of the casing 310. As described above, the plate-like members 321, 322, and the rotating member 330 rotate around the Z direction as the rotation axis, but the position of the casing 310 is fixed.

[0068] 6B, a gap (pocket) is formed between the casing 310 and the rotating member 330, and the electrode composition 22c introduced from the upper opening of the casing 310 is held in the pocket in a fixed amount. The electrode composition 22c held in the pocket is transported downward as the rotating member 330 rotates, and is discharged from the lower opening of the casing 310.

[0069] As described above, gas is ejected from the surface of the rotating member 330. Therefore, when the electrode composition 22c is ejected from the opening on the lower side of the casing 310, the electrode composition 22c is peeled off from the rotating member 330, and the electrode composition 22c is less likely to fit in the pocket.

[0070] The rotary feeder 300 may constantly send gas to the 12 through holes provided in the rotating member 330, or may send gas only for a certain period of time. For example, a valve may be provided in each through hole, and the gas may be sent only when the corresponding flat plate is located at the lower opening of the casing 310.

[0071] So far, an example has been described in which gas is introduced through the vent holes provided in plate-like members 321 and 322 and through holes provided in rotating member 330, and gas is ejected from the surface of rotating member 330. However, the embodiment is not limited to this.

[0072] For example, by constructing the entire rotating member including the surface from a porous member, it is possible to omit the plate-like members 321 and 322 and the through holes of the rotating member. For example, as shown in Fig. 7, the rotary feeder 300 includes a porous member 370 as the rotating member. In this case, gas is fed into the porous member 370 from the position of the shaft 360, for example, and the gas that has passed through the inside of the porous member 370 is ejected from the surface of the porous member 370.

[0073] 4 to 7, the cross-sectional shape of the rotating member is shown as a dodecagon, but this can be modified as appropriate. For example, the rotating member may be configured so that the cross-sectional shape is a decagon or an octagon.

[0074] In addition, in the examples shown in Figs. 4 to 7, the surface of the rotating member is composed of a plurality of flat surfaces, but the surface of the rotating member may be a curved surface. For example, as shown in Fig. 8, the rotary feeder 300 may include a porous member 370' having a surface composed of 12 curved surfaces as the rotating member. In the case shown in Fig. 8, the pocket formed between the casing 310 and the rotating member is larger than in the examples shown in Figs. 4 to 7. This increases the amount of electrode composition 22c that can be held in one pocket, and more electrode composition 22c can be supplied from the rotary feeder 300 to the electrode composition supply device 400. That is, in the case shown in Fig. 8, the supply capacity of the electrode composition 22c per unit time is higher than in the examples shown in Figs. 4 to 7. On the other hand, the larger the pocket, the easier it is for the electrode composition 22c to fit in the pocket. It is preferable that the surface shape of the rotating member is appropriately adjusted in consideration of the required supply capacity.

[0075] Returning to Fig. 2, the explanation will be continued. The press device 500 compresses the electrode composition 22c supplied to the current collector 21B. For example, as shown in Fig. 2, the press device 500 has an upper roller 501 and a lower roller 502. The press device 500 sandwiches and compresses the electrode composition 22c supplied to the current collector 21B between the upper roller 501 and the lower roller 502. That is, the press device 500 performs roll pressing on the electrode composition 22c.

[0076] The frame body supplying device 600 supplies the frame body 35 to the current collector 21B being transported. For example, the frame body supplying device 600 has a robot arm and places a prefabricated frame body 35 at a predetermined position on the current collector 21B being transported. Alternatively, the frame body supplying device 600 may manufacture the frame body 35 on the current collector 21B. As an example, the current collector 21B is used as a base material, and a predetermined material is discharged or applied in a predetermined shape onto the current collector 21B by a dispenser, a coater, or the like, to form the frame body 35 on the current collector 21B.

[0077] In FIG. 2, an example was described in which the frame body 35 was supplied by the frame body supplying device 600 to a position surrounding the electrode composition 22c compressed by the pressing device 500. However, the embodiment is not limited to this, and the frame body 35 may be supplied first, and the electrode composition 22c in the frame body 35 may be compressed by the pressing device 500. Also, in FIG. 2, an example was described in which the frame body supplying device 600 supplies the frame body 35 after the electrode composition 22c is supplied by the electrode composition supplying device 400. However, the embodiment is not limited to this. For example, after the frame body 35 is supplied by the frame body supplying device 600, the electrode composition 22c may be supplied by the electrode composition supplying device 400 to a position inside the frame body 35. Also, in FIG. 2, a case in which the frame body supplying device 600 is arranged inside the chamber 100 is shown, but the frame body supplying device 600 may be arranged outside the chamber 100.

[0078] As described above, in the embodiment, each step of supplying the electrode composition 22c by the electrode composition supplying device 400 and compressing the electrode composition 22c by the pressing device 500 is performed in the chamber 100 whose inside is reduced in pressure below atmospheric pressure. This can prevent air from remaining inside the electrode composition 22c, and can improve the uniformity of the electrode active material layer 22.

[0079] 1 is further supplied to produce the single cell 10. The separator 30 may be supplied continuously to the current collector 21B and the electrode composition 22c being transported along the transport direction Da, or may be supplied as a sheet after the current collector 21B and the electrode composition 22c are divided into predetermined units.

[0080] Specifically, the positive electrode 20a and the negative electrode 20b are manufactured according to the above-mentioned embodiment, and the positive electrode 20a and the negative electrode 20b are stacked with the separator 30 interposed therebetween, thereby manufacturing the single cell 10. For example, the separator 30 is supplied to the surface of the positive electrode 20a facing the positive electrode active material layer 22a, and the negative electrode 20b is further supplied so that the separator 30 and the negative electrode active material layer 22b are in contact with each other, thereby manufacturing the single cell 10. Alternatively, the separator 30 is supplied to the surface of the negative electrode 20b facing the negative electrode active material layer 22b, and the positive electrode 20a is further supplied so that the separator 30 and the positive electrode active material layer 22a are in contact with each other, thereby manufacturing the single cell 10.

[0081] For example, when a separator sheet is used as the base film, the electrode composition 22c is supplied onto the separator sheet, a frame 35 is supplied to a position on the separator sheet that surrounds the electrode composition 22c, a current collector 21B is supplied to the surface of the electrode composition 22c opposite the separator sheet, and the separator sheet and the current collector 21B are trimmed into a predetermined shape, thereby producing the positive electrode 20a or the negative electrode 20b.

[0082] When a release film is used as the base film, the electrode composition 22c is supplied onto the release film, a frame 35 is supplied to a position on the release film surrounding the electrode composition 22c, a current collector 21B is supplied onto the surface of the electrode composition 22c opposite the release film, the release film is collected, and then a separator sheet is supplied onto the surface opposite the current collector 21B, and the current collector 21B and the separator sheet are trimmed into a predetermined shape, thereby producing the positive electrode 20a or the negative electrode 20b. Note that instead of supplying the separator sheet and then trimming it, a separator 30 may be supplied to the electrode composition 22c.

[0083] Alternatively, the electrode composition 22c is supplied onto a release film, a frame 35 is supplied to a position on the release film surrounding the electrode composition 22c, a separator sheet is supplied onto the surface of the electrode composition 22c opposite the release film, the release film is collected, and then the current collector 21B is supplied onto the surface opposite the separator sheet, and the separator sheet and the current collector 21B are trimmed into a predetermined shape, thereby producing the positive electrode 20a or the negative electrode 20b. Note that instead of supplying the current collector 21B and then trimming it, the current collector 21 trimmed into a predetermined shape may be supplied to the electrode composition 22c.

[0084] 2 illustrates an example in which the electrode composition 22c is intermittently supplied to the base film. Specifically, the electrode composition 22c can be supplied at a predetermined length by repeatedly starting and stopping the supply of the electrode composition 22c to the base film. However, the embodiment is not limited to this, and the electrode composition 22c may be supplied to the current collector 21B continuously.

[0085] For example, a sheet of the electrode composition 22c alone can be produced by continuously supplying the electrode composition 22c onto a release film as a base film and compressing it, and then peeling the electrode composition 22c from the release film. The sheet of the electrode composition 22c alone can be trimmed to a predetermined size and combined with a frame 35, a current collector 21B, and a separator 30 to produce the positive electrode 20a or the negative electrode 20b. The order in which the frame 35, the current collector 21B, and the separator 30 are supplied to the trimmed electrode composition 22c is arbitrary.

[0086] Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the changes, combinations, deletions, etc. of the configurations within the scope of the present invention are also included. Furthermore, it goes without saying that the configurations shown in each embodiment can be used in appropriate combination. When the lithium ion secondary battery exemplified in the above description is used among the secondary batteries, it includes a battery using a liquid material for the electrolyte and a battery using a solid material for the electrolyte (so-called all-solid-state battery). Furthermore, the battery in this embodiment includes a battery having a metal foil (metal current collector foil) as a current collector, and includes a battery having a so-called resin current collector made of a resin to which a conductive material has been added instead of the metal foil. When the resin current collector is used as a resin current collector for a bipolar electrode, a positive electrode may be formed on one side of the resin current collector and a negative electrode may be formed on the other side to form a bipolar electrode. The battery in this embodiment includes a battery in which an electrode is formed by applying a positive or negative electrode active material, etc. to a positive or negative electrode current collector, respectively, using a binder, and in the case of a bipolar battery, includes a battery in which a bipolar electrode is formed by applying a positive electrode active material, etc. to one side of a current collector using a binder to form a positive electrode layer, and applying a negative electrode active material, etc. to the opposite side using a binder to form a negative electrode layer. [Explanation of symbols]

[0087] 10: Single cell 20: Electrode 20a: Positive electrode 20b: Negative electrode 21, 21B, 21B', 21C: current collector 21a: Positive electrode current collector layer 21b: Negative electrode current collector layer 21R: Current collector roll 21R': Recovery roll 22: Electrode active material layer 22a: Positive electrode active material layer 22b: Negative electrode active material layer 22C: Electrode composition 30: Separator 35:Frame body 100: Chamber 200: Transport device 300: Rotary feeder 310: Casing 320: Support member 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332: Block 340: Surface material 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352: Flat plate 360: Rotation axis 370:Porous materials 370': Porous material 400: Electrode composition supply device 410: Electrode composition supply unit 411: Electrode composition supply drive belt 412, 413: Drive roller 420: Fixing member 430: Shutter 500: Press equipment 501: Upper roller 502: Lower roller 600:Frame supply device 1000:Battery electrode manufacturing equipment

Claims

1. A conveying unit that conveys a strip-shaped base film; a supply unit that holds an electrode composition containing an active material in a hopper and supplies the electrode composition to the transported base film; a rotary feeder including a rotating member having at least a porous surface and a casing covering the rotating member, the rotary feeder conveying the electrode composition held in a pocket that is a gap between the rotating member and the casing by rotating the rotating member while ejecting gas from the surface of the rotating member to supply the electrode composition into the hopper; An apparatus for manufacturing a battery electrode comprising:

2. The rotary member further includes a plate-shaped member disposed on both ends of the rotary member in a direction parallel to a rotation axis, and a shaft that rotatably supports the plate-shaped member and the rotary member, the rotating member has a through hole parallel to the rotation axis near the surface, and at least a portion outside the through hole is made of a porous material; The battery electrode manufacturing apparatus of claim 1, wherein gas is supplied to the porous member through a vent provided in the shaft, a vent provided in the plate-shaped member, and the through hole, thereby causing the gas to be ejected from the surface of the rotating member.

3. The battery electrode manufacturing apparatus according to claim 1 , wherein the rotating member is made of a porous material.

4. An electrode composition containing an active material is held in a hopper, and the electrode composition is supplied to a belt-shaped base film being transported; The electrode composition is supplied into the hopper by rotating a rotating member having at least a porous surface, while conveying the electrode composition held in a pocket, which is a gap between the rotating member and a casing that covers the rotating member, and by ejecting gas from the surface of the rotating member. A method for manufacturing an electrode for a battery, comprising:

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