Conveyor

Abstract

To provide a conveyance device which can convey wet powder while suppressing sticking of the wet powder.SOLUTION: A conveyance device used in conveyance of wet powder containing at least an active material, a binder and a liquid component comprises: a hopper having a storage part for storing the wet powder and a discharge port for discharging the wet powder; a conveyance member which has a main surface arranged so as to be opposed via a gap to the discharge port in the hopper and conveys the wet powder discharged from the hopper; and a vibration member which applies vibration to the conveyance member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a transport device. [Background technology]

[0002] In battery manufacturing, it is known to transport powdered materials to processing equipment. For example, Patent Document 1 discloses an apparatus that uses a screw feeder to transport powder from a hopper to a powder container. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-007717 Summary of the Invention [Problem to be solved by the invention]

[0004] In the manufacture of batteries, powder (wet powder) containing a liquid component such as a solvent may be conveyed. As will be described in detail later, when conveying the wet powder using a screw feeder such as that disclosed in Patent Document 1, there is a risk that the wet powder will stick to the conveying member.

[0005] The present disclosure has been made in consideration of the above-described circumstances, and has as its main object to provide a conveying device that can convey wet powder while suppressing adhesion of the wet powder. [Means for solving the problem]

[0006] [1] A conveying device used for conveying a wet powder containing at least an active material, a binder, and a liquid component, the conveying device comprising: a hopper having a storage section for storing the wet powder and a discharge outlet for discharging the wet powder; a conveying member having a main surface arranged opposite the discharge outlet of the hopper via a gap, and for conveying the wet powder discharged from the hopper; and a vibrating member for imparting vibrations to the conveying member.

[0007] [2] The conveying device according to [1], wherein the gap is 1 mm or more and 10 mm or less.

[0008] [3] The conveying device according to [1] or [2], wherein the conveying member is a plate-shaped member.

[0009] [4] The conveying device according to any one of [1] to [3], wherein the conveying member has a guide wall for conveying the wet powder. [Effects of the Invention]

[0010] The present disclosure provides an effect of being able to transport the wet powder while suppressing adhesion of the wet powder. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view illustrating a conveying device according to the present disclosure. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating a conventional conveying device. [Figure 3] FIG. 2 is a schematic perspective view illustrating a conveying member according to the present disclosure. [Figure 4] FIG. 10 is a diagram showing the results of an experimental example. DETAILED DESCRIPTION OF THE INVENTION

[0012] The conveying device according to the present disclosure will be described in detail below.

[0013] Fig. 1 is a schematic cross-sectional view illustrating a conveying device according to the present disclosure. The conveying device 100 shown in Fig. 1 is used to convey a wet powder 1 containing at least an active material and a binder. The conveying device 100 includes a hopper 10 having a storage section 11 for storing the wet powder 1 and a discharge outlet 12 for discharging the wet powder 1. The conveying device 100 also includes a main surface section 21 arranged to face the discharge outlet 12 of the hopper 10 across a gap, and a conveying member 20 for conveying the wet powder 1 discharged from the hopper 10. The conveying device 100 also includes a vibrating member 30 that applies vibrations to the conveying member 20.

[0014] According to the present disclosure, a conveying device is provided that can convey wet powder while suppressing adhesion by applying vibrations to a conveying member having a main surface portion using a vibrating member. Here, a known method for manufacturing electrodes for batteries involves, for example, forming a slurry of an active material and a binder using a solvent (dispersion medium), applying the slurry to a current collector, drying it, and then pressing it. Another known method is moisture powder sheeting (MPS), which involves adding a small amount of liquid to a powder material containing an active material and a binder to produce granules (wet powder), and then pressing the granules onto a current collector to form an electrode. MPS has the advantage of requiring less time to dry the electrode than methods using a slurry because it requires a smaller amount of solvent.

[0015] As shown in FIG. 2, a conveying device equipped with a screw feeder is known as a powder conveying device. The conveying device 200 shown in FIG. 2 includes a hopper 210 that stores and discharges powder 201, and a screw feeder 220 having a rotating shaft 222 and a screw portion 223 disposed inside a cylindrical member 221. When using such a conveying device, the conveyed wet powder is subjected to a compressive force between the screw portion of the screw feeder and the inner wall of the cylindrical member. In particular, wet powder containing a liquid component is more likely to agglomerate than dry powder when compressed, and is more likely to adhere to the conveying member (the inner wall and screw portion of the cylindrical member). If the wet powder adheres to the conveying member, material loss may occur or the conveying member may become clogged.

[0016] In contrast, the conveying device of the present disclosure has a conveying member having a main surface disposed opposite the discharge outlet of the hopper, and vibration is applied to this conveying member, so that no compressive force is applied to the wet powder during conveyance, and as a result, the wet powder can be conveyed while suppressing adhesion of the wet powder.

[0017] 1. Hopper The hopper according to the present disclosure has a storage section for storing the wet powder and a discharge port for discharging the wet powder. As shown in Fig. 1, the discharge port is preferably located below the storage section in the direction of gravity. This is because the wet powder in the storage section is discharged from the discharge port due to its own weight.

[0018] As shown in Fig. 1, the discharge port of the hopper is usually configured to discharge the wet powder toward the conveying member. The shape of the discharge port is not particularly limited.

[0019] The wet powder stored and discharged by the hopper contains at least an active material, a binder, and a liquid component. The wet powder may also contain a conductive material. The active material may be a positive electrode active material or a negative electrode active material. Examples of positive electrode active materials include oxide active materials such as rock salt layer-type active materials. Examples of negative electrode active materials include metal active materials such as Si. Examples of binders include fluorine-containing binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), rubber-based binders such as butadiene rubber, and acrylic-based binders. Examples of conductive materials include carbon materials, metal particles, and conductive polymers.

[0020] The liquid component is not particularly limited, but examples thereof include water and organic solvents such as butyl butyrate, diisobutyl ketone, and xylene. The wet powder may also contain a liquid that dissolves the binder as the liquid component. Examples of methods for producing the wet powder include a method of kneading a mixture containing an active material, a binder, and a liquid component.

[0021] The proportion of solids such as the active material in the wet powder is, for example, 60% by weight or more, and may be 70% by weight or more, while the proportion of solids is, for example, 90% by weight or less.

[0022] Furthermore, in the conveying device of the present disclosure, there is a gap (distance D from the discharge outlet 12 to the conveying member 20 shown in FIG. 1) between the discharge outlet of the hopper described above and the conveying member described below. The distance from the discharge outlet to the conveying member is, for example, 1 mm or more. If the distance is less than 1 mm, there is a risk of interference between the hopper (discharge outlet) and the conveying path. The distance may be 2 mm or more, 3 mm or more, or 5 mm or more. On the other hand, the distance may be, for example, 10 mm or less, 8 mm or less, or 6 mm or less.

[0023] 2.Transportation components The conveying member according to the present disclosure has a main surface portion disposed opposite to the discharge outlet of the hopper with a gap therebetween, and is a member for conveying the wet powder discharged from the hopper.

[0024] As shown in FIG. 1, the conveying member is preferably disposed below the discharge opening of the hopper in the direction of gravity.

[0025] The shape of the main surface of the transport member may be flat or curved. The main surface may have a predetermined surface roughness (Ra). Ra is, for example, 0.1 μm or more and 5 μm or less.

[0026] As shown in FIG. 3(a), the conveying member may be a plate-like member. The plate-like member has a top surface, a bottom surface opposite the top surface, and four side surfaces (first, second, third, and fourth side surfaces) connecting the top and bottom surfaces. In FIG. 3(a), the main surface portion 21 is the top surface. On the other hand, as shown in FIG. 3(b), the conveying member may be a cylindrical member having a main surface portion and a bent portion. In this case, the conveying member may be a so-called belt conveyor having a rotating shaft 40 inside the cylinder. Although not shown, the conveying member may have a guide wall for conveying the wet powder. The guide wall is preferably arranged, for example, at the end of the main surface portion and extends along the conveying direction of the wet powder.

[0027] The material of the conveying member is not particularly limited. When the conveying member is a plate-shaped member, the material of the conveying member can be, for example, a metal such as SUS. When the conveying member is a cylindrical member, the material of the conveying member can be, for example, a resin such as rubber.

[0028] As shown in Fig. 1, the conveying member in the conveying device may be arranged so that the main surface is horizontal, or alternatively, the conveying member in the conveying device may be arranged at an angle.

[0029] 3. Vibration member The vibrating member in the present disclosure applies vibration to the conveying member.

[0030] The type of the vibrating member is not particularly limited, but examples thereof include a piezoelectric element such as a piezoelectric ceramic and a motor. The position of the vibrating member in the conveying device is not particularly limited, but it is preferably located below the conveying member.

[0031] The vibration applied by the vibrating member is not particularly limited. The frequency of the vibration is, for example, 50 Hz or more, and may be 100 Hz or more. On the other hand, the frequency of the vibration is, for example, 500 Hz or less, and may be 300 Hz or less.

[0032] 4.Transportation equipment The conveying device in the present disclosure is typically used in the manufacture of electrode layers for batteries. The electrode layer may be a positive electrode active material layer, a negative electrode active material layer, or an electrolyte layer. Examples of the battery include a Li-ion battery. The battery may also be a liquid-based battery in which the electrolyte layer contains a liquid electrolyte (electrolytic solution). Applications of the battery are not particularly limited, and examples include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, the battery is preferably used as a driving power source for hybrid electric vehicles, plug-in hybrid electric vehicles, or electric vehicles. The battery may also be used as a power source for mobile objects other than vehicles (e.g., trains, ships, and aircraft), or as a power source for electrical appliances such as information processing devices.

[0033] The present disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and any configuration that is substantially identical to the technical idea described in the claims of the present disclosure and that provides similar effects is included within the technical scope of the present disclosure. [Example]

[0034] [Experimental Example] The following experiment was conducted to confirm the conditions under which the wet powder would adhere. Wet powder containing a binder solution was placed on a SUS plate (surface roughness: 1.6 μm). Various compressive forces were applied to the placed wet powder. The adhesion force (the force per unit area bonding between the wet powder and the SUS plate) was measured, and the relationship with the applied compressive force was confirmed. The results are shown in Figure 4. Note that when the adhesion force is 4 kPa or greater, the wet powder is unlikely to peel off from the SUS plate due to its own weight, and therefore it can be determined that the wet powder has adhered to the SUS plate.

[0035] As shown in Figure 4, it was confirmed that the wet powder adhered to the SUS plate when a compressive force of 0.15 MPa or more was applied. It is extremely difficult to apply a compressive force of 0.15 MPa or less to the wet powder when a screw feeder is used. On the other hand, by using a conveying member as disclosed herein, the wet powder can be conveyed without applying a compressive force to the wet powder. This suggests that the conveying device disclosed herein can convey the wet powder while suppressing adhesion. [Explanation of symbols]

[0036] 1...Wet powder 10...Hopper 11...Storage section 12...Exhaust port 20...Transport member 21…Main surface part 30...Vibration member 100...Transportation device

Claims

1. A conveying device used to convey a wet powder containing at least an active material, a binder, and a liquid component, a hopper having a storage portion for storing the wet powder and a discharge port for discharging the wet powder; a conveying member for conveying the wet powder discharged from the hopper; a vibration member that applies vibration to the conveying member, the conveying member is disposed to face the discharge port of the hopper with a gap therebetween, and has a main surface portion which is a surface on a side that comes into contact with the wet powder, A conveying device, wherein the wet powder has a solid content of less than 90% by weight.

2. The conveying device according to claim 1 , wherein the gap is equal to or greater than 1 mm and equal to or less than 10 mm.

3. 3. The conveying device according to claim 1, wherein the conveying member is a plate-like member.

4. the conveying member has a guide wall for conveying the wet powder, 3. The conveying device according to claim 1, wherein the guide wall is disposed at an end of the main surface portion and extends along the conveying direction of the wet powder.

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