Electrode base material, electrode base material laminate, electrode and secondary battery, and method for manufacturing the same

Abstract

To provide an electrode base material, an electrode base material laminate, an electrode, and a secondary battery, and a method for manufacturing the same that have excellent ionic conductivity while mitigating volume fluctuations in active material particles and suppressing declines in output.SOLUTION: An electrode base material used in the manufacture of an electrode includes a resin base material, active material particles, and solid electrolyte particles, and when an average equivalent circular diameter of the active material particles is defined as ra and an average equivalent circular diameter of the solid electrolyte particles is defined as re, re / ra is in a specific range, and when, among the solid electrolyte particles, particles having a particle size exceeding a specific particle size are defined as first solid electrolyte particles, and particles having a particle size equal to or smaller than the specific particle size are defined as second solid electrolyte particles, the active material particles and the first solid electrolyte particles are disposed adjacent to each other, and, upon cross-sectional observation of the particle layer, 80% or more by number of the second solid electrolyte particles are unevenly distributed on the side in contact with the resin base material or on the opposite side with respect to a reference line at a specific position.SELECTED DRAWING: Figure 23

Description

[Technical field]

[0001] The present disclosure relates to an electrode substrate, an electrode substrate laminate, an electrode and a secondary battery, and a method for producing the same. [Background technology]

[0002] In general, secondary batteries are composed of electrodes (positive and negative electrodes) and an electrolyte, and are charged and discharged by the movement of ions between the electrodes via the electrolyte. Such secondary batteries are used in a wide range of applications, from small devices such as mobile phones to large devices such as electric vehicles. Therefore, there is a demand for further improvement in the performance of secondary batteries.

[0003] In recent years, research and development of so-called all-solid-state batteries, which use inorganic solid electrolytes as the electrolyte, has progressed. All-solid-state batteries are expected to improve the safety and increase the capacity and power output of secondary batteries by replacing conventional organic electrolytes with solid electrolytes. On the other hand, in the process of ion insertion and removal in the electrode of an all-solid-state battery, the volume of the active material particles changes, and the conductive paths in the electrode, particularly between the electrode and the current collector and between the electrode and the electrolyte, are easily cut off. As a result, deterioration is likely to occur when charging and discharging are repeated, and the so-called cycle characteristics are likely to decrease. Therefore, a technology is known in which a mitigation portion is provided inside the electrode to mitigate the effect of the volume change.

[0004] Patent Document 1 discloses an electrode having a plurality of ceramic crystal particles of an electrode active material or solid electrolyte material, with aggregates of carbon particles having voids at the grain boundaries between the crystals. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-002482 Summary of the Invention [Problem to be solved by the invention]

[0006] However, according to the study by the inventors, the aggregates of carbon particles having voids tend to form at the interface between large ceramic crystal particles, whereas the aggregates are less likely to form at the interface between small ceramic crystal particles, which tend to aggregate. That is, at the interface between ceramic crystal particles, there are sparse areas where the aggregates of carbon particles having voids are formed and areas where the aggregates are not formed, making it difficult to provide a uniform relaxation area inside the electrode, and it has been found that the effect of volume fluctuation is not sufficiently mitigated. On the other hand, it has been found that if the ratio of the aggregates to the ceramic crystal particles is increased for the purpose of mitigation, there is a problem that ion conduction is easily hindered and output is easily reduced.

[0007] Therefore, an object of the present disclosure is to provide an electrode substrate, an electrode substrate laminate, an electrode, and a secondary battery that have excellent ion conductivity while mitigating the effects of volume fluctuations in active material particles and are capable of suppressing a decrease in output, as well as methods for manufacturing the electrode substrate, the electrode substrate laminate, the electrode, and the secondary battery. [Means for solving the problem]

[0008] According to at least one aspect of the present disclosure, An electrode substrate used in the manufacture of an electrode, The electrode substrate is A resin substrate, and active material particles and solid electrolyte particles on the resin substrate, a particle layer including the active material particles and the solid electrolyte particles is formed on the resin substrate; When a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the active material particles is defined as an average equivalent circle diameter ra of the active material particles, and a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the solid electrolyte particles is defined as an average equivalent circle diameter re of the solid electrolyte particles, a ratio (re / ra) of the average equivalent circular diameter re to the average equivalent circular diameter ra is 0.01 or more and 2.0 or less, Among the solid electrolyte particles, Particles having a particle size exceeding a cumulative 10% particle size on a number basis from the small particle size side in the distribution of equivalent circle diameters of primary particles of the solid electrolyte particles are defined as first solid electrolyte particles, When the particles having a cumulative particle size of 10% or less are defined as second solid electrolyte particles, In the particle layer, the active material particles and the first solid electrolyte particles are disposed adjacent to each other, when a cross-sectional observation of the particle layer is performed, 80% or more by number of the second solid electrolyte particles are unevenly distributed on a side of the particle layer that is in contact with the resin substrate or on an opposite side to the resin substrate with respect to a reference line, The reference line indicates a peak position of the distribution of the active material particles in the particle layer in the lamination direction of the resin substrate and the particle layer, thereby providing an electrode base material characterized in that:

[0009] According to at least one embodiment of the present disclosure, there is provided an electrode substrate laminate in which a plurality of the above-described electrode substrates are laminated.

[0010] According to at least one aspect of the present disclosure, there is provided an electrode for a secondary battery, the electrode being a sintered body of the electrode base material described above. Also, there is provided an electrode being a sintered body of an electrode base material laminate in which a plurality of the electrode base materials are laminated.

[0011] According to at least one embodiment of the present disclosure, there is provided a secondary battery comprising an electrode that is a sintered body of the electrode base material described above, and an electrolyte layer adjacent to the electrode.

[0012] According to at least one aspect of the present disclosure, A method for producing an electrode substrate used in the production of an electrode, comprising the steps of: The production method comprises the steps of: preparing the resin substrate having an adhesive portion; disposing the active material particles and the first solid electrolyte particles on a surface of the adhesive portion; a particle settling step of settling the first solid electrolyte particles and the active material particles arranged on the surface of the adhesive portion onto the adhesive portion; and disposing second solid electrolyte particles in the adhesion portions between the settled first electrolyte particles and the active material particles.

[0013] Also, there is provided a method for producing an electrode base material used in the production of an electrode, comprising the steps of: The electrode substrate is The active material particles and the solid electrolyte particles are disposed on the resin substrate. a particle layer including the active material particles and the solid electrolyte particles is formed on the resin substrate; When a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the active material particles is defined as an average equivalent circle diameter ra of the active material particles, and a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the solid electrolyte particles is defined as an average equivalent circle diameter re of the solid electrolyte particles, a ratio (re / ra) of the average equivalent circular diameter re to the average equivalent circular diameter ra is 0.01 or more and 2.0 or less, the solid electrolyte particles include solid electrolyte particles P2 and solid electrolyte particles P3, the cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the solid electrolyte particles P2 is larger than the cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the solid electrolyte particles P3; The production method comprises the steps of: preparing the resin substrate having an adhesive portion on a surface thereof; disposing the active material particles and the solid electrolyte particles P2 adjacent to each other on a surface of the adhesion portion; a particle settling step of settling the solid electrolyte particles P2 and the active material particles arranged on the surface of the adhesive portion into the adhesive portion; disposing the solid electrolyte particles (P3) at the adhesion portions between the settled solid electrolyte particles (P2) and the active material particles; A method for producing an electrode substrate having the following structure is provided.

[0014] According to at least one aspect of the present disclosure, there is provided a method for producing an electrode, comprising the steps of: A step of laminating a plurality of the electrode base materials to form a laminate; removing the resin substrate from the laminate to obtain a three-dimensional object; and applying pressure to the three-dimensional object to obtain an electrode. Furthermore, according to at least one aspect of the present disclosure, there is provided a method for producing a secondary battery, comprising the steps of: The production method comprises the steps of: preparing an electrode by the electrode manufacturing method; and laminating the electrode, the current collector, and the electrolyte. Effect of the Invention

[0015] According to at least one aspect of the present disclosure, there are provided an electrode substrate, an electrode, and a secondary battery that have excellent ion conductivity while mitigating volume fluctuations in active material particles and are capable of suppressing a decrease in output, and methods for manufacturing the electrode substrate, the electrode, and the secondary battery. [Brief description of the drawings]

[0016] [Figure 1] 1 is a conceptual diagram showing a manufacturing method of an electrode substrate. [Diagram 2] FIG. 1 is a diagram showing a schematic configuration of a particle arrangement device 1. [Diagram 3] FIG. 2 is a diagram showing a schematic configuration of a filling device. [Figure 4] FIG. 2 is a schematic diagram of a filler being carried on a first substrate. [Diagram 5] FIG. 2 is an enlarged view of the vicinity of the surface of the first substrate. [Figure 6] FIG. 13 is a diagram showing a schematic configuration of a filling device when brush fibers are used as a support material. [Figure 7] FIG. 2 is a diagram illustrating a configuration of a transfer unit. [Figure 8] 13 is an enlarged view of the vicinity of the surface of the second substrate during the filling process by the second filling device. [Figure 9] FIG. 2 is a diagram showing a schematic view of a second substrate after first particles P1 and second particles P2 have been transferred. [Figure 10] FIG. 2 is a diagram showing a schematic configuration of a particle arrangement device 2. [Figure 11]FIG. 2 is a schematic diagram showing the devices for the third and fourth steps in the manufacturing method of the electrode substrate. [Figure 12] FIG. 2 is a schematic diagram of a cross section of a substrate for explaining sedimentation of particles on the substrate. [Figure 13] FIG. 4 is a schematic diagram of the electrode substrate after the third step in the manufacturing method thereof, viewed from above (the particle layer side). [Figure 14] FIG. 4 is a schematic diagram of the electrode substrate after a fourth step in the manufacturing method thereof, viewed from above (the particle layer side). [Figure 15] FIG. 13 is a schematic diagram showing a third filling device that does not use a belt device. [Figure 16] FIG. 4 is a schematic diagram illustrating the operation of the filling device. [Figure 17] FIG. 1 is an image diagram showing a method for manufacturing an electrode. [Figure 18] FIG. 2 is a diagram showing a schematic configuration of a laminate forming apparatus. [Figure 19] FIG. 2 is a diagram showing a schematic configuration of a sintering treatment apparatus. [Figure 20] SEM images of laminates and three-dimensional objects at each stage of the electrode manufacturing method. [Figure 21] FIG. 1 is a diagram illustrating an overall configuration of an additive manufacturing system. [Figure 22] FIG. 2 is a diagram showing a schematic structure of a first base material having a concave-convex pattern formed on its surface. [Diagram 23] 1 is an SEM image of the electrode substrate of Example 1. [Figure 24] 13 is an SEM image of the electrode substrate of Comparative Example 2. [Diagram 25] SEM image of the electrode substrate of Comparative Example 5. [Figure 26] 1 is a BIB-SEM image of a cross section of an electrode produced using the electrode base material of Example 1. [Figure 27] FIG. 2 is a schematic diagram of an electrode substrate produced using the electrode substrate of Example 1. [Figure 28] 13 is a BIB-SEM image of a cross section of an electrode produced using the electrode substrate of Comparative Example 2. [Figure 29] 13 is a BIB-SEM image of a cross section of an electrode produced using the electrode base material of Comparative Example 5. [Diagram 30] FIG. 2 is a diagram showing an example of an SEM image of the upper surface (particle layer side) of an electrode substrate. [Diagram 31] FIG. 11 is a diagram showing an example of an image used for calculating a coverage ratio. [Diagram 32] FIG. 4 is a diagram showing an example of a cross-sectional image of an electrode substrate photographed by an electron microscope. [Diagram 33] FIG. 13 shows an example of an image used to calculate ra. [Diagram 34] FIG. 13 is a diagram showing an example of an image used for calculating re. [Diagram 35] 1A and 1B show a BIB-SEM image and an example of a peak in the distribution of active material particles. [Diagram 36] FIG. 4 is a diagram showing an example of the center position and reference line of a second solid electrolyte particle. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In the present disclosure, the expressions "XX to YY" and "XX to YY" expressing a numerical range mean a numerical range including the lower and upper limits, unless otherwise specified. When a numerical range is described in stages, any combination of the upper and lower limits of each numerical range is also disclosed.

[0018] When an inorganic solid electrolyte is used as the electrolyte, the active material and the electrolyte are in contact with each other in a solid state, so it is difficult to obtain a sufficient contact area and to form an interface. In particular, if the active material aggregates, the aggregated active material has even less contact with the solid electrolyte, and the ion conductivity is likely to decrease. As described above, the active material particles undergo volumetric changes during the process of ion insertion and removal. This volumetric change can easily break the conductive paths within the electrode, particularly between the electrode and the current collector and between the electrode and the electrolyte, and can easily degrade the cycle characteristics.

[0019] In order to solve the above problems, the inventors have investigated a structure that can form a good interface between the active material and the electrolyte while providing a layer inside the electrode that can reduce the effect of the volumetric fluctuation of the active material. As a result of the investigation, it was found that it is important to provide a uniform void portion inside the electrode to reduce the effect of the volumetric fluctuation of the active material, while providing a uniform dense portion in the vicinity of the void portion to ensure sufficient contact between the active material and the electrolyte and maintain ionic conductivity. Specifically, it is considered important to control the arrangement of each particle in the electrode substrate so that specific electrolyte particles are unevenly distributed inside the electrode. By unevenly disposing specific electrolyte particles in the electrode substrate, a structure can be obtained in which a uniform dense portion of the electrolyte particles is provided on the substrate side or the opposite side to the substrate of the electrode substrate, and a uniform void portion is provided on the opposite side of the dense portion. By manufacturing an electrode using the electrode base material having such a configuration, it is possible to reduce the influence of volume fluctuations of the active material particles inside the electrode, while facilitating the conduction of ions from the active material particles to the electrolyte. Furthermore, in a secondary battery using such an electrode, a decrease in output can be suppressed even when charging and discharging are repeated.

[0020] In the present disclosure, the above-mentioned embodiment is realized by using an electrode base material in which active material particles and solid electrolyte particles are arranged on a resin base material with the characteristics of the present disclosure. A plurality of electrode base materials can be laminated to form an electrode base material laminate. The electrode base material and the electrode base material laminate can also be used as materials for electrodes. In the present disclosure, the mitigation of volumetric variation is evaluated conveniently using an index called the "cycle characteristics" of a prototype battery, and the ionic conductivity is evaluated conveniently using an index called the "rate characteristics" of a prototype battery. The electrode substrate, the electrode substrate laminate, the electrode, and the secondary battery using them, as well as the manufacturing method thereof, will be described in detail below.

[0021] The electrode substrate of the present disclosure can be used in the manufacture of electrodes for secondary batteries. Hereinafter, a positive electrode substrate using positive electrode active material particles will be described as an example, but the electrode substrate of the present disclosure can be used for both positive and negative electrodes. The electrode substrate includes a resin substrate, active material particles on the resin substrate, and solid electrolyte particles. A particle layer including the active material particles and the solid electrolyte particles is formed on the resin substrate.

[0022] The resin substrate is a substrate made of a material containing a resin. By using a substrate made of an organic material such as a resin as the substrate, it is possible to easily remove the substrate by heating in the manufacturing process of the electrode substrate described later. The resin contained in the material of the resin substrate is not particularly limited, and examples thereof include polyesters such as polyethylene (PE), polypropylene (PP) and polyethylene terephthalate (PET), as well as polyamides such as nylon. Of these, it is preferable to use PET from the viewpoints of its decomposition temperature and the low toxicity of gases generated during thermal decomposition.

[0023] The active material particles are not particularly limited and known active materials can be used. For example, a composite oxide containing lithium can be used. Specifically, for example, Li-Co oxide active material particles such as LiCoO2, LiMO2 (M is one element selected from the group consisting of Ni, Mn, and Co), Li-PO4 oxide active material particles, lithium vanadium compounds (Li3V2(PO4)3, LiVOPO4), olivine phosphate compounds (LiMPO4 (M is one or more elements selected from the group consisting of Co, Ni, Mn, Fe, Mg, V, Nb, Ti, Al, and Zr)), etc. may be used. In addition, a positive electrode active material that does not contain lithium may be used. Specifically, for example, metal oxides (MnO2, V2O5, etc.) and fluorides (FeF3, VF3, etc.) may be used. When a positive electrode active material that does not contain lithium is used, it can be used by disposing a metallic lithium containing lithium or a negative electrode active material doped with lithium ions as a negative electrode active material and starting with discharging.

[0024] The present inventors have revealed that the use of Li-Co oxide-based active material particles among the above positive electrode active material particles increases the surface area of ​​the positive electrode active material particles and improves the output characteristics of the secondary battery (JP Patent Publication No. 2020-198301). In addition, Li-PO4 oxide-based active material particles are very stable because the covalent bond between PO is strong and oxygen release is suppressed. For this reason, it is preferable to include Li-Co oxide-based active material particles and Li-PO4 oxide-based active material particles among the above positive electrode active material particles.

[0025] The active material particles may be a commercially available product, or may be prepared separately as a material. As the Li-Co oxide-based active material particles, for example, Cellseed C-5H (trade name, manufactured by Nippon Chemical Industry Co., Ltd.) (LiCoO2) can be used. As the LiMO2 (M is an element selected from the group consisting of Ni, Mn, and Co), Cellseed NMC (trade name, manufactured by Nippon Chemical Industry Co., Ltd.) (LiNi (1-x-y) Mn x Co y O2) As the Li-PO4 oxide-based active material particles, LiFePO4 (manufactured by Toshima Manufacturing Co., Ltd.) or the like can be used. When using active material particles with low electronic conductivity such as LiFePO4, the particle surfaces may be coated with carbon by a general method. The active material particles may be used alone or in combination of two or more kinds.

[0026] The solid electrolyte particles are not particularly limited, and ion-conductive solids that are normally used in all-solid-state batteries can be used. For example, Li-B oxide-based solid electrolyte particles, Li-Yb oxide-based solid electrolyte particles, Nasicon-type solid electrolyte particles (LiAlTi(PO4)3, LiAlGe(PO4)3, etc.), Li-PO-based solid electrolyte particles (Li3PO4, LiPON (particles in which part of O in Li3PO4 is replaced with N), etc.) can be mentioned. Among the above solid electrolyte particles, Li-B oxide-based solid electrolyte particles and Li-Yb oxide-based solid electrolyte particles can be sintered at a relatively low temperature (700°C or less), so that the reaction with the positive electrode active material particles during sintering can be suppressed and ion conductivity can be maintained. For this reason, among the above solid electrolyte particles, it is preferable to include Li-B oxide-based solid electrolyte particles and Li-Yb oxide-based solid electrolyte particles.

[0027] The solid electrolyte particles to be used may be commercially available products, or may be separately prepared as a material. As the Li-B oxide-based solid electrolyte particles, for example, Li3BO3 (manufactured by Toshima Manufacturing Co., Ltd.) or particles in which part of O in Li3BO3 is replaced with C can be used. As the Li-Yb oxide-based solid electrolyte particles, for example, Li 5.9 Yb 0.81 La 0.09 Zr 0.1 (BO3)3, etc. can be used.

[0028] The cumulative 50% particle size (by number) calculated from the distribution of the equivalent circle diameters of the primary particles of the active material particles is defined as the average equivalent circle diameter ra of the active material particles, and the cumulative 50% particle size (by number) calculated from the distribution of the equivalent circle diameters of the primary particles of the solid electrolyte particles is defined as the average equivalent circle diameter re of the solid electrolyte particles. The circle equivalent diameter refers to the diameter of a sphere (circle) with a volume (area) equal to the volume (area) of the particle. Note that ra and re are obtained by processing a cross section with a broad ion beam (BIB) of Ar, and obtaining a two-dimensional image of the cross section with a scanning electron microscope. Hereinafter, the above-mentioned method of observing two-dimensional images is called BIB-SEM. The details of the measurement method will be described later.

[0029] In the electrode substrate, among the solid electrolyte particles, particles having a particle size exceeding the cumulative 10% particle size (re10) on a number basis from the small particle size side in the distribution of the equivalent circle diameter of the primary particles of the solid electrolyte particles are defined as first solid electrolyte particles, and particles having a particle size equal to or smaller than the cumulative 10% particle size are defined as second solid electrolyte particles. That is, the second solid electrolyte particles are a particle group having a smaller equivalent circle diameter of the primary particles than the first solid electrolyte particles among all the solid electrolyte particles. By disposing the first solid electrolyte particles and the second solid electrolyte particles in specific regions of the electrode substrate by the method described below, it is possible to provide uniform voids and uniform dense portions inside the electrode. As a result, ions are easily conducted from the active material particles to the electrolyte while mitigating the effect of volume fluctuation of the active material particles inside the electrode.

[0030] The equivalent circle diameter of the primary particles of the first solid electrolyte particles is not particularly limited, but is preferably, for example, 1 to 100 μm, and more preferably 2 to 50 μm. The equivalent circle diameter of the primary particles of the second solid electrolyte particles is not particularly limited as long as it is smaller than that of the first solid electrolyte particles, but is preferably, for example, ½ or less, and more preferably ⅓ or less, of the equivalent circle diameter of the first solid electrolyte particles. The diameter of the primary particles of the second solid electrolyte particles relative to the circle equivalent diameter of the primary particles of the first solid electrolyte particles The value of the circle-equivalent diameter ratio (circle-equivalent diameter of second solid electrolyte particle / circle-equivalent diameter of first solid electrolyte particle) is not particularly limited, but is preferably, for example, 0.50 or less, and more preferably 0.30 or less.

[0031] The electrode base material has a particle layer including active material particles and solid electrolyte particles formed on a resin base material. In the particle layer, the active material particles and the first solid electrolyte particles are arranged adjacent to each other. By arranging in this manner, a uniform dense portion of the active material particles and the solid electrolyte particles is provided, and the active material particles and the solid electrolyte particles can be sufficiently contacted with each other. As a result, the ion conductivity can be improved. For example, first particles P1 as active material particles and second particles P2 that can correspond to first solid electrolyte particles are arranged on a resin substrate as a material of the electrode substrate by a method described later. This allows the active material particles and the first solid electrolyte particles to be controlled so as to be arranged adjacent to each other in the electrode substrate. The formation of a particle layer in the electrode substrate and the adjacent arrangement of the active material particles and the first solid electrolyte particles can be confirmed by, for example, observation with an SEM.

[0032] In addition, in a cross-sectional observation of the particle layer, 80% or more of the second solid electrolyte particles are unevenly distributed on the side of the particle layer that contacts the resin substrate (one side in the stacking direction of the resin substrate and the particle layer in the particle layer) or on the opposite side to the resin substrate side (the other side in the stacking direction of the resin substrate and the particle layer in the particle layer) with respect to the reference line. The reference line indicates the peak position of the distribution of the active material particles in the stacking direction of the resin substrate and the resin layer in the particle layer. The method of determining the reference line and the method of judging the uneven distribution will be described later. For example, when the electrode base material is observed from a cross section, the resin base material, the unevenly distributed second solid electrolyte particles, the active material particles, and the first solid electrolyte particles are arranged in this order from the lower side of the electrode base material (the side on which the particle layer is not formed). Alternatively, the resin base material, the active material particles, the first solid electrolyte particles, and the unevenly distributed second solid electrolyte particles may be arranged in this order from the lower side of the electrode base material (the side on which the particle layer is not formed). That is, in the particle layer in the electrode substrate, a dense portion of the solid electrolyte particles is provided on the side in contact with the resin substrate or on the side opposite to the resin substrate, and a uniform void portion is provided on the side opposite to the dense portion. By adopting such a configuration, the influence of the volume fluctuation of the active material particles can be mitigated. Preferably, 80% or more of the second solid electrolyte particles are unevenly distributed on the side opposite to the resin substrate.

[0033] For example, the third particles P3, which may correspond to the second solid electrolyte particles, are disposed on a resin substrate as the material of the electrode substrate by a method described later, whereby the second solid electrolyte particles can be controlled to be unevenly distributed in the electrode substrate in the above-mentioned state. In the present disclosure, in an electrode substrate, the second solid electrolyte particles present on the resin substrate are identified, and if 80% or more by number of the identified particles are present on the side in contact with the resin substrate or on the side opposite to the resin substrate, the second solid electrolyte particles are determined to be unevenly distributed. A method for identifying the second solid electrolyte particles and a method for determining uneven distribution will be described later.

[0034] The average equivalent circular diameter ra of the active material particles is defined as the cumulative 50% particle diameter (by number) calculated from the distribution of the equivalent circular diameters of the primary particles of the active material particles.The average equivalent circular diameter re of the solid electrolyte particles is defined as the cumulative 50% particle diameter (by number) calculated from the distribution of the equivalent circular diameters of the primary particles of the solid electrolyte particles.In this case, the ratio of the average equivalent circular diameter re to the average equivalent circular diameter ra (re / ra) is 0.01 or more and 2.0 or less.

[0035] Active material particles often have higher electronic conductivity than solid electrolyte particles, and the degree of contact between active material particles tends to affect electronic conductivity within the electrode. The re / ra ratio of 0.01 or more means that the average equivalent circle diameter r of the primary particles of the solid electrolyte particles This indicates that e is appropriately large relative to the average equivalent circle diameter ra of the active material particles, and as a result, the cohesive force and adhesive force of the solid electrolyte particles can be kept within an appropriate range. By controlling the cohesive force of the solid electrolyte particles to an appropriate range where the cohesive force is not excessive, the solid electrolyte particles can be easily mixed appropriately when stirred with a carrier, which will be described later. In addition, by controlling the adhesive force to an appropriate range where the adhesive force is not excessive, the solid electrolyte particles can be prevented from covering the upper part of the active material particles arranged on the electrode substrate. Therefore, contact between the active material particles is not hindered, and high electronic conductivity in the electrode is maintained.

[0036] The re / ra of 2.0 or less indicates that the average equivalent circular diameter re of the primary particles of the solid electrolyte particles is not excessively larger than the average equivalent circular diameter ra of the active material particles and is in an appropriate range, which results in a larger number of active material particles being disposed on the electrode substrate without impeding contact between the active material particles. As described above, the solid electrolyte particles and the active material particles are disposed on the resin substrate. When re / ra is 2.0 or less, the unevenness of the substrate surface is reduced. Therefore, when the electrode substrate is laminated by the method described below, the active material particles and the solid electrolyte particles, or the active material particles and the solid electrolyte particles in the substrate lamination direction can be sufficiently contacted without being hindered. This makes it possible to maintain high ion conductivity of the battery and improve the rate characteristics. In addition, since more active material particles can be disposed on the electrode substrate, a battery with high volumetric energy density can be manufactured.

[0037] re / ra is preferably 0.05 or more, more preferably 0.10 or more, and even more preferably 0.50 or more. It is also preferably 1.8 or less, more preferably 1.5 or less, and even more preferably 1.0 or less. For example, it is preferably in the range of 0.05 to 1.8, 0.10 to 1.5, or 0.50 to 1.0.

[0038] Although ra is not particularly limited, it is preferably 0.1 to 100 μm, more preferably 0.5 to 20 μm, and further preferably 1 to 10 μm. Although there are no particular limitations, re is preferably 0.01 to 50 μm, more preferably 0.05 to 10 μm, and further preferably 0.1 to 5 μm.

[0039] <Method of manufacturing electrode substrate> An example of a method for producing an electrode substrate will be described in detail below with reference to the drawings. Although a positive electrode substrate using positive electrode active material particles will be described below as an example, the method for producing an electrode substrate can be used for both positive and negative electrodes.

[0040] The method for producing the electrode substrate includes the following steps. (1) A preparation step of preparing a resin substrate having an adhesive portion. (2) A first step (S101 in FIG. 1) of disposing first particles P1 on the surface of the adhesive portion. (3) A second step (S102 in FIG. 1) of disposing second particles P2 on the surface of the adhesive portion. (4) A third step (S103 in FIG. 1) of allowing the first particles P1 and the second particles P2 to settle in the adhesive portion. (5) A fourth step (S104 in FIG. 1) of arranging third particles P3 having an average equivalent circular diameter smaller than those of the first particles P1 and the second particles P2 in contact with the settled first particles P1 or second particles P2.

[0041] (preparation process) In the preparation step, a resin substrate having an adhesive portion is prepared. In the present disclosure, the term "having an adhesive portion" refers to an adhesive portion being provided on a part or the entire surface of the resin substrate. As the resin substrate, a substrate containing the above-mentioned resin can be used. Although there is no particular limitation, a method of applying a pressure-sensitive adhesive to the surface of a resin substrate is preferred. The adhesive is not particularly limited, and any known adhesive can be used, for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, or a thermoplastic resin or a photocurable resin whose adhesive strength changes depending on disturbances such as heat or light.

[0042] (First and second steps) The first step is a step of arranging first particles P1 on the surface of the adhesive part of the resin substrate, and the second step is a step of arranging second particles P2 on the surface of the adhesive part of the resin substrate. 1, the second step (S102) is illustrated as following the first step (S101), but the order of the first step and the second step is not particularly limited. That is, the step of arranging the second particles P2 on the surface of the adhesive portion may be followed by the step of arranging the first particles P1.

[0043] The first particles P1 are active material particles. For example, the above-mentioned active material particles can be used as the first particles P1. The particle size of the primary particles of the first particles P1 is not particularly limited, but for example, the cumulative 10% particle size (r10) in the volumetric particle size distribution is preferably 0.1 to 10.0 μm, more preferably 1.0 to 7.0 μm. The cumulative 50% particle size (r50) in the volumetric particle size distribution is preferably 0.5 to 20.0 μm, more preferably 2.0 to 10.0 μm. Furthermore, the cumulative 90% particle size (r90) in the volumetric particle size distribution is preferably 2.0 to 20.0 μm, more preferably 3.0 to 15.0 μm.

[0044] The second particles P2 are solid electrolyte particles, and can correspond to the first solid electrolyte particles in the electrode substrate. The above-mentioned materials can be used as the solid electrolyte particles. The cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the second particles P2 is larger than the r50 of the primary particles of the third particles P3 described below.

[0045] The particle size of the primary particles of the second particles P2 is not particularly limited as long as it is larger than that of the third particles P3. For example, the second particles P2 preferably have a cumulative 10% particle size (r10) in the volume-based particle size distribution of the primary particles of 0.5 to 10.0 μm, more preferably 1.0 to 7.0 μm. Furthermore, the cumulative 50% particle size (r50) in the volume-based particle size distribution is preferably 1.0 to 20.0 μm, more preferably 5.0 to 15.0 μm. Furthermore, the cumulative 90% particle size (r90) in the volume-based particle size distribution is preferably 5.0 to 50.0 μm, more preferably 10.0 to 30.0 μm.

[0046] The ratio of the particle size of the primary particles of the first particles P1 to the particle size of the primary particles of the second particles P2 is not particularly limited. For example, the ratio {(r50(P1)) / (r50(P2))} of the cumulative 50% particle diameter (r50(P1)) in the volume-based particle size distribution of the primary particles of the first particle P1 to the cumulative 50% particle diameter (r50(P2)) in the volume-based particle size distribution of the primary particles of the second particle P2 is preferably 0.05 to 20.0, and more preferably 0.1 to 2.0.

[0047] As described above, the first particles P1 are active material particles. The second particles P2 are particles that can correspond to the first solid electrolyte particles in the manufactured electrode substrate. That is, in the manufacturing method of the electrode substrate, the first and second steps can be said to be steps of arranging the active material particles and the first solid electrolyte particles on the surface of the adhesive portion. In the first and second steps, particles are arranged on the adhesive portion of the resin substrate using a particle arrangement device. Hereinafter, the particle arrangement device will be referred to as Particle Arrangement Device 1 and Particle Arrangement Device 2. The following will be explained in order.

[0048] [Particle placement device 1] FIG. 2 is a diagram showing a schematic configuration of the particle arrangement device 1. As shown in FIG. The particle placement device 1 has a first storage container 21a that stores and supplies a first substrate 11a, a first belt device 22a that transports the first substrate 11a, and a pattern forming device 23 that forms a concave-convex pattern on the first substrate 11a. The particle arrangement device 1 has a first filling device 24a that arranges the first particles P1 in the recesses of the concave-convex pattern formed on the first substrate 11a. The particle arrangement device 1 has a second storage container 21b that stores and supplies the second substrate 11b, and a second belt device 22b that transports the second substrate 11b. The particle arrangement device 1 has a transfer section 25a in which the rollers 223 of the first belt device 22a and the second belt device 22b face each other, and the first particles P1 are transferred from the first substrate 11a to the second substrate 11b in the transfer section 25a.

[0049] Furthermore, the particle arrangement device 1 has a second filling device 24b that arranges second particles P2 in a non-transfer portion on the second base material 11b. Note that illustrations and detailed descriptions of devices that are less relevant to explaining the effects of the present invention, such as a peeling and collecting device for peeling and collecting the first base material 11a after transfer from the first belt device 22a and each cleaning device, are omitted.

[0050] In the particle arrangement device 1, the pattern forming device 23, the first filling device 24a, and the transfer unit 25a correspond to a first arrangement means that arranges the first particles P1 in a pattern on the second base material 11b. The second filling device 24b corresponds to a second arrangement means that arranges the second particles P2 in the areas on the second base material 11b where the first particles P1 are not arranged.

[0051] Hereinafter, a method for arranging particles on substrate 11 using particle arrangement device 1 will be described following the flow of each process. First, the first substrate 11a is supplied from the first storage container 21a to the first belt device 22a by a supplying means (not shown). When the ultraviolet-curable liquid is applied by a pattern forming device 23 (described later), it is preferable that at least the surface of the first base material 11a is made of a material that has high wettability with the ultraviolet-curable liquid. In addition, it is preferable that the surface of the first base material 11a is smooth.

[0052] The first substrate 11a may be a sheet made of a resin such as polyester that has been subjected to a hydrophilic or lipophilic treatment according to the ultraviolet-curable liquid (water-based or oil-based) to be used. The first substrate 11a may be a substrate that is individually cut like cut paper, a continuous substrate wound in a roll like roll paper, or a continuous substrate that is alternately folded like continuous paper.

[0053] The first belt device 22a transports the supplied first base material 11a to a pattern forming position of the pattern forming device 23. The first belt device 22a has driving rollers 221a and 222a, a pressure roller 223a, and a belt-like transport member 224a suspended between them. At this time, the pressure roller 223a is rotated by being driven.

[0054] The conveying member 224a is preferably made of resin or metal, and may be, for example, a polyimide resin belt. The driving rollers 221a and 222a are preferably made of metal, and may be, for example, stainless steel metal rollers. The pressure roller 223a is preferably a soft roller having an elastic layer on its surface, and may be, for example, a soft roller having a silicone rubber elastic layer on the surface of a stainless steel core.

[0055] 2, the first belt device 22a is used as a conveying device for conveying the first base material 11a, but a roller device may be used instead of the belt device. The same applies to the second belt device 22b described later.

[0056] The pattern forming device 23 forms a fine concave-convex pattern on the first base material 11a transported to the pattern forming position. Methods for forming the concave-convex pattern include a UV imprint method, a thermal imprint method, a UV inkjet method, a printing method, and a laser etching method.

[0057] When the pattern forming device 23 forms a concave-convex pattern by the UV imprint method, the pattern forming device 23 has a coating means for coating an ultraviolet-curable liquid on the first base material 11a. As the ultraviolet-curable liquid, for example, an ultraviolet-curable resin such as an ultraviolet-curable liquid silicone rubber can be used. The pattern forming device 23 also has an imprinting means for imprinting a mold having a concave-convex pattern formed on its surface onto the ultraviolet-curable liquid on the first base material 11a, and a light source for irradiating the ultraviolet-curable liquid with ultraviolet rays. Typically, an ultraviolet-curable liquid silicone rubber (PDMS) or resin is used as the ultraviolet-curable liquid, a film mold is used as the mold, and a UV lamp is used as the light source.

[0058] When the first filling device 24a fills the recesses on the first base material 11a with the first particles P1 using the support material S1 carrying the first particles P1, the opening diameter (width) of the recesses in the uneven pattern on the first base material 11a is preferably larger than the cumulative 50% particle diameter (median diameter) based on volume of the first particles P1. Also, the opening diameter (width) of the recesses is preferably smaller than the average size of the support material S1. Here, the opening diameter of the recesses in the uneven pattern is preferably the opening diameter in the short side direction of the recesses, and more preferably the maximum opening diameter in the short side direction of the recesses. The width of the recess can be appropriately adjusted depending on the particle sizes of the first particles P1 and the support material S1, etc. The width of the recess is not particularly limited, but is preferably, for example, 0.2 to 30 μm, and more preferably 2 to 15 μm.

[0059] By setting the opening diameter of the recesses of the uneven pattern as described above, the first particles P1 can contact the bottom and side (typically the bottom) of the recesses of the uneven pattern. On the other hand, the support material S1 cannot contact the bottom and side of the recesses. This allows the first particles P1 that contact the bottom and side of the recesses to be captured by the uneven pattern, while the support material S1 can be prevented from being captured by the uneven pattern. In other words, it is preferable that the first particles P1 can contact the bottom and side of the recesses of the uneven pattern, and the first support material S1 cannot contact the bottom and side of the recesses of the uneven pattern.

[0060] Although the pattern forming device 23 forms an uneven pattern on the first substrate 11a, a substrate on which an uneven pattern has been formed in advance on its surface may be used as the first substrate 11a. Alternatively, the pattern forming device 23 may directly form an uneven pattern on the surface of the transport member 224a of the first belt device 22a, or a transport member having an uneven pattern on its surface may be used as the transport member 224a. In this case, in consideration of durability, it is preferable to use a metal belt such as stainless steel or aluminum, and form an uneven pattern on the surface by a micromachining technique such as laser etching, wet etching, or dry etching.

[0061] The first base material 11a having the concave-convex pattern formed on its surface is transported by the first belt device 22a to the filling position of the first filling device 24a. 3 is a diagram showing a schematic configuration of the filling device. The configuration of the first filling device 24a will be described below, but the same applies to the second filling device 24b.

[0062] The first filling device 24a has a filling container 242a that contains a filler 241a, a stirring screw member 243a that stirs and conveys the filler 241a, a recovery member 244a that recovers the filler, and a magnetic member 247a.

[0063] The filler 241a has first particles P1 and a support material S1 that supports the first particles P1. The filler 241a is a mixture of multiple powders including a powder composed of multiple first particles P1 and a powder composed of multiple support materials S1. The filler 241a contained in the filling container 242a is sufficiently mixed when stirred and transported by the stirring screw member 243a. As a result, the first particles P1 are supported on the surface of the support material S1. The force acting between the particles when supported includes, in addition to electrostatic force due to frictional charging, van der Waals force, liquid bridge force, etc.

[0064] The support material S1 is a magnetic particle. The support material S1 is preferably a particle in which the surface of a resin particle in which ferrite core particles or a magnetic body is dispersed is coated with a resin composition. For example, a standard carrier (Standard Carrier P02 manufactured by the Imaging Society of Japan), which is a magnetic particle, can be used. The particle size and material of the support material S1 are appropriately selected according to the particle size and material of the first particles P1. This allows the support material S1 to stably support the first particles P1. In addition, even if the first particles P1 have a small particle size and tend to aggregate, the support material S1 plays a role of loosening the particles by stirring and transporting them. The particle size of the support material S1 can be adjusted appropriately by changing the size (area, width, depth) of the recesses. For example, the cumulative 50% particle size (median diameter) on a volume basis is preferably 50 to 100 μm.

[0065] Recovery member 244a has roller 245a rotatable in the direction of arrow d2 in the figure, and magnet 246a arranged inside roller 245a and fixed to filling container 242a. Magnetic member 247a is arranged facing filling container 242a via transport member 224a, and has magnet 248a inside.

[0066] The magnet 246a has a plurality of N poles and S poles arranged alternately along the rotation direction of the recovery member 244a. The magnet 248a has a plurality of N poles and S poles arranged alternately along the transport direction of the transport member 224a. The magnet 246a has a magnetic pole (N1 pole in FIG. 3) of a different polarity at a position closest to and facing the most downstream magnetic pole (S1 pole in FIG. 3) of the magnet 248a, and an N2 pole of the same polarity as the N1 pole is arranged at the most downstream position. The magnet 246a and the magnet 248a may be composed of a plurality of magnets, and the type of magnets constituting the magnet 246a and the magnet 248a is not particularly limited. For example, a permanent magnet such as a rare earth magnet, a ferrite magnet, a neodymium magnet, a samarium-cobalt magnet, or a plastic magnet, or a means for generating a magnetic field such as an electromagnet can be used. The magnet 248a may be configured to be movable in the transport direction of the first base material 11a or in the opposite direction.

[0067] In addition, a regulating member for regulating the filler 241a on the first base material 11a or a collecting member for re-collecting the filler 241a that cannot be collected by the collecting member 244a may be provided upstream or downstream of the collecting member 244a in the transport direction of the transport member 224a. As the collecting member for re-collecting, in addition to a member similar to the collecting member 244a, a simple member such as a fixed magnet or a regulating member, or a collecting member that collects by air blowing can be used.

[0068] Next, the process of filling the recesses on the first base material 11a with the first particles P1 by the first filling device 24a will be described with reference to FIGS. As the first conveying member 224a moves in the direction of the solid arrow d1 in FIG. 3, the first base material 11a carried and conveyed by the first conveying member 224a is conveyed, and the first filling device The container is transported to a loading position in the loading station 24a.

[0069] The filler 241a is transported by the stirring screw member 243a and supplied onto the first substrate 11a (dotted line a in FIG. 3). At this time, a magnetic field is formed by the magnetic member 247a and the recovery member 244a, and the filler 241a containing the support material S1, which is a magnetic particle, forms a plurality of magnetic chains on the first substrate 11a due to the magnetic field. The filler 241a supplied onto the first substrate 11a is transported on the first substrate 11a while forming magnetic chains as the first substrate 11a moves (dotted line b in FIG. 3).

[0070] 4A, 4B, and 4C are schematic diagrams of the filler 241a being transported on the first substrate 11a. For the sake of explanation, the filler 241a other than the filler forming one magnetic hair is omitted from the illustration. As described above, the filler 241a on the first substrate 11a forms a magnetic hair along the magnetic field lines of the formed magnetic field, and is transported while changing the shape of the magnetic hair as shown in FIG. 4A, FIG. 4B, and FIG. 4C with the movement of the first substrate 11a. At this time, since a particularly strong magnetic force acts in the vicinity of the magnet 248a, the transport speed v2 of the filler 241a is smaller than the moving speed v1 of the first substrate 11a when the filler 241a moves away from the magnetic pole, and is larger in the opposite case. That is, the filler 241a on the first substrate 11a has a relative speed that is not 0 with respect to the first substrate 11a.

[0071] Fig. 5 is an enlarged view of the vicinity of the surface of the first base material 11a in Fig. 4A to C. Although not shown in Fig. 4A to C, an uneven pattern 111a is formed on the first base material 11a as shown in Fig. 5. The uneven pattern can be formed as a desired pattern such as a honeycomb pattern or a line pattern. The filler 241a comes into contact with the concave-convex pattern 111a, and is transported together with the first substrate 11a while being subjected to a magnetic force (solid line Fm in the figure) in a direction perpendicular to the surface of the first substrate 11a and having a non-zero relative speed with respect to the first substrate 11a. As a result, the first particles P1 supported on the support material S1 are transported while being rubbed against the concave-convex pattern 111a on the surface of the first substrate 11a.

[0072] At this time, the particle size of the first particles P1 is smaller than the opening diameter of the recesses of the uneven pattern 111a, and the particle size of the first support material S1 is larger than the opening diameter of the recesses, so the first particles P1 can contact the bottom surface (bottom part) and side parts of the recesses of the uneven pattern 111a, but the support material S1 cannot. That is, only the first particles P1 in the filler 241a selectively contact the bottom surface and side parts of the recesses.

[0073] The first particles P1 that come into contact with the recesses are strongly bound by a physical binding force due to the structure of the concave-convex pattern 111a and non-electrostatic adhesive forces such as electrostatic adhesion and adhesive forces with the structural materials that constitute the first base material 11a and the concave-convex pattern 111a, and are detached from the support material S1. Note that, for the sake of explanation, in Fig. 5, the first particles P1 are supported on the surface of the support material S1, but it is acceptable for the first particles P1 to be present that are not supported by the support material S1 during the stirring, supply, or transport of the filler 241a.

[0074] Downstream of the magnetic member 247a, the recovery member 244a is disposed with a gap between it and the first transport member 224a, as shown in Fig. 3. As the first base material 11a moves, the filler 241a transported to the vicinity of the most downstream magnetic pole (pole S1) of the magnet 248a moves from the first base material 11a to the recovery member 244a under the influence of the magnetic field formed by the magnet 246a, and is recovered (dotted line c in Fig. 3).

[0075] As described above, during the conveying process (dotted lines a, b, and c in FIG. 3), the concave portions of the concave-convex pattern 111a on the surface of the first base material 11a are in sufficient contact with the plurality of fillers 241a. After the filler 241a is collected by the collecting member 244a, the first particles P1 are selectively and densely arranged in the recesses of the concave-convex pattern 111a.

[0076] 4A to 4C and 5, the first particles P1 are all shown with the same particle size, but in reality there is a particle size distribution, and depending on the material, they may form secondary particles by agglomeration. Also, they may not be spherical as shown. Even in such cases, only particles that can contact the recesses of the uneven pattern 111a are selectively densely packed, so that coarse powder and secondary particles that may adversely affect the particle arrangement process are easily excluded.

[0077] In this way, the amount of the first particles P1 filled into the recesses of the concave-convex pattern 111a can be controlled by the size (area, width, height) of the concave-convex pattern and the particle size of the first particles P1. Specifically, the area of ​​the recesses is approximately the filled area, and the layer thickness of the filled first particles P1 is determined by the height of the protrusions. The pitch of the convex portions is not particularly limited, but is preferably, for example, 1.0 to 20 μm, and more preferably 2.0 to 15 μm. The height of the convex portions is not particularly limited, but is preferably, for example, 0.1 to 20.0 μm, and more preferably 1.0 to 10.0 μm. The area ratio of the recesses (the ratio of the recesses to the area of ​​the recessed and concave pattern) is not particularly limited, but is preferably, for example, 50% or more, and more preferably 70% or more.

[0078] For example, to obtain a thin layer (single layer) that is 50% of the substrate area, the area ratio of the recesses (area ratio of the recesses to the entire recessed / protruding pattern) should be controlled to 50%, and the depth of the recesses should be controlled to the particle size of the first particles P1 or less. In this case, the opening width of the recesses should be larger than the median diameter of the first particles P1 and smaller than the average size (here, the average particle size) of the support material S1.

[0079] The first particles P1 may have a wide particle size distribution, but the support material S1 preferably has a narrow particle size distribution, and more preferably is monodisperse. This makes it easier to prevent the support material S1 from contacting the bottom (or bottom surface) or side of the recess. If the support material S1 can contact the bottom or side of the recess, there is a risk that the support material S1 will be restrained and filled in the recess.

[0080] Furthermore, the opening width of the recesses of the uneven pattern 111a is preferably smaller than four times the particle diameter of the first particles P1. By making the opening width smaller than four times the particle diameter of the first particles P1, the probability that the first particles P1 will come into contact with two points, the bottom and side surfaces of the recesses of the uneven pattern 111a, can be increased. In this way, the first particles P1 that come into contact with the recesses of the uneven pattern 111a at multiple points are strongly constrained by the uneven pattern 111a, and therefore the efficiency of filling the uneven pattern 111a with the first particles P1 can be increased. The same applies to the particle size of the second particles P2 described later and the size of the recesses of the uneven pattern formed by the first particles P1 on the second base material. In addition, when brush fibers are used as the support material, the "average particle size of the support material" in the above explanation becomes the "average fiber diameter of the support material."

[0081] The filler 241a collected by the collecting member 244a is transported by the roller 244a which is a rotating collecting member (dotted line in FIG. 3 d). The filler 241a transported by the roller 244a falls into the filling container 242a (dotted line in FIG. 3 e) due to the magnetic field of two adjacent and repelling same-polarity magnetic poles (N1, N2) and the influence of gravity. Thereafter, the filler 241a is stirred and transported again by the stirring screw member 243a, and this process is repeated thereafter.

[0082] The mass ratio of the first particles P1 and the support S1 in the filler 241a in the filling container 242a is measured by an inductance sensor that uses magnetic permeability, which is common in electrophotographic devices, or by a sensor on a substrate. The concentration is determined by a patch concentration sensor or the like that measures and predicts the reflection density of the first particles P1 and the support material S1. At least one of the first particles P1 and the support material S1 is replenished by a replenishing means (not shown) as necessary. This allows stable filling over a long period of time.

[0083] The mass % of the first particles P1 in the filler 241a (the ratio of the mass of the first particles P1 to the total mass of the filler 241a) is expressed by the following formula (1) using the coverage S1 of the surface area of ​​the magnetic particles (support material) by the supported first particles P1. The coverage S1 indicates the ratio of the total cross-sectional area of ​​the first particles P1 to the surface area of ​​the magnetic particles (support material). Mass% of the first particles P1 in the filler 241a=(400×ρ P1 ×r P1 ×S1) / (100×ρ c ×r c +4×ρ P1 ×r P1 ×S1) Formula (1) (The descriptions in formula (1) are as follows: ρ P1 : true density of the first particle P1, r P1 : particle size of the first particle P1 (r50), ρ c : true density of magnetic particles, r c : particle size of the magnetic particle (r50), S1: coverage rate of the first particle P1 to the surface area of ​​the magnetic particle)

[0084] The mass % of the first particles P1 in the filler 241a is not particularly limited, but is preferably in the range of 5 to 40 mass %, or 10 to 30 mass %. Moreover, the coverage S1 in the above formula (1) is preferably adjusted to be 30 to 200 area %, and more preferably adjusted to be 50 to 100 area %. The particle diameter (r50) of the first particle P1 and the magnetic particle (support material) can be determined by laser diffraction scattering type particle size distribution measurement, and the true density of the first particle P1 and the magnetic particle (support material) can be determined by the pycnometer method.

[0085] Although the filling device described here uses magnetic particles as a carrier material to form a so-called magnetic brush and fills the recesses with the particulate material, the type of filling device is not limited to this. Brush fibers can also be used as the carrier material. Alternatively, an elastic material, at least the surface of which is made of an elastic body, can also be used as the carrier material.

[0086] FIG. 6A is a diagram showing a schematic configuration of a filling device 24c in the case where brush fibers are used as the support material. The filling device 24c has a roller 2410 having brush fibers on its surface. The roller 2410 is a so-called brush roller, with brush fibers planted on its surface. The material of the fibers constituting the brush fibers of the roller 2410 may be, for example, nylon, rayon, acrylic, vinylon, polyester, or vinyl chloride. The surface of the fibers may be subjected to a surface treatment in order to adjust the electrostatic charge property or rigidity.

[0087] The filling device 24c has a supplying member that supplies the filler 241a to the roller 2410. The filler 241a contains a powder including the first particles P1, and is contained in a filling container 242a. In this example, the filler 241a does not contain the carrier material S1, which is a magnetic particle. The filler 241a is stirred and transported by a stirring screw member 243a, and is supplied to a supplying member 249.

[0088] The supply member 249 is a member that supplies the filler 241a to the roller 2410, and its configuration is not particularly limited. For example, the supply member 249 can be a roller having at least a surface made of a porous foam material having elasticity. Typically, an elastic sponge roller having a foamed skeletal structure and having a relatively low hardness polyurethane foam formed on a core metal can be used. Note that, in addition to urethane, various rubber materials such as nitrile rubber, silicone rubber, acrylic rubber, hydrin rubber, and ethylene propylene rubber can be used as the material of the foam material.

[0089] The supplied filler 241a is filled into the foam material on the surface of the supply member 249, and the roller 24 The foam material is transported to a supply section where the foam material comes into contact with the brush fibers of the roller 2410. In the supply section, the filler 241a filled in the foam material is charged by contact with the brush fibers of the roller 2410, and is carried by the brush fibers of the roller 2410. Furthermore, the supply member 249 may also have a function of peeling off the filler 241a remaining on the roller 2410 and refreshing it. The filler 241a supplied to the roller 2410 comes into contact with the first base material 11a by the movement of the brush fibers.

[0090] At this time, the first particles P1 in the filler 241a can contact the bottom and side surfaces of the recesses of the uneven pattern 111a on the surface of the first base material 11a, but the brush fibers cannot. That is, the fiber diameter of the brush fibers is made larger than the opening width of the recesses of the uneven pattern 111a. The fiber diameter of the brush fibers can be measured by placing glass on the surface of the roller 2410 and taking an image of the brush fibers through the glass using an optical microscope. At this time, the fiber diameters of about 100 brush fibers are measured, and the distribution of the fiber diameters is measured to calculate the average diameter.

[0091] The movement of the transport member 224a and the rotation of the roller 2410 cause the brush fibers of the roller 2410 to rub against the surface of the first base material 11a. As a result, the first particles carried by the brush fibers are densely arranged in the recesses of the uneven pattern 111a on the surface of the first base material 11a.

[0092] FIG. 6B is a diagram showing a schematic configuration of a filling device 24d when an elastic material is used as the support material. The filling device 24d has a similar configuration to the filling device 24c, but differs in that a roller 2411 having an elastic material is used instead of the roller 2410 having brush fibers. The roller 2411 is a roller having an elastic layer formed on its surface.

[0093] The elastic layer is formed of a material having elasticity, such as a rubber material, such as silicone rubber, acrylic rubber, nitrile rubber, urethane rubber, fluororubber, etc. The surface shape of the elastic layer may be controlled by adding fine particles, such as spherical resin particles. When the elastic layer has a convex portion on its surface, the size of the convex portion of the elastic layer is set to be larger than the size of the concave portion of the concave-convex pattern 111a. The size of the convex portion of the elastic layer can be measured in the same manner as the fiber diameter of the brush fiber described above.

[0094] The movement of the transport member 224a and the rotation of the roller 2411 causes the elastic material on the surface of the roller 2411 to rub against the surface of the first base material 11a. As a result, the first particles supported by the elastic material are densely arranged in the recesses of the concave-convex pattern 111a on the surface of the first base material 11a.

[0095] By using brush fibers or elastic materials as the carrier material as in Figures 6A and 6B, it is not necessary to include magnetic particles in the filler. In addition, the configuration of the filling device can be simplified. On the other hand, when magnetic particles are used as the carrier material as in Figure 3, there is a higher degree of freedom in the size and shape of the carrier material than in the case of brush fibers or elastic materials. In addition, the carrier material can move more freely on the substrate when magnetic particles are used.

[0096] For these reasons, when magnetic particles are used as the support material, the particles such as the first particles P1 can be more efficiently supplied onto the substrate, and the recesses on the substrate can be more efficiently filled. Also, when a magnetic material is used as the support material, even if the support material deteriorates during the process, the support material can be replenished or replaced without stopping the process.

[0097] According to the method of filling the recesses with particles by rubbing the support material carrying the particles, it is possible to supply more dispersed particles to the recesses and to fill the recesses stably and densely, compared to the filling method using a restricting member such as a blade. The smaller the particle size, the more pronounced the particle aggregation becomes.

[0098] The first base material 11a, in which the concaves of the concave-convex pattern 111a have been filled with the first particles P1 by the first filling device 24a, is transported to the transfer section 25a by the first belt device 22a. 2, the second belt device 22b has driving rollers 221b and 222b, a pressure roller 223b, and a belt-like conveying member 224b suspended therebetween, similar to the first belt device 22a. At this time, the pressure roller 223b is driven to rotate. At the transfer section 25a, the pressure roller 223a of the first belt device 22a and the pressure roller 223b of the second belt device 22b face each other.

[0099] The second substrate 11b is supplied from the second storage container 21b to the second belt device 22b and transported in the direction of the arrow in Fig. 2. The supplied second substrate 11b is transported in accordance with the timing at which the first substrate 11a is transported to the transfer section 25a. In the transfer section 25a, the first particles P1 filled in the first substrate 11a are transferred to the second substrate 11b.

[0100] That is, the first substrate 11a can be called a transfer substrate for transferring the first particles P1 to the second substrate 11b. The concave-convex pattern formed on the surface of the first substrate 11a can be called a transfer concave-convex pattern. Hereinafter, this transfer process will be described with reference to FIG. 7.

[0101] 7 is a diagram showing a schematic configuration of the transfer unit 25a. The transfer unit 25a is composed of the pressure roller 223a and the conveying member 224a of the first belt device 22a, and the pressure roller 223b and the conveying member 224b of the second belt device 22b. As described above, the pressure rollers 223a and 223b rotate drivenly, and the two rollers are in contact with each other via the conveying members 224a and 224b. At least one of the pressure rollers 223a and 223b is a soft roller having an elastic layer on its surface, and a nip portion is formed at the portion where the two rollers are in contact with each other.

[0102] The first substrate 11a and the second substrate 11b filled with the first particles P1 by the first filling device 24a are transported at substantially equal speeds by the respective transport members (224a and 224b) and enter a nip portion formed by contact between the pressure rollers 223a and 223b. In the nip portion, the first particles P1 on the first substrate 11a come into contact with the second substrate 11b and are transferred onto the second substrate 11b.

[0103] The second substrate 11b is a substrate having a stronger adhesive force to the first particles P1 than the adhesive force of the first substrate 11a to the first particles P1. In other words, the adhesive force of the first particles P1 to the second substrate 11b is stronger than the adhesive force of the first particles P1 to the first substrate 11a. As a result, the first particles P1 on the first substrate 11a are transferred onto the second substrate 11b at the nip portion.

[0104] The material of the second substrate 11b is not particularly limited, and a substrate made of the same material as the first substrate 11a can be used. Note that, like the first substrate 11a, the second substrate 11b may be a substrate that is individually cut off like cut paper, a continuous substrate that is wound into a roll like roll paper, or a continuous substrate that is alternately folded like continuous paper.

[0105] The second substrate 11b is preferably subjected to a surface treatment for increasing adhesive strength in order to transfer the contacted first particles P1. For example, the second substrate 11b preferably has an adhesive portion on its surface where an adhesive is applied. As a preparation step for preparing a resin substrate having an adhesive portion, for example, the second substrate 11b is prepared. The thickness of the second substrate is not particularly limited. Although the thickness of the adhesive portion is not particularly limited, it is preferably, for example, 1 to 10 μm. Furthermore, the thickness of the adhesive portion is not particularly limited, but it is preferably, for example, 0.1 μm or more, and more preferably 0.5 μm or more.

[0106] Furthermore, the back surface of the second substrate 11b (the surface to which the first particles P1 are not transferred) also preferably has an adhesive portion coated with the same adhesive as the front surface, and the front surface is further preferably covered with a protective film, etc. This prevents the substrates from shifting when stacking as described below, and the active material particles and solid electrolyte particles between the substrates are sandwiched between the top and bottom surfaces (stacking direction) and firmly fixed. As a result, particle movement is suppressed when stacking the electrode substrates, when storing the stack, when heat treating, or when applying pressure, and a desired electrode can be formed.

[0107] The adhesive is not particularly limited, and the above-mentioned adhesives can be used. The particle arrangement device 1 may also have an application means such as a dispenser, an inkjet head, a spin coater, or a bar coater that applies an adhesive to the surface of the second base material 11b during transportation. The type and amount of adhesive applied are appropriately adjusted depending on the shape and material of the concave-convex pattern used, and the particle size and material of the first particles P1 and the second particles P2, but it is preferable that the adhesive has a stronger adhesive strength than the concave-convex pattern 111a. Comparison of adhesive strengths can be measured by a general method using a nanoindenter.

[0108] In the nip portion, the first particles P1 are restrained by an adhesive force generated between the first particles P1 and the second substrate 11b. When the conveying members 224a and 224b pass the nip portion and are separated from each other, the first particles P1 on the first substrate 11a are transferred to the second substrate 11b.

[0109] The second base material 11b onto which the first particles P1 have been transferred is transported by the transport member 224b to the filling position of the second filling device 24b. The second filling device 24b has the same configuration and function as the first filling device 24a, except that a filling material 241b having second particles P2 and a support material S2 is contained in a filling container 242a instead of a filling material 241a having first particles P1 and a support material S1.

[0110] The second filling device 24b fills the second particles P2 into the portion on the second substrate 11b where the first particles P1 are not arranged. As described above, the first particles P1 are arranged on the second substrate 11b that has passed through the transfer unit 25a, but the adhesive portion is exposed in the portion where the first particles P1 are not arranged, and a recess is formed, so to speak. The second filling device 24b fills the recess (adhesive portion) with the second particles P2 in the same process as the first filling device 24a.

[0111] In this manner, the second particles P2 that can be filled are selectively filled into gaps on the second base material 11b where the first particles P1 are not arranged, thereby improving the coverage rate of the base material by the particles. The second particles P2 preferably have a median diameter equal to or smaller than the opening width of the gap between the first particles P1. Note that, although the case where magnetic particles are used as the carrier material will be described here, brush fibers or elastic material may be used as the carrier material, as in the first filling device 24a.

[0112] The filler 241b has second particles P2 and a support material S2 that supports the second particles P2. The filler 241b is a mixture of multiple powders including a powder composed of multiple second particles P2 and a powder composed of multiple support materials S2. The support material S2 may be the same as the support material S1 or may be different. It is appropriately selected according to the particle size and material of the second particles P2 and the opening width of the above-mentioned void portion.

[0113] FIG. 8 is an enlarged view of the vicinity of the surface of the second substrate 11b in the filling process by the second filling device 24b. On the second substrate 11b, an uneven pattern is formed having convex portions formed by arranging the first particles P1 and concave portions where the first particles P1 are not arranged. The adhesive portion 13b is exposed in the concave portion on the second substrate 11b where the first particles P1 are not arranged. In the filling process by the second filling device 24b, the second particles P2 are arranged on the adhesive portion 13b on the surface of the second substrate 11b. After the filling process by the second filling device 24b, the first particles P1 and the second particles P2 are arranged adjacent to each other on the surface of the adhesive portion of the second substrate 11b. That is, the first particles P1 and the second particles P2 can be arranged adjacent to each other by arranging the second particles P2 on the portion on the second substrate 11b where the first particles P1 are not arranged. Furthermore, it is not necessary that the second particles P2 are disposed adjacent to all of the first particles P1, and the first particles P1 or the second particles P2 may be adjacent to each other.

[0114] The filler 241b comes into contact with this uneven pattern, and is transported together with the second substrate 11b while having a non-zero relative speed with respect to the second substrate 11b, while being subjected to a magnetic force (solid line Fm in the figure) in a direction perpendicular to the surface of the second substrate 11b. As a result, the second particles P2 supported by the support material S2 are transported while being rubbed against the uneven pattern on the surface of the second substrate 11b.

[0115] The mass % of the second particles P2 in the filler 241b (the ratio of the mass of the second particles P2 to the total mass of the filler 241b) is expressed by the following formula (2) using the coverage S2 of the surface area of ​​the magnetic particles (support material) by the supported second particles P2. The coverage S2 indicates the ratio of the total cross-sectional area of ​​the second particles P2 to the surface area of ​​the magnetic particles (support material). Mass% of the second particles P2 in the filler 241b=(400×ρ P2 ×r P2 ×S2) / (100×ρ c ×r c +4×ρ P2 ×r P2 ×S2) Formula (2) (The descriptions in formula (2) indicate the following: ρ P2 : true density of the second particle P2, r P2 : Particle size of the second particle P2 (r50), ρ c : true density of magnetic particles, r c : particle size of the magnetic particle (r50), S2: coverage rate of the second particle P2 to the surface area of ​​the magnetic particle)

[0116] The mass % of the second particles P2 in the filler 241b is not particularly limited, but is preferably in the range of 5 to 40 mass %, or 10 to 30 mass %. Moreover, the coverage S2 in the above formula (2) is preferably adjusted to be 30 to 200 area %, and more preferably adjusted to be 50 to 100 area %. The particle diameter (r50) of the second particle P2 and the magnetic particle (support material) can be determined by laser diffraction scattering type particle size distribution measurement. The true density of the second particle P2 and the magnetic particle (support material) can be determined by the pycnometer method.

[0117] At this time, the opening width of the recesses of the uneven pattern is set to a size that allows the second particles P2 to contact the recesses but not the support material S2. That is, the opening diameter of the recesses of the uneven pattern on the second base material 11b is preferably larger than the cumulative 50% particle size (median diameter) in the volume-based particle size distribution of the second particles P2. Also, the opening diameter of the recesses is preferably smaller than the average size of the support material S2. Here, the opening diameter of the recesses of the uneven pattern is preferably the opening diameter in the short side direction of the recesses, and more preferably the maximum opening diameter in the short side direction of the recesses. This allows only the second particles P2 in the filler 241b to selectively contact the recesses.

[0118] The second particles P2 that come into contact with the recesses are strongly bound by the physical binding force due to the structure of the concave-convex pattern, and by the electrostatic adhesion and adhesive force with the second base material 11b and the structural material (here, the first particles P1) that constitutes the concave-convex pattern, and are detached from the support material S2. Note that, for the sake of explanation, in FIG. 8, the second particles P2 are supported on the surface of the support material S2, but when the filler 241b is stirred, the second particles P2 are supported on the surface of the support material S2. During the time of the dispersion or transportation, the second particles P2 that are not supported by the support material S2 may be present.

[0119] 9A is a schematic diagram of the second substrate 11b after the first particles P1 are transferred by the transfer unit 25a, and is a diagram of the second substrate 11b viewed from a direction perpendicular to the substrate surface. As shown in FIG. 9A, a honeycomb pattern is formed on the second substrate 11b, in which the arrangement regions in which the first particles P1 are arranged in a regular hexagonal shape are aligned.

[0120] The first particles P1 are densely arranged within this regular hexagonal region, and the first particles P1 are not arranged in other parts (white parts in FIG. 9A), and the adhesive part of the surface of the second base material 11b is exposed. The regular hexagonal region in which the first particles P1 are held is another way of saying the first pattern part. Also, the honeycomb pattern region in which the second particles P2 are held and which corresponds to the gaps in the first pattern part is another way of saying the second pattern part.

[0121] FIG. 9B is a schematic diagram of the second substrate 11b after the second particles P2 are filled by the second filling device 24b, and is a view of the second substrate 11b viewed from a direction perpendicular to the substrate surface. As shown in FIG. 9B, the second particles P2 are densely arranged in the region where the first particles P1 are not arranged and the adhesive portion is exposed. Also, the first particles P1 and the second particles P2 are densely arranged in the boundary between the region where the first particles P1 are arranged and the region where the second particles P2 are arranged. Note that the particles can be filled in the small gaps between the first particles P1 in a similar manner. In this case, it is possible to fill in the gaps between the first particles P1 in a similar manner to the above, using a filler containing particles with a particle size equivalent to the gaps between the first particles P1, and a more dense thin film can be formed.

[0122] [Particle placement device 2] 10 is a diagram showing a schematic configuration of the particle arrangement device 2. The particle arrangement device 2 is a device for forming a particle layer 12 on the substrate 11, and includes a storage container 21 for storing and supplying the substrate 11, and a belt device 22 for transporting the substrate 11. The particle arrangement device 2 may also include a liquid application device 201 for applying a liquid for providing an adhesive portion on the substrate 11. In this case, in order to densely arrange the particles on the substrate 11, it is preferable to apply the liquid in a pattern on the substrate 11.

[0123] As the liquid applying device 201, a device that ejects liquid by an inkjet method or a device that applies liquid can be used, but a plate-based method such as a flexographic plate can also be used. Among them, it is preferable to use a device that ejects liquid by an inkjet method as the liquid applying device. As a device for discharging liquid by the inkjet method, devices using various discharging methods, such as a thermal type, a piezoelectric type, an electrostatic type, and a continuous type, can be used.

[0124] The liquid applied by the liquid applying device 201 may be water-based or oil-based as long as it contains a material to which the first particles P1 can be attached. The liquid is appropriately selected, for example, by selecting a material that does not react with the first particles P1. The liquid applying device 201 may also form the pattern L1 with a plurality of types of liquid. For example, the liquid applying device 201 may apply two types of liquid that react with each other on the substrate 11 to increase adhesion. Examples of materials to which the first particles P1 can be attached include resins such as acrylic resins.

[0125] The powder applying device 202 applies a powder containing the first particles P1 to the substrate 11 on which the liquid has been arranged in a pattern. As a result, the first particles P1 are fixed by the material on the substrate 11, and the first particles P1 are fixed in a pattern corresponding to the pattern L1.

[0126] The means for applying the powder by the powder applying device 202 may be a means for spraying or sprinkling the powder toward the substrate 11. The powder applying device 202 may further include a means for removing the first particles P1 that are not fixed to the substrate 11 by means of vibration, centrifugation, air blowing, suction, or the like.

[0127] The particle arrangement device 2 may further include a drying device that evaporates at least a part of the liquid applied by the liquid application device 201 to control the amount of material on the substrate 11, the thickness of the pattern L1, and the like. This drying device may be provided downstream of the liquid application device 201 and upstream of the powder application device 202. The material on the substrate after drying may be a liquid, a liquid containing solids, or only solids.

[0128] After the first particles P1 are fixedly arranged on the substrate 11, a liquid is arranged by a liquid applicator 203 to provide an adhesive portion at least in the area where the first particles P1 were not arranged. The liquid applicator 203 has the same function as the liquid applicator 201. The second particles P2 are arranged on the substrate 11 to which the liquid has been applied by the liquid applicator 203, using a second filling device 24. As a result, a dense particle layer 12 is formed on the substrate 11.

[0129] Similarly to the particle arrangement device 1, the particle arrangement device 2 may have a transfer unit. In this case, the transfer unit is provided downstream of the powder applicator 202. The first particles P1 are transferred from the substrate 11 to another substrate having an adhesive portion. In the substrate to which the first particles P1 have been transferred, the second particles P2 can be arranged by using the second filling device 24 in the region where the first particles P1 are not arranged and the adhesive portion is exposed. This makes it possible to arrange the first particles P1 and the second particles P2 densely on the adhesive portion of the resin substrate.

[0130] Using the above-mentioned particle arrangement device 1 or particle arrangement device 2, first particles P1 are arranged on the adhesive portion of the resin substrate in the first step (S101 in FIG. 1) of FIG. 1, and second particles P2 are arranged on the adhesive portion of the same resin substrate in the second step (S102 in FIG. 1) of FIG. 1.

[0131] (Steps 3 and 4) The third step is a particle settling step in which the first particles P1 and the second particles P2 arranged on the surface of the adhesive portion on the resin substrate are allowed to settle into the adhesive portion. By the particle settling step, new adhesive portions are exposed between the settled first particles P1 and second particles P2. The fourth step is a step of obtaining an electrode substrate by disposing third particles P3 in the adhesion portions between the settled first particles P1 and second particles P2. The steps will be described below in order.

[0132] The third particles P3 are solid electrolyte particles, and may correspond to the second solid electrolyte particles in the electrode substrate. As the solid electrolyte particles, the above-mentioned materials may be used. Furthermore, the cumulative 50% particle size (r50) in the volume-based particle size distribution of primary particles of the third particle P3 is smaller than the r50 of the second particle P2.

[0133] The particle size of the third particles P3 is not particularly limited as long as it is smaller than that of the second particles P2. For example, the third particles P3 preferably have a cumulative 10% particle diameter (r10) in the volumetric particle size distribution of primary particles of 0.10 to 1.5 μm, more preferably 0.20 to 1.0 μm. Also, the cumulative 50% particle diameter (r50) in the volumetric particle size distribution is preferably 0.30 to 3.0 μm, more preferably 0.50 to 1.5 μm. Furthermore, the cumulative 90% particle diameter (r90) in the volumetric particle size distribution is preferably 0.5 to 20.0 μm, more preferably 1.0 to 15.0 μm.

[0134] For example, the cumulative 50% particle size (r The ratio of the cumulative 50% particle size (r50(P3)) in the volume-based particle size distribution of the primary particles of the third particle P3 to the cumulative 50% particle size (r50(P2)) {(r50(P3)) / (r50(P2))} is preferably 0.01 to 1.0, and more preferably 0.01 to 0.5.

[0135] The ratio of the particle size of the primary particles of the first particles P1 to the particle size of the primary particles of the third particles P3 is not particularly limited. For example, the ratio {(r50(P3)) / (r50(P1))} of the cumulative 50% particle size (r50(P3)) in the volume-based particle size distribution of the primary particles of the third particle P3 to the cumulative 50% particle size (r50(P1)) in the volume-based particle size distribution of the primary particles of the first particle P1 is preferably 0.01 to 1.0, and more preferably 0.01 to 0.5.

[0136] As described above, the first particles P1 are active material particles. The second particles P2 are particles that may correspond to the first solid electrolyte particles in the electrode substrate after manufacture. The third particles P3 are particles that may correspond to the second solid electrolyte particles in the electrode substrate after manufacture. That is, in the manufacturing method of the electrode substrate, the third step can be described as a particle settling step of settling the first solid electrolyte particles and active material particles arranged on the surface of the adhesive portion into the adhesive portion, and the fourth step can be described as a step of arranging the second solid electrolyte particles in the adhesive portion between the settled first electrolyte particles and active material particles.

[0137] 11 is a diagram showing a schematic diagram of each device in steps 3 and 4. The substrate 11 on which the particle layer 12 has been formed by the particle arrangement device 1 or the particle arrangement device 2 is transferred to the belt device of FIG. The belt device is provided with a particle settling device 25 on the upstream side and a third filling device 24 for disposing the third particles P3 downstream thereof. The particle settling device 25 has pressure rollers 223c and 223d, and the pressure roller 223d rotates by being driven. At least one of the pressure rollers 223c and 223d is preferably a soft roller having an elastic layer on its surface, for example, a soft roller having an elastic layer of silicone rubber or fluororubber on the surface of a stainless steel core metal. In addition, a heater (not shown) may be built in at least one of the pressure rollers 223c and 223d.

[0138] The substrate 11 is conveyed to the pressure section between the pressure rollers 223c and 223d by a belt device. When the substrate 11 is pressed by the pressure rollers 223c and 223d, the first particles P1 and the second particles P2 arranged on the surface of the adhesive part on the substrate are precipitated into the adhesive part on the substrate. At this time, the above-mentioned heater may be used to facilitate the particles to be precipitated into the adhesive part on the substrate. Also, a heat source may be provided upstream of the particle precipitation device 25 in order to heat the adhesive part on the substrate.

[0139] Since the pressure roller 223c comes into contact with the particle layer 12 on the substrate, it is preferable to coat the surface with a material having good releasability, such as fluorine, in order to suppress adhesion of particles. A cleaning mechanism for removing particles adhering to the pressure roller 223c may be provided. It is more preferable to apply pressure to the particle layer 12 while it is covered with a protective material (not shown). In this case, the protective material used is preferably a material with good releasability, and if it is resin, it is preferably a fluorine sheet, if it is metal, it is preferably nichrome foil, etc. When a protective material is used, a removal mechanism (not shown) for removing the protective material is provided downstream of the particle settling device 25 and upstream of the third filling device 24.

[0140] The particle settling device 25 may be any other known pressurizing device. For example, it may be an isostatic pressurizing device (CIP / HIP), a uniaxial pressurizing device, or even a device using weights or magnets. In addition, if the specific gravity of the particles is high, the particles may be allowed to settle by their own weight. In this case, It is preferable to promote sedimentation of the particles by storing the substrate on which the particles are placed under heating, such as in an oven.

[0141] When the substrate on which the particles are arranged is stored under heating, the temperature and storage time are appropriately adjusted according to the physical properties (shape, particle size, specific gravity, adhesiveness, and viscoelasticity) of the particles and adhesive material. If the temperature or storage time is insufficient, the particles do not settle sufficiently, and the adhesive part is not exposed on the surface from the gap between the particles. On the other hand, if the temperature or storage time is excessive, the particles move in the surface direction as they settle, and the denseness of the particles is greatly reduced. The temperature is preferably 10 to 90°C, and more preferably 40 to 80°C. The storage time is preferably 1 to 24 hours, and more preferably 3 to 15 hours.

[0142] In addition to a known pressurizing device, pressure may be applied by friction with magnetic particles. That is, the particle settling device 25 is performed by the fourth filling device 24. The fourth filling device contains only magnetic particles instead of a filler. The fourth filling device causes the magnetic particles to rub against the substrate 11, so that the particles P1 and P2 on the substrate are settled in the adhesive portion on the substrate.

[0143] In addition, the magnetic particles also have the effect of rearranging the first particles P1 and the second particles P2 on the substrate. Rearrangement refers to the fact that the first particles P1 and the second particles P2 are fixed more stably by arranging or removing the excess particles that are not fixed to the adhesive part on the substrate in the gaps between the particles, or by moving or rotating the particles that are unstably fixed to the adhesive part, and the densification of the particles on the substrate progresses. In other words, the rearrangement can make the particle layer on the resin substrate more dense.

[0144] 12A and 12B are schematic cross-sectional views of the substrate 11 to explain the settling of particles on the substrate 11 by the particle settling device 25. Fig. 12A shows the state before the third step in which the first particles P1 and the second particles P2 are settling on the adhesive portion 13 on the substrate 11, and Fig. 12B shows the state after the third step. Note that, for the sake of explanation, in Figs. 12A and 12B, the first particles P1 and the second particles P2 are depicted as being spherical and having the same particle size.

[0145] As shown in FIG. 12A, before the third step, the settling of the particles is limited. On the other hand, after the third step, the settling of the particles progresses significantly, and the adhesive portion 13 pushed out by the settling of the particles is exposed on the surface from the gap between the particles. For example, the adhesive portion is exposed on the surface side by the particle settling step. FIG. 13 is a schematic diagram of the substrate 11 after the third step from above (the particle layer side, i.e., the side where the first particles P1 and the second particles P2 are arranged). The cross section of the substrate 11 after the third step is shown in FIG. 12B. As the first particles P1 and the second particles P2 settle into the adhesive portion 13, the adhesive portion 13 is exposed on the upper surface of the particle layer from the gap between the particles, and a minute recess (for example, A in FIG. 13) having an adhesive portion on the bottom surface is formed between the particles.

[0146] In the fourth step, the base material 11 after the third step (FIGS. 12B and 13) is transported by a belt device to a filling position of a third filling device 24 for arranging third particles P3. The third filling device 24 is a filling device that fills using magnetic particles, brush fibers, or elastic material as a carrier material, similar to the first and second filling devices. Below, a configuration using magnetic particles as a carrier material will be described.

[0147] The filler 241c contained in the third filling device includes third particles P3 and a support material S3 supporting the third particles P3. Here, the third particles P3 may correspond to the second solid electrolyte particles. The third particles P3 (second solid electrolyte particles) have a smaller average circle equivalent diameter of primary particles than the second particles P2 (which may correspond to the first solid electrolyte particles). Therefore, the third particles P3 are selectively filled into the minute recesses having the adhesive portions by rubbing of the filler. At this time, the support material S3 is sufficiently large relative to the opening width of the minute recesses having the adhesive portions, and is therefore not filled. The support material S3 may be the same as the support materials S1 and S2 described above, or may be different. That's fine.

[0148] The mass % of the third particles P3 in the filler 241c (the mass ratio of the third particles P3 to the total mass of the filler 241c) is expressed by the following formula (3) using the coverage S3 of the supported third particles P3 to the surface area of ​​the magnetic particle (support material). The coverage S3 indicates the ratio of the total cross-sectional area of ​​the third particles P3 to the surface area of ​​the magnetic particle (support material). Mass% of the third particles P3 in the filler 241c=(400×ρ P3 ×r P3 ×S3) / (100×ρ c ×r c +4×ρ P3 ×r P3 ×S3) Formula (3) (The descriptions in formula (3) indicate the following: ρ P2 : true density of particle P3, r P2 : particle size of particle P3 (r50), ρ c : true density of magnetic particles, r c : particle size of magnetic particles (r50), S3: coverage rate of the third particles P3 relative to the surface area of ​​the magnetic particles)

[0149] The mass % of the third particles P3 in the filler 241c is not particularly limited, but is preferably in the range of 0.1 to 20 mass %, and more preferably 1 to 10 mass %. Moreover, the coverage S3 in the above formula (3) is preferably adjusted to be 30 to 200 area %, and more preferably 50 to 100 area %. The particle diameter (r50) of the third particle P3 and the magnetic particle (support material) can be determined by laser diffraction scattering type particle size distribution measurement, and the true density of the third particle P3 and the magnetic particle (support material) can be determined by the pycnometer method.

[0150] 14 is a schematic diagram of the upper side of the substrate 11 after the fourth step, i.e., the region where the particle layer is formed, observed from the substrate vertical direction. The third particles P3 are arranged in the minute recesses described above. For the sake of explanation, the third particles P3 are described as spherical and having the same particle size, but multiple amorphous particles (third particles P3) can be arranged to match the openings of the recesses.

[0151] A simple device that does not use a belt device can be used as the third filling device 24. Fig. 15 shows an example of the device. The third filling device 24 has a filling container 242, a stirring screw member 243, a magnetic member 247, a magnet 248, and a regulating member 250.

[0152] 16 is a schematic diagram illustrating the operation of the filling device. Filler 241 sufficiently stirred by stirring screw member 243 is supplied in an appropriate amount by magnetic member 247 (arrow a in the figure) that has moved from the home position and by regulation by regulating member 250. The supplied filler 241 is rubbed on substrate 11 as magnetic member 247 reciprocates (arrow b in FIG. 16). After the desired number of times of rubbing, the magnetic member 247 moves to a distant home position where the magnetic force acting on the filler 241 on the substrate is sufficiently weakened (arrow c in FIG. 16). The filler 241 on the substrate falls downward by gravity and is collected in a collection container (not shown). At this time, it is more preferable to use air blowing or vibration. Also, instead of rubbing on an inclined surface as shown in the figure, rubbing on a flat surface may be performed to collect the filler 241, and then the magnetic member 247 may be moved back and forth again to collect the filler 241 remaining on the substrate. At this time, it is more preferable to use air blowing or vibration at each collection. The first particles P1 and the second particles P2 can also be arranged in the same manner using the same simple device.

[0153] In the electrode substrate, the coverage rate of the resin substrate surface by the active material particles and solid electrolyte particles is preferably 60% or more, more preferably 70% or more, and even more preferably 80% or more. In the present disclosure, the coverage rate of the resin substrate surface refers to the ratio (area %) of the area covered by the active material particles and solid electrolyte particles to the total area of ​​the resin substrate surface. The coverage rate of the substrate surface by the active material particles and solid electrolyte particles can be measured by photographing the area where the particle layer is formed using an optical microscope from the substrate vertical direction, and calculating the area ratio of the area covered by the active material particles and solid electrolyte particles using image processing software. Measurement method Details will be provided below.

[0154] The upper limit of the coverage is not particularly limited, but is preferably 99% or less, and more preferably 98% or less. For example, the coverage of the resin substrate surface by the active material particles and solid electrolyte particles is preferably 60 to 99%, 70 to 99%, 80 to 99%, or 60 to 98%, 70 to 98%, or 80 to 98%. When the coverage rate is within the above range, a dense particle layer is formed on the substrate, and the denseness of the particles in the electrode can be improved, resulting in improved ion conductivity.

[0155] <Electrode manufacturing method> An example of a method for producing an electrode will be described in detail below with reference to the drawings. Although the following description will be given taking a positive electrode using positive electrode active material particles as an example, the method for producing an electrode described below can be used for both positive and negative electrodes.

[0156] The method for producing an electrode includes the following three steps (first step, second step, and third step). (1) The first step of laminating a plurality of electrode substrates to form a laminate (S201 in FIG. 17) (2) A second step (S202 in FIG. 17) of removing the resin substrate from the laminate to obtain a three-dimensional object; (3) A third step (S203 in FIG. 17) of applying pressure to the three-dimensional object to obtain an electrode.

[0157] That is, the electrode is an electrode manufactured by a manufacturing method including a step of laminating a plurality of electrode base materials and forming a laminate, a step of removing the resin base material from the laminate to obtain a three-dimensional object, and a step of pressing the three-dimensional object. For example, a sintered body of the above-mentioned electrode base material can be used as the electrode. Each step of the electrode manufacturing method will now be described in detail.

[0158] (1st step) The first step is a step of laminating a plurality of electrode base materials to form a laminate. The number of layers is not particularly limited and is determined according to the desired electrode capacity. For example, it is preferable to laminate three or more of the above-mentioned electrode base materials. In addition, the electrode base materials to be laminated may be the same, or different electrode base materials may be laminated.

[0159] That is, the electrode substrate can also be used as an electrode substrate laminate in which a plurality of electrode substrates are laminated. As described above, the electrode substrate has a resin substrate and a particle layer formed on the resin substrate. When laminating the electrode substrates, it is preferable to laminate the electrode substrate laminate so that the resin substrate and the particle layer are alternately arranged. That is, it is preferable that the electrode substrate laminate has a configuration in which the resin substrate and the particle layer are alternately arranged in the cross section of the electrode substrate laminate. For example, a sintered body of the electrode substrate laminate can be used as an electrode. In addition, the laminate is preferably formed on an electrode current collector as a substrate. That is, the electrode preferably has a substrate. As the electrode current collector, a known current collector such as Al foil, SUS foil, Cu foil, Cu-Ni foil, platinum foil, or gold foil can be used. An electrolyte may be used as the substrate.

[0160] In this case, the electrolyte may be a separately prepared solid electrolyte sheet or an electrolyte substrate consisting of only solid electrolyte particles on a similar substrate. That is, a solid electrolyte may be used as the electrolyte. In addition, the solid electrolyte sheet or electrolyte substrate may have a negative electrode or a negative electrode substrate formed on the opposite side to the lamination surface of the positive electrode substrate.

[0161] 18 is a diagram showing a schematic configuration of a laminate forming apparatus. The laminate forming apparatus includes a conveying device 31 for conveying a substrate 11 on which a particle layer 12 has been formed, and an actuator (not shown) for conveying the substrate 11 by the conveying device 31. and a stage 32 that is vertically movable.

[0162] The conveying device 31 receives the substrate 11 having the particle layer 12 formed using the particle arrangement device, and conveys it to the stage 32. Examples of the conveying device 31 capable of conveying the substrate 11 include a belt conveyor, a roller, and a robot arm. When the substrate 11 is transported to the stage 32 by the transport device 31, the stage 32 moves in the vertical direction by an amount equivalent to the thickness of the substrate 11 and the particle layer 12. By repeating the transport by the transport device 31 and the movement of the stage 32, a plurality of substrates 11 each having a particle layer 12 formed thereon are stacked, and the laminate 15 is formed.

[0163] In this case, it is preferable that the back surface of the substrate 11 on which the particle layer 12 is formed has an adhesive portion. This adhesive portion allows the substrates to adhere to each other, increasing the strength of the laminate and suppressing misalignment between the substrates even after the first step. Furthermore, the particle layer 12 between the substrates is sandwiched between the upper and lower adhesive portions, thereby suppressing misalignment during processing or storage of the laminate. The adhesive portion may be applied by a coating device (not shown) before lamination, or a substrate that has been previously coated may be used, and the protective film coated on the coated surface may be peeled off before lamination to laminate.

[0164] It is preferable to have a static elimination step of eliminating static electricity from the substrate immediately before forming the laminate 15. The particle layer 12 and substrate 11 formed using the particle arrangement device are easily charged, and electrostatic repulsion occurs between the substrates when they are laminated. Therefore, when they are laminated in the first step, the substrates tend to peel off or gaps tend to form between the substrates. In the static elimination step, it is preferable to eliminate static electricity in a non-contact manner using a static elimination blower or the like. In addition, after the laminate 15 is formed, it is preferable to have a degassing step of degassing the laminate in order to reduce voids between the substrates. In the degassing step, degassing is preferably performed using a vacuum packaging machine or the like.

[0165] (2nd process) The second step is a step of sintering the laminate to remove the resin substrate from the laminate. 19 is a diagram showing a schematic configuration of a sintering apparatus. The sintering apparatus includes a transport device 41 for transporting the laminate 15 and a heating furnace 42 for heating the laminate 15.

[0166] The conveying device 41 receives the laminate 15 from the laminate forming device and conveys it to the heating furnace 42. Like the conveying device 31, the conveying device 41 is preferably a device capable of conveying the laminate 15. Examples of devices capable of conveying the laminate 15 include a belt conveyor, a roller, and a robot arm.

[0167] The heating furnace 42 is a furnace that heats the laminate 15. The heating furnace 42 has a heating means 421, a pressurizing means 422, and an atmosphere adjusting means 423. A firing furnace used for firing ceramics or the like can be used as the heating furnace 42. The pressurizing means 422 pressurizes the laminate 15 that is being heated in the heating furnace 42, and pressurizes the laminate 15 before and after heating.

[0168] In addition, it is preferable that the pressurizing means 422 has a pressurizing portion for pressurizing the laminate 15 formed of a porous material that allows easy passage of gas. The atmosphere adjusting means 423 has an atmosphere gas supplying means 423a and a pressure reducing means 423b, and adjusts the atmosphere gas in the processing space of the heating furnace 42. The atmospheric gas that can be used includes an oxidizing atmosphere (O2), an inert atmosphere (Ar, N2, etc.) and a reducing atmosphere (Ar-H2), but sintering may be performed in air.

[0169] When the laminate is sintered, it is preferable to heat the laminate at a temperature equal to or higher than the thermal decomposition temperature of the substrate 11 in the laminate 15, and preferably at a temperature lower than the thermal decomposition temperature of each particle layer in the laminate 15. The temperature to which the laminate is heated is preferably from 200° C. to 1000° C., and more preferably from 400° C. to 800° C. The sintering temperature is preferably maintained for 30 minutes or more, and more preferably for 1 hour or more. The thermal decomposition temperature is the temperature at which the weight of the material starts to decrease when the temperature is gradually increased in the heating atmosphere in the sintering treatment device. Therefore, by heating the laminate at a temperature equal to or higher than the thermal decomposition temperature of the base material 11, the base material 11 in the laminate can be decomposed to reduce its weight, and the resin base material can be removed from the laminate.

[0170] The heating temperature is preferably equal to or higher than the thermal decomposition temperature of the base material 11, but it is preferable to heat the base material 11 at a temperature higher than the thermal decomposition temperature. Specifically, when the base material 11 is heated from room temperature (25°C) at a rate of 5°C / min in an atmosphere (typically air) during heating in a sintering treatment device and a thermogravimetric analysis is performed, the base material 11 is preferably heated at a temperature equal to or higher than the temperature at which the mass becomes 70% by mass of the initial mass. Specifically, the temperature is preferably 385°C or higher, for example.

[0171] Similarly, when a thermogravimetric analysis is performed, it is more preferable to heat at a temperature equal to or higher than the temperature at which the mass is reduced to 50% by mass of the initial mass, and even more preferable to heat at a temperature equal to or higher than the temperature at which the mass is reduced to 20% by mass of the initial mass. Specifically, for example, it is preferable to heat at a temperature equal to or higher than 400°C, and more preferably equal to or higher than 450°C. This can shorten the time required to remove the resin substrate and increase the removal rate of the resin substrate.

[0172] In this way, when the sintering treatment apparatus removes the base material 11 by heating, it is preferable that the active material particles and the solid electrolyte particles have a higher thermal decomposition temperature than the base material 11. In general, inorganic materials tend to have higher thermal decomposition temperatures than organic materials, so it is preferable that the active material particles and the solid electrolyte particles are inorganic materials and the material of the base material 11 is an organic material such as a resin. In addition, when the sintering treatment apparatus removes the base material 11 by heating, it is preferable that the active material particles have a softening point temperature higher than the thermal decomposition temperature of the base material 11.

[0173] The sintering apparatus preferably removes 90% by mass or more of the resin substrate in the laminate 15 by heating, more preferably removes 95% by mass or more, and even more preferably removes 97% by mass or more. At that time, the resin substrate is preferably burned or gasified and released to the outside as a gas. At this time, when the resin substrate gasified by pyrolysis is released to the outside of the laminate as a gas, it may push up the particle layer formed on the resin substrate and distort the shape. For this reason, it is preferable to reduce the thickness of the resin substrate to reduce the effect on the particle layer.

[0174] Specifically, the thickness (μm) of the resin substrate is preferably 10 times or less, more preferably 5 times or less, and even more preferably 2 times or less, the thickness of the particle layer on the resin substrate. Here, the thickness of the particle layer refers to the difference between the maximum and minimum values ​​of z in the region (x, y, z) where each particle arranged on the resin substrate exists, when the resin substrate surface is (x, y) and the lamination direction of the resin substrate is (z) in the electrode substrate. The thickness of the resin substrate is preferably 1 μm or more and 1 mm or less, and the thickness of the particle layer is preferably 0.1 μm or more and 100 μm or less.

[0175] The thickness of the particle layer on the resin substrate is calculated by observing the cross section of the laminate 15 with a BIB-SEM, determining the particle presence area (x, z) with image processing software, and calculating the difference between the maximum and minimum values ​​of z, where x is the resin substrate surface and z is the lamination direction of the resin substrate. Here, the BIB-SEM photographing conditions, the necessary image area, and the image processing method are the same as those described above.

[0176] The thickness of the resin substrate may be determined by BIB-SEM in the same manner as the particle diameter of the active material particles. The thickness may be measured using a gauge such as a thickness gauge. In addition, in SEM observation using a BIB-SEM, the active material particles, solid electrolyte particles, substrate, and adhesive portion may be identified by elemental composition analysis using EDS.

[0177] The sintering apparatus preferably exhausts the released gas to the outside of the heating furnace 42 by the pressure reducing means 423b. The resin base material can be burned and removed by creating an oxidizing atmosphere, i.e., an atmosphere containing oxygen gas such as air, inside the heating furnace 42 by the atmospheric gas supplying means 423a or the like. On the other hand, depending on the active material particles and solid electrolyte particles used, sintering in an oxidizing atmosphere may cause decomposition or composition change. In such cases, sintering in an inert atmosphere (Ar, N2, etc.) or a reducing atmosphere (Ar-H2) is preferable.

[0178] As described above, when the resin base material is gasified by pyrolysis from the laminate 15 and released as a gas, each particle layer in the laminate 15 may be pushed up and change shape. Therefore, when heating in the heating furnace 42, the laminate 15 may be pressurized by the pressurizing means 422 before or during heating.

[0179] FIG. 20A is a BIB-SEM image of the cross section of the laminate after the first step. The laminate 15 is formed by laminating six second base materials 11b, each having a particle layer 12 formed thereon, on a substrate 14. FIG. 20B is a BIB-SEM image of a three-dimensional object 16 (positive electrode) after the second step. The resin base material has been removed from the laminate 15, resulting in a three-dimensional object 16 consisting of six particle layers. FIG. 20C is an SEM image of the upper part of the three-dimensional object 16. The first particles P1 and second particles P2 periodically arranged on the second base material 11b in the first step are maintained even after the second step.

[0180] (3rd step) The third step is a step of pressing the three-dimensional object 16 from which the resin base material has been removed. As a method of applying pressure, the three-dimensional object 16 can be pressed by the pressurizing means 422 during cooling or heat dissipation after heating. Alternatively, after removing the resin base material by a sintering treatment device, pressure can be applied by a separate pressurizing device. Specific pressing methods are preferably vacuum degassing, isostatic pressing, or a general hydraulic press or roller press. Among them, pressing by a combination of vacuum degassing and isostatic pressing is preferable.

[0181] The pressure is preferably 5 MPa to 500 MPa. This fills the voids in the three-dimensional object from which the resin base material has been removed, improving the density and strength of the three-dimensional object. After the third step, the three-dimensional object may be heated again in a sintering device for sintering. Alternatively, the laminate may be permeated with a solution in which a conductive additive, a binder resin, etc. are dispersed in a solvent, and each material may be dispersed within the laminate.

[0182] An electrode can be manufactured by a manufacturing method including the above-mentioned steps. The electrode preferably has a substrate and a particle layer containing active material particles and solid electrolyte particles, and preferably has voids in the particle layer. With this configuration, it is possible to improve ion conductivity in the electrode and reduce volumetric fluctuations of the active material particles.

[0183] 21 is a diagram showing a schematic diagram of an overall configuration of an additive manufacturing system 100. The additive manufacturing system 100 includes a control unit U1, a particle layer forming unit U2, a lamination unit U3, a removal unit U4, and a post-processing unit U5.

[0184] The control unit U1 is responsible for controlling each part of the additive manufacturing system 100. In the particle layer forming unit U2, the above-mentioned particle placement device (FIG. 2) is used to deposit particles on the substrate 11. Layer 12 is formed. The lamination unit U3 uses the laminate molding apparatus described above (Figure 18) to laminate multiple substrates 11, each of which has a particle layer 12 formed in the particle layer forming unit U2, to form a laminate 15 including multiple particle layers 12 and multiple substrates 11. The removing unit U4 uses the above-mentioned sintering treatment device (FIG. 19) to remove the base material 11 from the laminate 15 formed in the lamination unit U3 to form a three-dimensional object 16 (electrode). The post-processing unit U5 performs post-processing of the three-dimensional object 16 formed by the removal unit U4. 21 is merely an example, and other configurations may be used. The configuration and operation of each unit will be described below.

[0185] [Control unit] The control unit U1 is responsible for controlling each part of the additive manufacturing system 100, specifically, the particle layer forming unit U2, the stacking unit U3, the removing unit U4, and the post-processing unit U5. The control unit U1 may include a three-dimensional shape data input unit that receives input of three-dimensional shape data of a solid object to be formed by the additive manufacturing system 100 from an external device (such as a personal computer). As the three-dimensional shape data, data created and output by a three-dimensional CAD, a three-dimensional modeler, a three-dimensional scanner, or the like can be used. The file format is not important, but for example, the STL (StereoLithography) file format can be preferably used.

[0186] The control unit U1 may be equipped with a slice data calculation section that slices the three-dimensional shape data at a predetermined pitch to calculate the cross-sectional shape of each layer, and generates image data (referred to as "slice data") to be used for image formation in the particle layer forming unit U2 based on the cross-sectional shapes.

[0187] Although the details will be described later, the particle layer forming unit U2 of this embodiment can use a plurality of types of materials to form a material layer in which each material is patterned. Therefore, data corresponding to the image of each material may be generated as slice data. As a file format for slice data, for example, multi-value image data (each value represents a type of material) or multi-plane image data (each plane corresponds to a type of material) can be used.

[0188] Although not shown, the control unit U1 also includes an operation unit, a display unit, and a memory unit. The operation unit has a function of receiving instructions from the user. For example, it is possible to input power on / off, various settings of the device, and operation instructions. The display unit has a function of presenting information to the user. For example, it is possible to present various setting screens, error messages, operation status, and the like. The memory unit has a function of storing three-dimensional shape data, slice data, various setting values, and the like.

[0189] In terms of hardware, the control unit U1 can be configured by a computer equipped with a CPU (Central Processing Unit), memory, auxiliary storage device (hard disk, flash memory, etc.), input device, display device, and various I / Fs. Each of the above-mentioned functions is realized by the CPU reading and executing a program stored in the auxiliary storage device or the like, and controlling the necessary devices. However, some or all of the above-mentioned functions may be configured by circuits such as ASIC or FPGA, or may be executed by another computer using technologies such as cloud computing or grid computing.

[0190] [Particle layer formation unit] The particle layer forming unit U2 is a unit that forms a particle layer 12 on the substrate 11. As the particle layer forming unit U2, the above-mentioned particle arrangement device (FIG. 2) can be used. The additive manufacturing system 100 may have a plurality of particle layer forming units U2. This allows the particle layer 12 to be formed on the substrate 11 in parallel at the same time, further improving the throughput of forming the laminate and the three-dimensional object. In addition, when the three-dimensional object is made of many different materials, a particle layer forming unit U2 is provided for each material type or for each group of material types, so that switching of material types and processes in the particle layer forming unit U2 can be omitted. This allows the three-dimensional object to be manufactured continuously.

[0191] [Stacked unit] The lamination unit U3 is a unit that laminates a plurality of base materials 11 on which a particle layer 12 has been formed in the particle layer forming unit U2, to form a laminate 15 including a plurality of particle layers 12 and a plurality of base materials 11. The laminate forming apparatus (FIG. 18) described above can be used. The lamination unit U3 may further include a conveying device 33 that conveys the formed laminate 15 to the removal unit U4 or the like, and a pressurizing device (not shown) that pressurizes the laminate 15 in the lamination direction. The conveying device 33 may have a configuration similar to that of the conveying device 31.

[0192] [Removal unit] The removing unit U4 is a unit that removes the base material 11 from the laminate 15 formed in the lamination unit U3 to form a three-dimensional object 16. The above-mentioned sintering treatment device (FIG. 19) can be used.

[0193] [Post-processing unit] The post-processing unit U5 is a unit that performs post-processing of the three-dimensional object 16 formed by the removal unit U4. The type of post-treatment performed by the post-treatment unit U5 is not particularly limited, but may be, for example, a process of further heating and sintering the three-dimensional object 16. When the post-treatment unit U5 performs a heat treatment as a post-treatment, the removal unit U4 may also have that function. By sintering the three-dimensional object 16, the particles in and between each particle layer can be sintered.

[0194] In addition, depending on the active material particles and solid electrolyte particles used, reducing gas such as carbon monoxide generated when the resin base material disappears may change the composition and reduce the ion conductivity. In that case, the composition can be changed again by sintering (oxidation) in the post-treatment unit U5 to improve the ion conductivity. Of course, in the sintering in the post-treatment unit U5, sintering may be performed in an inert atmosphere such as Ar or N2 or a reducing atmosphere such as ArH2, other than an oxidizing atmosphere with a controlled oxygen concentration.

[0195] As an example of a post-treatment other than sintering, a solution in which a conductive assistant, a binder resin, etc. are dispersed in a solvent is impregnated into the laminate, and each material is dispersed in the laminate. After dispersion, a drying process or a pressurizing process may be included to volatilize the solvent and fix the binder.

[0196] A secondary battery has electrodes (positive and negative electrodes), an electrolyte layer adjacent to the electrodes, and, if necessary, a current collector. For example, an electrode manufactured using the above-mentioned electrode base material can be used as the positive electrode. The electrode can be manufactured, for example, by the above-mentioned method. The negative electrode can be made of any known material without any particular limitation, such as a metal foil forming a lithium alloy layer, such as lithium metal, indium, tin, aluminum, zinc, or magnesium, or a negative electrode containing graphite particles (such as graphite, hard carbon, or soft carbon), silicone particles, or lithium titanate particles.

[0197] The electrolyte layer is not particularly limited and may be made of any known material. For example, Li 1.5 Al 0.5 Ge 1.5 P3O 12 (hereinafter referred to as LAGP), Li1 .3 Al 0.3 Ti 1.7 P3O 12 (hereinafter referred to as LATP), Li 5.9 Yb 0.81 La 0.09 Zr 0.1 (BO3)3 (hereinafter also written as LYbBO), Li3BO3 (hereinafter also written as LBO), Li 6.25 La3Zr2Al 0.25 O 12 (hereinafter referred to as LLZ), Li 0.33 La 0.55 The electrolyte may be an electrolyte sheet made by pelletizing the material with a pressurizing device and sintering it. The current collector is not particularly limited and may be any known material. For example, aluminum, stainless steel, platinum, gold, etc. may be used as the positive electrode current collector. Copper, copper nickel, platinum, gold, etc. may be used as the negative electrode current collector. The above metals that can be used as the current collector may be used as metal foil.

[0198] <Secondary battery manufacturing method> There are multiple possible methods for manufacturing secondary batteries using the above-mentioned additive manufacturing system 100, but several examples will be given below. A case where the system is used to manufacture a positive electrode or a negative electrode will be described. Using a current collector or an electrolyte formed by a different means as a base, the system can manufacture a positive electrode, a negative electrode, or both electrodes.

[0199] The secondary battery can be manufactured by stacking the electrodes, the current collectors, and the electrolyte, packaging the stack with an aluminum laminate film or the like as necessary, and molding and pressing the stack. That is, the manufacturing method of the secondary battery may include a step of stacking the electrodes, the current collectors, and the electrolyte. The electrodes may be the above-mentioned electrodes. The method for producing a secondary battery may include a step of preparing an electrode by the above-mentioned electrode production method, and a step of providing a solid electrolyte adjacent to the electrode. The method may also include a step of providing the above-mentioned electrode and the solid electrolyte adjacent to the electrode together. That is, the electrode and the solid electrolyte may be prepared in separate steps, or may be prepared together in the same step.

[0200] Here, the other means for forming the electrolyte is a known means, for example, forming solid electrolyte particles into pellets using a uniaxial pressurizing device or the like, and sintering them in an electric furnace, etc. The electrolyte may be an electrolyte sheet or the like. By stacking the manufactured components in the order of positive electrode current collector, positive electrode, electrolyte, negative electrode, and negative electrode current collector, it is possible to manufacture a laminate-type secondary battery to be packed in a laminate film or a coin-type secondary battery to be packed in a coin case.

[0201] The particles constituting the positive electrode, electrolyte, and negative electrode may have different appropriate temperatures and atmospheres during sintering. When handling such materials, it is preferable to separately manufacture the positive electrode, electrolyte, and negative electrode, which are the respective components, and assemble them into a battery. When lithium metal or indium is used as the negative electrode, it is preferable to use the negative electrode as a metal foil or to form it into a current collector or electrolyte by a vacuum process such as sputtering. Since lithium metal has a strong reducing power, it is easily decomposed depending on the type of solid electrolyte. In that case, a buffer layer may be provided between the electrode and the electrolyte. As the buffer layer, it is preferable to use a polymer electrolyte or the like.

[0202] The above example is an example in which a positive or negative electrode laminate is formed and an electrode is manufactured using the additive manufacturing system 100, but it is also possible to form a laminate containing two or more of the main components of a secondary battery, namely a positive electrode collector, a positive electrode, an electrolyte, a negative electrode, and a negative electrode collector, and manufacture it as a three-dimensional object.

[0203] For example, each of the substrates is prepared by the particle layer forming unit U2. That is, a positive electrode current collector substrate, a positive electrode substrate, an electrolyte substrate, a negative electrode substrate, and a negative electrode current collector substrate. Each of the substrates may contain multiple types of particles (positive electrode active material particles and solid electrolyte particles) like the positive electrode substrate, or may contain only a single type of particle. When only a single type of particle is contained, the same type of filler is filled in the filling devices 24a and 24b, respectively, to form a dense layer containing only a single type of particle on the substrate. A dense particle layer can be formed.

[0204] The electrolyte base material is formed of a particle layer containing at least solid electrolyte particles. The negative electrode base material is formed of a particle layer containing at least negative electrode active material particles. The current collector base material is formed of a particle layer containing at least conductive particles. These base materials are stacked in the order of positive electrode current collector base material, positive electrode base material, electrolyte base material, negative electrode base material, and negative electrode current collector base material by the stacking unit U3 to produce a stack, and a secondary battery can be manufactured by the removal unit U4 and the post-treatment unit U5. Furthermore, it is also possible to manufacture a bipolar type secondary battery in which electrode base materials are stacked on both sides of the current collector base material. EXAMPLES

[0205] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples. In the following examples, unless otherwise specified, the parts are based on parts by weight.

[0206] The above-described additive manufacturing system 100 was used to mold a positive electrode of a secondary battery. Specifically, a particle layer was formed on a resin substrate using the particle layer forming unit U2 shown in FIG. 21, and the substrate on which the particle layer was formed was laminated (three layers) on a current collector (Al foil) using the lamination unit U3 to form a laminate. Thereafter, the resin substrate was removed from the laminate by heating using the removal unit U4, and a three-dimensional positive electrode was formed by applying pressure. The sintering atmosphere and sintering temperature (maintained for 1 h) are as shown in Table 4 below.

[0207] The electrolyte is Li 1.5 Al 0.5 Ge 1.5 P3O 12 The electrolyte sheet (thickness 260 μm) was made by pelletizing the powder (hereinafter referred to as LAGP) using a uniaxial press and sintering it in an electric furnace (850 °C / 12 h). The negative electrode was indium foil (thickness 50 μm). An aluminum foil (thickness: 20 μm) was used as the positive electrode current collector, and a copper foil (thickness: 20 μm) was used as the negative electrode current collector. The above-mentioned materials were laminated in the order of positive electrode current collector, positive electrode, electrolyte, negative electrode, and negative electrode current collector, and packed in an aluminum laminate film so that the tab lead for the extraction electrode, which had been welded to the current collector in advance, was positioned outside the laminate. The resultant was then molded into a laminate cell type using a vacuum packaging machine, and pressed (196 MPa) using an isostatic pressure pressurizing device to produce an all-solid-state secondary battery.

[0208] A polyester (PET) sheet was used as the first base material 11a. A honeycomb-shaped concave-convex pattern was formed on the first base material 11a by a pattern forming device . First, an ultraviolet-curable resin (ultraviolet-curable liquid silicone rubber, PDMS, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied onto the first base material 11a. Then, a film mold (standard mold, manufactured by Soken Chemical & Engineering Co., Ltd.) having a honeycomb-shaped concave-convex pattern on its surface corresponding to the concave-convex pattern to be formed was pressed against the ultraviolet-curable resin on the first base material 11a. With the film mold pressed against it, ultraviolet rays were irradiated from a UV lamp to cure the ultraviolet-curable resin, and the film mold was released.

[0209] The structure of the first base material 11a having a concave-convex pattern 111a formed on its surface is shown in Figures 22A and 22B. Figure 22A is a top view of the first base material 11a, and Figure 22B is a cross-sectional view taken along line AA in Figure 22A. As shown in Figures 22A and B, a honeycomb-shaped concave-convex pattern having hexagonal frame-shaped convex portions is formed on the surface of the first base material 11a. Here, as shown in FIG. 22B, the width of adjacent convex portions is k (μm), the pitch of adjacent convex portions is s (μm), and the height of a convex portion is d (μm). In the following examples, the shape of the concave-convex pattern is measured using a non-contact surface / layer cross-sectional shape measurement system (Ver. 10001 manufactured by Ryoka Systems Co., Ltd.). The study was performed using tScan2.0.

[0210] As the second base material 11b, a polyester (PET) sheet with an acrylic adhesive applied to the front and back sides was used. The thickness of the second base material 11b used was 3 μm. The acrylic adhesive was applied to the front and back sides of the second base material 11b to form an adhesive portion. The thickness of the formed adhesive portion was 1 μm.

[0211] The first particles P1 are active material particles, such as LiCoO2 (hereinafter also referred to as LCO), LiMO2 (M is an element selected from the group consisting of Ni, Mn, and Co. Hereinafter, also referred to as NMC), or LiFePO4 (hereinafter also referred to as LFP). The second particles P2 and the third particles P3 are solid electrolyte particles, such as Li3BO3 (hereinafter also referred to as LBO), Li 5.9 Yb 0.81 La 0.09 Zr0.1 The LCO was manufactured by Nippon Chemical Industry Co., Ltd. (CellSeed C-5H), the NMC was manufactured by Nippon Chemical Industry Co., Ltd. (CellSeed NMC), the LFP was manufactured by Toshima Manufacturing Co., Ltd., and the Li3BO3 was manufactured by Toshima Manufacturing Co., Ltd.

[0212] Furthermore, the above-mentioned solid electrolyte particles were crushed and classified (by Nisshin Engineering Co., Ltd.) to separate them into seven levels of particle size distribution (small particle size side: A1 / A2 / A3 / B1 / B2 / B3: large particle size side). The particle sizes of each are shown in Table 2. The carrier S1 of the first particle P1, the carrier S2 of the second particle P2, and the carrier S3 of the third particle P3 were all magnetic particles, standard carriers (Standard Carrier P02 manufactured by the Imaging Society of Japan). The cumulative 50% particle size (median diameter) in the volumetric particle size distribution of the standard carrier was 81 μm.

[0213] <Method of manufacturing electrode substrate 1> Filler 241a was obtained by stirring and mixing LCO (first particles P1) and a standard carrier (support material S1). In a similar manner, filler 241b was obtained by stirring and mixing LBO (product B2) (second particles P2) and a standard carrier (support material S2). Also, filler 241c was obtained by stirring and mixing LBO (third particles P3) and a standard carrier (support material S3). Using the obtained fillers 241a-c, a particle layer 1 was formed on a resin substrate by a particle layer forming unit U2 to obtain an electrode substrate 1. At this time, the concave-convex pattern 111a on the first substrate 11a was controlled so that the width k of the concaves was 6 μm, the pitch s of the convexities was 7.5 μm, and the height d of the convexities was 5.5 μm. The obtained electrode substrate 1 was designated as Example 1.

[0214] <Method of manufacturing electrode substrates 2 to 7> Particle layers 2 to 7 were formed under the same conditions as for the particle layer 1, except that the type of the second particles P2, the type of the third particles P3, and the pitch s of the convex portions of the concave-convex pattern 111a on the first substrate 11a were changed as shown in Table 1, to obtain electrode substrates 2 to 7. The obtained electrode substrates 2 to 7 were designated as Comparative Examples 1 to 6.

[0215] Table 1 shows the compositions of the fillers 241a, 241b, and 241c used when forming a particle layer on a resin substrate using the particle layer forming unit U2 in the manufacturing process of the electrode substrates 1 to 7, and the shape of the concave-convex pattern 111a on the first substrate 11a. [Table 1] The support material S1 in the filler 241a, the support material S2 in the filler 241b, and the support material S3 in the filler 241c all used the standard carrier described above. In the table, the mass % of particles indicates the mass % of each particle in each filler.

[0216] Table 2 shows the particle size of the primary particles of each particle in the fillers 241a to c. The particle sizes shown in Table 2 are the particle sizes of the materials contained in the fillers before the particle layer is formed. The particle sizes (r10, r50, r90) of each particle are the particle sizes of the cumulative distribution in the volume-based particle size distribution of the primary particles, where r10 is the particle size at 10% cumulative, r50 is the particle size at 50% cumulative, and r90 is the particle size at 90% cumulative. In other words, r50 is the median diameter. The particle sizes were measured using a laser diffraction scattering type particle size distribution measuring device (LA-960 manufactured by Horiba, Ltd.). [Table 2] The standard carriers used as the supports S1, S2 and S3 had r10 of 60 μm, r50 of 81 μm and r90 of 113 μm.

[0217] Fig. 23A is an SEM image of the upper side (the side on which the particle layer is formed) of the electrode substrate 1 of Example 1. Within the surface of the electrode substrate, LCO particles P1 are periodically dispersed and arranged, and LBO particles P2 and P3 are arranged between the particles. That is, in Figs. 23A to C, P1 indicates the active material particles of the electrode substrate, P2 indicates the first solid electrolyte particles of the electrode substrate, and P3 indicates the second solid electrolyte particles of the electrode substrate. Figure 23B is an enlarged image of Figure 23A. The LBO contains particles P2, which are a group of particles with a large particle size, and particles P3, which are a group of particles with a small particle size.

[0218] 23C is a BIB-SEM image of a cross section of the electrode substrate 1. A particle layer containing particles P1, P2, and P3 was formed on the resin substrate (second substrate 11b) of the electrode substrate 1. In addition, in the particle layer, solid electrolyte particles LBO (B2 product) as particles P2 were disposed adjacent to LCO as particles P1. The solid electrolyte particles LBO (A2 product) which are particles P3 are smaller than the particles P2 and are unevenly distributed in the upper part of the particle layer (opposite side of the second base material 11b). When the uneven distribution was judged by the method described later, 80% or more of the particles P3 (solid electrolyte particles LBO (A2 product)) were unevenly distributed on the opposite side to the side contacting the resin base material. As described above, this is realized by the third and fourth steps (S103 and S104 in FIG. 1) in which the particles P1 and P2 are precipitated on the adhesive part on the resin base material and the particles P3 are arranged on the newly exposed adhesive part on the surface (FIGS. 12A, 12B, 13, and 14).

[0219] FIG. 24A is an SEM image (enlarged) of the upper side (the side on which the particle layer is formed) of the electrode substrate 2 of Comparative Example 2. Particles P2 and LBO (A2 product) which are particles P3 are arranged between the particles of LCO. FIG. 24B is a BIB-SEM image of a cross section of the electrode substrate 2. Particles P2 and LBO (A2 product) which are particles P3 are arranged adjacent to LCO which is particle P1, but since particles P2 and P3 have the same particle size, it can be seen that they are each arranged in the same way on the resin substrate. That is, in Comparative Example 2, uneven distribution of particle P3 as in Example 1 was not confirmed.

[0220] FIG. 25A is an SEM image (enlarged) of the upper side (the side on which the particle layer is formed) of the electrode substrate 5 of Comparative Example 5. Particles P2 and LBO (B2 product) which are particles P3 are arranged between the particles of LCO. FIG. 25B is a BIB-SEM image of a cross section of the electrode substrate 5. Particles P2 and LBO (B2 product) which are particles P3 are arranged adjacent to LCO which is particle P1, but as in Comparative Example 2, since particles P2 and P3 have the same particle size, it can be seen that they are arranged in the same way on the resin substrate. That is, in Comparative Example 5, uneven distribution of particle P3 as in Example 1 could not be confirmed. Similarly, in Comparative Examples 1, 3, 4 and 6, since the particle diameters of the particles P2 and the particles P3 are the same, uneven distribution of the particles P3 as in Example 1 could not be confirmed.

[0221] Table 3 shows the evaluation results of Example 1 and Comparative Examples 1 to 6. The evaluation method will be described. [Table 3] In the table, "coverage" refers to the coverage of the surface of the resin substrate by the active material particles and the solid electrolyte particles. "re" and "ra" refer to the coverage of the surface of the resin substrate by the solid electrolyte particles. indicates the average equivalent circle diameter of the primary particles of the active material particles. "re10" indicates the equivalent circle diameter of the solid electrolyte particles on the surface of the resin substrate that is 10% of the cumulative number of re (from the small particle diameter side). "re10 ratio" indicates the ratio of particles (second solid electrolyte particles) that are 10% or less of the cumulative number of the solid electrolyte particles on the resin substrate that are present on the far side of the resin substrate from a reference line described later. In other words, if the re10 ratio is 0.80 or more, it indicates that the second solid electrolyte particles are unevenly distributed on the opposite side to the resin substrate in the particle layer. In addition, "presence or absence of uneven distribution" indicates the presence or absence of uneven distribution of the second solid electrolyte particles in the particle layer. A specific method for determining uneven distribution will be described later. The average equivalent circle diameter re of the primary particles of the solid electrolyte particles in Example 1 was 1.1 μm, and the equivalent circle diameter corresponding to a cumulative 10% of re on a number basis was 0.48 μm. In other words, it was confirmed that the second particles P2 corresponded to the first solid electrolyte particles in the electrode substrate, and the third particles P3 corresponded to the second solid electrolyte particles in the electrode substrate.

[0222] The methods for evaluating the electrode substrate and calculating the various indices will be described below.

[0223] <Coverage rate> The images for calculating the coverage ratio were obtained by SEM observation. SEM observation was performed by photographing the top surface of the electrode substrate (the side on which the particle layer was formed) from the vertical direction using an electron microscope (S-4800: manufactured by Hitachi, Ltd.). An example of the photographed SEM image is shown in Figure 30. The photographing was performed under the following conditions. Detector: ESB (backscattered electron beam) Observation conditions: Accelerating voltage 2 kV Magnification: 1000x Filter: ESB filter biased to 1500V

[0224] Next, the elements and composition of each particle on the resin substrate were analyzed by SEM-EDX (PV77-47190ME manufactured by AMETEK Corporation) to distinguish between active material particles 17 and solid electrolyte particles 18. In Fig. 30, the active material particles are shown as white particles, and the solid electrolyte particles are shown as gray particles. Specifically, the active material particles and solid electrolyte particles are identified by the following method. The resin substrate is analyzed by X-ray diffraction (XRD) or the like to identify the materials that compose the resin substrate. Then, the specific elements contained in the active material particles and solid electrolyte particles can be detected and identified by SEM-EDX. When LCO is used as the first particle P1, which is an active material particle, and LBO is used as the second particle P2 and the third particle P3, which are solid electrolyte particles, the active material particles are identified by detecting Co by SEM-EDX, and the solid electrolyte particles are identified by detecting B by SEM-EDX.

[0225] The coverage rate was calculated by determining the ratio of the portion where particles are present across the entire screen of the SEM image obtained by the above-described method. Specifically, it was calculated through image processing as follows. OpenCV was used for image processing, and the analysis was performed in Python. The obtained SEM image was normalized so that the average brightness was 100 and the standard deviation was ±30. The normalized image was binarized using a threshold of brightness 60 to prepare an image in which all particles were represented by white pixels. An example of the prepared image is shown in Fig. 31. The ratio represented by white pixels among all the pixels constituting the image was analyzed and calculated as the coverage rate of the particles. For example, the coverage rate in Fig. 31 is 96.3%.

[0226] <Imaging method of BIB-SEM> In the calculation of re and ra and the determination of the non-uniform distribution of particles, BIB-SEM images were used. The imaging conditions of BIB-SEM are described below. Three resin substrates were laminated on a substrate (Al foil), and a sample that was vacuum-packaged and isotropically pressurized was prepared. The sample was cut with a wire saw (DWS3400 / wire diameter 170 μm · diamond diameter 30 μm), and the cut surface was subjected to cross-section processing (JEOL SM-09010 Cross Section Polisher) with a broad ion beam of Ar. The conditions for the cross-section processing were a voltage of 6 kV and a current of 150 - 200 mA. As a BIB-SEM image, a cross-section in the stacking direction of the resin substrate and the particle layer was obtained for cross-section observation.

[0227] The cross-section was photographed with an electron microscope (ULTRA55) under the following conditions. The photographing area was such that 5 images in which 100 solid electrolyte particles were counted per sheet were photographed from the central part of the cross-section by the method described later, so that a total of 500 solid electrolyte particles were counted. An example of the photographed image is shown in Fig. 32. Detector: ESB (reflected electron image) Observation conditions: acceleration voltage 3 kV Magnification: 1000 times Filter: Apply a bias of 1500 V to the ESB filter

[0228] Next, the elements and composition of each particle on the resin substrate were analyzed by SEM-EDX (XFlash Detector 630M manufactured by Bruker Corp.) to distinguish between active material particles 17 and solid electrolyte particles 18. The active material particles and solid electrolyte particles are identified by the method described above. The resin substrate is analyzed by X-ray diffraction (XRD) or the like to identify the materials that make up the resin substrate. Then, the specific elements contained in the active material particles and solid electrolyte particles are detected and identified by SEM-EDX using the method described above.

[0229] <re ra> The method for calculating re / ra using BIB-SEM images is described. <Method for calculating ra> Active material particles were detected from the BIB-SEM images taken under the above conditions. For the detection, the Watershed method, which is an image boundary detection method, was used. First, the BIB-SEM images were normalized so that the average brightness was 100 and the standard deviation was ±30. To count the active material particles on the resin substrate, an image representing only the particle layer on the resin substrate was cut out from the above-normalized image so as to include all the particles in the image. An example of the cut-out image is shown in FIG. 33A. The cut-out image was binarized with a threshold of brightness 120 to obtain an image in which only the active material particles are represented by white pixels. An example of the obtained image is shown in FIG. 33B. Next, for the purpose of noise removal, the areas surrounded by white pixels were filled with white, and then the opening process of morphological transformation was performed with a kernel size of 3×3 pixels to obtain an image after noise removal. An example of the image after noise removal is shown in FIG. 33C. To execute the Watershed method, the parts that are surely the background and the parts that are surely the foreground (here, the active material particles) in the image, and the parts where either cannot be determined are determined. The obtained image is subjected to dilation processing of the white part, and the black part is determined as the background. Subsequently, the distance between the foreground and the background is obtained, and the parts that are 20% or more away from the background are surely regarded as the foreground (active material particles). Also, the boundary region between the foreground and the background is defined, and each particle is detected by applying the Watershed method. An example of the image after detecting the particles is shown in FIG. 33D. For example, 21 particles are detected from FIG. 33D.

[0230] The number of pixels of each detected particle was counted as the area, and the diameter of a circle equivalent to that area was calculated. By calculating the size of one pixel from the scale of the original image, the diameter of the circle calculated from the number of pixels was converted into the actual diameter, and the equivalent circle diameter of the primary particles was calculated. Specifically, ra can be calculated as follows. ra = (number of pixels of the detected particles) × (length per pixel of the SEM image (μm)) The particle size of the particles corresponding to 50% cumulative on a number basis from the smaller particle size side of the equivalent circle diameter of the primary particles of each of the calculated active material particles was defined as the average equivalent circle diameter ra of the active material particles. For example, in FIG. 33D, ra = 64.7 (pixels) × 0.04 (μm) = 2.6 (μm).

[0231] <Method for calculating re> The BIB-SEM image was normalized by the above method, and an image of the particle layer on the resin substrate was cut out from the normalized image. The cut-out image was binarized with a brightness of 120 as the threshold value to obtain an image in which only the active material particles were represented by white pixels. An example of the obtained image is shown in FIG. 33B. Further, the cut-out image was binarized with a brightness of 90 as the threshold value to obtain an image representing both the solid electrolyte particles and the active material particles by white pixels. An example of the obtained image is shown in FIG. 34A. By subtracting the white pixel portion of the image in which only the active material particles are represented by white pixels from the image in which both the solid electrolyte particles and the active material particles are represented by white pixels, an image in which only the solid electrolyte particles are represented by white pixels is obtained. An example of the obtained image is shown in FIG. 34B. Next, for the purpose of noise removal, after filling the regions surrounded by white pixels with white, an opening process of morphological transformation was performed with a kernel size of 3 × 3 pixels to obtain an image after noise removal. An example of the obtained image is shown in FIG. 34C.

[0232] Subsequently, in order to execute the Watershed method, a portion that is surely the background in the image, a portion that is surely the foreground (here, the solid electrolyte particles), and a portion that cannot be determined either way are determined. An expansion process of the white portion was performed on the obtained image, and the black portion was determined as the background. An example of the obtained image is shown in FIG. 34D. Subsequently, the distance between the foreground and the background was obtained, and a portion that is 10% or more away from the background was defined as a portion that is surely the foreground (solid electrolyte particles). Also, the region between the foreground and the background was defined as the boundary region. An example of the image showing the boundary region is shown in FIG. 34E. By applying the Watershed method to this image, each particle was detected. An example of the image after detecting the particles is shown in FIG. 34F. For example, 28 particles are detected from FIG. 34F.

[0233] The number of pixels of each detected particle was counted as the area, and the diameter of the circle equivalent to that area was calculated. By calculating the size of one pixel from the scale of the original image, the diameter of the circle calculated from the number of pixels was converted to an actual diameter, and the equivalent circle diameter of the primary particle was calculated. Specifically, re can be calculated as follows: re = (number of pixels of detected particles) x (length per pixel in SEM image (μm)) The particle size of the cumulative 50% by number of particles counting from the smallest particle size of the calculated equivalent circle diameters of the primary particles of each solid electrolyte particle was defined as the average equivalent circle diameter re of the solid electrolyte particles. For example, in Fig. 34F, ra = 16.9 (pixels) × 0.04 (µm) = 0.68 µm. Therefore, in the example shown in Fig. 33D and 34F, re / ra = 0.68 / 2.6 = 0.26, which is 0.01 or more and 2.0 or less.

[0234] <Determination of uneven distribution> The uneven distribution of the solid electrolyte particles was evaluated by the following method. The following describes how to determine the reference line for uneven distribution, and how to confirm the relationship between the position of the solid electrolyte particle that is 10% of the cumulative particle diameter and the reference line to judge the uneven distribution. The uneven distribution is judged by observing the cross section of the particle layer using a BIB-SEM. The means for obtaining the BIB-SEM image is as described above.

[0235] <Determining the baseline for uneven distribution> First, a reference line of uneven distribution is determined. As an example, a method of determining the reference line of uneven distribution in a BIB-SEM image shown in FIG. 35 will be described below. The distribution of the active material particles on the resin substrate in the z-axis direction (the lamination direction of the resin substrate and the particle layer) was taken as the reference line for the uneven distribution, and the peak position was taken as the reference line. The BIB-SEM image obtained by the above-mentioned method was normalized to an average brightness of 100 and a standard deviation of ±30, and then binarized at a brightness threshold of 120. At this time, the particles represented by white pixels are active material particles. By counting the number of white pixels in each raster lined up in the z-axis direction, the distribution of active material particles in the particle layer on the resin substrate in the lamination direction of the resin substrate and the particle layer is obtained. In the particle layer on the resin substrate, the position where the distribution of active material particles peaks is set as the reference line of uneven distribution. That is, a reference line perpendicular to the z-axis direction is drawn at the position where the distribution of active material particles peaks in the z-axis direction. An example of a BIB-SEM image and a peak in the distribution of active material particles is shown in FIG. 35. FIG. 35 is a diagram showing a BIB-SEM image of a cross section of an electrode substrate laminate in which three electrode substrates are laminated. From the bottom (the base point side of the z-axis) of FIG. 35, three electrode substrates formed in this order of a resin substrate and a particle layer are shown laminated. The reference line is determined by identifying the position where the distribution of active material particles peaks in each electrode substrate. For example, in FIG. 35, the dotted line at the position where the peak on the right side (active material distribution) and the dotted line overlap indicates the reference line.

[0236] <Method of determining uneven distribution> Next, a method for determining uneven distribution of solid electrolyte particles in a BIB-SEM image will be described. By the above-mentioned method, the solid electrolyte particles on the resin substrate were detected on the SEM image, and the circle equivalent diameter was calculated. In the distribution of the circle equivalent diameters of the primary particles of the obtained solid electrolyte particles, particles having a cumulative diameter of 10% or less on a number basis were extracted from the small particle side, and the second solid electrolyte particles were identified. For each of the identified second solid electrolyte particles, the shortest distance in the z-axis direction from the surface of the resin substrate is defined as the minimum value min, and the longest distance is defined as the maximum value max. The longest distance is the position of the second solid electrolyte particle farthest from the surface of the resin substrate in the z-axis direction. The average value of min and max was then determined as the central position of the second solid electrolyte particle, and this was defined as the position of the second solid electrolyte particle. For example, in Fig. 36, 19 (the center of the circled portion) is the center position of the second solid electrolyte particle, i.e., the position of the particle. The dashed line in the figure is the reference line determined by the above-mentioned method.

[0237] In the electron microscope images taken by the above-mentioned method (images taken so that a total of 500 solid electrolyte particles are counted), the positions of the second solid electrolyte particles are compared with the reference line of uneven distribution. The positions of the second solid electrolyte particles are determined by the above-mentioned method for all of the second solid electrolyte particles in the five images. Also, the reference line is determined in each image by the above-mentioned method. Next, in each image, it is confirmed whether 80% or more by number of the second solid electrolyte particles are located on the side in contact with the resin substrate or on the opposite side to the resin substrate from the reference line. One judgment is made for all 500 second solid electrolyte particles in the five images. As described above, the position of the second solid electrolyte particles is determined based on the position of the center of the particle. That is, when the center positions of 80% or more of the second solid electrolyte particles among the second solid electrolyte particles are located on the resin substrate side or the opposite side to the resin substrate from the reference line, the second solid electrolyte particles are determined to be unevenly distributed. For example, in FIG. 36, it can be seen that 80% or more of the second solid electrolyte particles are located farther from the resin substrate than the reference line. When 80% or more by number of the identified second solid electrolyte particles are located on the resin substrate side or the opposite side to the resin substrate from the reference line, the second solid electrolyte particles are determined to be unevenly distributed.

[0238] As described above, the electrode substrate can also be used as an electrode substrate laminate in which electrode substrates are laminated. That is, in an electrode substrate in which a particle layer is formed on a resin substrate, another resin substrate may be present on the particle layer. In that case, any one side of the particle layer is set as the resin substrate side, and the other side is set as the opposite side to the resin substrate, and the uneven distribution can be determined by the above-mentioned method. can. In the present disclosure, the electrode substrate may be formed by laminating a resin substrate, a particle layer, and a resin substrate in this order. In this case, the uneven distribution can be determined by the above-mentioned method, with one side being the resin substrate side and the other side being the opposite side, as in the above.

[0239] Electrodes (positive electrodes) were prepared from the electrode substrates of Example 1 and Comparative Examples 1 to 6, and all-solid-state batteries were assembled by the above-mentioned method. The results of evaluation of rate characteristics and cycle characteristics of the all-solid-state battery 1 produced using the electrode substrate of Example 1, and the comparative all-solid-state batteries 1 to 6 produced using the electrode substrates of Comparative Examples 1 to 6 are shown below. [Table 4] In the table, "AIR" indicates that sintering was performed in air. As described above, only Example 1 was evaluated as A in both rate characteristics and cycle characteristics, and it was confirmed that excellent ion conductivity and mitigation of volume fluctuation could be achieved at the same time.

[0240] The methods for evaluating the rate characteristics and cycle characteristics will be described below. <Rate characteristics> Mass of active material particles per unit area of ​​electrode substrate M (g / cm 2 ) to calculate the mass of the active material particles in the electrode (M × number of layers × electrode area (cm 2 )) to determine the current rate. The mass M of the active material particles per unit area is determined as follows. The weight of the first substrate 11a is measured after the first particles P1 are filled by the first filling device. Next, the weight of the first substrate 11a is measured after the particles P1 on the first substrate 11a are transferred to the second substrate 11b. The difference is measured and divided by the area of ​​the first substrate 11a (area of ​​the uneven region) to calculate the active material particle mass M per unit area. In the present disclosure, the active material particle mass M per unit area is calculated by the above method. Another calculation method is to use ICP emission spectroscopy. The active material particle mass per unit area M (g / cm) is calculated in advance by the above-mentioned method or the like. 2 Three levels of first base materials 11a with clear Co concentration are prepared. These first base materials 11a are dissolved by microwave acid decomposition (ETHOS PRO), and the acid decomposition solution is diluted with ultrapure water and subjected to ICP-AES measurement (CIROS CCD) to quantify the Co element. The active material particle mass per unit area M (g / cm) for the obtained element concentration is 2 From the calibration curve, the active material particle mass M (g / cm 2 ) can be obtained. The actual capacity of the LCO was 120 mAh / g, and the cutoff voltage (vs. Li) was 4.2 V (charge) / 2.6 V (discharge). Charge / discharge measurements (constant current mode) were performed at each rate using a charge / discharge device (manufactured by Biologic), and the capacity retention rate (discharge capacity / charge capacity x 100) was calculated. The maximum rate R at which the capacity retention rate was 80% or more was determined and evaluated according to the following criteria. A:R≧0.4C B: 0.4C>R≧0.3C C:0.3C>R

[0241] <Cycle characteristics> A cycle evaluation (repeated charge / discharge measurement in constant current mode) was performed at the rate R obtained in the rate characteristic evaluation above. Charge / discharge measurement was performed repeatedly until the capacity retention rate of the initial capacity was 80% or less, the number of times n was calculated, and the battery was evaluated according to the following evaluation criteria. A: n≧10 B: 10>n≧5 C:5>n

[0242] It was determined that both excellent ion conductivity and mitigation of volume fluctuation were achieved when the rate characteristics and cycle characteristics were both evaluated as A. As a result, only Example 1 was evaluated as A for both the rate characteristics and cycle characteristics, and it was confirmed that both excellent ion conductivity and mitigation of volume fluctuation were achieved.

[0243] FIG. 26 is a BIB-SEM image of the cross section of an electrode manufactured using the electrode substrate 1 of Example 1. The substrate has been removed by sintering, and sintering of the particles has progressed. LCO, which is the first particle P1, LBO (B2 product), which is the second particle P2, and LBO (A2 product), which is the third particle P3, are arranged on the positive electrode current collector (Al foil) of the substrate 14, and voids are confirmed around the LCO. In addition, the voids are unevenly distributed on the substrate 14 side of the LCO particles (the resin substrate side before the substrate is removed). This is achieved by the particle arrangement on the substrate.

[0244] 27 is a schematic diagram of an electrode substrate produced using the electrode substrate 1 of Example 1. For the sake of explanation, particles P1, P2, and P3 are described as being spherical and having the same particle diameter. As described above, in the electrode substrate 11 of Example 1, the particles P3 are unevenly distributed on the side opposite to the resin substrate side, forming a dense region. On the other hand, on the substrate side, voids (e.g., SP part in FIG. 27) are uniformly distributed between the particles P1 and P2. Even if the substrate is removed by sintering, the dense regions and uniform voids of each substrate are maintained, and it is believed that the structure shown in FIG. 27 is realized.

[0245] In the electrode manufactured using the electrode substrate 1 of Example 1, voids are provided around the active material particles, and the voids are unevenly distributed on the current collector 14 side as a substrate in the particle layer containing the active material particles and the solid electrolyte particles. Furthermore, a dense region is formed on the side of the particle layer opposite to the current collector side. It is considered that this allows both ion conduction in the electrode and mitigation of volumetric fluctuations of the active material particles to be achieved.

[0246] Fig. 28 is a BIB-SEM image of a cross section of an electrode produced using electrode substrate 3 of Comparative Example 2. No voids present around the LCO as in Fig. 26 (Example 1) are observed. 29 is a BIB-SEM image of a cross section of an electrode produced using electrode substrate 6 of Comparative Example 5. Although voids can be confirmed around the LCO, there are many voids throughout the particle layer, and the density is low.

[0247] <Method of manufacturing electrode substrates 9 to 13> Particle layers 9 to 13 were formed under the same conditions as for the particle layer 1, except that the type of the second particles P2, the type of the third particles P3, and the pitch s of the convex portions of the concave-convex pattern 111a on the first substrate 11a were changed as shown in Table 5, to obtain electrode substrates 9 to 13. The obtained electrode substrates 9 to 13 were designated as Examples 2 to 6. Table 5 shows the fillers 241a, 241b, and 241c used in Examples 1 to 6 and the concave-convex pattern 111a on the first base material 11a. [Table 5] The support material S1 in the filler 241a, the support material S2 in the filler 241b, and the support material S3 in the filler 241c all used the standard carrier described above. In the table, the mass % of particles indicates the mass % of each particle in each filler.

[0248] Table 6 shows the particle size of each particle in the filler used in Examples 1-6. [Table 6] The standard carriers used as the supports S1, S2 and S3 had r10 of 60 μm, r50 of 81 μm and r90 of 113 μm.

[0249] Table 7 shows the evaluation results of Examples 1-6. [Table 7]

[0250] An electrode (positive electrode) was prepared from the electrode substrate of Examples 1 to 6, and an all-solid-state battery was assembled by the above-mentioned method. Table 8 shows the results of all-solid-state batteries 1 to 6 prepared using the electrode substrate of Examples 1 to 6. The results of evaluation of rate characteristics and cycle characteristics are shown. [Table 8] In the table, "Ar-H2" indicates that sintering was carried out in a reducing atmosphere (Ar-H2).

[0251] In the evaluation of the rate characteristics and cycle characteristics of Examples 1 to 6, the actual capacity of each positive electrode active material was 120 mAh / g for LCO, 130 mAh / g for NMC, and 150 mAh / g for LFP. The cutoff voltages were 4.2 V / 2.6 V for LCO, 4.2 V / 2.6 V for NMC, and 3.8 V / 2.5 V for LFP.

[0252] In Examples 1 to 6, a laminate in which three sheets of the same positive electrode substrate were laminated was used, but a laminate in which multiple types of positive electrode substrates having the configuration of the present disclosure are laminated can also be used. In addition, the electrode substrate may be used as a material for a coating process (including a multilayer capacitor (MLCC) manufacturing technique) or a powder pressing process, which are conventionally known manufacturing methods.

[0253] The present disclosure relates to the following configurations and methods. (Configuration 1) An electrode substrate used in the manufacture of an electrode, The electrode substrate is A resin substrate, and active material particles and solid electrolyte particles on the resin substrate, a particle layer including the active material particles and the solid electrolyte particles is formed on the resin substrate; When a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the active material particles is defined as an average equivalent circle diameter ra of the active material particles, and a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the solid electrolyte particles is defined as an average equivalent circle diameter re of the solid electrolyte particles, a ratio (re / ra) of the average equivalent circular diameter re to the average equivalent circular diameter ra is 0.01 or more and 2.0 or less, Among the solid electrolyte particles, Particles having a particle size exceeding a cumulative 10% particle size on a number basis from the small particle size side in the distribution of equivalent circle diameters of primary particles of the solid electrolyte particles are defined as first solid electrolyte particles, When the particles having a cumulative particle size of 10% or less are defined as second solid electrolyte particles, In the particle layer, the active material particles and the first solid electrolyte particles are disposed adjacent to each other, when a cross-sectional observation of the particle layer is performed, 80% or more by number of the second solid electrolyte particles are unevenly distributed on a side of the particle layer that is in contact with the resin substrate or on an opposite side to the resin substrate with respect to a reference line, The reference line indicates a peak position of the distribution of the active material particles in the particle layer in the stacking direction of the resin substrate and the particle layer. An electrode substrate comprising: (Configuration 2) the first solid electrolyte particles include Li-B oxide-based electrolyte particles, 2. The electrode substrate according to claim 1, wherein the active material particles include Li-Co oxide-based active material particles. (Configuration 3) 3. The electrode substrate according to claim 1, wherein the second solid electrolyte particles include Li—B oxide-based electrolyte particles. (Configuration 4) the first solid electrolyte particles include Li-B oxide-based electrolyte particles, 2. The electrode substrate according to claim 1, wherein the active material particles include Li-PO4 oxide-based active material particles. (Configuration 5) 5. The electrode substrate according to claim 1, wherein the second solid electrolyte particles include Li—B oxide-based electrolyte particles. (Configuration 6) 6. The electrode base material according to any one of configurations 1 to 5, wherein a coverage rate of the surface of the resin base material with the active material particles and the solid electrolyte particles is 60% or more and 99% or less. (Configuration 7) An electrode substrate laminate comprising a plurality of electrode substrates according to any one of configurations 1 to 6 laminated together. (Configuration 8) The electrode substrate laminate according to configuration 7, the resin substrate and the particle layer are alternately arranged in a cross section of the electrode substrate laminate. (Configuration 9) 7. An electrode for a secondary battery, the electrode being a sintered body of the electrode base material according to any one of aspects 1 to 6. (Configuration 10) the solid electrolyte particles include Li-B oxide-based solid electrolyte particles, 10. The electrode of embodiment 9, wherein the active material particles comprise Li-Co oxide based active material particles. (Configuration 11) 11. A secondary battery comprising the electrode according to configuration 9 or 10, and an electrolyte layer adjacent to the electrode. (Method 1) A method for producing an electrode base material according to any one of configurations 1 to 6, which is used in the production of an electrode, The production method comprises the steps of: preparing the resin substrate having an adhesive portion; disposing the active material particles and the first solid electrolyte particles on a surface of the adhesive portion; a particle settling step of settling the first solid electrolyte particles and the active material particles arranged on the surface of the adhesive portion onto the adhesive portion; and disposing second solid electrolyte particles in the adhesion portions between the settled first electrolyte particles and the active material particles. (Method 2) A method for producing an electrode substrate used in the production of an electrode, comprising the steps of: The electrode substrate is The active material particles and the solid electrolyte particles are disposed on the resin substrate. a particle layer including the active material particles and the solid electrolyte particles is formed on the resin substrate; When a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the active material particles is defined as an average equivalent circle diameter ra of the active material particles, and a cumulative 50% particle size (by number) calculated from the distribution of equivalent circle diameters of primary particles of the solid electrolyte particles is defined as an average equivalent circle diameter re of the solid electrolyte particles, a ratio (re / ra) of the average equivalent circular diameter re to the average equivalent circular diameter ra is 0.01 or more and 2.0 or less, the solid electrolyte particles include solid electrolyte particles P2 and solid electrolyte particles P3, the cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the solid electrolyte particles P2 is larger than the cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the solid electrolyte particles P3; The production method comprises the steps of: preparing the resin substrate having an adhesive portion on a surface thereof; disposing the active material particles and the solid electrolyte particles P2 adjacent to each other on a surface of the adhesion portion; a particle settling step of settling the solid electrolyte particles P2 and the active material particles arranged on the surface of the adhesive portion into the adhesive portion; disposing the solid electrolyte particles (P3) at the adhesion portions between the settled solid electrolyte particles (P2) and the active material particles; A method for producing an electrode substrate having the above structure. (Method 3) A method for manufacturing an electrode, comprising the steps of: A step of laminating a plurality of electrode base materials according to any one of configurations 1 to 6 to form a laminate; removing the resin substrate from the laminate to obtain a three-dimensional object; and applying pressure to the three-dimensional object to obtain an electrode. (Method 4) A method for manufacturing a secondary battery, comprising: The production method comprises the steps of: Providing an electrode by the method for producing an electrode according to method 3; laminating the electrode, current collector and electrolyte; A method for manufacturing a secondary battery having the above structure. (Method 5) A method for manufacturing a secondary battery, comprising: The production method comprises the steps of: Providing an electrode by the method for producing an electrode according to method 3; and providing a solid electrolyte adjacent to the electrode. (Method 6) A method for manufacturing a secondary battery, comprising: The method includes providing the electrode according to aspect 9 or 10 and a solid electrolyte adjacent to the electrode at the same time.< / re>

Claims

1. A material sheet applicable to a secondary battery, The material sheet is, A resin substrate, and active material particles and solid electrolyte particles on the resin substrate, A particle layer containing the active material particles and the solid electrolyte particles is formed on the resin substrate. When the cumulative 50% particle size (based on the number of particles) calculated from the distribution of the equivalent circular diameters of the primary particles of the active material is defined as the average equivalent circular diameter of the active material particles, and the cumulative 50% particle size (based on the number of particles) calculated from the distribution of the equivalent circular diameters of the primary particles of the solid electrolyte is defined as the average equivalent circular diameter of the solid electrolyte particles, The ratio of the average circle equivalent diameter re to the average circle equivalent diameter ra (re / ra) is 0.01 or more and 2.0 or less. Among the solid electrolyte particles, In the distribution of the equivalent circular diameter of the primary particles of the solid electrolyte, particles with a particle size exceeding the cumulative 10% particle size on a number basis, starting from the small particle size side, are defined as the first solid electrolyte particles. When particles with a cumulative particle size of 10% or less are used as second solid electrolyte particles, In the particle layer, The active material particles and the first solid electrolyte particles are arranged adjacent to each other. In cross-sectional observation of the particle layer, more than 80 percent of the second solid electrolyte particles are found to be unevenly distributed with respect to the reference line, on the side of the particle layer that contacts the resin substrate, or on the side opposite to the resin substrate. The reference line indicates the peak position of the distribution of the active material particles in the particle layer in the lamination direction of the resin substrate and the particle layer. A material sheet characterized by the following features.

2. The first solid electrolyte particle comprises a Li-B oxide-based electrolyte particle, The material sheet according to claim 1, wherein the active material particles include Li-Co oxide-based active material particles.

3. The material sheet according to claim 1, wherein the second solid electrolyte particles include Li-B oxide-based electrolyte particles.

4. The first solid electrolyte particle comprises a Li-B oxide-based electrolyte particle, The active material particles are Li-PO ４ A material sheet according to claim 1, comprising oxide-based active material particles.

5. The material sheet according to claim 1, wherein the second solid electrolyte particles include Li-B oxide-based electrolyte particles.

6. The material sheet according to any one of claims 1 to 5, wherein the coverage rate of the active material particles and the solid electrolyte particles on the surface of the resin substrate is 60% or more and 99% or less.

7. A laminate of material sheets comprising a plurality of material sheets according to any one of claims 1 to 5.

8. A laminate of material sheets according to claim 7, A material sheet laminate in which the resin substrate and the particle layer are alternately present in a cross-section of the material sheet laminate.

9. An electrode for a secondary battery, which is a sintered body of the material sheet described in claim 1.

10. The solid electrolyte particles include Li-B oxide-based solid electrolyte particles, The electrode according to claim 9, wherein the active material particles include Li-Co oxide-based active material particles.

11. A secondary battery comprising an electrode according to claim 9 or 10 and an electrolyte layer adjacent to the electrode.

12. A method for manufacturing a material sheet according to any one of claims 1 to 5, The manufacturing method is A step of preparing the resin substrate having an adhesive portion, A step of arranging the active material particles and the first solid electrolyte particles on the surface of the adhesive portion, A particle sedimentation step in which the first solid electrolyte particles and the active material particles arranged on the surface of the adhesive portion are settled in the adhesive portion, A method for manufacturing a material sheet, comprising the step of placing the second solid electrolyte particles in the adhesive portion between the settled first solid electrolyte particles and the active material particles.

13. A method for manufacturing a material sheet applicable to a secondary battery, The material sheet is, The resin substrate contains active material particles and solid electrolyte particles, A particle layer containing the active material particles and the solid electrolyte particles is formed on the resin substrate. When the cumulative 50% particle size (based on the number of particles) calculated from the distribution of the equivalent circular diameters of the primary particles of the active material is defined as the average equivalent circular diameter of the active material particles, and the cumulative 50% particle size (based on the number of particles) calculated from the distribution of the equivalent circular diameters of the primary particles of the solid electrolyte is defined as the average equivalent circular diameter of the solid electrolyte particles, The ratio of the average circle equivalent diameter re to the average circle equivalent diameter ra (re / ra) is 0.01 or more and 2.0 or less. The solid electrolyte particles include solid electrolyte particles P2 and solid electrolyte particles P3. The cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the solid electrolyte particle P2 is greater than the cumulative 50% particle size (r50) in the volume-based particle size distribution of the primary particles of the solid electrolyte particle P3. The manufacturing method is A step of preparing the resin substrate having an adhesive portion on its surface, A step of arranging the active material particles and the solid electrolyte particles P2 adjacent to each other on the surface of the adhesive portion, The solid electrolyte particles P2 and the active material particles arranged on the surface of the adhesive portion are settled in the adhesive portion. A particle sedimentation process, A step of placing the solid electrolyte particles P3 in the adhesive portion between the settled solid electrolyte particles P2 and the active material particles, A method for manufacturing a material sheet having [a certain characteristic].

14. A method for manufacturing electrodes, A step of laminating a plurality of material sheets according to any one of claims 1 to 5 to form a laminate, A step of removing the resin substrate from the laminate to obtain a three-dimensional object, A method for manufacturing an electrode, comprising the step of pressurizing the three-dimensional object to obtain an electrode.

15. A method for manufacturing a secondary battery, The manufacturing method is A step of preparing an electrode by the electrode manufacturing method described in claim 14, A step of stacking the electrode, current collector and electrolyte, A method for manufacturing a secondary battery having [a certain feature].

16. A method for manufacturing a secondary battery, The manufacturing method is A step of preparing an electrode by the electrode manufacturing method described in claim 14, A method for manufacturing a secondary battery, comprising the step of providing a solid electrolyte adjacent to the electrode.

17. A method for manufacturing a secondary battery, The manufacturing method is a method for manufacturing a secondary battery, comprising the step of providing the electrode described in claim 9 or 10 and the solid electrolyte adjacent to the electrode all at once.

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