Battery substrate of secondary battery and method for manufacturing the same

Abstract

To provide a battery base material in which removal of a base material containing a resin is easy in a manufacturing process, and which is excellent in transferability of a particle layer even when an area is enlarged, and to provide a method of manufacturing the same.SOLUTION: A battery base material applied to a secondary battery, the battery base material comprising a first base material and a particle layer disposed on one surface of the first base material and containing particles of at least one of an active material and a solid electrolyte, wherein the particle layer has a coating film containing a resin as a second base material, and the coating film forms a relief structure having at least one of a projection and a recess on a surface of the particle layer, A total number concentration of the convex portions and the concave portions measured using a confocal laser microscope in a region in which the undulation structure is formed is 1 portion / cm2 or more and 40000 portions / cm2 or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a battery substrate applied to a secondary battery and a manufacturing method thereof. [Background technology]

[0002] In recent years, various new manufacturing methods using additive manufacturing technologies have been developed. However, the technology for designing and arranging multiple material particles to create functional structures remains challenging, posing challenges for achieving advanced implementation. For example, the technology for arranging toner particles using electrophotography is widely used. However, toner particles are made of composite materials that already contain several times the amount of binder as the functional material pigment in order to obtain charging properties. Furthermore, due to the properties of electrostatic charges, it is fundamentally difficult to position individual particles. This phenomenon also applies to electrostatic screen printing, which can pattern particles without binders. If functional particles can be arranged in any pattern in the right place, unnecessary particles can be avoided, and greater effects can be achieved, for example, with expensive materials such as battery materials. Patent Document 1 discloses a technology for producing a solid-state battery with a larger capacity by laminating particles arranged on a resin substrate together with the resin substrate in multiple layers to obtain a laminate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-137060 Summary of the Invention [Problem to be solved by the invention]

[0004] In the laminate manufactured by the method of Patent Document 1, the resin substrate contributes little to the properties of the solid-state battery and is therefore removed during the manufacturing process. Therefore, it is desirable that the proportion of the resin substrate in the total volume of the laminate be small. However, because the resin substrate also serves as a support for the particles, it may be difficult to make the resin substrate thinner than a certain thickness. In recent years, secondary batteries have become more widespread, leading to demands for higher performance and larger size. All-solid-state batteries and battery substrates must also meet similar demands, but increasing the area of ​​the battery substrate makes it more likely for shape irregularities to occur. Furthermore, when handling material layers, such as during transfer lamination in the manufacturing process of battery substrates, transfer defects are more likely to occur. Therefore, controlling the shape of the material layer is important.

[0005] The present disclosure provides a battery substrate and a manufacturing method thereof that can reduce the proportion of the resin substrate in the total volume of the laminate, particularly to control the shape of a material layer when the area of ​​the material layer is enlarged. At least one aspect of the present disclosure is directed to providing a battery substrate that allows easy removal of a resin-containing substrate during a manufacturing process and exhibits excellent transferability of a particle layer even when the area is enlarged. Also, at least one aspect of the present disclosure is directed to providing a method for manufacturing the battery substrate. [Means for solving the problem]

[0006] The present disclosure provides a battery substrate applied to a secondary battery, a first substrate; a particle layer disposed on one surface of the first substrate and including particles of at least one of an active material and a solid electrolyte; Equipped with the particle layer has a coating containing a resin that is a second base material, the coating forms an undulating structure having at least one of protrusions and recesses on the surface of the particle layer, The total density of the convex portions and concave portions in the region where the undulating structure is formed is 1 / cm as measured using a confocal laser microscope. 2 More than 40,000 pieces / cm 2 Below is the The present invention relates to a battery substrate characterized by the above. [Effects of the Invention]

[0007] The present disclosure relates to a battery substrate suitable for transfer lamination. That is, at least one aspect of the present disclosure is directed to providing a battery substrate that allows easy removal of a resin-containing substrate during a manufacturing process and has excellent transferability of a particle layer even when the area is enlarged. Furthermore, at least one aspect of the present disclosure is directed to providing a method for manufacturing the battery substrate. [Brief explanation of the drawings]

[0008] [Figure 1] Image showing the manufacturing method of battery substrate [Figure 2] An explanatory diagram illustrating the manufacturing process of the battery substrate and material layer. [Figure 3] Schematic diagram of the battery substrate and laminate manufacturing equipment [Figure 4] Schematic diagram of the binder application process [Figure 5] Explanatory diagram of a laminate [Figure 6] Conceptual diagram of the method for adding binder in parts [Figure 7] Schematic diagram of the undulating structure of the coating [Figure 8] Schematic diagram illustrating particle-exposed portions of a material layer DETAILED DESCRIPTION OF THE INVENTION

[0009] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the upper and lower limits, which are the endpoints, unless otherwise specified. Furthermore, when a numerical range is described in stages, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0010] In the present disclosure, a layer of material particles is completed on a first substrate as an intermediate transfer member, and then a binder is infiltrated between the particles to form a resin-containing coating, which is a second substrate.The first substrate is then peeled off to obtain a material layer that is an integral combination of the particles and the resin-containing coating.Furthermore, the material layers can be stacked to obtain a laminate. The resin-containing coating, which is the second substrate, contributes little to the battery characteristics and is therefore removed during the manufacturing process of the material layer or laminate. According to the present disclosure, the amount of the second substrate (resin-containing coating) contained in the laminate can be reduced. This makes it easier to remove the second substrate. For example, when removing the second substrate by heating, the heating temperature can be lowered and the heating time can be shortened.

[0011] It is also possible to form a pattern using material particles, and in this case, the patterned particles are held by a first substrate as an intermediate transfer body, thereby maintaining the accuracy of the pattern until an integrated product of the particles and a coating containing a resin is obtained. Furthermore, a material layer can be produced while maintaining the particle pattern, thereby obtaining a laminate of material layers.

[0012] Specifically, for example, material particles are temporarily fixed as a pattern on a weakly adhesive surface that has elastic deformation, such as silicone rubber, without using a fixing material. Then, a processing liquid containing a resin is allowed to penetrate into the gaps in the particle pattern, and after removing the solvent, the pattern is transferred to a transfer target. This method allows the particles to be fixed with the minimum amount of resin according to the particle size used, and also allows the use of an appropriate resin material that is easily removed in the manufacturing process of the laminate. Details of the manufacturing methods of the battery substrate and the laminate will be described later.

[0013] <Battery substrate> The battery substrate of the present disclosure is a battery substrate for use in a secondary battery, and includes a first substrate and a particle layer disposed on one surface of the first substrate, the particle layer including particles of at least one of an active material and a solid electrolyte. The particle layer has a coating containing a resin as a second base material, and the coating forms an undulating structure having at least one of protrusions and recesses on the surface of the particle layer. The total number density of the convex portions and the concave portions in the region where the undulating structure is formed, as measured using a confocal laser microscope, is 1 / cm 2 More than 40,000 pieces / cm 2 The following is the result.

[0014] The battery substrate includes a first substrate. A particle layer containing particles of at least one of an active material and a solid electrolyte is formed on one surface of the first substrate. The first substrate functions as an intermediate transfer member that transfers the particles to a material layer described below.

[0015] One surface of the first substrate preferably has an attachment portion, that is, particles are preferably disposed in the attachment portion present on one surface of the first substrate. The adhesive portion refers to an adhesive portion having adhesive force. For example, a material such as silicone rubber has a weakly adhesive surface and can be used as the first substrate having the adhesive portion. Alternatively, the adhesive portion may be formed by applying an adhesive material such as a pressure-sensitive adhesive to the surface of the first substrate.

[0016] The first substrate preferably has a particle-supporting layer. The particle-supporting layer preferably has a resin portion and an adhesive portion. That is, the particle-supporting layer preferably contains a resin. Furthermore, the particles are preferably disposed in the adhesive portion of the particle-supporting layer.

[0017] The material of the first substrate is not particularly limited, but for example, a metal material as a support coated with silicone rubber as a particle-carrying layer can be used. Details of materials that can be used as the first substrate will be described later. The first substrate preferably comprises a support and a particle-carrying layer, but the support alone can also be used as the first substrate.

[0018] The particle layer contains particles of at least one of an active material and a solid electrolyte. The active material and the solid electrolyte may each be a single particle or a combination of multiple particles. Details of materials that can be used as the active material and the solid electrolyte will be described later.

[0019] The particles contained in the particle layer are preferably patterned. The particle pattern forming method is not limited, and a particle layer having a particle pattern formed thereon can be obtained by arranging particles on the first substrate by any patterning means. Since the particles are held by the adhesive force at the interface between the adhesion surface, which is the adhesion portion of the first substrate, and the particles, regardless of the patterning means used, the particle layer is basically formed to a thickness equivalent to approximately a monolayer of particles.

[0020] The method for forming the particle pattern can be suitably selected depending on the particles to be used, whether it is a plate-based method such as relief printing or intaglio printing, or a plateless method such as electrophotography. Among them, a patterning method using a mask is preferred. The details of the particle pattern formation method will be described later.

[0021] The particle layer has a coating containing a resin. In the present disclosure, the coating refers to the entire surface of the particle layer or This refers to a film that partially covers the surface of the particle layer. The film preferably covers 70 to 100% by area of ​​the surface of the particle layer. In other words, the ratio of the area of ​​the region where the film is formed to the area of ​​the first base material is preferably 70% by area or more. The coating more preferably covers 80 to 100% by area, and even more preferably 90 to 100% by area, of the surface of the particle layer. For example, a coating can be formed by applying a solution containing a resin to the surface of the particle layer. The method for forming a coating containing a resin will be described in detail below.

[0022] The coating forms an undulating structure on the surface of the particle layer, which has at least one of protrusions and recesses and reflects the shape of the particles. If the coating does not have an undulating structure, it becomes difficult to make the coating thickness uniform when the particle layer is enlarged. For example, when a solution containing a resin is applied to the entire surface of the particle layer at once, a coating without an undulating structure is formed, and the coating thickness becomes thicker in the central region of the particle layer and thinner in the edge region. If the thickness is thus uneven, when the particle layer is transferred from the first substrate to the desired transfer target, the particle layer may be damaged from thin parts of the coating, and the transfer may not be successful.

[0023] On the other hand, the above density is 1 particle / cm 2 More than 40,000 pieces / cm 2 By forming an undulating structure in the coating that reflects the particle shape within the following range, it is possible to obtain a coating that has a uniform film thickness overall, even when the particle layer is made large in area. As a result, when the particle layer is transferred to a desired transfer target in the process described below, defects are less likely to occur in the particle layer, and the transferability of the particles can be improved. For example, by applying a solution containing a resin in portions to the surface of the particle layer by the method described below, it is possible to form an undulating structure having at least one of convex portions and concave portions.

[0024] A schematic diagram of the undulating structure is shown in Figure 7. A particle layer containing particles 63 is disposed on the surface of particle support layer 29. A coating having an undulating structure consisting of protrusions 61 and recesses 62 is formed on the surface of the particle layer. Reference numeral 64 denotes one of the protrusions. In Figure 7, reference numeral 66 denotes the undulating width of protrusion 61, and 65 denotes the undulating height.

[0025] In the area where the relief structure is formed, the total number density of the convex and concave portions measured using a confocal laser microscope is 1 / cm 2 More than 40,000 pieces / cm 2 The following is the result. Preferably, the coating forms an undulating structure having protrusions on the surface of the particle layer, and the number density of the protrusions is 1 / cm 2 More than 40,000 pieces / cm 2 The following is the result.

[0026] The coating may have an undulating structure having recesses, and the number density of the recesses is 1 / cm 2 More than 40,000 pieces / cm 2 It may be the following: In the present disclosure, the number density of protrusions refers to the number of protrusions per unit area of ​​the coating, and the number density of recesses refers to the number of recesses per unit area of ​​the coating.

[0027] The total density of the convex and concave portions is 20 / cm 2 More than 20,000 pieces / cm 2 Preferably, it is 25 pieces / cm or less. 2 More than 15,000 pieces / cm 2 More preferably, it is 100 particles / cm or less. 2 More than 10,000 pieces / cm 2 It is even more preferable that:

[0028] The total density of convex and concave portions is 1 / cm 2 More than 40,000 pieces / cm 2 By ensuring that the thickness is equal to or less than 100 μm, the coating can have a uniform thickness overall, which reduces the risk of defects occurring when the material layer is peeled off from the battery substrate, improving the transferability of particles. The total number density of the protrusions and recesses can be controlled, for example, by applying droplets of a resin-containing solution to the surface of the particle layer in divided portions, as will be described later.

[0029] <Method for observing the shape of battery substrate> The shapes of the convex and concave portions are observed using a confocal laser microscope, and the number density of the convex and concave portions and the shape of the convex portions (height, width of undulations) are measured from the observation results. The following describes the method for measuring the number density of convex and concave portions, as well as the height and width of the convex portions. The number density and shape of the convex portions are measured using a confocal laser microscope (Keyence VK-X3000). The undulating structure of the coating can be analyzed using a 3D measurement method in which the objective lens is moved from bottom to top to determine the focused position.

[0030] Specifically, the shape is observed by the following method, and the number density, height of the convex portions, and width of the undulations are measured. (1) With the battery substrate to be observed in close contact with the stage, observe the surface to which the resin is applied. A laser microscope (VK-X3000, manufactured by Keyence Corporation) and measurement software (VK-X3000 observation application, manufactured by Keyence Corporation) are used for the observation. The measurement conditions are the measurement software's simple measurement mode, scan mode, laser confocal, and observation magnification: 50x. (2) After setting the surface of the first substrate as the reference surface, the shape of the surface to which the resin was applied was observed based on the microscope observation data. Analysis software (VK-X3000 Multi-File Analysis Application, Keyence Corporation) was used for the observation. The observation area was a 10 mm x 1 mm area. (3) Profile measurements (length and angle of cross-sectional shape) and surface measurements (measurement of height difference within the surface) are performed within the observation range to quantify the shape and number density of convex and concave portions. In the present disclosure, the above measurement was performed three times, and the arithmetic average value was adopted. When the area of ​​the battery substrate was 10 mm x 10 mm, the same observation was performed three times for the entire battery substrate.

[0031] The convex and concave portions were determined as follows: A convex portion is a portion where the coating is disposed so that the height of the undulations from the surface of the first substrate exceeds the thickness of the particle layer. A convex portion is defined as a portion that has a maximum height point toward the outer surface of the coating and is convex toward the outer surface, as determined by the profile measurement and area measurement.

[0032] The recesses are defined as areas where the coating is thin and has no undulating height. The profile and surface measurements reveal that the coating has a minimum height in the first substrate direction (i.e., the depth direction) and is recessed. It is preferable that the height of the recessed areas does not exceed the thickness of the particle layer.

[0033] Specifically, convex and concave portions are determined by the following method. From the wavelength distribution obtained by Fourier transforming the cross-sectional profile obtained by the above measurement, components with wavelengths of 100 μm or more and 3000 μm or less are extracted, and then an inverse Fourier transform is performed to obtain an extracted distribution of concave and convex portions. In this process, convex portions can be determined by removing low-frequency and high-frequency components using a known bandpass filter. For example, convex portions can be determined by analysis using MATLAB (registered trademark) (MathWorks, Inc.).

[0034] The undulation width was the distance between the centers of adjacent convex portions (reference numeral 66 in Figure 7). When there was only one convex portion in the observation area, the width of one convex portion was measured (reference numeral 64 in Figure 7). The measurement was carried out three times, and the arithmetic mean value of the undulation widths of all the observed convex portions was used.

[0035] The height of the convex portion is the height of the convex portion from the reference surface. Measurements are carried out three times, and the arithmetic mean value of the heights of all the observed convex portions is taken as the average height.

[0036] The average height of the projections from the surface of the first substrate is preferably 1 μm or more and 100 μm or less. The average height refers to the average value of the heights of all the convex portions. The average height of the protrusions is more preferably 1 μm or more and 50 μm or less, and even more preferably 1 μm or more and 30 μm or less. By keeping the average height of the protrusions within this range, it is possible to reduce the amount of resin in the battery substrate and also to prevent the particle pattern from being disturbed during the heating and pressure process during transfer.

[0037] The average height of the protrusions is preferably 2.0 to 6.0 times the volume-based median diameter of the particles contained in the particle layer, i.e., the value of average height of the protrusions / volume-based median diameter of the particles is preferably 2.0 to 6.0.

[0038] The particle layer may contain a plurality of particles with different particle sizes. In this case, the median particle size refers to the volume-based median size of all particles contained in the particle layer. The volume-based median particle size (D50) is the cumulative 50% particle size in the particle size distribution on a volume basis. The particle size can be measured using a laser diffraction / scattering particle size distribution analyzer (LA-960, manufactured by Horiba, Ltd.).

[0039] The average height of the convex portions is more preferably 2.0 to 5.0 times the volume-based median diameter of the particles, and even more preferably 2.0 to 4.0 times. By satisfying the above, the amount of resin in the battery substrate can be reduced, and the particle pattern can be prevented from being disturbed during the heating and pressure process during transfer.

[0040] The ratio of the undulating width to the undulating height of the undulating structure is preferably 10.0 or more and 250.0 or less. The undulation height of the undulating structure refers to the average height of the protrusions. The undulation width is the distance between the centers of adjacent protrusions (reference numeral 66 in Figure 7). As mentioned above, when there is one protrusion in the observation area, it is the width of one protrusion (reference numeral 64 in Figure 7). The center of a protrusion refers to the point with the highest height from the surface of the first substrate. Furthermore, the distance between the centers of protrusions refers to the distance from the center of a protrusion to the center of an adjacent protrusion.

[0041] The ratio of the undulation width to the undulation height is more preferably 10.0 to 200.0, and even more preferably 30.0 to 150.0. When the ratio of the undulation width to the undulation height is within the above range, the particle layer can easily follow the transfer target side during transfer, and a coating having a more uniform film thickness overall can be obtained. As a result, defects are less likely to occur in the particle layer even after peeling off the first substrate in the process described below, and the transferability of the particles can be further improved.

[0042] The height and width of the protrusions can be controlled by adjusting the conditions for applying the resin solution to the surface of the particle layer. For example, in the divided application described below, the shape of the protrusions can be controlled by changing the number of divided applications to control the diameter of the applied droplets or by changing the resin content in the solution. The shape of the protrusions can also be controlled by changing the time interval between droplet application in the divided application or by controlling the temperature of the first substrate and particle layer to which the droplets are applied.

[0043] The time interval and temperature for applying the droplets are preferably adjusted depending on the type of solvent used for preparing the resin solution, the resin content in the resin solution, and the materials of the first substrate and particle layer to which the droplets are applied. For example, when a 5 mass % resin solution prepared using N-methyl-2-pyrrolidone (NMP) as a solvent is applied to the surface of the particle layer on which active material particles are arranged, the temperatures of the first substrate and particle layer are preferably set to 80 to 180°C, more preferably 100 to 150°C.

[0044] For example, the height of the convex portions can be increased by increasing the resin content in the resin. For example, by reducing the diameter of the applied droplets, the width of the undulations of the convex portions can be reduced, and by increasing the diameter of the applied droplets, the width of the undulations of the convex portions can be increased. When the droplet diameter is reduced, the required amount of resin can be applied by increasing the number of times the resin solution is divided. The method for applying the resin solution in portions will be described in detail later.

[0045] The height of the convex portions and the width of the undulations can be measured by the above-mentioned method using a confocal laser microscope (VK-X3000 manufactured by Keyence Corporation).

[0046] <Method of manufacturing battery substrate> The method for manufacturing a battery substrate according to the present disclosure will be described below step by step. FIG. 1 is a flowchart of a method for manufacturing a battery substrate. FIG. 2 is a schematic diagram showing a specific example of a method for manufacturing a battery substrate in the order of steps. The method for manufacturing a battery substrate includes a particle layer forming step of arranging material particles on a first substrate to form a particle layer, and a coating step of forming a coating containing a resin, which is a second substrate, on the surface of the formed particle layer.

[0047] <Particle layer formation process> Below, an example will be described in which particles contained in a particle layer are arranged in a pattern using a mask, but the method for arranging the particles is not limited to this. The active material and / or solid electrolyte contained in the particle layer may be a single particle, or multiple particles may be used in combination. Furthermore, the multiple particles may include first particles, second particles, third particles, ..., nth particles. For example, multiple particles can be arranged using multiple masks.

[0048] In the particle layer forming step, particles are disposed on one surface of the first substrate to form a particle layer. The particles are particles of at least one of an active material and a solid electrolyte. The process of arranging a plurality of particles on the adhesion surface preferably includes a first process of forming a mask on the adhesion surface, a second process of arranging first particles in areas of the adhesion surface where the mask is not formed, a third process of removing the mask from the adhesion surface, and a fourth process of arranging second particles in areas of the adhesion surface where the first particles are not arranged.

[0049] 2A to 2G show a specific example of the particle layer forming process in the order of steps. First, a particle-carrying layer 29 is formed on the surface of the support A1 to obtain a first substrate 20 (intermediate transfer member) having an attachment surface 21 (FIG. 2A).

[0050] Next, a mask 22 having openings 23 is formed on the attachment surface 21 of the first substrate 20 (FIG. 2D). The method for forming the mask 22 is not particularly limited, and known methods can be used. For example, a mask layer 3 is formed on the surface of a separately prepared support B 28, and then patterned to obtain the desired openings 23 to form the mask 22 (FIG. 2C). A UV laser, for example, can be used as a patterning method. Thereafter, the support B 28 on which the mask 22 has been formed is brought into contact with the first substrate 20 so that the mask 22 adheres to the attachment surface 21 of the first substrate, and the mask 22 is transferred from the support B 28 to the attachment surface 21.

[0051] Then, first particles 24 are disposed in the openings 23, which are the portions of the attachment surface 21 where the mask 22 is not formed (FIG. 2E). The first particles 24 are an active material or a solid electrolyte. This allows the first particles 24 to be attached to the attachment surface 21 of the first substrate 20. Next, the mask 22 is removed from the attachment surface 21 (FIG. 2F). There are no particular limitations on the method for removing the mask 22, and any known means may be used. For example, the mask 22 can be removed using a mask removal unit, which will be described later.

[0052] By removing the mask, the attachment surface 21, which is the non-arrangement portion of the first particles, is newly exposed on the surface of the particle support layer 29. Second particles 25 are arranged on the exposed attachment surface 21, which is the non-arrangement portion of the first particles (FIG. 2E). The second particles 25 are an active material or a solid electrolyte. The second particles 25 may be the same as or different from the first particles 24. That is, the first particles and the second particles 25 may both be active materials or solid electrolytes.

[0053] This allows the second particles 25 to adhere to the attachment surface 21, and a pattern of the first particles and the second particles is formed on the surface of the particle support layer 29. That is, by the above method, a particle layer containing particles of at least one of an active material and a solid electrolyte can be formed on one surface of the first substrate.

[0054] <Film formation process> In the coating formation step, a coating containing a resin as a second base material is formed on the surface of the particle layer formed in the particle layer formation step. The coating formation step will be described in detail below.

[0055] A binder 27 is filled between the particles in the pattern of the first particles and the second particles of the particle layer formed in the particle layer forming step. The binder 27 is a solution containing a resin. The resin contained in the binder 27 is preferably peelable from the attachment surface 21. The binder not only holds the particle layer together but also forms a coating containing the resin. The resin-containing solution fills the spaces between the particles in the particle layer and simultaneously forms protrusions of an undulating structure on the surface of the particle layer, i.e., a coating having an undulating structure is formed on the surface of the particle layer.

[0056] As a result, a battery substrate according to the present disclosure can be obtained, which includes a first substrate and a particle layer, the particle layer having a coating containing the resin that is the second substrate, and the coating forming an undulating structure having at least one of protrusions and recesses along the surface of the particle layer. For example, a resin solution containing the resin is allowed to penetrate between the particles, and then the resin solution is dried to remove the solvent, thereby obtaining a battery substrate that is an integrated body of the first substrate, the particle layer, and the coating containing the resin (FIG. 2H).

[0057] The resin solution contains a resin and a solvent. The resin solution is applied to the particle layer as droplets. The resin solution penetrates and fills the spaces between the particles by capillary action, and the solution containing the resin that has not filled the spaces between the particles is present in a thickness on the surface of the particle layer. In other words, after the droplets are applied, the resin is present in a thickness of dots on the surface of the particle layer, forming an undulating structure having at least one of convex portions and concave portions.

[0058] The method for applying the droplets is not particularly limited, but for example, a dispenser, a micropipette, etc. Among these, it is preferable to apply the droplets using a dispenser. Thereafter, the solvent in the resin solution is removed to form a coating containing the resin.

[0059] That is, the coating formation step includes a step of applying droplets of a resin solution containing a resin and a solvent to the surface of the particle layer, and a step of removing the solvent to form a coating containing the resin.

[0060] A method for applying a solution containing a resin to a particle layer will be described with reference to Fig. 4. As a method for applying the resin solution, it is preferable to use a flying dispenser 13 as shown in Fig. 4, for example. In the example of FIG. 4, the resin solution is filled in a supply unit 43 and supplied to the flying dispenser 13 via a supply tube 42. The first substrate 20 having the particle layer 40 disposed on its surface is transported in a transport direction A. The flying dispenser 13 moves along a main scanning direction B. While this is happening, droplets of the resin solution are applied to the particle layer 40.

[0061] A specific method of dividing and allocating will be described with reference to FIGS. 6A to 6D. 6A to 6D show a method in which a resin-containing solution is applied to the surface of the particle layer in four separate applications. In the first pass, 1 / 4 of the solution to be applied is applied as droplets to the surface of the particle layer 40 (FIG. 6A). Next, in the second pass, 1 / 4 of the solution to be applied is applied to areas where droplets were not applied in the first pass (FIG. 6B). Similarly, in the third pass, 1 / 4 of the solution to be applied is applied to areas where droplets were not applied in the first and second passes (FIG. 6C). Finally, in the fourth pass, 1 / 4 of the solution to be applied is applied to areas where droplets were not applied in the first to third passes (FIG. 6D). After four applications, the total amount of solution to be applied is arranged in dots on the surface of the particle layer.

[0062] The droplets containing the resin are applied to the surface of the particle layer and arranged in dots. 6A to 6D, successive droplets are applied in each pass with a gap between them to prevent them from coalescing. The droplets thicken or dry while the droplets of the next pass are being applied. The droplets of the next pass are deposited independently in dot form at positions where no droplets were deposited in the previous pass, or at positions where the droplets deposited in the previous pass have thickened or dried. The above operation is repeated until droplets containing resin are deposited over a predetermined area. Hereinafter, this operation is also referred to as divided deposition.

[0063] 6A to 6D show the droplet application divided into four times, with four droplets applied each time, but the number of times the droplets are applied and the number of droplets applied each time are not limited. For example, 2 The number of times droplets are applied per unit time is preferably 1 to 40,000, more preferably 20 to 20,000, even more preferably 25 to 15,000, and even more preferably 100 to 10,000. The amount of droplets of resin solution to be applied is not particularly limited, but it is preferable to control the amount of resin applied so that an undulating structure that reflects the shape of the particles can be formed.

[0064] The step of applying droplets of the resin solution preferably includes the following steps (i) to (iv). (i) Dividing the surface of the particle layer into a plurality of blocks (ii) applying the droplets to a portion of the area of ​​the block; (iii) A step of allowing the applied droplets to stand and thicken or dry them (iv) applying the droplets to positions where the droplets were not applied in the step (ii) or positions where the droplets overlap with the droplets that have been thickened or dried in the step (iii).

[0065] It is preferable to apply droplets to the entire area of ​​the block by repeating the above steps (ii) to (iv). Furthermore, it is preferable that the droplets applied in steps (ii) and (iv) are applied successively with a gap between each droplet applied previously so that the droplets do not coalesce.

[0066] As described above, the resin solution contains a resin and a solvent. The droplets of the resin solution applied to the surface of the particle layer thicken or dry over time as the solvent evaporates. That is, step (iii) is a step of thickening or drying the droplets by waiting a certain time between performing step (ii) and performing step (iv). The time period between step (ii) and step (iv) is preferably adjusted depending on the type of solvent used in preparing the resin solution, the resin content in the resin solution, and the first substrate and particle layer to which the droplets are applied.

[0067] Furthermore, when droplets are applied at positions overlapping the thickened or dried droplets in step (iv), the newly applied droplets may completely or partially overlap the thickened or dried droplets. Even when droplets are arranged so as to overlap, the thickened or dried droplets and the newly applied droplets do not merge. Therefore, additional droplets can be applied on top of droplets that have already been thickened or dried. Step (iv) is preferably a step of applying further droplets to positions where no droplets have been applied in step (ii). The droplets are preferably applied at intervals greater than the diameter of the previously formed droplets. The next droplet is preferably applied to a position that does not overlap with the previously applied position, and this operation is preferably repeated until droplets are applied to the entire surface on which the coating is to be formed. This facilitates the formation of an undulating structure.

[0068] By applying the droplets by the above-described method, it is possible to prevent the droplets from coalescing on the surface of the particle layer, and to form a coating having an undulating structure of a specific shape on the surface of the particle layer.

[0069] The first substrate is then peeled off from the resulting battery substrate, yielding a material layer 50 in which the particle layer and the resin-containing coating are integrated (FIG. 2I). Furthermore, a plurality of the resulting material layers 50 can be stacked to obtain a laminate 401 (FIG. 5A). The battery substrate and laminate can be used as materials for secondary batteries.

[0070] <Battery substrate and laminate manufacturing equipment> 3 shows an example of a battery substrate and laminate manufacturing apparatus 100. This apparatus is an apparatus for, for example, manufacturing a battery substrate containing a positive electrode material, peeling off a first substrate from the battery substrate to obtain a positive electrode material layer, and then manufacturing a positive electrode material layer laminate.

[0071] 3, for example, a PET film mask with openings formed by a UV laser 6 is attached to a first substrate 20 having a surface made of silicone rubber as a particle support layer. Then, particles of a battery positive electrode material are supplied by a first particle supply unit 7, and after the mask is peeled off, particles of a battery solid electrolyte are supplied by a second particle supply unit 11, thereby forming a particle layer 40.

[0072] Furthermore, a treatment liquid containing dissolved resin is applied to the surface of the particle layer using a flying dispenser 13 in the manner described above, and is supplied to and penetrates into the gaps between the particles. The solvent in the resin solution is then removed to produce a battery substrate having a coating of a specific shape. The particle layer having the resin-containing coating is then peeled off from the battery substrate to produce a positive electrode material layer. These material layers are then stacked in a stacking device 15 to produce a stack of positive electrode material layers.

[0073] The manufacturing apparatus 100 shown in FIG. 3 will be described below. The manufacturing apparatus 100 is equipped with a first substrate 20 arranged in the form of a belt as an intermediate transfer body, a conveying device 2 that conveys the first substrate 20 between processes, and processing means that execute the processes shown in Fig. 2. The first substrate 20 is a first substrate having the above-mentioned attachment surface 21. In Fig. 3, the first substrate 20 is in the form of a belt, but the shape of the first substrate is not particularly limited. For example, the first substrate 20 may be in the form of a roller or a flat plate. The material and shape of the first substrate will be described in detail later.

[0074] The manufacturing apparatus 100 is centered around a conveying device 2 that drives a first substrate 20, and includes a mask layer applying unit that includes a mask layer supplying means 30 that supplies a mask layer 3 and a pressure roller 4, a mask manufacturing unit 6 (e.g., a UV laser generating device), a first particle supplying unit 7, and, if necessary, an air blower 8.

[0075] The manufacturing apparatus 100 includes a mask removing unit that is composed of a peeling roller 9 and a winding device 10. The mask removing unit removes the mask 22 from the attachment surface 21 on which the first particles 24 are arranged. The manufacturing apparatus 100 also includes a second particle supply unit 11 and, if necessary, an air blower 12. The second particle supply unit 11 deposits second particles 25 on the attachment surface 21 exposed in the area where the mask 22 has been removed (FIGS. 2E to 2G).

[0076] The manufacturing apparatus 100 includes a flying dispenser 13 as a means for applying a treatment liquid containing a binder 27 to fill the particles with the binder, and a solvent removal promoting means 14 for removing the solvent after the treatment liquid has been applied.

[0077] The treatment liquid may be a resin solution containing the above-mentioned resin and a solvent. The solvent can be removed by drying, etc. The solvent removal promoting means 14 is, for example, a heating means such as a hot plate.

[0078] The flying dispenser applies droplets of the resin solution to the surface of the particle layer using the method described above. That is, the resin solution is filled between the first particles and the second particles by the flying dispenser 13, and the solvent is removed by the solvent removal promoting means 14, thereby forming a coating containing the resin, which is the second substrate, on the surface of the particle layer. As a result, a battery substrate is obtained that includes the first substrate and the particle layer, and in which a coating containing the resin having a specific shape is formed on the surface of the particle layer.

[0079] The particle layer having the resin-containing coating is peeled off from the battery substrate to obtain the material layer 50. That is, the material layer 50 has a configuration in which the first substrate is removed from the battery substrate. The manufacturing apparatus 100 includes a lamination device 15 for laminating material layers 50. The material layers are laminated while heating the binder with a heater 16, and the binder is cooled with a cooling fan 17, so that the material layers can be laminated while peeling them off from the first substrate. By carrying out the treatments in these units in sequence, a battery substrate, a material layer, and a laminate in which material layers are stacked can be manufactured.

[0080] 3 is configured to process each step in a series, but is not limited to this and may be configured to divide each step appropriately. The following description will be given using the apparatus of FIG. 3 as an example.

[0081] The first substrate 20 needs to have the property of being able to transfer particles while retaining material particles on its surface. To achieve this, the first substrate 20 has an attachment surface 21. The outer surface of the first substrate 20 serves as the attachment surface 21. For example, the first substrate 20 has a particle-carrying layer 29 having an attachment surface 21. That is, the first substrate preferably has a support 1 and a particle-carrying layer 29 having an attachment surface 21 laminated on the support 1.

[0082] The first substrate 20 temporarily holds the particles and is eventually peeled off from the battery substrate. That is, the first substrate transfers the particle layer to a desired transfer target. Therefore, the particle support layer 29 needs to have a property that allows the material layer to be peeled off. A preferable property is that the particle support layer 29 is an elastically deformable layer, for example.

[0083] If the particle support layer 29 is rigid, the contact points with the particles held on the surface tend to be point contacts, resulting in a small contact area. As a result, a strong adhesive force is required to hold the particles, which can lead to incomplete peeling of the material layer during the transfer process or damage to parts of the material layer or the surface of the first substrate.

[0084] On the other hand, if the particle-carrying layer 29 is an elastically deformable layer, some of the contact points of the particles sink into the particle-carrying layer, increasing the contact area. As a result, the particles can be reliably held with a weaker adhesive force than if the particle-carrying layer were rigid, allowing the material layer to be stably peeled off without causing any damage. In other words, the transferability of the particle layer can be improved.

[0085] On the other hand, if the adhesive layer is made of a plastically deforming material, the particles will be held in a buried state, which may make it difficult to peel off the material layer. The amount of particle sinking can be controlled by the rubber hardness of the surface of the intermediate transfer body. In other words, it is preferable that the particle carrying layer 29 has an appropriate degree of elastic deformation and a hardness sufficient to hold the particles without completely burying them.

[0086] In addition, as another property for stabilizing peeling (transferability) from the first substrate, it is desirable that the adhesion surface 21 has low compatibility (adhesion and solubility) with the treatment liquid containing resin. Therefore, it is preferable to select the particle-carrying layer 29 having the adhesion surface 21 based on its compatibility with the treatment liquid, particularly the solvent of the treatment liquid.

[0087] As a specific material for the particle support layer 29 that satisfies the above characteristics, urethane rubber is preferred when an aqueous treatment liquid is used as the resin solution. Fluorocarbon rubber and silicone rubber are also preferred because they are compatible with a wide range of materials, not just aqueous treatment liquids. Silicone rubber is particularly suitable because it has a wide range of adjustable adhesiveness and rubber hardness. The particle support layer 29 does not need to be made of a single material; multiple types can be combined depending on the properties.

[0088] For example, the adhesive strength of the adhesive surface 21 measured by a peeling analysis device is preferably 0.2 to 10 mN / 20 mm, more preferably 0.4 to 5 mN / 20 mm, even more preferably 0.5 to 5 mN / 20 mm, and even more preferably 0.5 to 2 mN / 20 mm.

[0089] The adhesive strength can be measured using a VPA-3 manufactured by Kyowa Interface Science Co., Ltd. In the present disclosure, the measurement was carried out under the following measurement conditions. In the examples described later, the sample size was 20 mm in width and 150 mm in length. The measurement conditions were a peel angle of 90°, a measurement temperature of 25°C, and a peel speed of 300 mm / min. PET film was used as the target substrate.

[0090] From the viewpoint of sufficiently holding the particles, the adhesive force is preferably 0.2 mN / 20 mm or more, and from the viewpoint of better transferability, the adhesive force is preferably 10 mN / 20 mm or less.

[0091] In terms of elastic properties, the rubber hardness of the adhesive surface 21 is preferably 10° to 80° (JIS Type A, durometer hardness in accordance with JIS K6253-3), more preferably 15° to 40°, even more preferably 18° to 40°, and even more preferably 18° to 30°. When the rubber hardness of the adhesion surface 21 is within the above range, the particles can be held without being completely buried, and the adhesion surface can be easily and stably peeled off from the material layer.

[0092] The thickness of the particle-supported layer 29 is preferably, for example, 10 to 200 μm, or 40 to 120 μm. When the thickness of the particle-supported layer 29 is within the above range, the degree of elastic deformation can be maintained at an appropriate level, and the particles can be held without being completely buried, making it easier to stably peel the material layer from the adhesion surface.

[0093] Specifically, the material of the particle support layer 29 that forms the adhesion surface 21 preferably contains silicone rubber, urethane rubber, or fluororubber. Alternatively, it may be a mixture of any of the above materials with other materials. The particle support layer 29 preferably contains at least one selected from the group consisting of, for example, silicone rubber, urethane rubber, and fluororubber. The particle support layer 29 more preferably contains silicone rubber, and even more preferably is silicone rubber.

[0094] The particle support layer 29 preferably contains 10 to 100 mass %, more preferably 50 to 100 mass %, and even more preferably 80 to 100 mass % of at least one selected from the group consisting of silicone rubber, urethane rubber, and fluororubber. The particle support layer 29 preferably contains 10 to 100 mass % of silicone rubber, more preferably 50 to 100 mass %, and even more preferably 80 to 100 mass %.

[0095] The support 1 of the first substrate 20 is not limited, and known materials can be used depending on the application. For example, plastics such as polyamide resin, polyimide resin, polyacetal resin, and polyester resin, and metal materials such as aluminum, stainless steel (SUS), and Invar alloy can be used as the support. Furthermore, if the first substrate is in the shape of a roll or a flat plate, glass, ceramics, and the like can also be used as the support.

[0096] For example, the surface of the support 1 may be coated with silicone rubber to an appropriate thickness as the particle support layer 29 , and the resulting belt-shaped support may be used as the first substrate 20 . Since the particle-carrying layer 29 is easily stretched and contracted when used alone, and the dimensional accuracy may be unstable, it is preferable to use a rigid body for the support. In the apparatus 100 shown in Fig. 3, the lamination device 15 uses a heat-pressing method, so it is preferable to use an Invar material, which has high thermal conductivity and dimensional stability, as the support.

[0097] When the first substrate 20 is in the form of a belt, the thickness of the support 1 is not particularly limited, but may be, for example, 0.01 to 1.0 mm, or 0.05 to 0.5 mm.

[0098] The method for forming the particle pattern on one surface of the first substrate is not limited. A general patterning technique can be applied. For example, the above-described method for forming a mask can be used to arrange particles in any pattern on one surface of the first substrate.

[0099] For example, a method can be used in which a polyester film is used as the mask layer 3, and a mask 22 with openings formed therein by a UV laser on a glass pressure roller 4 is attached to the first substrate 20 by the pressure roller 4. The attachment surface 21 of the first substrate 20 has an adhesive strength sufficient to allow peeling, and this can be used to hold the mask 22 in place.

[0100] Next, battery cathode material particles are applied as first particles to the non-formation areas of the mask. The particles adhere to the attachment surface 21 exposed in the mask openings after the mask film is peeled off, forming a pattern. Next, solid electrolyte particles are applied as second particles to the non-arrangement areas of the attachment surface 21 where the first particles are not arranged. As a result, the second particles selectively adhere to the areas where the first particles are not attached, i.e., the exposed attachment surface, completing a pattern made of the two particle materials.

[0101] Therefore, the manufacturing method of the battery substrate includes a first step of forming a mask on the attachment surface 21. The means for forming the mask is not particularly limited, and may include, for example, a step of providing a mask layer 3 on the attachment surface 21 and a step of forming an opening 23 in the mask layer 3 to form a mask 22.

[0102] 3 includes, for example, a supplying means for supplying the mask layer 3, a UV laser 6 as a means for forming openings 23 in the mask layer 3, and a pressure roller 4 as a means for attaching the mask 22 to the attachment surface. It may also include a cleaning roller 5 as necessary.

[0103] There are no restrictions on the material of the mask layer 3, but a material that is uniform in thickness and easy to process is suitable. For example, plastics such as polyimide resin, polyacetal resin, and polyester resin, and metal foils such as aluminum, stainless steel (SUS), and invar alloy are available in high quality on the market, so these are suitable for use. Plastics are preferred, and polyester film is preferred.

[0104] The thickness of the mask is preferably selected to be equal to or less than the diameter of the particle material used. The arrangement of the first particles is not limited to a thin film equivalent to a particle monolayer, but is particularly suitable for forming a thin film equivalent to a particle monolayer. That is, the thickness of the arranged particle layer is, for example, 0.80 to 1.20 times, or 0.90 to 1.10 times the average particle diameter of the first particles. The arranged particle layer is preferably approximately a monolayer. This is because, in principle, a laminate made by stacking two-dimensionally patterned sheets with a thickness equivalent to a particle monolayer offers the greatest degree of freedom in particle pattern arrangement.

[0105] The thickness of the mask is preferably 0.10 to 1.10 times the average particle size of the first particles, more preferably 0.20 to 1.00 times, and even more preferably 0.20 to 0.50 times. The thickness of the mask layer is, for example, 0.5 to 100 μm, 1 to 50 μm, or 1 to 5 μm. Within the above range, the thicker the mask, the greater the durability of the mask, making it easier to handle and increasing the number of times it can be reused. This is suitable for cases where there are few pattern changes or when producing large quantities. On the other hand, the thinner the mask, the less material is required, making it suitable for cases where there are many pattern changes or for small-scale production. In other words, it is preferable to select the mask thickness appropriately within the above range depending on the degree of pattern change and the required amount.

[0106] There are no restrictions on the method for forming the openings, and it is best to select an appropriate method based on the material of the mask layer and the resolution of the design pattern. If few pattern changes are required and high resolution is desired, methods such as etching metal foil using photolithography are suitable. On the other hand, if relatively low resolution is sufficient, methods such as creating openings in a resin film using a thermal head are suitable. For example, openings can be formed using a UV laser.

[0107] The shape of the mask portion is not particularly limited, but can be, for example, a stripe or honeycomb shape. When the mask portion is stripe-shaped, the width of the opening is not particularly limited, but can be, for example, 1 to 200 μm or 2 to 100 μm. When the mask portion is stripe-shaped, the width is not particularly limited, but can be, for example, 1 to 200 μm or 2 to 100 μm.

[0108] The formation of the mask openings 23 may be carried out with the mask layer 3 attached to the first substrate 20, but from the viewpoint of protecting the surface of the particle-carrying layer from contamination and damage, it is preferable to form the mask layer 3 separately on a support member (support B 28), form the openings, and then transfer it to the first substrate.

[0109] For example, a material with a lower absorption rate for the laser used than the mask layer is suitable for the support member used to form the opening. Specifically, when a thin plastic mask is used as the mask layer, it is preferable to use glass as the support member. Plastic has a higher absorption rate for CO2 lasers and UV lasers than glass. Glass is also preferred because it is a material that can easily produce high surface smoothness.

[0110] 3 uses a pressure roller 4 as a support member. A glass cylinder, for example, can be used as the pressure roller 4. The support member may be a flat plate, or it can be in the form of a roll if a flexible material such as polyimide film or SUS foil is used.

[0111] The technology for machining glass cylinders with high precision is commonplace and is currently produced and utilized in a wide range of industries, making it easy to obtain. In the case of laser machining, the focal length significantly affects precision, so a high-precision glass cylinder is also preferred. The mask layer 3 being transported on the pressure rollers 4 can be drilled to form the openings 23.

[0112] 3, a polyester film, which is the material for the mask layer 3, is wound in a roll and fed by a pressure roller 4 while being irradiated with a UV laser 6 according to a design pattern to perform perforation. Then, the mask is continuously attached to the attachment surface 21 of the first substrate 20, and the subsequent particle supply process and the mask peeling process are performed in an integrated manner, but the present invention is not limited to this. For example, a configuration for batch processing of sheet films is also possible.

[0113] The advantage of using a roller-shaped opening forming material as the mask layer 3 is that it is possible to use the curvature, which makes it easier to handle during mask transfer. By using an elastic material as the particle-carrying layer 29 on the surface of the first substrate 20, a mask made of a thin film can be attached to the surface of the first substrate 20 without any problems and pressure can be applied even if the pressure roller is a rigid body such as glass. The device shown in Figure 3 uses one mask to pattern two material particles, but by using multiple masks, it is possible to create patterns of three or more types of materials.

[0114] Following the first step, a second step is carried out in which first particles are disposed on the non-mask-formed portions of the attachment surface 21. That is, after a mask having openings formed therein is disposed on the first substrate 20, the first particles are disposed. The method for supplying the first particles is not particularly limited, and known methods can be widely applied. Specifically, the first particles can be sprinkled by gravity and spread by vibration, attached by spraying, or supplied using a roller, brush, or blade. If it is desired to densely fill the mask openings with particles, it is preferable to apply a rubbing force.

[0115] Among these, when a mask is used, rubbing using magnetic particles is preferred. That is, the first particles are preferably arranged by using magnetic particles as a carrier material to support the first particles and then rubbing the first particles against the attachment surface 21. The first particles can be supported by forming a magnetic brush using magnetic particles as a carrier material. The rubbing force can be easily changed depending on the particles to be placed by controlling the magnetic force. Large magnetic particles are a good match because they can be filled while pressing the mask against the transfer body. The first particles may be a single material or a premix of multiple particles. Of course, the particle surface may be subjected to a surface treatment or coating.

[0116] In the apparatus 100 of FIG. 3, magnetic particles carrying material particles on their surfaces are used as the first particle supply unit 7, and the backside magnet is operated to rub the patterning area and increase the particle density. In addition, an excess particle removal step for removing excess particles may be performed after the second step of disposing the first particles on the non-forming portions of the mask. The apparatus 100 in Fig. 3 has an air blower 8 as an excess particle removal means for facilitating the removal of particles that have formed in two layers on the single layer of particles after the pattern has been completed. The particles are held to the intermediate transfer body by adhesive force at the interface, so that in principle they are held at a thickness equivalent to a single layer of particles, regardless of the patterning method used.

[0117] The method for manufacturing the material layer includes a third step of removing the mask from the deposition surface. The means for removing the mask is not particularly limited, and any known means may be used. For example, the mask may be peeled off. As a mechanism for peeling the mask from the first substrate, the device shown in Fig. 3 uses a system in which the mask is wound up in the form of a continuous film by a peeling roller 9 and a winding device 10.

[0118] Next, a fourth step is performed in which second particles are disposed in the areas on the attachment surface 21 where the first particles are not disposed. That is, the second particles are disposed in the areas where the mask has been removed. The particle-supported layer of the first substrate, which was protected by the mask, is now exposed, and the second particles selectively adhere to these areas. The second particles may be the same as or different from the first particles. That is, both the first particles and the second particles may be active materials or solid electrolytes.

[0119] As with the arrangement of the first particles, the supply method is not limited and can be selected according to the particles to be used. In FIG. The second particle supply unit 11 may be the same as the first particle supply unit 7. After the second particles are supplied, excess particles may be removed in the same manner as after the placement of the first particles. For example, in FIG. 3, the manufacturing apparatus 100 includes an air blower 12.

[0120] In the device shown in Figure 3, a pattern consisting of two types of particles was formed using one mask, but this is not limited to this. For example, if two masks are used, offset from one another, a pattern consisting of three types of particles can be obtained by repeating the same process.

[0121] Next, a solution containing a resin that can be peeled off from the attachment surface 21 is filled between the particles arranged on the attachment surface 21. For example, droplets of a solution containing a dissolved resin are applied to the surface of the particle layer using the method described above. This forms a coating having an undulating structure on the surface of the particle layer. As a result, a battery substrate having a first substrate and a particle layer and a coating containing a resin on the surface of the particle layer can be obtained.

[0122] The resin solution supply method is not limited, and known methods can be used. For example, as described above, a flying dispenser 13 or a micropipette can be used as a means for applying the resin solution. From the viewpoint of maintaining the particle layer with a smaller amount of resin, a coating means that supplies the resin solution to a predetermined position on the particle layer, such as a flying dispenser, is preferred. Furthermore, a non-contact flying dispenser is preferred in terms of maintaining the particle arrangement pattern. The droplets of the resin solution are preferably applied in portions by the method described above.

[0123] The resin contained in the resin solution is not particularly limited as long as it is a material that can hold the particles and be peeled off from the adhesive layer. Thermoplastic resins are more preferred as the resin.

[0124] Preferred resins include polyester resins, polyolefin resins, vinyl resins such as ethylene vinyl acetate, fluorine resins such as polyvinylidene fluoride, cellulose resins such as carboxymethyl cellulose, and rubber resins such as styrene-butadiene copolymer rubber.

[0125] The resin preferably contains at least one selected from the group consisting of, for example, acrylic resin, polyester resin, and polyolefin resin. By including such a resin, it is possible to easily control the undulating structure of the coating to a preferred shape, which is preferable. A combination of multiple resins may also be used. The resin may also be a material having ionic conductivity. Furthermore, thermosetting resin, UV curable resin, and two-component curable resin are also suitable. Acrylic resin is a particularly preferred example.

[0126] The solvent in the resin solution containing the binder is not particularly limited and may be selected appropriately. It is preferable that: The solvent may be at least one selected from the group consisting of water, N-methyl-2-pyrrolidone (NMP), methyl ethyl ketone (MEK), and the like. The resin solution may be a solution prepared by dissolving the resin in the solvent. Commercially available resin solutions may be used. Examples of commercially available resin solutions include MH-03041 (trade name, manufactured by NOF Corporation) and JMR-10M (trade name, manufactured by Nippon Vinyl Acetate & Poval Corporation).

[0127] The concentration of the resin in the binder-containing resin solution is not particularly limited, as long as it is within a range that allows the resin to fill between particles and form an integrated product. The resin content in the resin solution is preferably 1 to 50% by mass, 2 to 20% by mass, or 2 to 10% by mass. By setting the resin content within the above range, it becomes easier to control the convex portions into a preferred shape. The amount of resin applied to 100 parts by mass of particles is preferably 0.1 to 10% by mass, and more preferably 5 to 10% by mass.

[0128] The device shown in Figure 3 uses N-methyl-2-pyrrolidone (NMP) as the solvent for the treatment liquid, which is a combination that has low compatibility with the silicone rubber of the particle-supporting layer. In this disclosure, the treatment liquid can be applied without being repelled because it can penetrate into the gaps between the particles on the attachment surface by capillary action. Therefore, the particle surfaces may be made lyophilic to improve compatibility with the treatment liquid.

[0129] Generally, it is extremely difficult to form a thin film in which particles and a resin-containing coating are integrated in a state that can be peeled off from the first substrate.For example, when the resin-containing treatment liquid and the adhesion surface of the first substrate are easily compatible, a thin film can be formed, but the peelability from the adhesion surface of the first substrate may be reduced, that is, the particle transferability may be reduced.On the other hand, when the resin-containing treatment liquid and the adhesion surface of the first substrate are not easily compatible, the particle transferability can be ensured, but the treatment liquid is repelled, making it difficult to form a thin film. This is a fundamental phenomenon that generally occurs when applying a slurry liquid in which particles and a resin solution are mixed in advance. To resolve this contradiction, the present disclosure uses a process in which the particles are first temporarily fixed to the application surface as a solid, and then the resin solution is applied later.

[0130] The method of the present disclosure is particularly suited to forming thin layers with high particle density. In other words, with the aforementioned general slurry coating method, creating a film with high particle density requires a high particle concentration in the slurry, which results in a high viscosity of the slurry. The higher the viscosity, the more difficult it becomes to apply a thin layer, especially on surfaces that are poorly adhered to and prone to repelling.

[0131] On the other hand, by temporarily fixing particles to the attachment surface to form a particle layer and then applying a resin solution, a thin layer can be formed while maintaining a high particle density. Furthermore, even when the particle layer is enlarged, it is possible to form a coating having a uniform thickness overall. As a result, even after peeling off the first substrate, defects are less likely to occur in the particle layer, improving particle transferability.

[0132] Although it is a binder liquid, there are no limitations on the type of binder that can be used. Resin materials are preferred because they are easily soluble in solvents and the lower the viscosity of the solution, the easier it is to apply. For example, a resin solution can be prepared by dissolving the above-mentioned resin in the above-mentioned solvent. As mentioned above, unlike a slurry liquid in which particles and binder liquid are premixed, this can be applied without containing particles, so it can be applied with low viscosity. Also, since there is no requirement for dispersion stabilization with particles, a wide variety of materials can be used depending on the purpose. The device in Figure 3 uses a thermoplastic acrylic binder that is easy to degrease and remove.

[0133] After supplying the resin solution, the solvent in the resin solution is removed to obtain a battery substrate. The device shown in FIG. 3 includes a mechanism for heating the back surface of the first substrate 20 with a hot plate as the solvent removal promoting means 14. Furthermore, the particle layer having the resin-containing coating can be peeled off from the battery substrate to form a material layer. That is, the material layer includes a particle layer and a resin-containing coating formed on the surface of the particle layer.

[0134] The thickness of the material layer is not particularly limited, but is preferably 1.0 to 100.0 μm, more preferably 2.0 to 50.0 μm, even more preferably 3.0 to 20.0 μm, and even more preferably 3.0 to 10.0 μm.

[0135] Next, the resulting material layer is peeled from the attachment surface of the first substrate and stacked multiple times to obtain a stack of material layers. After peeling multiple material layers, the desired number of layers may be stacked to obtain a stack, or the stack may be obtained by repeatedly peeling and stacking material layers. In the apparatus of Figure 3, the stack is obtained by repeatedly peeling and stacking material layers.

[0136] The peeling means is not particularly limited, and any known means may be used. For example, a peeling roller or the like may be used, similar to the mask 22. In the present disclosure, the process for obtaining a laminate preferably includes a process of heating a battery substrate to bring a transfer target (transferee) into contact with a particle layer having a resin-containing coating, followed by a process of cooling to separate the material layer from the adhesive surface of the first substrate, thereby transferring the material layer to the transfer target. A laminate can be obtained by repeating the process of transferring the material layer to the transfer target. That is, the transfer target is the desired transfer material (e.g., a current collector) when the material layer is transferred for the first time, and the transfer target for the second or subsequent transfers is the material layer transferred in the previous process.

[0137] A material layer that is an integral combination of particles and binder is brittle and difficult to peel off, but the heating and cooling process described above allows for better peeling, transfer and lamination even with a smaller amount of binder.

[0138] The heating temperature of the material layer during transfer is not particularly limited as long as it can provide adhesion between the material layer and the transfer target, and is, for example, 150 to 300°C, preferably 180 to 250°C. The cooling temperature during peeling is not particularly limited as long as it allows the material layer to be peeled off from the adhesive surface, and may be, for example, 25 to 150°C, and preferably 25 to 80°C.

[0139] The apparatus 100 in FIG. 3 has a lamination device 15 for laminating material layers. The apparatus shown in FIG. 3 can change the mask pattern on demand. Therefore, material layers on which particle patterns are formed can be continuously laminated in the designed lamination order. The lamination device 15 also has a rotation mechanism, which allows the lamination angle of the pattern to be changed. Depending on the shape and material of the pattern, the ease of forming the pattern may change depending on the transport direction, so the angle and position can be changed here to address this.

[0140] The resin can be made to have surface tackiness (plasticity) by heating. In the device shown in Figure 3, a heater 16 is disposed below the first substrate 20, which is an intermediate transfer body, and the particle layer and resin-containing coating on the first substrate 20 can be heated by moving the heater at a predetermined temperature up and down (contact and separation). When the resin becomes plastic through heating and can be laminated, the particle layer and resin-containing coating are pressed into contact with the transfer target (for example, aluminum foil that will become the current collector of a battery).

[0141] After the particle layer and the resin-containing coating are brought into contact with the transfer target, the material layer is peeled off from the adhesion surface of the first substrate 20 by cooling. Cooling makes it easier to reduce the adhesiveness of the resin. It is preferable to cool the material layer from the side where the material layer is attached. The device shown in Figure 3 is equipped with a mechanism that lowers the heater after pressure contact and blows air with a cooling fan 17 to lower the temperature of the first substrate 20, in order to ensure reliable transfer. As the temperature drops, the adhesiveness of the thermoplastic resin in the material layer decreases, and then the lamination device is raised to complete the transfer. This process is repeated a predetermined number of times to complete a laminate of material layers. The number of layers to be laminated is not particularly limited and can be any desired number.

[0142] In the device shown in FIG. 3, the laminating device 15 is repeatedly brought into contact with the material layer conveyed by the first substrate 20 at predetermined intervals, thereby repeatedly peeling and transferring the material layer to obtain a laminate. The lamination process is not limited to this example, and for example, the same pattern may be created multiple times for a certain number of sheets, and the patterns may be selected and laminated one after another later. The configuration of the device is not limited to the flat plate pressing type shown in FIG. 3, but may be a belt type rotary type or a roller type.

[0143] Here, the surface of the transferred material layer, that is, the surface that was in contact with the attachment surface 21 of the first substrate 20, has a characteristic shape. The first particles 24 and the second particles 25 are held in a state where they are slightly sunk into the particle support layer 29 (FIGS. 8A and 8B). After the resin is applied, the portions of the first particles 24 and the second particles 25 that are sunk into the particle support layer 29 are not covered with the resin (FIG. 8B). Therefore, after the first substrate is peeled off, portions of the surfaces of the first particles 24 and the second particles 25 are exposed on one surface of the material layer 50 (FIG. 8C).

[0144] That is, at least some of the particles that have been sunk and held in the particle support layer 29 of the first substrate 20 are in a state where part of the particle surface is exposed on the surface of the material layer 50. This characteristic allows for a wide range of applications, for example, when creating a three-dimensional wiring pattern using metal particles, as it ensures contact points.

[0145] The material layer is an integral body of a plurality of particles and a resin, with the resin filling the spaces between the plurality of particles. The entire surface of the material layer is covered with a coating containing the resin.

[0146] It is preferable that at least a portion of the surface of the plurality of particles is exposed on at least one surface of the material layer. At least a portion of the plurality of particles may be exposed on both surfaces of the material layer, or at least a portion of the plurality of particles may be exposed on one surface of the material layer. That is, it is preferable that at least one surface of the material layer has a coating containing a resin and a surface of particles whose surface is partially exposed from the coating.

[0147] The material layer can be produced by peeling off a particle layer having a resin-containing coating from the battery substrate as described above. The plurality of particles preferably includes first particles and second particles. The first particles and second particles are active materials and / or solid electrolytes.

[0148] <Method of manufacturing laminate> As described above, a material layer including a substantially single-layer particle pattern can be produced using the production apparatus shown in Fig. 3. These material layers can then be stacked to form a laminate. Fig. 5A shows an example of a laminate in which five material layers are stacked. The laminate includes a particle layer and a resin-containing coating formed on the surface of the particle layer. By removing the resin-containing coating, which serves as the second substrate, from laminate 401, a laminate (three-dimensional object 402) in which particle layers are stacked can be obtained (Fig. 5B).

[0149] On the other hand, an example of a conventional laminate 501 in which particles arranged on a resin substrate 51 by a conventional method are laminated is shown. This is shown in Figure 5C. Because conventional laminate 501 contains a high proportion of resin substrate, it can be very time-consuming to remove resin substrate 51 from laminate 501 to obtain particle laminate 502 (Figure 5D). For example, removing the resin substrate by heating may require more heat or a longer heating time.

[0150] Compared to conventional laminate 501, laminate 401 according to the present disclosure has a coating containing a resin, which is the second substrate, formed on the surface of the particle layer, and has a low resin content in the laminate, making it possible to remove the second substrate with little energy and obtain a laminate of particle layers. The number of layers in the laminate is not particularly limited and can be changed depending on the purpose of the laminate.

[0151] As described above, three-dimensional object 402 can be manufactured by removing the second base material from laminate 401 and forming a three-dimensional object including a particle layer. In other words, three-dimensional object 402 is a patterned laminate consisting only of particles. The method for removing the second base material is not particularly limited, but for example, the laminate can be degreased at high temperature to remove the second base material and obtain three-dimensional object 402. Therefore, the method for manufacturing a laminate includes a step of laminating material layers. The method for manufacturing a three-dimensional object includes a step of laminating material layers to obtain a laminate, and preferably a step of heating the laminate to remove the second base material.

[0152] When the second substrate is to be finally removed, a resin with high removability can be selected depending on the removal method and used as the material for the second substrate. The removal method can be selected depending on the characteristics of the particles used. For example, a method of dissolving and removing the resin using a solvent can be used. When using a solvent, the conditions should be selected so that the fluidity of the solvent does not disrupt the particle pattern. Another method is to use a photodegradable photosensitive material as the resin, but depending on the particle material, the particles may block the light, so the conditions must be selected appropriately.

[0153] If the particulate material is resistant to high temperatures, the second substrate can be removed by heating. This method is preferred because the second substrate can be easily removed by selecting an appropriate resin material. For example, as described above, an acrylic resin can be used as the resin and the resin can be degreased by heating.

[0154] Although the conditions for high-temperature degreasing are not particularly limited, it is preferable to heat the battery substrate and laminate at a temperature equal to or higher than the thermal decomposition temperature of the resin, and preferably at a temperature lower than the thermal decomposition temperature of each particle layer in the laminate. The battery substrate and laminate of the present disclosure can be degreased at a lower temperature and for a shorter time than conventional laminates. As a result, the second substrate can be easily removed during the manufacturing process.

[0155] The temperature to which the laminate is heated is preferably 200°C or higher and 1000°C or lower, more preferably 300°C or higher and 600°C or lower, particularly preferably 300°C or higher and 500°C or lower, and even more preferably 300°C or higher and 400°C or lower.

[0156] The heating time is preferably 10 minutes or more, more preferably 20 minutes or more, at the sintering temperature. The upper limit is not particularly limited, but may be, for example, 3 hours or less, 1 hour or less, or 40 minutes or less. For example, it is preferable to maintain the sintering temperature for 10 minutes to 3 hours, 20 minutes to 1 hour, or 20 to 40 minutes.

[0157] The thermal decomposition temperature is the temperature at which the weight of a material begins to decrease when the temperature is gradually increased in a heating atmosphere in a sintering treatment device. Therefore, by heating the laminate at a temperature equal to or higher than the thermal decomposition temperature of the resin, the resin in the laminate can be decomposed to reduce its weight, and the second substrate can be removed from the laminate.

[0158] <Material particles> Higher performance is expected from battery materials by functionally arranging the materials in the electrode layers and efficiently arranging the paths of ions and electrons. In particular, all-solid-state batteries do not use electrolytes, so this disclosure makes it possible to improve the paths of ions and batteries by functionally arranging the positive and negative electrode materials and solid electrolyte materials according to an optimized pattern.

[0159] The particle layer contains particles of at least one of an active material and a solid electrolyte. The material particles used in the battery substrate of the present disclosure will be described below.

[0160] The active material particles are not particularly limited, and known active material particles can be used, such as composite oxides containing lithium. Specific examples include Li-Co oxide active material particles such as LiCoO2 (lithium cobalt oxide), LiMO2 (wherein M is an element selected from the group consisting of Ni, Mn, and Co), Li-PO4 oxide active material particles, lithium vanadium compounds (Li3V2(PO4)3, LiVOPO4), and olivine-type phosphate compounds (LiMPO4 (wherein M is one or more elements selected from the group consisting of Co, Ni, Mn, Fe, Mg, V, Nb, Ti, Al, and Zr)). Active material particles that do not contain lithium may also be used. Specific examples include metal oxides (MnO2, V2O5, etc.) and fluorides (FeF3, VF3, etc.).

[0161] Among the above active material particles, it is preferable to use Li-Co oxide-based active material particles and Li-PO4 oxide-based active material particles. It is also possible to use negative electrode active material particles such as graphite, Si, lithium titanate (LTO), etc. In other words, the battery substrate of the present disclosure can be used to manufacture positive and negative electrodes of secondary batteries.

[0162] The solid electrolyte is not particularly limited, and any known solid electrolyte can be used. For example, these include Li-B oxide solid electrolyte particles such as lithium borate, Li-Yb oxide solid electrolyte particles, Nasicon-type solid electrolyte particles (LiAlTi(PO4)3, LiAlGe(PO4)3, etc.), and Li-PO solid electrolyte particles (Li3PO4, LiPON (particles in which some of the O in Li3PO4 is replaced with N)). Among the above solid electrolyte particles, it is preferable to use Li-B oxide-based solid electrolyte particles and Li-Yb oxide-based solid electrolyte particles.

[0163] The above-mentioned active material or solid electrolyte can be used as the first particles and second particles. Both the first particles and the second particles may be active materials or solid electrolytes. The first particles and the second particles may each be one type used alone or a combination of multiple types. When multiple types are combined, multiple types of particles may be premixed in advance. The particle surfaces may be surface-treated or coated.

[0164] The particle layer may contain other particles in addition to the active material and / or solid electrolyte. The other particles are not particularly limited, and desired resin particles, inorganic particles, etc. can be used. Examples of resin particles include (meth)acrylic resin particles, urethane resin particles, and ester resin particles. Metal particles such as copper particles may also be used.

[0165] <Electrode manufacturing method> The battery substrate of the present disclosure can be used to manufacture electrodes for all-solid-state batteries. As described above, the battery substrate of the present disclosure can be used to transfer a material layer containing an active material and / or a solid electrolyte to a transfer target. Alternatively, a laminate can be obtained by the above-described method, and the second substrate can be removed from the laminate. By molding a three-dimensional object containing the particles, an electrode for an all-solid-state battery can be obtained. The above-mentioned processes can be used as the process for obtaining a laminate and the process for molding a three-dimensional object.

[0166] The electrode may be a positive electrode or a negative electrode. The number of layers in the laminate is not particularly limited and can be changed depending on the purpose of the electrode to be manufactured. For example, three or more layers may be used. [Example]

[0167] The present disclosure will be specifically described below with reference to examples, but these examples are not intended to limit the present disclosure in any way. In the following formulations, parts are by mass unless otherwise specified.

[0168] Example 1 The positive electrode material layer of the all-solid-state battery was produced using the production device shown in Figure 3. The first particles were positive electrode active material: lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.: volume-based median diameter (D50) 5 μm), and the second particles were solid electrolyte: lithium borate (Toshima Manufacturing Co., Ltd.: volume-based median diameter (D50) 5 μm).

[0169] The first substrate was a belt made of 0.1 mm thick Invar coated with 80 μm of silicone rubber (SE9186 manufactured by Dow Toray) as a particle-carrying layer with an adhesive surface. The adhesive surface had a rubber hardness of 20° and a surface adhesive force of 0.5 mN / 20 mm. The particle-carrying layer was a square measuring 5 cm in length and width.

[0170] A polyester film (1.5 μm thick, Mitsubishi Chemical: K917) was used as the mask layer, and a UV laser processing machine (Kokyo: Fine UV Laser Marker) was used to create the mask openings. Magnetic particles (Japan Imaging Society: Standard Carrier P02) were used as carriers in particle supply units 7 and 11, and the first and second particles were placed on the adhesion surface to form a particle layer. The mask openings were formed in a 10 μm stripe pattern with lines and spaces, that is, in a stripe pattern with openings having a width of 10 μm.

[0171] Furthermore, an acrylic resin (Kyoeisha Chemical: Oricox KC-1700P) was dissolved in N-methyl-2-pyrrolidone (NMP) to prepare a resin solution with a resin content of 5 mass %. The resin solution was applied using a flying dispenser 13 (non-contact jet dispenser, SuperJet2 manufactured by Musashi Engineering Co., Ltd.) shown in FIG.

[0172] In order to prevent the droplets that landed on the surface of the particle layer from coalescing, the resin solution was applied in portions, following the conceptual diagram shown in Figure 6. The droplets of the resin solution formed dots when they landed on the surface of the particle layer. A droplet of the binder liquid was applied at an interval equal to or greater than the diameter of the previous dot, and the next droplet was applied at a position that did not overlap with the previous one. This process was repeated.

[0173] In Example 1, the particle layer was 1 cm 2 The resin solution was applied so that the number of droplets applied per 100 parts by mass of the particles was 100. The amount of resin applied was 7% by mass.

[0174] Thereafter, the solvent was removed using the device shown in Figure 3, and a coating containing a resin was formed to produce a battery substrate including a positive electrode material layer for an all-solid-state battery. A hot plate was used as the solvent removal promoting means 14, and heating was performed at 120°C for 30 minutes. In the battery substrate of Example 1, a particle layer is formed on the entire surface of the first substrate, and resin is formed on the entire surface of the particle layer. A coating containing oil was formed. That is, the ratio of the area of ​​the region where the coating was formed to the area of ​​the first substrate was 100% by area.

[0175] <Observation of the shape of battery substrate> A Keyence confocal laser microscope (VK-X3000) was used to observe the shape of the battery substrate. Using the base layer surface (the surface of the silicone rubber layer in Example 1) to which no particles were applied as a reference, the shape of the battery substrate was observed, focusing on the undulating convex portions, undulating concave portions, undulating height, and undulating width (FIG. 7). The total number density of the convex portions and concave portions in the region where the undulating structure was formed was also calculated. The measurement method was as described above.

[0176] Following the production of the battery substrate including the positive electrode material layer, the positive electrode material layer was peeled off from the battery substrate and laminated using the lamination device 15 in the apparatus of Fig. 3. Specifically, three material layers were laminated on an aluminum foil (thickness: 20 µm) while shifting the lamination angle by 90 degrees (pressure welding temperature: 190°C, peeling temperature: 140°C) to obtain a laminate.

[0177] <Evaluation of transferability> The transferability of the material layer in the manufacturing process of the laminate was evaluated. To evaluate the transferability, the particle-carrying layer was image-analyzed before and after peeling of the material layer, and evaluated as a transfer rate using the following formula. Transfer rate (%) = (particle area before peeling - particle area after peeling) / particle area before peeling × 100 In the above formula, the "particle area before peeling" refers to the area of ​​the particle layer disposed on the surface of the particle-supported layer of the battery substrate, and the "particle area after peeling" refers to the area of ​​the region where particles remain on the surface of the particle-supported layer after the material layer is peeled from the battery substrate.

[0178] The particle area before and after peeling of the material layer was quantified as follows: An image of the fabricated battery substrate was taken from above, and the area corresponding to the particle-supported layer and the area corresponding to the particles in the image were digitized by black and white binarization, and the area of ​​the particle layer disposed on the surface of the particle-supported layer was calculated. After that, an image of the particle-supported layer after peeling the material layer from the battery substrate was taken and digitized in the same manner to calculate the area of ​​the region where particles remained on the surface of the particle-supported layer. Based on the calculated area, the transfer rate (%) was calculated using the above formula.

[0179] The image analysis software used was Adobe Photoshop (registered trademark). The transfer rate was determined according to the following steps. 1) Import an image of the battery substrate into a PC at a resolution of 600 dpi. 2) Select an area of ​​10mm length x 10mm width in the captured image. 3) Process the image to grayscale. 4) The image processed in grayscale is processed into two shades of monochrome. 5) The image processed into two-tone monochrome is subjected to error diffusion processing. 6) The error-diffused image is converted to grayscale. 7) Count the number of pixels in the grayscale processed image that have a histogram (256 levels) of 0 (black).

[0180] The ratio of the number of pixels at level 0 corresponds to the area of ​​the region where particles are arranged. After the material layer is peeled off and the particle layer is completely transferred, the number of pixels at level 0 on the surface of the particle-carrying layer is 0. In other words, the transfer rate after all of the particles arranged on the particle-carrying layer have been completely transferred to the material layer is quantified as 100%. The number of pixels may be affected by the color of the underlying first base material. In such cases, the number of pixels of the first base material before particle application was used as the background for correction, or the particle area was calculated by image correction.

[0181] The transcription rate was evaluated using the average value of three samples. That is, the transfer rate (%) was determined for each of the three material layers used in the manufacturing process of the laminate, and the average value was calculated using the method described above. The obtained average values ​​were ranked and evaluated according to the following criteria.

[0182] [Table 1] Table 2 shows the observation results of the shape of the battery substrate in Example 1 and the evaluation rank of the transfer rate.

[0183] Example 2 As the active material particles, lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.) was classified and one component with a median diameter (D50) of 30 μm was applied to the entire surface without a mask. The resin content in the resin solution was changed to 20% by mass, and 1 cm 2 The droplets were applied to the particle layer once for each of the four layers. The other conditions were the same as in Example 1, and a battery substrate was produced. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0184] Example 3 As the active material particles, lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.) was classified and one component with a median diameter (D50) of 0.5 μm was applied to the entire surface without a mask. 2The number of times droplets were applied per layer was set to 40,000, and a predetermined amount of binder liquid was applied in portions to the particle layer. The other conditions were the same as in Example 1, and a battery substrate was produced. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0185] Example 4 As the active material particles, lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.) was classified and one component with a median diameter (D50) of 0.5 μm was applied to the entire surface without a mask. The resin content in the resin solution was changed to 1 mass %, and 1 cm 2 The number of droplets applied per layer was set to 4,900, and a predetermined amount of binder liquid was applied to the particle layer in portions. The other conditions were the same as in Example 1, and a battery substrate was produced. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0186] Example 5 As the active material particles, lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.) was classified and one component with a median diameter (D50) of 10 μm was applied to the entire surface without a mask. The resin content in the resin solution was changed to 10 mass%. The other conditions were the same as in Example 1, and a battery substrate was produced. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0187] Example 6 A 0.1 mm thick Invar substrate was used as the first substrate without being coated with silicone rubber. 2 The number of droplets per layer was set to 25, and a predetermined amount of binder liquid was applied to the particle layer in portions. The other conditions were the same as in Example 1, and a battery substrate was produced. The results of observing the shape of the battery substrate and the evaluation rank of the transfer rate are shown in Table 2. The coating layer was formed in the desired shape and the transfer rate was excellent, but the impact of the droplets from the dispenser caused particle particles to break. There was some disruption in some of the turns.

[0188] Example 7 1cm 2A battery substrate was produced in the same manner as in Example 1, except that the number of times droplets were applied per layer was set to 10,000, and a predetermined amount of binder liquid was applied in portions to the particle layer. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0189] Example 8 As the active material particles, lithium cobalt oxide (Nippon Chemical Industry Co., Ltd.) was classified and one component with a median diameter (D50) of 7.5 μm was applied to the entire surface without a mask. 2 The number of times droplets were applied per layer was set to 900, and a predetermined amount of binder liquid was applied in portions to the particle layer. The other conditions were the same as in Example 1, and a battery substrate was produced. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0190] Example 9 1cm 2 A battery substrate was produced in the same manner as in Example 1, except that the number of droplets per layer was set to 25, and a predetermined amount of binder liquid was applied to the particle layer in portions. Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0191] Example 10 A battery substrate was produced in the same manner as in Example 1, except that the resin solution was applied manually using a micropipette. The observation results of the shape of the battery substrate and the evaluation rank of the transfer rate are shown in Table 2. The coating layer was formed in the desired shape and the transfer rate was excellent, but productivity was significantly reduced.

[0192] Example 11 A battery substrate was produced in the same manner as in Example 1, except that the resin solution was changed to MH-03041 (NOF Corporation). Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0193] Example 12 A battery substrate was produced in the same manner as in Example 1, except that the resin solution was changed to JMR-10M (Japan Vinyl Acetate & Poval Corporation). Table 2 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0194] (Comparative Example 1) 25cm of resin solution 2 A battery substrate was produced in the same manner as in Example 1, except that the coating was applied to the area in 22 separate applications. Table 3 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0195] (Comparative Example 2) 1cm 2 A battery substrate was produced in the same manner as in Example 1, except that the number of times droplets were applied per unit area was set to 44,100, and a predetermined amount of binder liquid was applied in portions. The results of observing the shape of the battery substrate and the evaluation ranking of the transfer rate are shown in Table 3. 2 Because the number of times the binder was applied per droplet was large, a decrease in the landing accuracy of droplets ejected from the dispenser was observed.

[0196] (Comparative Example 3) 5cm of resin solution 2 A battery substrate was produced in the same manner as in Example 1, except that the solution was applied to the area 1 in four separate applications by manual work using a micropipette. Table 3 shows the observation results of the shape of the battery substrate and the evaluation rank of the transfer rate.

[0197] [Table 2] In the table, the average particle size refers to the volume-based median size of all particles contained in the particle layer. In Examples 1 to 12 and Comparative Examples 1 to 3, no recesses were observed. [Table 3]

[0198] The present disclosure relates to the following configurations and methods. (Configuration 1) A battery substrate applied to a secondary battery, a first substrate; a particle layer disposed on one surface of the first substrate and including particles of at least one of an active material and a solid electrolyte; Equipped with the particle layer has a coating containing a resin that is a second base material, the coating forms an undulating structure having at least one of protrusions and recesses on the surface of the particle layer, The total density of the convex portions and concave portions in the region where the undulating structure is formed is 1 / cm as measured using a confocal laser microscope. 2 More than 40,000 pieces / cm 2 Below is the A battery substrate characterized by: (Configuration 2) 2. The battery substrate according to claim 1, wherein the average height of the protrusions from the surface of the first substrate is 1 μm or more and 100 μm or less. (Configuration 3) the first substrate has a particle-supporting layer; 3. The battery substrate according to claim 1, wherein the particle-supporting layer includes a resin portion and an attachment portion, and the particles are disposed in the attachment portion. (Configuration 4) The average ratio of the width of the undulations to the height of the undulations of the undulating structure is 10.0 or more and 250.0 or less 4. The battery substrate according to any one of Aspects 1 to 3, wherein: (Configuration 5) 5. The battery substrate according to any one of aspects 1 to 4, wherein the height of the convex portions is 2.0 to 6.0 times the volume-based median diameter of the particles. (Configuration 6) 6. The battery substrate according to any one of configurations 1 to 5, wherein the ratio of the area of ​​the region where the coating film is formed to the area of ​​the first substrate is 70% or more by area. (Method 7) A method for manufacturing a battery substrate applied to a secondary battery, comprising: The battery substrate is a first substrate; a particle layer including particles of at least one of an active material and a solid electrolyte, the particle layer being disposed on one surface of the first substrate; the particle layer has a coating containing a resin that is a second base material, the coating forms an undulating structure having at least one of protrusions and recesses along the surface of the particle layer, The total density of the convex portions and concave portions in the region where the undulating structure is formed is 1 / cm as measured using a confocal laser microscope. 2 More than 40,000 pieces / cm 2 is as follows: The manufacturing method includes: a particle layer forming step of arranging material particles on the first substrate to form the particle layer; a coating formation step of forming the coating, which is the second substrate, on the surface of the particle layer; and The coating forming step includes: applying droplets of a resin solution containing the resin and a solvent to a surface of the particle layer; removing the solvent to form the coating; The method for manufacturing a battery substrate comprising the steps of: (Method 8) A method for producing a battery substrate according to method 7, comprising: The step of applying the droplets includes: (i) dividing the surface of the particle layer into a plurality of blocks; (ii) applying the droplets to a portion of the area of ​​the block; (iii) allowing the applied droplets to stand and thicken or dry; and (iv) applying the droplets to positions where the droplets have not been applied in the step (ii) or positions where the droplets overlap with the droplets that have been thickened or dried in the step (iii), The method for producing a battery substrate includes repeating steps (ii) to (iv) to apply the droplets to the entire area of ​​the block. (Method 9) The method for producing a battery substrate according to Method 7 or 8, wherein the droplets are applied using a dispenser.

Claims

1. A battery substrate applied to a secondary battery, a first substrate; a particle layer disposed on one surface of the first substrate and including particles of at least one of an active material and a solid electrolyte; Equipped with the particle layer has a coating containing a resin that is a second base material, the coating forms an undulating structure having at least one of protrusions and recesses on the surface of the particle layer, The total density of the convex portions and the concave portions in the region where the undulating structure is formed is 1 / cm as measured using a confocal laser microscope. ２ More than 40,000 pieces / cm ２ Below is the A battery substrate characterized by:

2. The battery substrate according to claim 1 , wherein an average height of the convex portions from the surface of the first substrate is 1 μm or more and 100 μm or less.

3. the first substrate has a particle-supporting layer; The battery substrate according to claim 1 , wherein the particle-supporting layer includes a resin portion and an attachment portion, and the particles are disposed in the attachment portion.

4. The battery substrate according to claim 1 , wherein the average ratio of the undulating width to the undulating height of the undulating structure is 10.0 or more and 250.0 or less.

5. The battery substrate according to claim 1 , wherein the height of the convex portions is 2.0 to 6.0 times the volume-based median diameter of the particles.

6. The battery substrate according to claim 1 , wherein the ratio of the area of ​​the region where the coating film is formed to the area of ​​the first substrate is 70 area % or more.

7. A method for manufacturing a battery substrate applied to a secondary battery, comprising: The battery substrate is a first substrate; a particle layer including particles of at least one of an active material and a solid electrolyte, the particle layer being disposed on one surface of the first substrate; the particle layer has a coating containing a resin that is a second base material, the coating forms an undulating structure having at least one of protrusions and recesses along the surface of the particle layer, The total density of the convex portions and the concave portions in the region where the undulating structure is formed is 1 / cm as measured using a confocal laser microscope. ２ More than 40,000 pieces / cm ２ is as follows: The manufacturing method includes: a particle layer forming step of arranging material particles on the first substrate to form the particle layer; a coating formation step of forming the coating, which is the second substrate, on the surface of the particle layer; and The coating forming step includes: applying droplets of a resin solution containing the resin and a solvent to a surface of the particle layer; removing the solvent to form the coating; The method for manufacturing a battery substrate comprising the steps of:

8. The method for producing a battery substrate according to claim 7, The step of applying the droplets includes: (i) dividing the surface of the particle layer into a plurality of blocks; (ii) applying the droplets to a portion of the area of ​​the block; (iii) leaving the applied droplets to stand and thickening or drying; and (iv) further applying the droplets to positions where the droplets have not been applied in the step (ii) or positions where the droplets overlap with the droplets that have been thickened or dried in the step (iii), The method for manufacturing a battery substrate, wherein the steps (ii) to (iv) are repeated to apply the droplets to the entire area of ​​the block.

9. The method for manufacturing a battery substrate according to claim 7 or 8, wherein the droplets are applied using a dispenser.

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