Coating device, manufacturing method of cathode and manufacturing method of solid battery

Abstract

To provide a coating device which can suppress discharged slurry from dragging at an end edge thereof when intermittently discharging the slurry from a die head.SOLUTION: A coating device comprises: a transportation roller which continuously transports a sheet-like material to be painted; a first die head which intermittently discharges a first slurry toward a first surface area of the material to be painted that is continuously transported to discontinuously form a first coating part; a first storage tank which stores the first slurry; a first supply pipe 14 which supplies the first slurry from the first storage tank to the first die head; and a first cut-out valve 15 which is arranged in the first supply pipe 14 to be capable of cutting out supply of the first slurry. The first supply pipe 14 includes a region 14a whose inner diameter is approximately the same as an outer diameter of the first cut-out valve 15 in a movable range of the first cut-out valve 15.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a coating device, a method for manufacturing a positive electrode, and a method for manufacturing a solid-state battery. [Background technology]

[0002] In recent years, research and development into batteries that contribute to energy efficiency has been conducted to ensure that many people have access to affordable, reliable, sustainable and advanced energy.

[0003] The battery includes a positive electrode having a positive electrode current collector and a positive electrode composite layer, a negative electrode having a negative electrode current collector and a negative electrode composite layer, and an electrolyte, and a coating device is used when manufacturing the battery.

[0004] Patent Document 1 describes an intermittent coating device in which a liquid storage tank, a liquid delivery pump, and a liquid discharge die are connected in that order by liquid delivery piping, and an intermittent supply valve is provided between the liquid delivery pump and the die. Here, the intermittent supply valve is a two-way valve that starts and stops the supply of coating liquid, and includes a piston with a valve body, a valve seat whose liquid passage is closed by the valve body, and a moving means for moving the piston, and the valve body is attached to the piston so as to be movable in the axial longitudinal direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-38276 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the coating device described in Patent Document 1, when the coating liquid is intermittently discharged from the die, drag occurs at the trailing edge of the discharged coating liquid.

[0007] An object of the present invention is to provide a coating device that can suppress drag at the trailing end of the discharged slurry even when the slurry is discharged intermittently from a die head. [Means for solving the problem]

[0008] (1) A coating device comprising: a conveying section that continuously conveys a sheet-shaped substrate; a first die head that intermittently ejects a first slurry toward a first surface area of ​​the continuously conveyed substrate to intermittently form a first coated area; a first storage section that stores the first slurry; a first supply path that supplies the first slurry from the first storage section to the first die head; and a first shut-off valve provided in the first supply path that can shut off the supply of the first slurry, wherein the first supply path has a region within the movable range of the first shut-off valve whose inner diameter is approximately the same as the outer diameter of the first shut-off valve.

[0009] (2) The coating device according to (1), wherein the first shutoff valve has a slope formed on the outer periphery on the side of the first storage section such that the thickness of the outermost periphery increases.

[0010] (3) The coating device according to (2), wherein the first shutoff valve has a recess formed between an outer periphery on the side of the first storage section and a main body on the side of the first storage section.

[0011] (4) The coating device according to any one of (1) to (3), further comprising a first solenoid valve and a first slurry suction unit connected to the first supply path downstream of the first shut-off valve via the first solenoid valve, and configured to suck in the first slurry.

[0012] (5) A coating device according to any one of (1) to (4), further comprising: a second die head that intermittently ejects a second slurry toward a second surface region of the continuously transported workpiece to intermittently form a second coated portion; a second storage section that stores the second slurry; a second supply path that supplies the second slurry from the second storage section to the second die head; and a second shut-off valve provided in the second supply path that can shut off the supply of the second slurry, wherein the second surface region is downstream of the first surface region, and the second coated portion is formed in an area where the first coated portion is not formed.

[0013] (6) The coating device according to (5), wherein the second supply path has a region in the movable range of the second shutoff valve where the inner diameter is substantially the same as the outer diameter of the second shutoff valve.

[0014] (7) The coating device according to (5) or (6), wherein the second shutoff valve has a slope formed on the outer periphery on the side of the second storage section such that the thickness of the outermost periphery increases.

[0015] (8) The coating device according to any one of (5) to (7), further comprising a second solenoid valve and a second slurry suction unit connected to the second supply path downstream of the second shutoff valve via the second solenoid valve and configured to suck the second slurry.

[0016] (9) A method for producing a positive electrode using the coating device according to any one of (5) to (8), wherein the substrate is a positive electrode current collector, the first slurry is a slurry for a positive electrode composite layer, and the second slurry is a slurry for an insulating layer.

[0017] (10) A method for producing a solid-state battery, comprising the step of obtaining a positive electrode by the method for producing a positive electrode according to (9). [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a coating device that can suppress dragging at the trailing end of the discharged slurry even when the slurry is discharged intermittently from the die head. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a perspective view showing a coating device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the coating device of FIG. 1. [Figure 3] FIG. 2 is a top view illustrating a first coating unit. [Figure 4] FIG. 3 is an enlarged cross-sectional view of the shutoff valve of FIG. 2. [Figure 5] FIG. 10 is a top view showing the drag at the end of the first slurry. [Figure 6] FIG. 2 is a schematic diagram showing the coating device of FIG. 1. [Figure 7] FIG. 2 is a top view illustrating a second coating section. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] [Coating equipment] 1 and 2, the coating device 10 includes a transport roller 11 as a transport section that continuously transports a sheet-like material M to be coated, and a first die head 12 that intermittently discharges a first slurry L1 toward a first surface region S1 of the continuously transported material M to intermittently form first coated regions C1 (see FIG. 3). The first die head 12 extends in the width direction W of the material M to have a slit-shaped first discharge port 12a that discharges the first slurry L1, and discharges the first slurry L1 in a direction approximately perpendicular to the transport direction of the material M in the first surface region S1. The coating device 10 also includes a first storage tank 13 as a first storage section for storing the first slurry L1, a first supply pipe 14 as a first supply path for supplying the first slurry L1 from the first storage tank 13 to the first die head 12, and a first shut-off valve 15 provided in the first supply pipe 14 and capable of shutting off the supply of the first slurry L1.

[0022] As shown in FIG. 4, the first shutoff valve 15 has a truncated conical body on the side of the first storage tank 13, and a slope 15a is formed on the outer periphery on the side of the first storage tank 13, sloping so that the thickness of the outermost periphery increases. That is, a recess is formed between the truncated conical body and the outer periphery where the slope 15a is formed. Furthermore, the first supply pipe 14 has a region 14a within the movable range of the first shutoff valve 15, where the inner diameter is substantially the same as the outer diameter of the first shutoff valve 15. Here, movement A of the first shutoff valve 15 cuts off the supply of the first slurry L1. Furthermore, movement B of the first shutoff valve 15 reduces the internal pressure of the first supply pipe 14, thereby drawing in the first slurry L1 supplied to the first die head 12. This suppresses drag at the end of the first slurry L1 discharged from the first die head 12, resulting in improved shape accuracy of the first coating section C1.

[0023] In this case, the angle of inclination 15a is not particularly limited, but is, for example, greater than 0° and equal to or less than 70°. Note that inclination 15a does not have to be formed on the outer periphery of first shutoff valve 15. In other words, first shutoff valve 15 may have a flat outer periphery.

[0024] The coating speed of the first slurry L1 (the conveying speed of the workpiece M) is not particularly limited, but is, for example, 10 m / min to 60 m / min. The viscosity of the first slurry L1 at 25°C is not particularly limited, but is, for example, 2000 mPa·s to 2500 mPa·s.

[0025] Furthermore, if the movable range of the first shut-off valve 15 of the first supply pipe 14 does not have a region 14a whose inner diameter is approximately the same as the outer diameter of the first shut-off valve 15, drag will occur at the end of the first slurry L1 discharged from the first die head 12 (see Figure 5).

[0026] The first die head 12 is not particularly limited as long as it is capable of intermittently discharging the first slurry L1 to intermittently form the first coated portions C1, and any known die head can be used.

[0027] As shown in FIG. 2, the coating device 10 further includes a first solenoid valve 16 and a chamber 17 as a first slurry suction unit that is connected to the first supply pipe 14 downstream of the first shutoff valve 15 via the first solenoid valve 16 and that sucks in the first slurry L1. When the supply of the first slurry L1 is shut off, if the first solenoid valve 16 is opened, the first slurry L1 is sucked in, and the first slurry L1 supplied to the first die head 12 is further drawn in. When the supply of the first slurry L1 begins, the first solenoid valve 16 is closed. The coating device 10 may be used with the first solenoid valve 16 always closed.

[0028] As shown in FIG. 6, the coating apparatus 10 further includes a second die head 22 that intermittently discharges a second slurry L2 toward a second surface region S2 of the continuously transported workpiece M to intermittently form second coated sections C2 (see FIG. 7). The second die head 22 extends in the width direction W of the workpiece M and has a slit-shaped second discharge port 22a for discharging the second slurry L2. The second slurry L2 is discharged in a direction substantially perpendicular to the transport direction of the workpiece M in the second surface region S2. The second surface region S2 is located downstream of the first surface region S1, and the second coated section C2 is formed in an area where the first coated section C1 is not formed. As a result, the high shape accuracy of the first coated section C1 also increases the shape accuracy of the second coated section C2. The coating device 10 also includes a second storage tank 23 as a second storage section for storing the second slurry L2, a second supply pipe 24 as a second supply path for supplying the second slurry L2 from the second storage tank 23 to the second die head 22, and a second shut-off valve 25 provided in the second supply pipe 24 and capable of shutting off the supply of the second slurry L2.

[0029] Similar to the first shutoff valve 15 (see FIG. 4), the second shutoff valve 25 has a truncated conical body on the second storage tank 23 side, and a slope formed on the outer periphery on the second storage tank 23 side, such that the thickness of the outermost periphery increases. That is, a recess is formed between the truncated conical body and the sloped outer periphery. Similarly to the first supply pipe 14 (see FIG. 4), the second supply pipe 24 has a region within the movable range of the second shutoff valve 25 where the inner diameter is substantially the same as the outer diameter of the second shutoff valve 25. Here, after the supply of the second slurry L2 is cut off as the second shutoff valve 25 moves, the internal pressure of the second supply pipe 24 decreases as the second shutoff valve 25 moves, and the second slurry L2 supplied to the second die head 22 is drawn in. This suppresses drag at the end of the second slurry L2 discharged from the second die head 22, resulting in improved shape accuracy of the second coating section C2.

[0030] The coating speed of the second slurry L2 (the conveying speed of the substrate M) is not particularly limited, but is, for example, 10 m / min to 60 m / min. Furthermore, the viscosity of the second slurry L2 at 25°C is not particularly limited, but is, for example, 2000 mPa·s to 2500 mPa·s.

[0031] The second die head 22 is not particularly limited as long as it is capable of intermittently discharging the second slurry L2 to intermittently form the second coated portions C2, and any known die head can be used.

[0032] The coating device 10 further includes a second solenoid valve 26 and a chamber 27 connected via the second solenoid valve 26 to the second supply pipe 24 downstream of the second shutoff valve 25, serving as a second slurry suction unit for sucking the second slurry. When the second solenoid valve 26 is opened at the timing when the supply of the second slurry L2 is shut off, the second slurry L2 is sucked in, and the second slurry L2 supplied to the second die head 22 is further drawn in. When the supply of the second slurry L2 starts, the second solenoid valve 26 is closed. The coating device 10 may be used with the second solenoid valve 26 constantly closed.

[0033] If necessary, second supply pipe 24 may not have a region in the movable range of second shutoff valve 25 where the inner diameter is substantially the same as the outer diameter of second shutoff valve 25. Furthermore, second shutoff valve 25 may not have a slope formed on its outer periphery, and second die head 22, second storage tank 23, second supply pipe 24, and second shutoff valve 25 may be omitted.

[0034] Furthermore, the coating device 10 does not necessarily have to include the second die head 22, the second storage tank 23, the second supply pipe 24, the second shutoff valve 25, the second solenoid valve 26, and the chamber 27. In other words, the coating device 10 may be a device that coats only the first slurry L1.

[0035] [Coating method] The coating method of this embodiment includes a step of using a coating device 10 to continuously transport a sheet-shaped substrate M, and intermittently ejecting a first slurry L1 from a first die head 12 toward a first surface region S1 of the continuously transported substrate M to intermittently form a first coated portion C1.

[0036] The coating method of this embodiment may further include a step of using the coating device 10 to intermittently eject a second slurry L2 from the second die head 22 toward a second surface region S2 of the continuously transported workpiece M to intermittently form a second coating section C2.

[0037] The coating method of this embodiment may further include a step of heating and drying the workpiece M on which the first coated portion C1 (and the second coated portion C2) have been formed.

[0038] The coating method of this embodiment can be applied to, for example, the production of a positive electrode, a negative electrode, and a solid electrolyte layer that constitute a battery.

[0039] [Cathode manufacturing method] The positive electrode manufacturing method of this embodiment is a method for manufacturing a positive electrode by the coating method of this embodiment. Here, the coating material M is a positive electrode current collector, the first slurry is a slurry for a positive electrode composite layer, and the second slurry is a slurry for an insulating layer. Therefore, a positive electrode with high shape accuracy of the positive electrode composite layer and the insulating layer can be obtained.

[0040] The positive electrode current collector is not particularly limited, but may be, for example, aluminum foil.

[0041] The positive electrode mixture layer slurry contains, for example, a positive electrode active material. The positive electrode active material is not particularly limited, but may be, for example, lithium iron phosphate.

[0042] The insulating layer slurry contains an insulating material, which is not particularly limited, but may be, for example, alumina.

[0043] The method for manufacturing a positive electrode according to the present embodiment may further include a step of continuously forming second insulating layers on both sides of the positive electrode composite layer in the width direction W. In this case, the second insulating layers may also be formed when the positive electrode composite layer is formed.

[0044] [Solid-state battery manufacturing method] The method for manufacturing a solid-state battery of this embodiment includes a step of obtaining a positive electrode by the method for manufacturing a positive electrode of this embodiment, which prevents short circuits in the solid-state battery.

[0045] The method for manufacturing a solid state battery of this embodiment may further include a step of forming a solid electrolyte layer on the positive electrode mixture layer to form a positive electrode-solid electrolyte layer stack.

[0046] The solid-state battery is not particularly limited, but may be, for example, an all-solid-state lithium metal battery, which will be described below.

[0047] The all-solid-state lithium metal battery includes a negative electrode having a negative electrode current collector and a lithium metal layer, a positive electrode having a positive electrode current collector and a positive electrode mixture layer, and a solid electrolyte layer.

[0048] The negative electrode current collector is not particularly limited, but may be, for example, copper foil.

[0049] The positive electrode composite layer includes a positive electrode active material and may further include a solid electrolyte, a conductive additive, a binder, etc. The positive electrode active material is not particularly limited as long as it is capable of absorbing and releasing lithium ions, and examples thereof include lithium nickel cobalt manganese composite oxide. The solid electrolyte is not particularly limited as long as it has lithium ion conductivity, and examples thereof include oxide-based electrolytes and sulfide-based electrolytes. The conductive additive is not particularly limited as long as it has electronic conductivity, and examples thereof include carbon black. The binder is not particularly limited as long as it can improve binding properties, and examples thereof include styrene butadiene rubber.

[0050] The positive electrode current collector is not particularly limited, but may be, for example, aluminum foil.

[0051] The solid electrolyte layer includes a solid electrolyte and may further include a binder, etc. The solid electrolyte is not particularly limited as long as it has lithium ion conductivity, and examples thereof include inorganic solid electrolytes such as oxide-based electrolytes and sulfide-based electrolytes. The binder is not particularly limited as long as it can improve binding properties, and examples thereof include styrene butadiene rubber.

[0052] An intermediate layer having the function of uniformly depositing lithium metal may be formed between the negative electrode and the solid electrolyte layer. This stabilizes the interface between the intermediate layer and the solid electrolyte layer. In this case, the all-solid-state lithium metal battery may be an anode-free battery in which a lithium metal layer is not formed at the time of initial charge. In the anode-free battery, a lithium metal layer is formed after the initial charge / discharge.

[0053] The intermediate layer contains a metal capable of alloying with lithium and amorphous carbon, and may further contain a binder, etc. The metal capable of alloying with lithium and amorphous carbon are preferably nanoparticles. Examples of metals capable of alloying with lithium include tin (Sn), silicon (Si), zinc (Zn), magnesium (Mg), gold (Au), platinum (Pt), palladium (Pd), silver (Ag), aluminum (Al), bismuth (Bi), and antimony (Sb). Examples of amorphous carbon include carbon blacks such as acetylene black, furnace black, and ketjen black, as well as coke and activated carbon. The amorphous carbon may be graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), CNT (carbon nanotube), fullerene, or graphene. The binder is not particularly limited as long as it can improve binding properties, and examples include polyvinylidene fluoride (PVDF).

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the above-described embodiments may be modified as appropriate within the scope of the spirit of the present invention. [Example]

[0055] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0056] [Example 1] Using coating device 10 (see FIG. 1), a positive electrode composite layer was intermittently formed on a positive electrode current collector. Specifically, while continuously conveying aluminum foil (positive electrode current collector) as a coating material M, a positive electrode composite layer slurry (first slurry L1) was intermittently discharged from first die head 12 (see FIG. 2) toward first surface region S1 of the continuously conveyed coating material M to intermittently form a positive electrode composite layer (first coating section C1). During this operation, coating device 10 was used with first solenoid valve 16 constantly closed. Here, the inclination angle of inclined plane 15a formed on the outer periphery of first shutoff valve 15 was set to 64°. In addition, the slurry for the positive electrode composite layer contained lithium iron phosphate as a positive electrode active material and had a viscosity of 2000 mPa·s or more and 2500 mPa·s or less at 25°C, and the coating speed of the first slurry L1 (the conveying speed of the substrate M) was 60 m / min.

[0057] [Comparative Example 1] The inner diameter of region 14a of first supply pipe 14 was made smaller than the outer diameter of first shutoff valve 15, i.e., region 14a of first supply pipe 14 was not set as the range of movement of first shutoff valve 15. Except for this, a positive electrode composite layer was intermittently formed on the positive electrode current collector in the same manner as in Example 1.

[0058] [Drag] The drag at the end of the discharged first slurry L1 was measured.

[0059] Table 1 shows the drag evaluation results.

[0060] [Table 1]

[0061] From Table 1, it can be seen that in Example 1, dragging at the end of the discharged first slurry L1 is suppressed. [Explanation of symbols]

[0062] 10 Coating device 11 Conveyor roller 12 First die head 12a 1st outlet 13 First Storage Tank 14 1st supply piping 14a area 15 First shutoff valve 15a slope 16 First solenoid valve 17 Chamber 22 No. 2 die head 22a 2nd outlet 23 Second storage tank 24 2nd supply piping 25 Second shutoff valve 26 Second solenoid valve 27 Chamber C1 1st Coating Department C2 2nd Coating Department L1 First slurry L2 Second slurry M Covered material S1 1st surface area S2 2nd surface area W width direction

Claims

1. A conveying unit that continuously conveys a sheet-shaped material to be coated; a first die head that intermittently ejects a first slurry toward a first surface region of the continuously transported workpiece to intermittently form a first coated portion; a first storage unit that stores the first slurry; a first supply path that supplies the first slurry from the first storage portion to the first die head; a first shutoff valve provided in the first supply path and capable of shutting off the supply of the first slurry; the first supply path has a region in a movable range of the first shutoff valve where the inner diameter is substantially the same as the outer diameter of the first shutoff valve.

2. The coating device according to claim 1 , wherein the first shutoff valve has an outer periphery on the side of the first storage section that is tapered so that the thickness of the outermost periphery becomes larger.

3. The coating device according to claim 2 , wherein the first shutoff valve has a recess formed between an outer periphery on the side of the first storage portion and a main body on the side of the first storage portion.

4. A first solenoid valve; 4. The coating device according to claim 1, further comprising: a first slurry suction unit connected to the first supply path downstream of the first shutoff valve via the first solenoid valve, and configured to suck the first slurry.

5. a second die head that intermittently ejects a second slurry toward a second surface region of the continuously transported workpiece to intermittently form a second coated portion; a second storage section that stores the second slurry; a second supply path that supplies the second slurry from the second storage portion to the second die head; a second shutoff valve provided in the second supply line and capable of shutting off the supply of the second slurry; the second surface region is downstream of the first surface region; The coating device according to claim 1 , wherein the second coated portion is formed in an area where the first coated portion is not formed.

6. The coating device according to claim 5 , wherein the second supply path has a region in a movable range of the second shutoff valve, the region having an inner diameter substantially equal to an outer diameter of the second shutoff valve.

7. The coating device according to claim 5 , wherein the second shutoff valve has an outer periphery on the second storage section side that is tapered so that the thickness of the outermost periphery becomes larger.

8. A second solenoid valve; 6. The coating device according to claim 5, further comprising: a second slurry suction unit connected to the second supply path downstream of the second shutoff valve via the second solenoid valve, and configured to suck the second slurry.

9. A method for producing a positive electrode using the coating device according to claim 5, The substrate is a positive electrode current collector, the first slurry is a slurry for a positive electrode composite layer, The method for manufacturing a positive electrode, wherein the second slurry is a slurry for an insulating layer.

10. A method for producing a solid-state battery, comprising the step of obtaining a positive electrode by the method for producing a positive electrode according to claim 9.

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