Powder layer composite for energy device and manufacturing method thereof

Abstract

To provide a powder layer composite for an energy device capable of improving the performance of the energy device.SOLUTION: A powder layer composite 4 includes a current collector 1, and a powder layer 3 having a film thickness of 50 μm or more formed on the current collector 1. The powder layer 3 includes powder 2 composed of at least one particulate material. The solvent concentration contained in the powder layer 3 is 50 ppm or less. In an arbitrary 30 mm×30 mm region of the powder layer 3, the variation in basis weight of the powder layer 3 is 10% or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a powder layer composite for an energy device, a method for manufacturing the same, and a powder coating apparatus for an energy device. [Background technology]

[0002] BACKGROUND ART Conventionally, a technique has been known in which a powder is applied to the surface of a current collector while the current collector or other member is being transported.

[0003] For example, Patent Document 1 discloses a technique in which a composite material of powder containing an active material is applied to the surface of a long (large) current collector.

[0004] Patent Document 1 describes a method of supplying powder onto the surface of a current collector, and then flattening the supplied powder with a squeegee to adjust the thickness of the layer formed by the powder (hereinafter referred to as the "powder layer") to be uniform. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6067636 Summary of the Invention [Problem to be solved by the invention]

[0006] In thin-layer energy devices such as all-solid-state batteries, it is necessary to improve the quality of the powder layer to enhance the performance of the energy device. Therefore, the present disclosure provides a powder layer composite for an energy device, etc., which can enhance the performance of the energy device. [Means for solving the problem]

[0007] A powder layer composite for an energy device according to one embodiment of the present disclosure comprises a current collector and a powder layer having a film thickness of 50 μm or more formed on the current collector, wherein the powder layer contains a powder composed of at least one type of particulate material, the concentration of a solvent contained in the powder layer is 50 ppm or less, and the variation in basis weight of the powder layer within any 30 mm x 30 mm area of ​​the powder layer is 10% or less.

[0008] A method for manufacturing a powder layer composite for an energy device according to one embodiment of the present disclosure includes: supplying powder onto a surface of a current collector to form a powder layer containing the powder; and adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer by using a squeegee vibrated at a frequency of 2 kHz or more and 300 kHz or less while moving the current collector relative to a squeegee positioned so as to form a gap between the current collector and the squeegee in a predetermined direction, the squeegee being positioned so as to form a gap between the current collector and the squeegee; wherein, in adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer, the powder is filled in the powder layer so that the filling rate of the powder in the powder layer is equal to or greater than the tap filling rate of the powder.

[0009] A powder coating apparatus for an energy device according to one embodiment of the present disclosure includes a powder supply unit that supplies powder onto the surface of a current collector, a squeegee that is arranged so as to form a gap between the current collector and the squeegee and vibrates at a frequency of 2 kHz to 300 kHz, and that adjusts the basis weight and filling rate of the powder supplied onto the surface of the current collector by the powder supply unit, a drive unit that moves the current collector relative to the squeegee in a predetermined direction, and a control unit that controls at least one of the gap and the vibration of the squeegee. [Effects of the Invention]

[0010] According to the present disclosure, the performance of energy devices can be improved. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram for explaining a powder layer according to a comparative example. [Figure 2] FIG. 2 is a schematic diagram of a powder bed composite according to an embodiment. [Figure 3] FIG. 3 is a flowchart showing the steps of manufacturing a powder layer composite according to an embodiment. [Figure 4A] FIG. 4A is a schematic diagram for explaining a step of filling the surface of the current collector with powder supplied thereon in the powder aligning step according to the embodiment. [Figure 4B] FIG. 4B is a schematic view for explaining a state in which excess powder is ejected onto the top of the powder layer in the powder alignment step according to the embodiment. [Figure 4C] FIG. 4C is a schematic diagram for explaining a state in which excess powder has been scraped off to make the powder layer have a uniform thickness in the powder aligning step according to the embodiment. [Figure 5] FIG. 5 is a schematic diagram of a powder coating device used in the production of a powder layer composite according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (How one aspect of the present disclosure was achieved) The present inventors have found that the powder layer formed on the surface of a current collector has the following problems. As in Patent Document 1, even if the thickness of the powder layer is made uniform using a squeegee, variations in the powder weight occur in large powder layers. As a result, problems are likely to occur in the quality of large energy devices that use such powder layers. The powder weight is a value expressed as the amount of powder per unit area, expressed in weight, and the unit of weight is, for example, g / cm. 2 is.

[0013] Here, the variation in the powder layer will be specifically explained using FIG. 1. FIG. 1 is a schematic diagram for explaining a powder layer according to a comparative example. The white arrow in FIG. 1 indicates the conveyance direction of the current collector 1X. The squeegee 5X shown in FIG. 1 is fixed so that a gap is formed between it and the current collector 1X. As shown in FIG. 1, as the current collector 1X is conveyed, the powder 2X is smoothed by the squeegee 5X, and the film thickness of the powder layer 3X is controlled to be constant. However, since it is not possible to control the variation in the packing condition (denseness) of the powder 2X, it is difficult to control the basis weight of the powder layer 3X to be constant.

[0014] Therefore, the present disclosure provides a powder layer composite for an energy device, etc., which can improve the performance of a large-sized energy device by forming a large-sized powder layer with little variation in basis weight on a current collector.

[0015] (Summary of the Disclosure) An outline of one aspect of the present disclosure is as follows.

[0016] A powder layer composite for an energy device in one embodiment of the present disclosure comprises a current collector and a powder layer having a film thickness of 50 μm or more formed on the current collector, wherein the powder layer contains powder composed of at least one type of particulate material, the concentration of a solvent contained in the powder layer is 50 ppm or less, and the variation in basis weight of the powder layer within any 30 mm x 30 mm area of ​​the powder layer is 10% or less.

[0017] This results in a powder layer composite with small variations in the powder layer basis weight and suppressed deterioration of the powder layer due to solvents. Therefore, by using such a powder layer composite in an energy device, the output and quality of the energy device can be improved, resulting in an energy device with higher performance.

[0018] Furthermore, for example, the filling rate of the powder in the powder layer may be equal to or greater than the tap filling rate of the powder.

[0019] This reduces the gaps between the powder particles in the powder layer compared to when the powder is filled by tapping, and makes it possible to further reduce variations in the powder weight of the powder layer.

[0020] Furthermore, for example, the particle size distribution represented by (D90-D10) / D50 of the main powder, which is the particulate material having the largest volume fraction among the at least one type of particulate material, may be greater than 75%, and the filling rate of the powder in the powder layer may be 1.1 times or more the tap filling rate of the powder.

[0021] When the particle size distribution of the powder is large, the fluidity of the powder deteriorates and the basis weight of the powder layer is likely to vary. However, by making the powder filling rate in the powder layer 10% or more higher than when the powder is filled by tapping, the gaps between the powder particles in the powder layer are reduced, and the basis weight variation in the powder layer can be reduced.

[0022] Furthermore, for example, the filling rate of the powder in the powder layer may be 80% or more.

[0023] This increases the contact between the powder particles, thereby improving the performance of energy devices using the powder bed composite.

[0024] Furthermore, for example, the current collector may be a positive electrode current collector, and the powder may contain, as the at least one kind of particulate material, a positive electrode active material and a solid electrolyte having ion conductivity.

[0025] This allows the powder layer composite to be used as a positive electrode of an all-solid-state battery.

[0026] Furthermore, for example, the current collector may be a negative electrode current collector, and the powder may contain, as the at least one kind of particulate material, a negative electrode active material and a solid electrolyte having ion conductivity.

[0027] This allows the powder layer composite to be used as a negative electrode of an all-solid-state battery.

[0028] In addition, a manufacturing method of a powder layer composite for an energy device in one embodiment of the present disclosure includes supplying powder onto a surface of a current collector to form a powder layer containing the powder, and adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer by using a squeegee vibrated at a frequency of 2 kHz to 300 kHz while moving the current collector relative to a squeegee positioned so as to form a gap between the current collector and the squeegee in a predetermined direction, wherein the squeegee is vibrated at a frequency of 2 kHz to 300 kHz, and in adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer, the powder is filled in the powder layer so that the filling rate of the powder in the powder layer is equal to or greater than the tap filling rate of the powder.

[0029] This increases the powder packing rate in the powder layer, reducing voids in the resulting powder layer. As a result, the number of voids that cause variations in powder density in the powder layer is reduced, allowing the production of a powder layer composite with reduced variation in powder weight per unit area. Therefore, by using such a powder layer composite in an energy device, the output and quality of the energy device can be improved, resulting in higher performance of the energy device.

[0030] Furthermore, for example, when the powder contains at least one type of particulate material powder and the particle size distribution expressed by (D90-D10) / D50 of a main powder, which is the material particle having the largest volume fraction among the at least one type of particulate material, is greater than 75%, the powder may be filled in the powder layer so that the filling rate of the powder in the powder layer is 1.1 times or more the tap filling rate of the powder, by adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer.

[0031] As a result, when the particle size distribution of the powder is large, the fluidity of the powder becomes poor and variations in the basis weight of the powder layer are likely to occur. However, by increasing the powder filling rate in the powder layer by 10% or more compared to when the powder is filled by tapping, the gaps between the powder particles in the powder layer become smaller, and the variations in the basis weight of the powder layer can be reduced.

[0032] Furthermore, for example, adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer may include ejecting a portion of the powder in the powder layer at a position whose height from the current collector is higher than the gap.

[0033] This makes it possible to confirm the high powder filling rate in the powder layer without having to measure it using a separate measuring device, etc., and to easily and reliably stabilize the quality of the powder layer.

[0034] Also, for example, adjusting the thickness of the powder layer and the filling rate of the powder in the powder layer may include scraping off some of the ejected powder with the squeegee to adjust the thickness of the powder layer.

[0035] This removes some of the powder that has been sprayed onto the top of the powder layer, making the thickness of the powder layer uniform and reducing variations in the powder weight per unit area of ​​the powder layer.

[0036] In addition, a powder coating apparatus for an energy device in one embodiment of the present disclosure includes a powder supply unit that supplies powder onto the surface of a current collector, a squeegee that is arranged so as to form a gap between the current collector and the squeegee and vibrates at a frequency of 2 kHz to 300 kHz, and that adjusts the basis weight and filling rate of the powder supplied onto the surface of the current collector by the powder supply unit, a drive unit that moves the current collector relative to the squeegee in a predetermined direction, and a control unit that controls at least one of the gap and the vibration of the squeegee.

[0037] As a result, the control unit controls at least one of the gap between the squeegee and the current collector and the vibration of the squeegee, thereby increasing the packing rate of the powder layer formed by the powder supplied onto the surface of the current collector, which is adjusted by the squeegee. Therefore, by using a powder coating device, it is possible to manufacture a powder layer composite with an increased packing rate of the powder layer and reduced variation in the powder layer weight. Therefore, by using such a powder layer composite in an energy device, the output and quality of the energy device can be increased, and the energy device can have higher performance.

[0038] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0039] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step sequences shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components not described in independent claims are described as optional components.

[0040] Furthermore, in this specification, terms indicating the relationship between elements, such as parallelism, terms indicating the shape of elements, such as rectangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0041] In addition, each drawing is a schematic diagram in which emphasis, omission, or adjustment of proportions has been appropriately made to illustrate the present disclosure, and is not necessarily an exact illustration, and may differ from the actual shape, positional relationship, and proportion. In each drawing, substantially identical components are assigned the same reference numerals, and duplicated explanations may be omitted or simplified.

[0042] In this specification, the terms "upper" and "lower" in the configuration of an all-solid-state battery do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "upper" and "lower" are applied not only to the case where two components are arranged in close contact with each other, but also to the case where two components are arranged with a gap between them and another component is present between the two components.

[0043] In this specification, each schematic diagram shows the powder layer composite as viewed from a direction perpendicular to the thickness direction of the powder layer.

[0044] (Embodiment) [Composition of powder layer composite] First, the configuration of the powder layer composite according to the embodiment will be described. Fig. 2 is a schematic diagram of a powder layer composite 4 according to the embodiment.

[0045] 2, powder layer composite 4 includes current collector 1 and powder layer 3 formed on current collector 1. Powder layer composite 4 is a powder layer composite for an energy device and is used, for example, as an electrode of an energy device. Note that powder layer composite 4 may further include another layer, such as a connection layer made of a conductive carbon material, located between current collector 1 and powder layer 3.

[0046] The powder layer 3 has a film thickness of 50 μm or more. There is no particular upper limit to the film thickness of the powder layer 3, but it is, for example, 1000 μm or less.

[0047] The powder layer 3 includes powder 2 made of at least one kind of particulate material. The powder layer 3 is made of, for example, powder 2.

[0048] The concentration of the solvent contained in the powder layer 3 is 50 ppm or less. In other words, the powder layer 3 does not substantially contain a solvent. "Substantially not containing" means that the powder layer 3 does not contain any solvent at all, or that the solvent is unavoidably contained at 50 ppm or less as an impurity or the like. The solvent concentration is a concentration based on weight.

[0049] The size of powder layer 3 in plan view is, for example, 30 mm×30 mm or more. There is no particular upper limit to the size of powder layer 3 in plan view, but it is, for example, 300 mm×500 mm or less.

[0050] In any 30 mm × 30 mm area of ​​the powder layer 3, the variation in basis weight of the powder layer 3 is 10% or less. Here, the basis weight represents the weight of the powder 2 per unit area, and is expressed in, for example, g / cm 2 It can be expressed in units of

[0051] The basis weight is measured, for example, by the following method. First, the powder layer composite 4 is pressed from above and below to compact it, and then the powder layer composite 4 is punched out into a circle with a diameter of 5 mm to 9 mm, and the total weight of the punched powder layer 3 and current collector 1 is measured. The weight of the powder layer 3 is then found by subtracting the weight of the current collector 1 from the same lot that was punched out to a diameter of 5 mm to 9 mm, which was previously measured, from the total weight. The basis weight can be found by dividing this weight by the area of ​​the circle with a diameter of 5 mm to 9 mm.

[0052] The measurement of the variation in basis weight is performed, for example, by the following method. First, an arbitrary 30 mm × 30 mm region is selected in the powder layer composite 4 in a planar view. This region may be a central region of the powder layer composite 4, or may be a region including an end portion. Then, within this region, for example, five or more circular regions having a diameter of 5 mm or more and 9 mm or less are punched out, and the basis weight is measured using the method described above. From the viewpoint of improving the accuracy of the measurement of variation, nine or more may be punched out. The variation in basis weight is calculated by dividing the difference (more specifically, the absolute value of the difference) between the average basis weight of all punched out regions and the basis weight of the region among the punched out regions that has the largest difference from the average by the average. In other words, a variation in basis weight of 10% or less means that the difference from the average basis weight at any punched out region is 10% or less of the average.

[0053] Furthermore, the filling rate of the powder 2 in the powder layer 3 is equal to or higher than the tap filling rate of the powder 2. This makes it difficult for the powder 2 to vary in density within the powder layer 3, and reduces variations in the basis weight of the powder layer 3.

[0054] The packing rate of the powder 2 in the powder layer 3 is the ratio of the true volume of the powder 2 to the apparent volume of the powder layer 3, and can be calculated, for example, by dividing the basis weight by the thickness (unit: cm, for example) of the powder layer 3. As will be described later, the powder layer 3 is produced by passing the powder 2 through the squeegee 5, and therefore the thickness of the powder layer 3 is, for example, the thickness after passing through the squeegee 5.

[0055] The tap packing ratio of the powder 2 is the value obtained by dividing the tap density of the powder 2 by the true density of the powder 2. The tap density and the true density are expressed in units of, for example, g / cm 3 It can be expressed in units of

[0056] The tap density is the apparent density when the powder 2 is filled into a container of a predetermined size while tapping the container, and is measured, for example, by the following method.

[0057] First, powder 2 is gently poured into a container with a space of 20 mm in diameter and 20 mm in height until it overflows. Then, the container containing powder 2 is tapped. Specifically, the tapping operation is performed 100 times at a height of 10 mm and a tapping speed of 100 times per 30 seconds. After that, powder 2 is gently added until it overflows, and the tapping operation is performed again. After repeating the above-mentioned supply of powder 2 to the container and tapping operation 10 times, the powder 2 that has overflowed above the height of the space in the container is scraped off by smoothly moving a straight spatula that is vertically in contact with the top surface of the container.

[0058] After this operation, the weight of the powder 2 in the container is measured and divided by the volume of the container to obtain the tap density (g / cm) of the powder 2. 3 ) can be obtained. Then, by dividing the tap density of the powder 2 by the true density of the powder 2, the tap packing ratio of the powder 2 can be obtained.

[0059] When the powder 2 is a mixture powder made of a plurality of types of particulate materials, the tap filling rate of the mixture powder is determined.

[0060] Furthermore, in this embodiment, even if the particle size of the powder 2 varies greatly and the powder 2 has poor fluidity, it is possible to realize a powder layer composite 4 in which the basis weight of the powder layer 3 varies little.

[0061] In the powder layer 3, the particle size distribution represented by (D90-D10) / D50 of the main powder, which is the particulate material having the largest volume fraction among the at least one type of particulate material constituting the powder 2, may be greater than 75%. In this case, the packing rate of the powder 2 in the powder layer 3 may be 1.1 times or more the tap packing rate of the powder 2. This reduces the variation in the basis weight of the powder layer 3. When the powder 2 is composed of multiple types of particulate materials, it is susceptible to the influence of the particulate material having the largest volume fraction, and therefore, attention is focused on the particle size distribution of the main powder having the largest volume fraction.

[0062] In the case of powder 2 with poor fluidity, the powder 2 is difficult to arrange, which makes it easy for unevenness to occur in the voids between the powder 2 in the powder layer 3, and therefore the basis weight is likely to vary. Therefore, by increasing the filling rate of the powder 2, the voids can be reduced and the basis weight variation can be suppressed.

[0063] When the particle size distribution of the powder 2 is large, the fluidity is poor because large particles and small particles tend to combine and the powder tends to aggregate, resulting in poor fluidity.

[0064] In (D90-D10) / D50, which represents the particle size distribution, D10, D50, and D90 represent particle sizes based on the particle size distribution on a volume basis. Specifically, the particle size at a cumulative frequency of 10% on a volume basis is represented by D10, the particle size at 50% is represented by D50, and the particle size at 90% is represented by D90. D50 is also referred to as the median size. The particle size distribution is measured, for example, using a commercially available laser analysis / scattering particle size distribution measuring device. The particle size distribution may also be determined by analyzing images using a scanning electron microscope (SEM).

[0065] The filling rate of the powder 2 in the powder layer 3 is, for example, 80% or more, which increases contact between the powder particles 2 and allows the energy device using the powder layer composite 4 to have higher performance.

[0066] The powder layer 3 is formed, as will be described in detail later, by, for example, applying high-frequency vibrations to the powder 2 to impart fluidity to the powder 2 and filling the powder 2 in the powder layer 3. This makes it possible to produce a powder layer 3 that is 30 mm × 30 mm or larger in size and 50 μm or larger in thickness, and the powder layer 3 can be used in large, high-capacity energy devices.

[0067] Furthermore, by producing the powder layer 3 through, for example, a solvent-free coating process, it is possible to form a powder layer 3 that is substantially free of solvent. This prevents damage to the powder layer 3 due to the solvent. Therefore, deterioration of the powder layer 3 is suppressed, and a powder layer composite 4 is formed in which the basis weight of the powder 2 in the powder layer 3 has little variation, thereby realizing a powder layer composite 4 for a large-scale, high-capacity energy device that has high output and excellent quality.

[0068] The powder layer composite 4 can be used, for example, as a positive electrode or a negative electrode of an energy device such as an all-solid-state battery.

[0069] When the powder layer composite 4 is a positive electrode, for example, the current collector 1 is a positive electrode current collector, and the powder layer 3 containing the powder 2 is a positive electrode mixture layer. The positive electrode mixture layer is formed on the positive electrode current collector. The powder 2 in the positive electrode mixture layer contains, as at least one type of particulate material, a positive electrode active material and an ionically conductive solid electrolyte.

[0070] When the powder layer composite 4 is a negative electrode, for example, the current collector 1 is a negative electrode current collector, and the powder layer 3 containing the powder 2 is a negative electrode mixture layer. The negative electrode mixture layer is formed on the negative electrode current collector. The powder 2 in the negative electrode mixture layer contains, as at least one type of particulate material, a negative electrode active material and an ionically conductive solid electrolyte.

[0071] The positive electrode mixture layer and the negative electrode mixture layer can be produced by using the following materials for the powder 2 and by the production method described below.

[0072] The concentration of the solvent contained in the positive electrode mixture layer and the negative electrode mixture layer is 50 ppm or less. That is, the positive electrode mixture layer and the negative electrode mixture layer are substantially free of solvent. "Substantially free of solvent" means that the solvent is not contained at all, or that the solvent is unavoidably contained at 50 ppm or less as an impurity or the like.

[0073] The solvent is, for example, an organic solvent. The method for measuring the solvent is not particularly limited, and can be measured using, for example, gas chromatography, mass variation analysis, etc. Examples of organic solvents include nonpolar organic solvents such as heptane, xylene, and toluene, polar organic solvents such as tertiary amine solvents, ether solvents, thiol solvents, and ester solvents, and combinations thereof. Examples of tertiary amine solvents include triethylamine, tributylamine, and triamylamine. Examples of ether solvents include tetrahydrofuran and cyclopentyl methyl ether. Examples of thiol solvents include ethane mercaptan. Examples of ester solvents include butyl butyrate, ethyl acetate, and butyl acetate.

[0074] Next, the materials used in the positive electrode mixture layer and the negative electrode mixture layer will be described in detail.

[0075] The positive electrode active material is a material in which metal ions such as lithium (Li) are inserted into or extracted from the crystal structure at a higher potential than the negative electrode, and oxidation or reduction occurs along with the insertion or extraction of the metal ions such as lithium. The type of positive electrode active material is appropriately selected depending on the type of all-solid-state battery, and examples thereof include oxide active materials and sulfide active materials.

[0076] In this embodiment, for example, an oxide active material (lithium-containing transition metal oxide) is used as the positive electrode active material. Examples of oxide active materials include LiCoO2, LiNiO2, LiMn2O4, LiCoPO4, LiNiPO4, LiFePO4, LiMnPO4, and compounds obtained by substituting one or two different elements for the transition metals in these compounds. Examples of compounds obtained by substituting one or two different elements for the transition metals in the above compounds include LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNi 0.8 Co 0.15 Al 0.05 O2, LiNi 0.5 Mn 1.5 Known materials such as O2 can be used. The positive electrode active material may be used alone or in combination of two or more.

[0077] Examples of the shape of the positive electrode active material include particulate and thin film forms. When the positive electrode active material is particulate, the particle diameter of the positive electrode active material is, for example, in the range of 50 nm to 50 μm, and may be in the range of 1 μm to 15 μm. By setting the particle diameter of the positive electrode active material to 50 nm or more, handling is likely to be improved, while by setting the particle diameter to 50 μm or less, the use of an active material with a small particle size increases the surface area, making it easier to obtain a high-capacity positive electrode. Note that the particle diameter of the material contained in the positive electrode mixture layer or the negative electrode mixture layer in this specification is, for example, the above-mentioned D50.

[0078] The content of the positive electrode active material in the positive electrode mixture layer is not particularly limited, but may be, for example, in the range of 40% by weight to 99% by weight, or 70% by weight to 95% by weight.

[0079] The surface of the positive electrode active material may be coated with a coating layer. This is because it is possible to suppress the reaction between the positive electrode active material (e.g., oxide active material) and the solid electrolyte (e.g., sulfide-based solid electrolyte). Examples of materials for the coating layer include Li-ion conductive oxides such as LiNbO3, Li3PO4, and LiPON. The average thickness of the coating layer is, for example, in the range of 1 nm to 20 nm, and may be in the range of 1 nm to 10 nm.

[0080] The ratio of the positive electrode active material to the solid electrolyte contained in the positive electrode mixture layer, expressed as a weight ratio of positive electrode active material / solid electrolyte, may be within a range of 1 to 19, or may be within a range of 2.3 to 19. When the weight ratio is within this range, both the lithium ion conduction path and the electron conduction path are likely to be secured in the positive electrode mixture layer.

[0081] The negative electrode active material is a substance in which metal ions such as lithium are inserted into or extracted from the crystal structure at a potential lower than that of the positive electrode, and which undergoes oxidation or reduction as the metal ions such as lithium are inserted or extracted.

[0082] Examples of the negative electrode active material in this embodiment include metals that are easily alloyed with lithium, such as lithium, indium, tin, and silicon, carbon materials such as hard carbon and graphite, and Li4Ti5O 12 , SiO x Known materials such as oxide active materials, etc., can be used. Furthermore, as the negative electrode active material, a composite in which the above-mentioned negative electrode active materials are appropriately mixed can also be used.

[0083] The particle size of the negative electrode active material is, for example, 50 μm or less. By using an active material with a small particle size, the surface area becomes large, and a high capacity can be achieved.

[0084] The ratio of the negative electrode active material to the solid electrolyte contained in the negative electrode mixture layer, calculated as a weight ratio of negative electrode active material / solid electrolyte, may be, for example, in the range of 0.6 to 19, or in the range of 1 to 5.7. When the weight ratio is within this range, both the lithium ion conduction path and the electron conduction path are likely to be secured in the negative electrode mixture layer.

[0085] The solid electrolyte may be selected appropriately depending on the type of conductive ion (e.g., lithium ion), and can be broadly divided into sulfide-based solid electrolytes, oxide-based solid electrolytes, and halide-based solid electrolytes, for example.

[0086] The type of sulfide-based solid electrolyte in this embodiment is not particularly limited. Examples of sulfide-based solid electrolytes include Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, and Li2S-P2S5. 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. Furthermore, the sulfide-based solid electrolyte may be crystalline, amorphous, or glass ceramic. Note that the above description "Li2S-P2S5" refers to a sulfide-based solid electrolyte formed using a raw material composition containing Li2S and P2S5, and the same applies to other descriptions.

[0087] In the present embodiment, one form of the sulfide-based solid electrolyte is a sulfide glass ceramic containing Li2S and P2S5, and the ratio of Li2S and P2S5, when expressed in terms of moles as Li2S / P2S5=molar ratio, is, for example, in the range of 2.3 to 4, and may be in the range of 3 to 4. By keeping the molar ratio within this range, it is possible to obtain a crystal structure with high ion conductivity while maintaining the lithium concentration that affects the battery characteristics.

[0088] The shape of the sulfide-based solid electrolyte in this embodiment may be, for example, a particulate shape such as a spherical shape or an oval spherical shape, or a thin film shape. When the sulfide-based solid electrolyte material is particulate, the particle diameter of the sulfide-based solid electrolyte is not particularly limited, but may be 40 μm or less, 20 μm or less, or 10 μm or less, since this facilitates improving the filling rate in the positive electrode or negative electrode. On the other hand, the particle diameter of the sulfide-based solid electrolyte may be 0.001 μm or more, or 0.01 μm or more.

[0089] Next, the oxide-based solid electrolyte in this embodiment will be described. The type of oxide-based solid electrolyte is not particularly limited, but examples thereof include LiPON, Li3PO4, Li2SiO2, Li2SiO4, Li 0.5 La0.5 TiO3, Li 1.3 Al 0.3 Ti 0.7 (PO4)3, La 0.51 Li 0.34 TiO 0.74 , Li 1.5 Al 0.5 Ge 1.5 (PO4)3, etc. The oxide-based solid electrolyte may be used alone or in combination of two or more.

[0090] Next, the positive electrode current collector and the negative electrode current collector will be described in detail.

[0091] The positive electrode in this embodiment includes a positive electrode current collector made of, for example, a metal foil, etc. The positive electrode current collector may be, for example, a foil, plate, mesh, or the like made of aluminum, gold, platinum, zinc, copper, SUS, nickel, tin, titanium, or an alloy of two or more of these metals.

[0092] The thickness and shape of the positive electrode current collector may be appropriately selected depending on the application of the positive electrode.

[0093] The negative electrode in this embodiment includes a negative electrode current collector made of, for example, a metal foil, etc. The negative electrode current collector may be, for example, a foil, plate, mesh, etc. made of SUS, gold, platinum, zinc, copper, nickel, titanium, tin, or an alloy of two or more of these metals.

[0094] The thickness and shape of the negative electrode current collector may be appropriately selected depending on the application of the negative electrode.

[0095] [Method for manufacturing powder bed composite] Next, a method for producing a powder layer composite according to the present embodiment will be described with reference to FIGS. 3, 4A, 4B, and 4C.

[0096] 3 is a flowchart showing the manufacturing process of the powder layer composite 4 according to the embodiment. The powder layer composite 4 is formed through, for example, three steps.

[0097] As shown in FIG. 3, the method for manufacturing the powder layer composite 4 includes, for example, a powder supplying step (S10) and a powder aligning step (S20), and may further include a powder sheeting step (S30) as necessary.

[0098] First, the powder 2 to be used in the powder supplying step is prepared. The raw material of the powder 2 is not particularly limited, and for example, a mixture powder containing the above-mentioned active material may be used as the powder 2. The active material and the solid electrolyte are mixed, and additives such as a binder and a conductive material, if necessary, to prepare the powder 2. Examples of the mixing method include a method using a mortar, a ball mill, or a mixer. Alternatively, the mixing method may be a method in which the respective particle materials are mixed without using a solvent, for example. This can suppress material deterioration of the powder 2.

[0099] In the powder supplying step (S10), powder 2 is supplied onto the surface of current collector 1 to form powder layer 3. For example, while moving current collector 1 in a predetermined direction using a conveying device, powder 2 is supplied onto the surface of current collector 1 using a powder supply unit such as a hopper. Current collector 1 may be in the form of a sheet. In the powder supplying step, for example, powder 2 is supplied onto the surface of current collector 1 without using a solvent. This forms powder layer 3 that is substantially free of solvent. Note that when supplying powder 2, instead of moving current collector 1, the powder supply unit may be moved in a predetermined direction relative to current collector 1.

[0100] Next, in the powder alignment step (S20), a squeegee is used to adjust the thickness of the powder layer 3 and the packing rate of the powder 2 in the powder layer 3. For example, in the powder alignment step, the squeegee is used to align the powder 2 on the surface of the current collector 1. The squeegee is also used to adjust the basis weight of the powder 2 supplied onto the surface of the current collector 1. That is, in the powder alignment step, the basis weight of the powder layer 3 formed in the powder supply step is adjusted to a desired value. At this time, the squeegee is vibrated at a frequency of 2 kHz or more and 300 kHz or less. The powder alignment step will be described in detail later.

[0101] In the powder sheeting step (S30), the powder 2 aligned on the current collector 1, i.e., the powder layer 3 whose thickness and packing rate have been adjusted as described above, is compressed by a press or the like. This compresses the powder layer 3 on the surface of the current collector 1, further increasing the packing rate of the powder layer 3. For example, the packing rate of the powder layer 3 after the powder sheeting step is 80% or more. By compressing and compacting the powder layer 3, the powder 2 does not break down, improving the transportability of the powder layer composite 4.

[0102] As described above, in the method for producing the powder layer composite 4, the powder supplying step (S10), the powder aligning step (S20), and the powder sheet forming step (S30) are carried out in this order to obtain the powder layer composite 4 in which the powder layer 3 containing the powder 2 is formed on the surface of the current collector 1. Such a powder layer composite 4 of the current collector 1 and the powder layer 3 can be used in an energy device. For example, when a powder containing an active material is used as the powder 2, a battery electrode can be produced.

[0103] Next, the powder aligning step (S20) will be described in detail with reference to FIGS. 4A, 4B, and 4C.

[0104] In the powder alignment step, by filling the powder 2, voids in the powder layer 3 are reduced, the difference in density of the powder 2 in the powder layer 3 is reduced, and the variation in basis weight of the powder layer 3 can be reduced.

[0105] Fig. 4A is a schematic diagram illustrating the process of filling the surface of current collector 1 with supplied powder 2 in the powder alignment process. Fig. 4B is a schematic diagram illustrating the state in which excess powder 6 is ejected onto the top of powder layer 3 in the powder alignment process. Fig. 4C is a schematic diagram illustrating the state in which excess powder 6 is scraped off to keep the thickness of powder layer 3 constant in the powder alignment process. In Figs. 4A to 4C, the direction of movement of the current collector is indicated by arrows.

[0106] As shown in FIG. 4A , a powder layer 3 composed of powder 2 supplied in the powder supplying step is formed on the surface of the current collector 1. While the current collector 1 is moved in a predetermined direction, the thickness of the powder layer 3 and the packing rate of the powder 2 in the powder layer 3 are adjusted using a squeegee 5. At this time, the powder 2 in the powder layer 3 is packed so that the packing rate of the powder 2 in the powder layer 3 is equal to or greater than the tap packing rate of the powder 2. In this way, a powder layer composite 4 including the current collector 1 and the powder layer 3 is formed. Note that the squeegee 5 may be moved in the predetermined direction instead of the current collector 1. In other words, the current collector 1 is moved in the predetermined direction relative to the squeegee 5. The predetermined direction is a direction perpendicular to the thickness direction of the current collector 1, and is, for example, the longitudinal direction of the current collector 1 when the current collector 1 is a long sheet.

[0107] The squeegee 5 is positioned so as to form a gap between it and the current collector 1. This gap is set according to the thickness of the powder layer 3 to be formed. The squeegee 5 vibrates at a frequency of 2 kHz to 300 kHz. That is, the squeegee 5 is vibrated at a high frequency close to the ultrasonic band. In the powder alignment process, the squeegee 5 vibrated at a frequency of 2 kHz to 300 kHz is used to adjust the thickness of the powder layer 3 and the packing rate of the powder 2 in the powder layer 3. By vibrating the squeegee 5 at a high frequency close to the ultrasonic band, the fluidity of the powder 2 is increased, and the powder 2 is aligned and packed.

[0108] The fluidity of the powder 2 tends to increase as the vibration frequency of the squeegee 5 increases. Therefore, by vibrating the squeegee 5 at a frequency of 2 kHz or higher, which is in the high-frequency range near the ultrasonic band, the fluidity of the powder 2 can be sufficiently increased. High frequencies near the ultrasonic band are easily attenuated, so if the frequency is too high, the vibrations are difficult to transmit, but by vibrating the squeegee 5 at a frequency of 300 kHz or lower, the fluidity of the powder 2 can be sufficiently increased. By vibrating the squeegee 5 at a high frequency near the ultrasonic band, the powder 2 in contact with the squeegee 5 is less susceptible to frictional resistance due to powder pressure, and the increased fluidity allows the powder 2 to be aligned and filled.

[0109] In this way, the current collector 1 moves in a predetermined direction, and the powder 2 on the top of the powder layer 3 passes over the squeegee 5 while contacting the squeegee 5, and the squeegee 5 vibrates at a high frequency near the ultrasonic band, causing the powder 2 to flow and align, thereby increasing the packing rate of the powder 2 in the powder layer 3. To further improve the packing rate of the powder 2, the powder 2 may be passed over the squeegee 5 multiple times. When passing the powder 2 over the squeegee 5 multiple times, the current collector 1 may be moved in the same direction each time, or may be moved by alternately reversing the moving direction.

[0110] The direction of high frequency vibration of the squeegee 5 in the vicinity of the ultrasonic band may be only vertical or only horizontal to the surface of the squeegee 5 .

[0111] The vertical direction is a direction perpendicular to the main surface of the squeegee 5 facing the powder layer 3. Vibrations in the vertical direction tend to propagate longitudinal waves to the powder 2 (waves in the direction in which the squeegee 5 vibrates so as to move toward and away from the powder 2).

[0112] The vibration component in the vertical direction has a large effect on reducing the frictional resistance between the powder particles 2. Specifically, the vertical vibration is the direction in which the squeegee 5 vibrates so as to move closer to and away from the powder particles 2, causing repeated collisions between the powder particles 2 and facilitating transmission of the vibration to the powder 2. High frequencies in the vicinity of the ultrasonic band are high, and therefore there is a risk that vibrations between the powder particles 2 are difficult to transmit, but with vertical vibration, vibrations are particularly easily transmitted to the powder 2.

[0113] In particular, the vibration component in the vertical direction can greatly move the powder 2 in the accumulation portion where the powder 2 has accumulated. This makes it easier for the powder 2 to collide with each other, and therefore makes it easier for the powder 2 to flow.

[0114] The horizontal direction is a direction parallel to the main surface of the squeegee 5 facing the powder layer 3 and parallel to the axis of the squeegee 5. Vibrations in the horizontal direction tend to transmit transverse waves (waves in the direction in which the squeegee 5 vibrates as it rubs against the powder 2) to the powder 2. Note that the axis of the squeegee 5 refers to an axis parallel to the width direction, which is perpendicular to the longitudinal direction of the powder layer 3, when the squeegee 5 is elongated, such as cylindrical. The axis of the squeegee 5 may be parallel to the longitudinal direction of the squeegee 5.

[0115] The main surface of the squeegee 5 is, for example, a surface parallel to the upper surface of the current collector 1. Furthermore, when vibrating the squeegee 5, high-frequency vibrations near the ultrasonic band in both the vertical and horizontal directions may be used in combination. This can further improve the fluidity of the powder 2. When focusing on a single particle of powder, the vibration direction of the powder 2 becomes random and vibration is applied to the entire powder surface, so there are no surfaces where the vibration is not transmitted and where frictional resistance is high, thereby improving fluidity.

[0116] When the squeegee 5 vibrates vertically and horizontally at a high frequency near the ultrasonic band, the magnitude of the horizontal vibration of the squeegee 5 may be greater than the magnitude of the vertical vibration of the squeegee 5. That is, in the vibration of the squeegee 5, the magnitude of the shear wave component of the powder 2 (the direction in which the surface of the squeegee 5 and the surface of the powder 2 vibrate so as to rub against each other) may be greater than the magnitude of the longitudinal wave component of the powder 2 (the direction in which the squeegee 5 vibrates so as to approach and move away from the powder 2). The high-frequency horizontal vibration of the squeegee 5 near the ultrasonic band not only reduces the frictional resistance between the powder particles 2, but also significantly contributes to reducing the frictional force between the squeegee 5 and the powder 2. Therefore, the horizontal vibration of the squeegee 5 can reduce the frictional resistance at the interface between the squeegee 5 and the powder 2, where frictional resistance is particularly likely to be high, and can also reduce the frictional resistance between the powder particles 2, thereby further improving the fluidity of the powder 2.

[0117] The magnitude of the vertical vibration of the squeegee 5 is, for example, 2 μm or more. That is, the vertical amplitude of the squeegee 5 is, for example, 2 μm or more. This makes it possible to sufficiently reduce the frictional resistance between the powder particles 2 and further increase the fluidity of the powder particles 2. Furthermore, the vertical amplitude of the squeegee 5 is, for example, 20 μm or less. This makes it possible to suppress large vertical vibration of the powder particles 2 and reduce film thickness variations.

[0118] The magnitude of the horizontal vibration of the squeegee 5 is, for example, 4 μm or more. That is, the horizontal amplitude of the squeegee 5 is, for example, 4 μm or more. This makes it possible to sufficiently reduce the frictional resistance at the interface between the squeegee 5 and the powder 2, and further increase the fluidity of the powder 2. The horizontal amplitude of the squeegee 5 is, for example, 40 μm or less. This prevents the powder 2 from vibrating significantly in the horizontal direction, and reduces the size variation in the powder layer 3 in the width direction, which is caused by the powder 2 moving significantly at the width direction ends of the powder layer 3.

[0119] The squeegee 5 is, for example, cylindrical, and is arranged so that the axial direction of the cylinder (the height direction of the cylinder) is parallel to the top surface of the current collector 1 and intersects (for example, perpendicular to) the direction of movement of the current collector 1. The cylindrical squeegee 5 is arranged such that both ends of the axial direction of the cylinder of the squeegee 5 are fixed to supports with bearings so that the squeegee 5 can slide horizontally. In this case, by shaping the axis of the squeegee 5 to fit into the bore of a circular bearing, it is possible to create a relationship in which the horizontal amplitude is greater than the vertical amplitude.

[0120] In this way, by increasing the filling rate of the powder 2 in the powder layer 3, it is possible to reduce variations in the basis weight of the powder layer 3 and obtain a good powder layer 3. Furthermore, in the powder alignment step, in order to adjust the thickness of the powder layer 3 and the filling rate of the powder 2 in the powder layer 3, at least one of the gap between the squeegee 5 and the current collector 1, the vibration of the squeegee 5 (for example, at least one of the frequency and amplitude), and the number of times the powder 2 is passed over the squeegee 5 is adjusted.

[0121] When the filling rate of the powder 2 is low, the difference in density of the powder 2 in the powder layer 3 becomes large. Therefore, the variation in basis weight of the powder layer 3 also becomes large. Therefore, as described above, the powder 2 is aligned to increase the filling rate of the powder 2 in the powder layer 3. As a result, the voids in the powder layer 3 are replaced with powder 2, and the voids become smaller. Therefore, the difference in density of the powder 2 in the powder layer 3 becomes small, and a powder layer 3 with small variation in basis weight can be obtained.

[0122] In this embodiment, in order to further reduce variations in the basis weight of the powder layer 3, the following steps may be carried out.

[0123] 4B , the powder alignment step includes ejecting a portion of the powder 2 in the powder layer 3 to a position that is higher from the current collector 1 than the gap between the squeegee 5 and the current collector 1. In other words, excess powder 6, which is a portion of the powder 2 in the powder layer 3, is ejected onto the top of the powder layer 3.

[0124] The state in which part of the powder 2 in the powder layer 3 is ejected means that the powder 2 in the powder layer 3 is fully aligned and fully packed, and it is difficult to pack more powder 2 into the powder layer 3, causing the excess powder 6 to eject. In other words, whether the powder layer 3 is sufficiently packed with powder 2 can be determined by observing the state of ejection of the excess powder 6 from the powder layer 3. In other words, it is possible to confirm the high packing state of the powder 2 without measuring the packing rate of the powder 2 in the powder layer 3 using a separate measuring device, etc., and the quality of the powder layer 3 can be stabilized simply and reliably.

[0125] For example, by adjusting the vibration conditions of the squeegee 5 and the gap between the squeegee 5 and the current collector 1, or by repeatedly passing the powder 2 through the squeegee 5, the filling rate of the powder 2 in the powder layer 3 is increased and the excess powder 6 is ejected.

[0126] The state in which the excess powder 6 is ejected in this manner means that there are almost no voids in the powder layer 3. In other words, there are almost no voids between the powder particles 2, which are the cause of differences in density of the powder 2 in the powder layer 3, i.e., the variation in the basis weight of the powder layer 3. Therefore, by ejecting the excess powder 6, the variation in the basis weight of the powder layer 3 is further reduced.

[0127] In this way, when the excess powder 6 is ejected and the powder layer 3 is sufficiently filled, the filling rate of the powder 2 in the powder layer 3 is equal to or greater than the tap filling rate of the powder 2 or equal to or greater than 1.1 times the tap filling rate of the powder 2.

[0128] Furthermore, the powder alignment step may include, after the excess powder 6 is ejected, scraping off the excess powder 6 with a squeegee 5 to adjust the thickness of the powder 2, as shown in FIG. 4C.

[0129] By scraping off the excess powder 6, the excess powder 6 sprayed onto the upper part of the powder layer 3 is removed, making the film thickness of the powder layer 3 uniform and reducing variation in the basis weight of the powder layer 3. In this step of scraping off the excess powder 6, the amplitude of the squeegee 5 may be smaller than in the step of filling the powder 2 before spraying the excess powder 6. Since the main purpose of the step of scraping off the excess powder 6 is to level the thickness of the powder layer 3, reducing the amplitude makes it possible to scrape off the excess powder 6 while suppressing further spraying of the excess powder 6. Furthermore, in the step of scraping off the excess powder 6, the squeegee 5 does not need to be vibrated.

[0130] The method for removing the excess powder 6 is not limited to scraping it off with the squeegee 5. For example, the excess powder 6 may be removed using a scraping tool other than the squeegee 5, or by sucking the excess powder 6 using a suction device, or by blowing gas onto the excess powder 6 to blow it away.

[0131] [Powder coating equipment] Next, a powder coating apparatus used in manufacturing the powder layer composite according to the present embodiment will be described with reference to Fig. 5. In the following description, the contents described in the above-described method for manufacturing the powder layer composite 4, such as the description of the squeegee 5, will be omitted or simplified.

[0132] FIG. 5 is a schematic diagram of a powder coating apparatus 10 used to manufacture the powder layer composite 4 according to this embodiment.

[0133] As shown in FIG. 5, powder coating apparatus 10 includes a squeegee 5, a powder supply unit 11, a drive unit 12, and a control unit 13. Powder coating apparatus 10 is a powder coating apparatus for energy devices and is used to manufacture powder layer composites for energy devices. Powder coating apparatus 10 coats powder 2 onto the surface of current collector 1 while transporting current collector 1 using drive unit 12, which is a transport device. Specifically, powder coating apparatus 10 transports current collector 1 using drive unit 12, and continuously supplies powder 2 onto the surface of current collector 1 using powder supply unit 11.

[0134] The drive unit 12 is a device that moves the current collector 1 in a predetermined direction. The drive unit 12 is not particularly limited as long as it can transport the current collector 1. For example, the drive unit 12 is a roll-to-roll transport device that continuously unwinds the current collector 1 wound in a roll shape, but is not limited thereto. The drive unit 12 may be, for example, a conveyor-type transport device having a conveyor that moves the current collector 1. The drive unit 12 may also unwind the current collector 1 intermittently. Note that the transport path of the current collector 1 may be provided with a guide roller that rotates as the current collector 1 moves, a control device that corrects meandering of the current collector 1, and the like. The drive unit 12 may also be a device that moves the squeegee 5 and the powder supply unit 11 in a predetermined direction. In other words, the drive unit 12 moves the current collector 1 in a predetermined direction relative to the squeegee 5 and the powder supply unit 11.

[0135] The powder supply unit 11 supplies the powder 2 onto the surface of the current collector 1. The powder supply unit 11 is, for example, a hopper. The hopper stores the powder 2 therein and supplies the powder 2 onto the surface of the current collector 1. The powder supply unit 11 is disposed upstream of the squeegee 5 in the moving direction of the current collector 1. The powder 2 supplied onto the surface of the current collector 1 by the powder supply unit 11 forms a powder layer 3 and reaches the squeegee 5 as the current collector 1 moves. Note that, although a hopper is used as the powder supply unit 11 in this embodiment, the present invention is not limited thereto, and the powder supply unit 11 may be any device capable of supplying the powder 2 onto the surface of the current collector 1. The powder supply unit 11 may be, for example, a feeder.

[0136] The squeegee 5 applies a coating by adjusting the basis weight and packing rate of the powder 2 supplied onto the current collector 1. In the present embodiment, the squeegee 5 has an end face parallel to the current collector 1. The shape of the squeegee 5 is not particularly limited, but may be, for example, a cylinder. The squeegee 5 vibrates at a frequency of 2 kHz or more and 300 kHz or less. The squeegee 5 is capable of adjusting, for example, the frequency and amplitude of vibration. The vibration direction and amplitude of the squeegee 5 are as described above in the method for producing the powder layer composite 4.

[0137] The squeegee 5 is disposed on the surface side of the current collector 1 to which the powder 2 is supplied, so as to form a predetermined gap between the squeegee 5 and the current collector 1. The squeegee 5 is also disposed, for example, so that the gap between the squeegee 5 and the current collector 1 can be adjusted. The gap between the squeegee 5 and the current collector 1 may be adjusted by moving the position of the squeegee 5, or may be adjusted by moving the position of the current collector 1.

[0138] The squeegee 5 is disposed downstream of the powder supply unit 11 in the direction of movement of the current collector 1. This allows the powder 2 supplied onto the surface of the current collector 1 to pass through the gap between the squeegee 5 and the current collector 1. That is, the powder 2 supplied onto the surface of the current collector 1 from the powder supply unit 11 reaches the squeegee 5 as the current collector 1 moves and is smoothed by the squeegee 5. The squeegee 5 also vibrates while contacting the powder 2 supplied onto the surface of the current collector 1, imparting fluidity to the powder 2 supplied onto the surface of the current collector 1, aligning the powder 2, and reducing voids in the powder layer 3. That is, the squeegee 5 adjusts and increases the packing rate of the powder 2 in the powder layer 3. The squeegee 5 also scrapes off the powder 2 located higher than the gap between the squeegee 5 and the current collector 1, thereby adjusting the basis weight and thickness of the powder layer 3.

[0139] The control unit 13 is a control mechanism (control device) for controlling at least one of the gap between the squeegee 5 and the current collector 1 and the vibration of the squeegee 5. To control the gap between the squeegee 5 and the current collector 1, the control unit 13 adjusts, for example, the position of at least one of the squeegee 5 and the current collector 1. The control unit 13 also controls the vibration of the squeegee 5 by, for example, adjusting at least one of the amplitude and frequency of the vibration of the squeegee 5. By controlling at least one of the gap between the squeegee 5 and the current collector 1 and the vibration of the squeegee 5, the squeegee 5 fills the powder layer 3 with powder 2 at a filling rate equal to or greater than the tap density of the powder 2. This reduces voids in the powder layer 3 and reduces variations in the basis weight of the powder layer 3. This is because uneven distribution of voids in the powder layer 3 is a cause of variations in basis weight, and reducing the voids reduces the uneven distribution of voids.

[0140] In addition, in order to adjust the filling rate of the powder 2 in the powder layer 3, the control unit 13 may control the supply amount of the powder 2 by the powder supply unit 11 and / or the relative movement speed of the current collector 1 by the drive unit 12.

[0141] (Other embodiments) The powder bed composite and the like according to the present disclosure have been described above based on the embodiments, but the present disclosure is not limited to the above embodiments. The above embodiments are merely examples, and anything that has substantially the same configuration as the technical idea and exhibits similar effects within the scope of the claims of the present disclosure is included within the technical scope of the present disclosure. Furthermore, various modifications that a person skilled in the art could conceive of to the embodiments and other forms constructed by combining some of the components of the embodiments are also included within the scope of the present disclosure, as long as they do not deviate from the gist of the present disclosure.

[0142] For example, although the above embodiment has been described with reference to an example in which the ions conducted between the positive electrode and the negative electrode are lithium ions, the present invention is not limited to this example and may be ions other than lithium ions, such as sodium ions, magnesium ions, potassium ions, calcium ions, or copper ions, conducted between the positive electrode and the negative electrode. [Industrial Applicability]

[0143] The powder composite for an energy device according to the present disclosure is substantially free of solvent, has small variations in basis weight, and has a uniform powder layer, and therefore can be used in a variety of applications, such as electrodes for high-quality all-solid-state batteries. [Explanation of symbols]

[0144] 1 Current collector 2 powder 3 Powder layer 4 Powder bed composite 5 Squeegee 6. Excess powder 10 Powder coating equipment 11 Powder supply section 12 Drive unit 13 Control Unit

Claims

1. A current collector; a powder layer having a film thickness of 50 μm or more formed on the current collector, the powder bed includes a powder made up of at least one type of particulate material; The concentration of the solvent contained in the powder layer is 50 ppm or less, In any 30 mm × 30 mm area of ​​the powder layer, the variation in basis weight of the powder layer is 10% or less, the particle size distribution of the main powder, which is the particulate material having the largest volume ratio among the at least one particulate material, expressed as (D90-D10) / D50 is greater than 75%; The packing rate of the powder in the powder layer is 1.1 times or more of the tap packing rate of the powder. Powder bed composite for energy devices.

2. The filling rate of the powder in the powder layer is 80% or more. The powder layer composite for an energy device according to claim 1 .

3. the current collector is a positive electrode current collector, The powder contains, as the at least one kind of particulate material, a positive electrode active material and an ion-conductive solid electrolyte. The powder layer composite for an energy device according to claim 1 or 2.

4. the current collector is a negative electrode current collector, The powder contains, as the at least one kind of particulate material, a negative electrode active material and an ion-conductive solid electrolyte. The powder layer composite for an energy device according to claim 1 or 2.

5. supplying powder onto a surface of a current collector to form a powder layer containing the powder; adjusting the thickness of the powder layer and the packing rate of the powder in the powder layer by using a squeegee that is vibrated at a frequency of 2 kHz to 300 kHz while moving the current collector relatively in a predetermined direction with respect to the squeegee that is arranged so as to form a gap between the current collector and the squeegee, In adjusting the thickness of the powder layer and the packing rate of the powder in the powder layer, the powder is packed in the powder layer so that the packing rate of the powder in the powder layer is equal to or greater than a tap packing rate of the powder; the powder comprises at least one type of particulate material powder; When the particle size distribution expressed by (D90-D10) / D50 of the main powder, which is the material particle having the largest volume ratio among the at least one kind of particulate material, is greater than 75%, In adjusting the thickness of the powder layer and the packing rate of the powder in the powder layer, the powder is packed in the powder layer so that the packing rate of the powder in the powder layer is 1.1 times or more the tap packing rate of the powder. A method for manufacturing powder bed composites for energy devices.

6. Adjusting the thickness of the powder layer and the packing rate of the powder in the powder layer is a part of the powder in the powder layer is ejected to a position whose height from the current collector is higher than the gap. A method for producing the powder layer composite for an energy device according to claim 5.

7. Adjusting the thickness of the powder layer and the packing rate of the powder in the powder layer is scraping off the part of the ejected powder with the squeegee to adjust the thickness of the powder layer. The method for producing the powder layer composite for an energy device according to claim 6.

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