Powder adjustment unit

Abstract

To provide a powder adjustment unit capable of forming a powder layer with less variation in weight.SOLUTION: The powder adjustment unit includes: a squeegee 3; a first vibrator 1 placed on one end of the squeegee 3 and excites a wave to the one end; and a second vibrator 2 on the other end of the squeegee 3 to excite waves on the other end. By making the phase of the first vibrator 1 and the second vibrator 2 different, the squeegee 3 vibrates by a traveling wave moving from one end to the other end or vibrates by a traveling wave moving from one end to the other end.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a powder adjustment unit.

Background Art

[0002] In recent years, a dry coating method of directly coating powder has attracted attention as a method capable of forming a powder layer with high performance and low environmental impact compared to a wet coating method of dispersing powder in a solvent and then coating. According to the dry coating method, (i) damage to the powder by the solvent is small and high performance can be maintained, and (ii) a powder layer can be obtained in which it is not necessary to dry the solvent and the amount of energy consumed can be significantly reduced.

[0003] As a method of dry coating powder, conventionally, a technique of coating powder on the surface of a substrate such as a metal foil while transporting the substrate by a transport device is known.

[0004] For example, Patent Document 1 discloses a technique of coating powder on the surface of a long metal foil. Patent Document 1 describes that after supplying powder onto the surface of a metal foil, the thickness of the powder is uniformly adjusted by flattening it with a squeegee that vibrates the powder. In the present disclosure, a mechanism that includes a squeegee and levels the powder supplied onto a substrate such as a metal foil to adjust the amount of powder is referred to as a powder adjustment unit.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in a powder layer formed by a dry coating method, in order to improve the quality of the powder layer, uniformity of the basis weight may be required in some cases.

[0007] Therefore, an object of the present disclosure is to provide a powder adjusting unit capable of forming a powder layer with suppressed basis weight variation. **Means for Solving the Problems**

[0008] A powder adjusting unit according to an aspect of the present disclosure includes a squeegee, a first vibrator disposed at one end of the squeegee for exciting waves at the one end, and a second vibrator disposed at the other end of the squeegee for exciting waves at the other end. By making the phases of the first vibrator and the second vibrator different, the squeegee vibrates by a traveling wave traveling from the one end to the other end, or vibrates by a traveling wave traveling from the other end to the one end. **Advantages of the Invention**

[0009] According to a powder adjusting unit according to an aspect of the present disclosure, a powder layer with suppressed basis weight variation can be formed. **Brief Description of the Drawings**

[0010]

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

[0011] (Background Leading to an Aspect of the Present Disclosure) First, the inventors will explain the background leading to an aspect of the present disclosure with reference to FIGS. 1 to 2B.

[0012] FIG. 1 is a diagram showing an example of a powder coating apparatus 30. FIG. 2A is a diagram showing the vibration of a squeegee 23 when viewed from the front in the advancing direction of a sheet 25, which is provided in the powder coating apparatus 30 shown in FIG. 1. FIG. 2B is a diagram showing the case where a powder layer 28 coated by the powder coating apparatus 30 shown in FIG. 1 is viewed from the front. Further, in FIG. 2A, when the squeegee 23 is viewed from the front, a vibration waveform in the case where the squeegee 23 resonates (vibrates at its natural frequency) with a sinusoidal stationary wave is schematically shown.

[0013] As shown in FIG. 1, the squeegee 23 levels the powder 24 supplied onto the sheet 25 while vibrating at a high frequency in the vicinity of the ultrasonic band (for example, a frequency of 2 kHz or more and 300 kHz) by a vibration generator such as a vibrator (not shown) to form a powder layer 28. In the powder coating apparatus 30, for example, as the sheet 25 moves in the direction indicated by the white arrow, the powder 24 passes through the gap between the sheet 25 and the squeegee 23, and the powder layer 28 is formed. At this time, the vibration of the squeegee 23 is transmitted to the powder 24, and by improving the fluidity of the powder 24, coating with suppression of powder clogging is realized.

[0014] Further, as shown in FIG. 2A, when the squeegee 23 is vibrated at a high frequency, the squeegee 23 vibrates in a sinusoidal stationary wave due to resonance (natural vibration). Therefore, as shown in FIG. 2B, an uneven structure scraped in a sinusoidal stationary wave shape is formed on the surface of the powder layer 28 that has passed through the gap between the sheet 25 and the squeegee 23. As a result, in the powder layer 28, the variation in basis weight becomes large.

[0015] From the above, the inventors focused on the fact that when the squeegee 23 is vibrated to improve the fluidity of the powder 24 in the formation of the powder layer 28, a large variation in the basis weight of the powder layer 28 occurs due to the vibration of the squeegee 23, and a low-quality powder layer 28 is formed.

[0016] Therefore, in the present disclosure, even when the squeegee 23 is vibrated, a powder adjusting unit or the like that can form a powder layer 28 with suppressed basis weight variation is provided.

[0017] (Summary of the Present Disclosure) Examples of the powder adjusting unit and the powder coating apparatus according to the present disclosure are shown below.

[0018] The powder adjusting unit according to the first aspect of the present disclosure is a powder adjusting unit that adjusts the amount of powder by leveling the powder supplied onto a substrate, and includes a squeegee, a first vibrator disposed at one end of the squeegee and exciting a wave at one end, and a second vibrator disposed at the other end of the squeegee and exciting a wave at the other end. By making the phases of the first vibrator and the second vibrator different, the squeegee vibrates by a traveling wave traveling from one end to the other end, or vibrates by a traveling wave traveling from the other end to one end.

[0019] Therefore, it becomes difficult for nodes and antinodes of vibration, such as a sinusoidal standing wave, to occur in the squeegee. Thus, unevenness due to the vibration of the squeegee is less likely to occur in the powder layer formed by leveling the powder, and a powder layer with reduced basis weight variation can be formed.

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0021] Note that each of the embodiments described below shows comprehensive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps (processes), the order of steps (processes), etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. In addition, among the components in the following embodiments, the components not described in the independent claims are described as optional components.

[0022] In addition, in this specification, terms indicating the relationship between elements such as parallel, terms indicating the shape of elements such as rectangular, and numerical ranges are not expressions representing only a strict meaning, but are expressions meaning substantially equivalent ranges, for example, including differences of about several percent.

[0023] Also, each figure is a schematic diagram that has been appropriately emphasized, omitted, or adjusted in ratio to show the present disclosure, and is not necessarily drawn precisely, and may be different from the actual shape, positional relationship, and ratio. In each figure, the same reference numerals are given to substantially the same configurations, and duplicate explanations may be omitted or simplified.

[0024] (Embodiment) Hereinafter, the embodiments will be described with reference to FIGS. 3 and 4.

[0025] [Powder adjustment unit 11] First, the powder adjustment unit 11 according to the present embodiment will be described with reference to FIGS. 3 and 4.

[0026] FIG. 3 is a perspective view showing the powder adjustment unit 11 according to the present embodiment. FIG. 4 is a view showing the powder adjustment unit 11 according to the present embodiment as seen from the front. In FIG. 4, when the squeegee 3 is seen from the front, the vibration waveform when the squeegee 3 vibrates with a progressive wave is schematically shown. Also, in FIG. 4, the case where the squeegee 3 is seen from the front means the case where it is seen from the front in the relative movement direction of the powder 4 with respect to the squeegee 3.

[0027] As shown in FIGS. 3 and 4, the powder adjustment unit 11 includes a squeegee 3, a first vibrator 1 disposed at one end of the squeegee 3 in a predetermined direction and exciting waves at the one end, and a second vibrator 2 disposed at the other end of the squeegee 3 in a predetermined direction and exciting waves at the other end. In the present embodiment, the case where a standing wave is used as an example of the wave to be excited is illustrated. Note that the wave to be excited is not limited to a standing wave.

[0028] Further, the powder adjustment unit 11 includes a function generator 9. The sine wave signal generated by the function generator 9 is amplified by the first amplifier 6 and causes the first vibrator 1 to vibrate.

[0029] On the other hand, the sine wave signal with the same frequency (same wavelength) and a shifted phase generated by the function generator 9 is amplified by the second amplifier 7 and causes the second vibrator 2 to vibrate. As a result, the first vibrator 1 and the second vibrator 2 vibrate with sine wave signals that have the same frequency (wavelength) but different phases. The squeegee 3 is excited by the first vibrator 1 and the second vibrator 2. By making the phases of the vibration of the first vibrator 1 and the vibration of the second vibrator 2 different, the squeegee 3 vibrates due to a traveling wave traveling from one end to the other end, or vibrates due to a traveling wave traveling from the other end to one end.

[0030] As a method of sending sine wave signals with the same wavelength (same frequency) and the same amplitude but with different phases between the vibration of the first vibrator 1 and the vibration of the second vibrator 2 to the first vibrator 1 and the second vibrator 2, a method using a function generator 9 having two-channel output terminals and a function of making the phases different has been described, but it is not limited to this method.

[0031] The powder adjustment unit 11 levels the powder 4 supplied onto the sheet 5 using the squeegee 3, thereby adjusting the amount of the powder 4 on the sheet 5 to form a powder layer 8.

[0032] In the present embodiment, the squeegee 3 is elongated, and the first vibrator 1 is disposed at one end of the squeegee 3 in the longitudinal direction, and the second vibrator 2 is disposed at the other end of the squeegee 3 in the longitudinal direction. In this specification, the "end portion" of the squeegee 3 does not mean only the tip of the squeegee 3 in a certain direction, but means a portion within a predetermined range from the tip of the squeegee 3 in a certain direction. Specifically, in the present embodiment, the "end portion" is a portion outside the region through which the powder 4 passes in the squeegee 3. Further, the "end portion" may be a portion within a range of 25% or less of the length of the squeegee 3 in a certain direction from the tip of the squeegee 3 in a certain direction. In this specification, "elongated" means that the length in a certain direction is twice or more the length in any direction orthogonal to the certain direction.

[0033] The squeegee 3 is vibrated by a traveling wave traveling from one end of the squeegee 3 to the other end by the first vibrator 1 and the second vibrator 2. Also, the direction of the traveling wave may be reversed. Therefore, the position where the amplitude is maximized in the squeegee 3 moves over time. As shown in FIGS. 3 and 4, the traveling wave travels in the longitudinal direction of the squeegee 3. When forming the powder layer 8, the longitudinal direction of the squeegee 3 is, for example, a direction intersecting (specifically, orthogonal) the relative traveling direction of the squeegee 3 with respect to the sheet 5 in a top view of the sheet 5. That is, in the squeegee 3, the traveling direction of the traveling wave intersects (specifically, is orthogonal) the relative traveling direction of the squeegee 3 with respect to the sheet 5.

[0034] The powder 4 is supplied onto the sheet 5 which is a sheet-like member. Then, by moving the powder adjusting unit 11, the film thickness and the filling rate of the powder 4 are adjusted using the squeegee 3, and a powder layer 8 with a desired powder amount (hereinafter, basis weight) and reduced basis weight variation is formed while making the powder 4 into a desired powder amount. In the present embodiment, the sheet 5 is an example of a base material.

[0035] Here, the basis weight is a value indicating the powder amount per unit area in terms of weight, and the unit of the basis weight is, for example, g / cm 2 as shown.

[0036] In the formation of the powder layer 8, it is only necessary that the squeegee 3 and the powder 4 move relative to each other. The powder adjustment unit 11 may be fixed, and the sheet 5 and the mask may be moved. Also, in the formation of the powder layer 8, both the powder adjustment unit 11 and the sheet 5 and the mask may be moved. Further, the means for moving these is not particularly limited, and a driving device may be used or it may be manual.

[0037] In the formation of the powder layer 8, a predetermined gap is formed between the squeegee 3 and the sheet 5. The powder 4 supplied onto the sheet 5 passes through this gap. When the powder 4 passes through the gap, the squeegee 3 adjusts the film thickness and the filling rate of the powder 4 supplied to the surface of the sheet 5, and reduces the variation in the basis weight of the powder layer 8.

[0038] In the present embodiment, the sheet 5 is, for example, a current collector including a metal foil, but the material and shape of the base material onto which the powder 4 is supplied are not particularly limited.

[0039] The powder 4 may be any powdery substance. That is, the raw material of the powder 4, the composition of the powder 4, and the particle shape of the powder 4 are not particularly limited. In the present embodiment, the powder 4 is a particle group containing at least one of an active material and a solid electrolyte.

[0040] The particle diameter (D50) of the powder 4 is, for example, 0.005 μm or more and 30 μm or less. When the particle diameter of the powder 4 becomes small, the fluidity of the powder 4 tends to decrease, but the fluidity of the powder 4 is promoted by the vibration of the squeegee 3. Therefore, since the retention and aggregation of the powder 4 are suppressed, a powder layer 8 with little variation in basis weight can be formed. Here, the particle diameter (D50) is the volume-based median diameter calculated from the measured values of the particle size distribution by the laser diffraction / scattering method or the like. This particle diameter (D50) can be measured using a commercially available laser analysis / scattering type particle size distribution measuring device.

[0041] Also, the powder 4 may contain only one type of powder or may contain two or more types of powders.

[0042] Hereinafter, the details of the squeegee 3, the first vibrator 1, and the second vibrator 2 will be described.

[0043] [Squeegee 3, First Vibrator 1, and Second Vibrator 2] The squeegee 3 vibrates by the first vibrator 1 and the second vibrator 2. Therefore, nodes and antinodes do not occur even when the squeegee 3 vibrates as in the case where the squeegee 3 vibrates with a sinusoidal stationary wave. That is, the positions where the amplitude becomes maximum and minimum in the squeegee 3 change. Thus, even when the squeegee 3 vibrates, variation in basis weight due to nodes and antinodes does not occur, so that a powder layer 8 with little variation in basis weight in the coating width direction can be formed. In this specification, the coating width direction of the powder layer 8 may be simply referred to as the "width direction".

[0044] Hereinafter, the details of the generation of a traveling wave in the squeegee 3 will be described.

[0045] As described above, the first vibrator 1 is disposed at one end of the squeegee 3, and the first vibrator 1 is connected to the squeegee 3. Further, the second vibrator 2 is disposed at the other end of the squeegee 3, and the second vibrator 2 is connected to the squeegee 3. In other words, the first vibrator 1 is attached to one end of the squeegee 3 in the longitudinal direction of the squeegee 3, and the second vibrator 2 is attached to the other end of the squeegee 3 in the longitudinal direction of the squeegee 3. The first vibrator 1 and the second vibrator 2 are excitation vibrators that apply an excitation force for vibrating the squeegee 3 with stationary waves having different phases.

[0046] The sine wave signal generated from the function generator 9 is amplified by the first amplifier 6 and vibrates the first vibrator 1. That is, the function generator 9 vibrates the first vibrator 1 with a sine wave.

[0047] On the one hand, sine waves of the same frequency (same wavelength) with a phase shift are amplified by the second amplifier 7 and cause the second vibrator 2 to vibrate. That is, the function generator 9 causes the second vibrator 2 to vibrate with a sine wave that has a phase shift relative to the sine wave that causes the first vibrator 1 to vibrate. In other words, the function generator 9 causes the first vibrator 1 and the second vibrator 2 to vibrate with signals that are sine waves of the same frequency (wavelength) but have a phase shift relative to each other. As a result, a traveling wave is generated in the squeegee 3. Specifically, while the first vibrator 1 vibrates the squeegee 3 with a sine wave, the second vibrator 2 vibrates the squeegee 3 with a sine wave that has a phase shift, so that the squeegee 3 vibrates due to a traveling wave that travels from one end to the other end, or vibrates due to a traveling wave that travels from the other end to one end.

[0048] The length of the squeegee 3 is set to a length that is offset from n / 2 times the wavelength of the exciting wave. That is, the total length of the squeegee 3 is a length that is further offset by less than 1 / 2 wavelength from n times 1 / 2 wavelength of the sine wave excited on the squeegee 3. This is because when the total length of the squeegee 3 is equal to n times 1 / 2 wavelength, a standing sine wave is excited on the squeegee 3 even if there is a phase shift.

[0049] Next, a phase difference is given to the sine wave generated in the squeegee 3 by an amount corresponding to the length offset from n times 1 / 2 wavelength of the sine wave. The phase difference is the phase difference between the wave excited by the first vibrator 1 and the wave excited by the second vibrator 2, and is equal to the offset length. n is a natural number of 1 or more. For example, when the phase difference is Φ, the offset length is L, and the wavelength is λ, the phase difference Φ is as shown in Equation (1). For example, when L is (1 / 4)λ, Φ becomes π / 2.

[0050]

Equation

[0051] In such a state, in squeegee 3, a traveling wave is generated from the first oscillator 1 toward the second oscillator 2. This is because no reflection of the sine wave occurs in squeegee 3, no standing sine wave is generated in squeegee 3, and a traveling wave is generated in squeegee 3 (because a standing sine wave is generated by the superposition of a traveling wave and a reflected wave).

[0052] Also, when a phase difference of -Φ is provided, a traveling wave is generated from the second oscillator 2 toward the first oscillator 1.

[0053] Note that this is the case of an ideal state, and it is preferable to adjust the phase difference so that a traveling wave is generated according to the actual vibration state.

[0054] Next, the traveling wave will be described with reference to FIG. 5.

[0055] FIG. 5 is a graph showing the relationship between the squeegee position and the amplitude. The squeegee position indicates the displacement in the axial direction of squeegee 3. The amplitude is the value obtained by measuring the amplitude of the vibrating squeegee 3. The measurement is performed by measuring the amplitude of squeegee 3 using a laser Doppler vibrometer. The amplitude indicates the maximum value of the amplitude amount at each point in squeegee 3. The ratio of the occurrence of the traveling wave is represented by the standing wave ratio. Since the measured amplitude contains a part of the standing wave component, a state where the antinode and node are repeated occurs. If the part with the maximum value of the amplitude (antinode) is A and the part with the minimum value (node) beside it is B, the standing wave ratio can be expressed as A / B. It is preferable that the standing wave is smaller than 1.4. When the standing wave ratio is smaller than 1.4, the traveling wave component occupies a large proportion. When the standing wave ratio is smaller than 1.4, the amplitude difference becomes small, so the amount of powder in the axial direction (coating width direction) of squeegee 3 can be adjusted accurately. On the other hand, when the standing wave ratio component is high, the amplitude difference becomes large between the part of the maximum value (antinode) of the standing wave and the part of the minimum value (node), indicating that a large amount of the standing wave component is contained. At this time, since the amplitude difference is large, the variation in the amount of powder in the axial direction (coating width direction) of squeegee 3 becomes large.

[0056] Since the squeegee 3 levels the powder 4 using the vibration of a traveling wave, it is possible to suppress the variation in basis weight in the width direction of the powder layer 8 caused by the antinode and node portions of the standing wave. That is, by using the powder adjusting unit 11, it is possible to form a powder layer 8 with little variation in basis weight in the width direction. The width direction of the powder layer 8 is a direction orthogonal to the thickness direction of the powder layer 8 and the direction in which the squeegee 3 moves relative to the powder 4.

[0057] The squeegee 3 is made of, for example, a metal material. By using a metal material as the material of the squeegee 3, it is possible to suppress the attenuation of the high-frequency vibration propagating through the squeegee 3. This is because high-frequency vibrations with short wavelengths are easily attenuated, but metal materials have the property of easily transmitting vibrations, so attenuation can be suppressed. For this reason, the amplitude of the sine wave generated from the first vibrator 1 and the amplitude of the sine wave generated from the second vibrator 2 can be made equal, and a traveling wave is likely to be generated in the squeegee 3.

[0058] Therefore, the variation in basis weight in the width direction of the powder layer 8 becomes even less. Note that the squeegee 3 may contain materials other than metal materials. For example, the squeegee 3 may be a composite member made of a resin material and a metal material in which the portion where the traveling wave propagates is formed of a metal material. Also, the squeegee 3 may be formed of a ceramic material.

[0059] As the metal material, for example, stainless steel, titanium, aluminum, copper, iron, nickel, etc. are used. From the viewpoint of corrosion resistance, among these metal materials, stainless steel or titanium may be used. Also, when titanium is used as the metal material, since titanium has a smaller specific gravity than stainless steel, titanium is more likely to vibrate at high frequencies than stainless steel.

[0060] Each of the first vibrator 1 and the second vibrator 2 includes, for example, a plurality of piezoelectric bodies and electrodes provided on end faces of each of the plurality of piezoelectric bodies. In the first vibrator 1 and the second vibrator 2, each of the plurality of piezoelectric bodies is sandwiched between a plurality of electrodes. Therefore, each of the first vibrator 1 and the second vibrator 2 has a sandwich structure of a piezoelectric body and an electrode. The number of piezoelectric bodies included in each of the first vibrator 1 and the second vibrator 2 is, for example, an even number such as 2, 4, and 6. The electrode is a thin metal plate made of, for example, copper and phosphor bronze.

[0061] The first vibrator 1 and the second vibrator 2 are, for example, directly attached to the squeegee 3. The first vibrator 1 and the second vibrator 2 are arranged so as to be separated from each other by a distance equal to or greater than the width of the powder layer 8 to be formed.

[0062] Examples of the piezoelectric body include piezoelectric ceramics such as lead zirconate titanate-based (PbTiO 3 -PbZrO 3 system, commonly known as PZT) and barium titanate (BaTiO 3 ), and piezoelectric single crystals such as quartz and LiNbO 3 . When the piezoelectric body is a piezoelectric ceramic such as PZT, the thickness per sheet is, for example, 2 mm or more and 5 mm or less.

[0063] Further, the first vibrator 1 and the second vibrator 2 may each be a Langevin type vibrator having a sandwich structure in which a piezoelectric body is sandwiched between a front metal plate and a back plate, and the overall length thereof is set to the length of a half wavelength. In this case, the Langevin type vibrator may be connected to the squeegee 3 or may be connected via a horn. Specifically, the Langevin type vibrator has a structure in which the front plate and the back plate arranged on both sides of a piezoelectric body such as PZT are tightened with bolts. Each of the front plate and the back plate is made of, for example, duralumin. The bolts are made of, for example, steel or titanium alloy. A screw hole for connecting to the squeegee 3 is provided at the center of the front plate, and by inserting and tightening the squeegee 3 into the screw hole, the first vibrator 1 and the second vibrator 2 are firmly adhered to and connected to the squeegee 3. Alternatively, a screw hole may be provided in the squeegee 3, and the squeegee 3 and the front plate may be connected by a set screw (stop screw).

[0064] When connecting the first vibrator 1 and the second vibrator 2 to the squeegee 3 via a horn, screw holes are provided at both ends of the horn, and one end of the horn and the squeegee 3 may be connected by a set screw, and the other end of the horn may be connected to the front plate by a set screw.

[0065] Further, the first vibrator 1 and the second vibrator 2 may be connected to the squeegee 3 by inserting and tightening the squeegee 3 into the screw hole of the front plate.

[0066] Thereby, the vibrations generated by the first vibrator 1 and the second vibrator 2 can be transmitted to the squeegee 3.

[0067] The first vibrator 1 and the second vibrator 2 are vibrators that excite waves with respect to the squeegee 3, and positive charges and negative charges are applied to the metal plates provided on the end faces on both sides of the piezoelectric body, respectively. Thereby, electrical energy is converted into mechanical energy. Specifically, an electrical signal is converted into mechanical vibration, the vibrator vibrates at a high frequency, and this vibration propagates to the squeegee 3.

[0068] The function generator 9 sends a sine wave signal with the same frequency (wavelength) and the same amplitude but with a phase shift to the first vibrator 1 and the second vibrator 2. As a result, the squeegee 3 is in a non-reflective state where the sine wave is substantially not reflected. Since the first vibrator 1 and the second vibrator 2 apply an exciting force to the squeegee 3 based on the sine wave signal, a traveling wave is excited in the squeegee 3. This is because it is difficult for a phenomenon to occur in which the sine wave from the first vibrator 1 is reflected at the other end of the squeegee 3 or the sine wave from the second vibrator 2 is reflected at one end of the squeegee 3, and the wave before reflection and the reflected wave resonate to generate a standing sine wave.

[0069] The squeegee 3 vibrates, for example, at a frequency of 2 kHz or more and 300 kHz or less. That is, the squeegee 3 vibrates at a high frequency near the ultrasonic band. Specifically, when the powder 4 supplied on the sheet 5 passes through the gap between the squeegee 3 and the sheet 5, the high-frequency vibration of the squeegee 3 is transmitted to the powder 4, thereby increasing the fluidity of the powder 4. For this reason, clogging of the powder when the powder 4 passes through the gap between the squeegee 3 and the sheet 5 is suppressed. This is because when the squeegee 3 vibrates at a high frequency, the powder 4 in contact with the squeegee 3 is less likely to receive frictional resistance due to powder pressure and its fluidity increases. As a result, the retention and aggregation of the powder 4 are suppressed, so clogging of the powder when passing through the gap between the squeegee 3 and the sheet 5 is suppressed.

[0070] Also, for the powder 4 located near the squeegee 3, the vibration of the squeegee 3 reduces the frictional force between the powder particles and increases the fluidity, thereby suppressing the aggregation of the powder 4.

[0071] The fluidity of the powder 4 tends to increase as the frequency of the vibration of the squeegee 3 is higher. Therefore, by vibrating the squeegee 3 at a frequency of 2 kHz or more in the high-frequency region near the ultrasonic band, it can be expected to sufficiently increase the fluidity of the powder 4. However, if the frequency is too high, the vibration is likely to decay, so it becomes difficult for the vibration of the squeegee 3 to be transmitted through the powder 4. By setting the frequency of the vibration applied to the squeegee 3 to 300 kHz or less, the fluidity of the powder 4 can be sufficiently increased.

[0072] Thus, even when using the low-fluidity powder 4 with a particle size of 30 μm or less, the vibrating squeegee 3 suppresses the powder 4 from staying or aggregating, allowing it to pass through the gap between the squeegee 3 and the sheet 5. Therefore, the film thickness of the powder 4 (the thickness of the powder layer 8) and the filling rate are adjusted. Thus, the powder adjustment unit 11 can form a powder layer 8 with little variation in basis weight.

[0073] The direction in which the high-frequency vibration of the squeegee 3 propagates includes at least one of a vertical component and a horizontal component. That is, the squeegee 3 vibrates along at least one of the vertical and horizontal directions.

[0074] The vertical direction is perpendicular to the main surface of the squeegee 3. The main surface of the squeegee 3 is the surface that contacts the powder 4 in the squeegee 3, is parallel to the longitudinal direction of the squeegee 3, and is also the surface disposed on the sheet 5 side in the squeegee 3. In the vertical vibration, a longitudinal wave (a wave in the vibration direction in which the squeegee 3 approaches and separates from the powder 4) is likely to be transmitted to the powder 4.

[0075] The vertical component of the high-frequency vibration of the squeegee 3 has a great effect on reducing the frictional resistance between the powders 4. This is because the vertical vibration is in the vibration direction in which the squeegee 3 approaches and separates from the powder 4, so the powders 4 collide repeatedly, and the vibration is easily transmitted to the powder 4. Since high-frequency waves generally do not propagate easily, there is a risk that the vibration between the powders 4 will not be transmitted easily, but in the case of vertical vibration, the vibration is particularly easily transmitted to the powder 4.

[0076] Also, the horizontal direction is parallel to the main surface of the squeegee 3 and parallel to the axis of the squeegee 3. In the horizontal vibration, a transverse wave (a wave in the vibration direction in which the squeegee 3 rubs against the powder 4 and vibrates) is likely to be transmitted to the powder 4. Here, the axis of the squeegee 3 means an axis parallel to the width direction of the sheet 5. The axis of the squeegee 3 may be parallel to the longitudinal direction of the squeegee 3.

[0077] The horizontal component of the high-frequency vibration of squeegee 3 significantly contributes not only to reducing the frictional resistance between powders 4 but also to reducing the frictional force between squeegee 3 and powders 4. If the vertical vibration component is made too large, the vibration may be transmitted too much to powders 4, causing powders 4 to vibrate greatly and potentially increasing the film thickness variation. However, since the horizontal vibration component can also reduce the frictional force between squeegee 3 and powders 4, the fluidity of powders 4 can be particularly enhanced.

[0078] The direction of the high-frequency vibration of squeegee 3 may be only in the vertical direction or only in the horizontal direction. However, if high-frequency vibrations near the ultrasonic band propagating along both the vertical and horizontal directions are used in combination, the fluidity of powders 4 can be further enhanced. For example, when focusing on a single powder 4, the vibration direction of powder 4 applied by squeegee 3 becomes random, and vibration is applied to the entire surface of powder 4. As a result, there is no surface where vibration is not transmitted and the frictional resistance becomes high, improving the fluidity of powder 4.

[0079] When squeegee 3 vibrates at a high frequency near the ultrasonic band in both the vertical and horizontal directions, the magnitude of the horizontal vibration of squeegee 3 is, for example, larger than the magnitude of the vertical vibration of squeegee 3. That is, in squeegee 3, for example, the magnitude of the vibration of the shear wave component of powders 4 (the direction in which squeegee 3 rubs against powders 4 and vibrates) is larger than the magnitude of the vibration of the longitudinal wave component of powders 4 (the vibration direction in which squeegee 3 approaches and separates from powders 4). In this case, the frictional resistance at the interface between squeegee 3 and powders 4, where the frictional resistance is particularly likely to increase, can be reduced by the horizontal vibration of squeegee 3, and the frictional resistance between powders 4 can also be reduced. Therefore, the fluidity of powders 4 can be further enhanced.

[0080] The magnitude of the vertical vibration of squeegee 3 is, for example, 10 nm or more. That is, the amplitude of squeegee 3 in the vertical direction is, for example, 10 nm or more. In this case, the frictional resistance between powders 4 can be sufficiently reduced, and the fluidity of powders 4 can be further enhanced. Also, the amplitude of squeegee 3 in the vertical direction is, for example, 10 μm or less. Thereby, it is possible to suppress powders 4 from vibrating too largely and becoming dust and scattering to contaminate the surroundings.

[0081] The magnitude of the horizontal vibration of squeegee 3 is, for example, 20 nm or more. That is, the amplitude of squeegee 3 in the horizontal direction is, for example, 20 nm or more. In this case, the frictional resistance at the interface between squeegee 3 and powders 4 can be sufficiently reduced, and the fluidity of powders 4 can be further enhanced. Also, the amplitude of squeegee 3 in the horizontal direction is, for example, 20 μm or less. Thereby, it is possible to suppress powders 4 from vibrating too largely and becoming dust and scattering to contaminate the surroundings.

[0082] Squeegee 3 is, for example, a cylindrical shape with a long axial direction. For example, the axial direction of the cylinder (the height direction of the cylinder) is parallel to the upper surface of sheet 5 and arranged to intersect (for example, be orthogonal to) the relative movement direction of sheet 5 with respect to squeegee 3. The longitudinal direction of squeegee 3 is the axial direction of the cylinder. In squeegee 3, the traveling wave travels in the axial direction. Note that the shape of squeegee 3 is not particularly limited, and it may be, for example, a polygonal prism with a polygonal cross section. Also, the cross-sectional area of squeegee 3 does not have to be constant, and squeegee 3 may change in thickness along the longitudinal direction.

[0083] By forming squeegee 3 into a cylindrical structure, the axial vibration of the vibrator can be efficiently converted into the vertical vibration of squeegee 3. Squeegee 3 can be deformed so that it has a cylindrical structure and the thickness of the cylindrical structure in squeegee 3 is made thinner.

[0084] Note that squeegee 3 may be a solid circular cylinder with a long axial direction.

[0085] Powder Coating Apparatus Next, the powder coating apparatus according to the present embodiment will be described.

[0086] The powder coating apparatus includes a powder adjustment unit 11, a pair of support columns that support the squeegee 3 of the powder adjustment unit 11, a drive unit that moves the sheet 5, and a powder supply unit. The powder adjustment unit 11 is arranged such that a gap is formed between the squeegee 3 and the sheet 5. Thereby, the squeegee 3 adjusts the thickness of the powder 4 supplied onto the sheet 5 by the powder supply unit. The sheet 5 is supported by, for example, a stage. Note that the sheet 5 may be supported by a conveying roll or the like.

[0087] In the powder coating apparatus, the drive unit conveys the sheet 5 along the traveling direction. In the powder coating apparatus, the powder 4 is continuously supplied onto the surface of the conveyed sheet 5 using the powder supply unit. Then, in the powder coating apparatus, the squeegee 3 is used to adjust the film thickness and filling rate of the powder 4 supplied onto the surface of the sheet 5, and while making the powder layer 8 have a desired basis weight, the basis weight variation is reduced.

[0088] As described above, a traveling wave is propagating in the squeegee 3 in the powder adjustment unit 11. In the powder coating apparatus, since the vibration of the traveling wave is used to level the powder 4, it is possible to suppress the basis weight variation of the powder layer 8 in the width direction caused by the antinode portion and node portion of the standing wave. That is, in the powder coating apparatus, a powder layer 8 with little basis weight variation in the width direction can be formed.

[0089] The drive unit is, for example, a conveying device that moves the sheet 5 in a predetermined direction. Note that the conveying device may be any device as long as it can convey the sheet 5, and is not particularly limited. The conveying device may be, for example, a conveying device capable of continuously feeding out the sheet 5 wound in a roll shape, or a conveying device capable of intermittently feeding out the sheet 5.

[0090] Note that on the conveyance path of the sheet 5, a guide roller that rotates as the sheet 5 moves, a control device for correcting the meandering of the sheet 5, and the like may be provided. Further, the drive unit may be a device that moves the squeegee 3 and the powder supply unit. That is, the drive unit relatively moves the sheet 5 in a predetermined direction with respect to the squeegee 3 and the powder supply unit.

[0091] In this embodiment, the sheet 5 is, for example, a long and narrow strip-shaped thin plate and is wound. Note that the sheet 5 is not limited to a long and narrow strip-shaped thin plate. For example, a sheet 5 having a desired shape may be fed out from the conveying device, the powder 4 may be applied to the sheet 5, and then a new sheet 5 may be fed out from the conveying device. Further, the sheet 5 does not have to be wound in a roll shape. That is, the sheet 5 may have any shape as long as the powder 4 can be applied using the powder coating device. Therefore, the shape of the sheet 5 is not particularly limited.

[0092] The powder supply unit supplies the powder 4 to the surface of the sheet 5. In this embodiment, the powder supply unit is, for example, a hopper. The hopper stores the powder 4 therein and supplies the powder 4 to the surface of the sheet 5.

[0093] The powder supply unit is arranged upstream of the squeegee 3 in the advancing direction of the sheet 5. The powder 4 supplied to the surface of the sheet 5 by the powder supply unit reaches the squeegee 3 as the sheet 5 moves. Note that in this embodiment, a hopper is used as the powder supply unit, but the present invention is not limited to this, and the powder supply unit may be any device that can supply the powder 4 to the surface of the sheet 5. The powder supply unit may be, for example, a feeder such as a screw feeder.

[0094] In this embodiment, the squeegee 3 is cylindrical, and both axial ends of the cylinder of the squeegee 3 are fixed and arranged with struts with bearings so that the squeegee 3 can slide horizontally. The horizontal sliding amount can be adjusted by attaching a stopper or the like to the squeegee 3. Also, both axial ends of the cylindrical squeegee 3 are shaped to be inserted into the diameter of the circular bearing, and by adjusting the difference between the diameter of the squeegee 3 and the bearing diameter, the vibration amount in the vertical direction can be adjusted. The relationship between the amplitude in the horizontal direction and the amplitude in the vertical direction can be adjusted by this method, and a relationship in which the amplitude in the horizontal direction is larger than the amplitude in the vertical direction can also be created.

[0095] Note that the powder coating apparatus does not necessarily need to be provided with struts as long as the squeegee 3 is arranged so that a gap is formed between the squeegee 3 and the sheet 5. For example, when the powder adjustment unit 11 is driven by a driving unit, the squeegee 3 may be attached to the driving unit.

[0096] [Method for manufacturing the powder layer 8] Hereinafter, the method for manufacturing the powder layer 8 will be described. The powder layer 8 can be manufactured by using a powder coating apparatus.

[0097] The method for manufacturing the powder layer 8 includes supplying powder 4 to the surface of the sheet 5 while moving the sheet 5 such as a current collector in a predetermined direction (powder supply step), and adjusting the thickness and basis weight of the powder layer 8 formed by the powder 4 supplied to the surface of the sheet 5 by using the squeegee 3 (powder alignment step).

[0098] First, the powder 4 is produced. The raw material of the powder 4 is not particularly limited. For example, a particle group containing at least one of an active material and a solid electrolyte may be used. When using a particle group containing an active material, the active material and appropriate additives (for example, a binder, a conductive material, a solid electrolyte, etc.) are added and mixed to produce the powder 4. As a mixing method, for example, there is a method of mixing with a mortar, a ball mill, a mixer, or the like. In particular, a method of mixing the powder 4 without using a solvent or the like is preferable because there is no material deterioration.

[0099] In the powder supply process, while moving the sheet 5 in a predetermined direction, powder 4 is supplied onto the surface of the sheet 5 using a powder supply unit such as a hopper. The substrate onto which the powder 4 is supplied may have a shape other than sheet-like, for example, plate-like or block-like. In this case, the movement of the substrate in the powder supply process may be in a form of intermittently flowing the plate or block.

[0100] The powder alignment process is a process of aligning the powder 4 on the surface of the sheet 5 using the squeegee 3 of the powder coating apparatus. That is, in the powder alignment process, the thickness and basis weight of the powder layer 8 formed by the powder 4 supplied onto the surface of the sheet 5 are adjusted using the squeegee 3. Thereby, a powder layer 8 with an adjusted basis weight is formed on the sheet 5. At this time, the squeegee 3 vibrates, for example, at a frequency of 2 kHz or more and 300 kHz or less. Also, in the squeegee 3, a traveling wave propagates from the first vibrator 1 toward the second vibrator 2, or a traveling wave propagates from the second vibrator 2 toward the first vibrator 1.

[0101] The method for manufacturing the powder layer 8 may further include a powder sheeting process. The powder sheeting process is, for example, a process of compressing the powder layer 8 formed by the powder 4 aligned on the sheet 5 through a roll pressing process using a press machine such as a roll press. Thereby, a compressed powder layer obtained by compressing the powder layer 8 on the surface of the sheet 5 is formed.

[0102] As described above, in the method for manufacturing the powder layer 8, by performing the powder supply process and the powder alignment process in this order, a powder layer 8 composed of the powder 4 is formed on the surface of the sheet 5. Such a laminate of the sheet 5 and the powder layer 8 can be used for an energy device. For example, when using a current collector as the sheet 5 and a particle group containing an active material as the powder 4, an electrode for an energy device can be manufactured.

[0103] An energy device produced using a powder coating apparatus can have a powder layer 8 with a small variation in basis weight, which is directly coated by imparting fluidity to the powder 4. Therefore, according to the method for manufacturing the powder layer 8, since the step of dispersing the powder 4 in a solvent or the like and then drying it is not used, and the step of directly coating the powder 4 is used, deterioration of the material due to the solvent can be suppressed, leading to an increase in the capacity of the energy device.

[0104] Also, in the method for manufacturing the powder layer 8, it is possible to suppress the cost increase due to using a solvent and drying the solvent. Furthermore, the method for manufacturing the powder layer 8 can suppress a large amount of energy consumption in the drying process, resulting in an environmentally considerate manufacturing method. On the other hand, when the uniformity of the basis weight of the powder layer 8 is high, the quality as an electrode in the energy device can be improved, and a high-capacity energy device with good quality can be manufactured at low cost.

[0105] [Powder layer 8] Next, the powder layer 8 formed using the powder coating apparatus will be described.

[0106] The powder layer 8 according to the present embodiment is used, for example, in an energy device. The film thickness of the powder layer 8 is, for example, 30 μm or more. Also, the powder layer 8 contains a powder 4 composed of at least one kind of particle material. Also, the concentration of the solvent contained in the powder layer 8 is 50 ppm or less. Also, the variation in basis weight in the powder layer 8 is small.

[0107] Thereby, it is possible to form a powder layer 8 with a small variation in basis weight and suppressed deterioration due to the solvent. Also, since drying of the solvent is not required, the energy consumption for drying the solvent can be reduced, thus suppressing the environmental load and suppressing an increase in manufacturing cost. Therefore, by using such a powder layer 8 in an energy device, it is possible to increase the capacity and quality of the energy device, reduce the environmental load, and achieve cost reduction.

[0108] Note that the powder layer 8 may be a compressed powder layer obtained by pressing the powder layer 8 formed by a powder coating apparatus.

[0109] The powder layer 8 of the present embodiment can be used, for example, in an all-solid-state battery.

[0110] Hereinafter, details of the case where the powder layer 8 is used in an all-solid-state battery will be described.

[0111] The powder layer 8 is formed, for example, on the sheet 5 serving as a current collector and is used as an electrode (that is, a positive electrode or a negative electrode) of an all-solid-state battery. The electrode includes a current collector and the powder layer 8.

[0112] Note that the electrode may further include another layer located between the current collector and the powder layer 8. The other layer is, for example, a connection layer made of a conductive carbon material or the like.

[0113] The film thickness of the powder layer 8 is 30 μm or more. The upper limit value of the film thickness of the powder layer 8 is not particularly limited, but the film thickness of the powder layer 8 is, for example, 2000 μm or less.

[0114] Also, the powder layer 8 contains the powder 4 composed of at least one kind of particle material.

[0115] The concentration of the solvent contained in the powder layer 8 is 50 ppm or less. That is, the powder layer 8 substantially does not contain a solvent. Here, substantially not containing means the case of not containing at all and the case of being unavoidably contained at 50 ppm or less as impurities or the like. The concentration of the solvent is a concentration based on weight.

[0116] The size of the powder layer 8 in plan view is, for example, 30 mm × 30 mm or more. The upper limit of the size of the powder layer 8 in plan view is not particularly limited, but the size of the powder layer 8 in plan view is, for example, 300 mm × 600 mm or less.

[0117] In an arbitrary 30 mm × 30 mm region on the surface of the powder layer 8, the variation in the basis weight of the powder layer 8 is, for example, 8% or less.

[0118] As a method for measuring the basis weight, for example, the following method is used. First, the powder layer 8 and the current collector are pressed from above and below to compact them, and then the powder layer 8 and the current collector are punched out into a circle with a diameter of 5 mm or more and 9 mm or less. The total weight of the punched-out powder layer 8 and the current collector is measured. Then, the weight of the current collector of the same lot that has been punched out with a diameter of 5 mm or more and 9 mm or less, which has been measured in advance, is subtracted from the above total weight to obtain the weight of the powder layer 8. By dividing this weight by the area of the circle with a diameter of 5 mm or more and 9 mm or less that has been punched out, the basis weight can be obtained.

[0119] Also, the measurement of the basis weight variation is performed, for example, by the following method. First, an arbitrary 30 mm × 30 mm area on the surface of the powder layer 8 in plan view is selected. This area may be the central area on the surface of the powder layer 8 or an area including the end of the powder layer 8. Then, within the range of this area, for example, it is punched out in 5 or more circular shapes with a diameter of 5 mm or more and 9 mm or less, and the basis weight is measured using the above method. From the viewpoint of improving the accuracy of the variation measurement, it may be punched out in 9 or more places. The basis weight variation is calculated by dividing the difference (specifically, the absolute value of the difference) between the average of the basis weights of all the punched-out locations and the basis weight of the location with the largest difference from the average among the basis weights of each punched-out location by the average. That is, the basis weight variation being 8% or less means that for any of the punched-out locations, the difference between the basis weight and the average is 8% or less of the average.

[0120] As described above, the powder layer 8 is formed by applying high-frequency vibration to the powder 4 supplied to the surface of the sheet 5, thereby imparting fluidity to the powder 4 and aligning the powder 4 in the powder layer 8. Since the squeegee 3 vibrates by a traveling wave, the basis weight variation in the powder layer 8 is small even in the width direction, so a powder layer 8 with a size of 30 mm × 30 mm or more and a thickness of 30 μm or more can be produced with high quality. Therefore, the powder layer 8 can be used for large-sized high-capacity energy devices.

[0121] Further, the powder layer 8 is produced, for example, through a coating process that substantially does not contain a solvent. Therefore, a powder layer 8 that substantially does not contain a solvent can be formed. As a result, the powder layer 8 is not damaged by the solvent. Accordingly, deterioration of the powder layer 8 is suppressed, and the variation in the basis weight of the powder 4 in the powder layer 8 is small, so that a powder layer 8 of a large-sized high-capacity energy device having a high capacity and excellent quality can be formed.

[0122] Further, the powder layer 8 can be used, for example, for a positive electrode, a negative electrode, or a solid electrolyte layer of an energy device such as an all-solid-state battery.

[0123] When the powder layer 8 is used for the positive electrode, for example, the sheet 5 is a positive electrode current collector, and the powder layer 8 containing the powder 4 is a positive electrode mixture layer. That is, the positive electrode mixture layer is formed on the positive electrode current collector. The powder 4 in the positive electrode mixture layer contains, for example, a positive electrode active material and a solid electrolyte having ion conductivity.

[0124] When the powder layer 8 is used for the negative electrode, for example, the sheet 5 is a negative electrode current collector, and the powder layer 8 containing the powder 4 is a negative electrode mixture layer. That is, the negative electrode mixture layer is formed on the negative electrode current collector. The powder 4 in the negative electrode mixture layer contains, for example, a negative electrode active material and a solid electrolyte having ion conductivity.

[0125] When the powder layer 8 is used for the solid electrolyte layer, for example, the powder layer 8 containing the powder 4 is a solid electrolyte layer. The solid electrolyte layer is formed on the surface of the positive electrode mixture layer formed on the above positive electrode current collector or on the surface of the negative electrode mixture layer formed on the negative electrode current collector. That is, the sheet 5 is, for example, a positive electrode mixture layer formed on the positive electrode current collector or a negative electrode mixture layer formed on the negative electrode current collector. The powder 4 in the solid electrolyte layer contains, for example, a solid electrolyte having ion conductivity.

[0126] The concentration of the solvent contained in the above-described positive electrode active material layer, negative electrode active material layer, and solid electrolyte layer is 50 ppm or less. That is, the positive electrode active material layer, negative electrode active material layer, and solid electrolyte layer substantially do not contain the solvent. Here, substantially not containing the solvent means the case where these layers do not contain the solvent at all, and the case where these layers unavoidably contain 50 ppm or less of the solvent as impurities or the like.

[0127] Note that the solvent is, for example, an organic solvent. Further, the method for measuring the solvent is not particularly limited, and for example, it can be measured using gas chromatography, the mass change method, or the like. Examples of the organic solvent include nonpolar organic solvents such as heptane, xylene, and toluene, polar organic solvents such as tertiary amine-based solvents, ether-based solvents, thiol-based solvents, and ester-based solvents, and combinations thereof. Examples of the tertiary amine-based solvent include triethylamine, tributylamine, and triamylamine. Examples of the ether-based solvent include tetrahydrofuran and cyclopentyl methyl ether. Examples of the thiol-based solvent include ethanethiol. Examples of the ester-based solvent include butyl butyrate, ethyl acetate, and butyl acetate.

[0128] Next, details of the materials used for the positive electrode active material layer, negative electrode active material layer, and solid electrolyte layer will be described.

[0129] The positive electrode active material is a substance in which metal ions such as lithium (Li) are inserted into or removed from the crystal structure at a potential higher than that of the negative electrode, and oxidation or reduction occurs with the insertion or removal of metal ions such as lithium. The type of the positive electrode active material is appropriately selected according to the type of the all-solid-state battery, and examples thereof include oxide active materials and sulfide active materials.

[0130] In the present embodiment, for example, an oxide active material (lithium-containing transition metal oxide) is used as the positive electrode active material. Examples of the oxide active material include LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCoPO 4 , LiNiPO 4 , LiFePO4 , LiMnPO 4 and compounds obtained by substituting the transition metals of these compounds with one or two different elements, etc. Examples of the compounds obtained by substituting the transition metals of the above compounds with one or two different elements include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 , LiNi 0.8 Co 0.15 Al 0.05 O 2 , LiNi 0.5 Mn 1.5 O 2 etc. Known materials are used. The cathode active material may be used alone or in combination of two or more.

[0131] Examples of the shape of the cathode active material include particulate form. When the cathode active material is particulate, the particle diameter of the cathode active material is, for example, in the range of 50 nm or more and 30 μm or less, and may be in the range of 1 μm or more and 15 μm or less. If the particle diameter of the cathode active material is 50 nm or more, the handleability tends to be good. On the other hand, if the particle diameter is 30 μm or less, by using a small particle diameter active material, the surface area becomes large and a high-capacity cathode is easily obtained. Note that the particle diameter of the material contained in the cathode binder layer or the anode binder layer in this specification is, for example, the above-described D50.

[0132] The surface of the cathode active material may be coated with a coating layer. This is because the reaction between the cathode active material (for example, an oxide active material) and the solid electrolyte (for example, a sulfide-based solid electrolyte) can be suppressed. Examples of the material of the coating layer include LiNbO 3 , Li 3 PO 4 , LiPON and other Li-ion conductive oxides. The average thickness of the coating layer is, for example, in the range of 1 nm or more and 20 nm or less, and may be in the range of 1 nm or more and 10 nm or less.

[0133] The ratio of the positive electrode active material to the solid electrolyte contained in the positive electrode mixture layer may be in the range of 1 or more and 99 or less, or may be in the range of 2.3 or more and 19 or less, when the weight ratio is defined as positive electrode active material / solid electrolyte in terms of weight. By being within this weight ratio range, it is easy to ensure both the lithium ion conduction path and the electron conduction path within the positive electrode mixture layer.

[0134] The negative electrode active material is a substance in which metal ions such as lithium are inserted into or removed from the crystal structure at a potential lower than that of the positive electrode, and oxidation or reduction occurs with the insertion or removal of metal ions such as lithium.

[0135] Examples of the negative electrode active material in this embodiment include easily alloying metals with lithium such as lithium, indium, tin, and silicon, carbon materials such as hard carbon and graphite, and 4 Ti 5 O 12 , SiO x and other known materials such as oxide active materials. As the negative electrode active material, a composite obtained by appropriately mixing the above-described negative electrode active materials may also be used.

[0136] The particle size of the negative electrode active material is, for example, 30 μm or less. By using a negative electrode active material with a small particle size, the surface area increases and a high capacity can be achieved.

[0137] The ratio of the negative electrode active material to the solid electrolyte contained in the negative electrode mixture layer is, for example, in the range of 0.6 or more and 19 or less, or may be in the range of 1 or more and 9 or less, when the weight ratio is defined as negative electrode active material / solid electrolyte in terms of weight. By being within this weight ratio range, it is easy to ensure both the lithium ion conduction path and the electron conduction path within the negative electrode mixture layer.

[0138] The solid electrolyte may be appropriately selected according to the conductive ion species (for example, lithium ions). Examples of the solid electrolyte include sulfide-based solid electrolytes, oxide-based solid electrolytes, and halide-based solid electrolytes.

[0139] The type of sulfide-based solid electrolyte in this embodiment is not particularly limited. Examples of the sulfide-based solid electrolyte include, for example, Li 2 S-SiS 2 、LiI-Li 2 S-SiS 2 、LiI-Li 2 S-P 2 S 5 、LiI-Li 2 S-P 2 O 5 、LiI-Li 3 PO 4 -P 2 S 5 and Li 2 S-P 2 S 5 etc. In particular, from the viewpoint of excellent lithium ion conductivity, the sulfide-based solid electrolyte may contain Li, P, and S. The sulfide-based solid electrolyte may be used alone or in combination of two or more. Also, the sulfide-based solid electrolyte may be crystalline, amorphous, or glass ceramics. Note that the description of "Li 2 S-P 2 S 5 " means a sulfide-based solid electrolyte formed using a raw material composition containing Li 2 S and P 2 S 5 , and the same applies to other descriptions.

[0140] In this embodiment, one form of the sulfide-based solid electrolyte is sulfide glass ceramics containing Li 2 S and P 2 S 5 . When the ratio of Li 2 S and P 2 S 5 is in terms of molar conversion, for example, when the molar ratio is Li 2 S / P 2 S 5 = molar ratio, it is within the range of, for example, 2.3 or more and 4 or less, and may also be within the range of 3 or more and 4 or less. By being within this molar ratio range, a crystal structure with high ionic conductivity can be obtained while maintaining the lithium concentration that affects battery characteristics.

[0141] Examples of the shape of the sulfide solid electrolyte in this embodiment include particle shapes such as true spherical and elliptical spherical. When the sulfide solid electrolyte material is in a particle shape, the particle diameter of the sulfide solid electrolyte is not particularly limited. However, in order to easily improve the filling rate in the positive electrode or the negative electrode, it may be 30 μm or less, may be 20 μm or less, or may be 10 μm or less. On the other hand, the particle diameter of the sulfide solid electrolyte may be 0.001 μm or more, or may be 0.01 μm or more.

[0142] Next, the oxide solid electrolyte in this embodiment will be described. The type of the oxide solid electrolyte is not particularly limited, but examples include LiPON, Li 3 PO 4 、Li 2 SiO 2 、Li 2 SiO 4 、Li 0.5 La 0.5 TiO 3 、Li 1.3 Al 0.3 Ti 0.7 (PO 4 ) 3 、La 0.51 Li 0.34 TiO 0.74 、Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 and the like. The oxide solid electrolyte may be used alone or in combination of two or more.

[0143] Next, the details of the positive electrode current collector and the negative electrode current collector will be described.

[0144] The positive electrode in this embodiment includes, for example, a positive electrode current collector made of a metal foil or the like. As the positive electrode current collector, for example, a foil-shaped body, a plate-shaped body, a mesh-shaped body, etc. made of aluminum, gold, platinum, zinc, copper, stainless steel (SUS), nickel, tin, titanium, or an alloy of two or more of these are used.

[0145] In addition, with regard to the thickness, shape, etc. of the positive electrode current collector, they may be appropriately selected according to the use of the positive electrode.

[0146] The negative electrode in the present embodiment includes, for example, a negative electrode current collector made of a metal foil or the like. As the negative electrode current collector, for example, a foil-shaped body, a plate-shaped body, a mesh-shaped body, etc. made of stainless steel (SUS), gold, platinum, zinc, copper, nickel, titanium, tin, or an alloy of two or more of these are used.

[0147] In addition, with regard to the thickness, shape, etc. of the negative electrode current collector, they may be appropriately selected according to the use of the negative electrode.

[0148] (Other embodiments) As described above, the powder adjustment unit and the powder coating apparatus according to the present disclosure have been described based on the embodiments, but the present disclosure is not limited to these embodiments. Without departing from the gist of the present disclosure, various modifications conceived by those skilled in the art applied to the embodiments, and other forms constructed by combining some components in the embodiments are also included in the scope of the present disclosure.

[0149] For example, in the above embodiment, the squeegee 3 vibrated at a high frequency near the ultrasonic band, but it is not limited thereto. The vibration frequency of the squeegee 3 may be set according to the characteristics of the powder 4, and may be, for example, 2 kHz or less.

Industrial applicability

[0150] The powder adjustment unit and the powder coating apparatus according to the present disclosure can form a powder layer with little variation in film thickness and uniform without using a solvent, and thus can be used for forming various powder layers such as a paste layer of a high-quality all-solid-state battery.

Explanation of reference numerals

[0151] 1 First vibrator 2 Second vibrator 3, 23 Squeegee 4, 24 Powder 5, 25 Sheet 6 First amplifier 7 Secondary amplifier 8, 28 Powder layer 9 Function generator 11 Powder adjustment unit 30 Powder coating apparatus

Claims

1. A squeegee, a first vibrator disposed at one end of the squeegee to excite waves at the one end, and a second vibrator disposed at the other end of the squeegee to excite waves at the other end, wherein by making the phases of the first vibrator and the second vibrator different, the squeegee vibrates by a traveling wave traveling from the one end to the other end or vibrates by a traveling wave traveling from the other end to the one end a powder adjusting unit.

2. The length of the squeegee is a length deviated from n / 2 times the wavelength of the excited wave, where n is a natural number, and the phase difference between the wave excited by the first vibrator and the wave excited by the second vibrator is equal to the deviated length The powder adjusting unit according to Claim 1.

3. The wavelength of the wave excited from the first vibrator is equal to the wavelength of the wave excited from the second vibrator The powder adjusting unit according to Claim 2.

4. The amplitude of the wave excited from the first vibrator is equal to the amplitude of the wave excited from the second vibrator The powder adjusting unit according to Claim 3.

5. The squeegee vibrates at a frequency of 2 kHz or more and 300 kHz or less The powder adjusting unit according to any one of Claims 1 to 4.

6. The squeegee has a cylindrical structure The powder adjusting unit according to Claim 5.

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