Manufacturing apparatus for dry sheet for battery and manufacturing method for dry sheet for battery

Abstract

To provide an apparatus and method for manufacturing a dry sheet for a battery that is less likely to cause defects.SOLUTION: A manufacturing apparatus for a dry sheet for a battery includes a support plate, a roller, a heater, and a scraper. The heater is configured to be able to heat the material to be stretched. When stretching the material to be stretched, the height position of the tip of the scraper in the vertical direction perpendicular to the support surface is equal to or on the side of the support surface with respect to the height position of the roller's central axis in the same vertical direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus for manufacturing a dry sheet for batteries and a method for manufacturing a dry sheet for batteries. [Background technology]

[0002] With the remarkable development of electronics technology, portable electronic devices are becoming smaller, lighter, thinner, and more multifunctional. There is also a strong demand for batteries, which serve as the power source for electronic devices, to be smaller, lighter, thinner, more reliable, and safer. All-solid-state batteries, which use solid electrolytes, are attracting attention because they are safer than lithium-ion secondary batteries, which use liquid electrolytes.

[0003] An all-solid-state battery can be fabricated by preparing a cathode dry sheet, an anode dry sheet, and a solid electrolyte layer dry sheet and laminating them. For example, Patent Document 1 discloses that the sheets constituting a fuel cell are molded by hot pressing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 3-63183 Summary of the Invention [Problem to be solved by the invention]

[0005] Molding methods such as hot pressing have limitations in production efficiency. On the other hand, simply producing a dry sheet for a battery using a manufacturing device that is also applicable to the roll-to-roll method may not be successful. For example, the dry sheet for a battery may be damaged or may have uneven thickness. The dry sheet for a battery is a general term for a positive electrode dry sheet, a negative electrode dry sheet, and a dry sheet for a solid electrolyte layer.

[0006] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a manufacturing apparatus for a dry sheet for batteries and a manufacturing method for a dry sheet for batteries that are less likely to produce defects. [Means for solving the problem]

[0007] In order to solve the above problems, the following means are provided.

[0008] The manufacturing apparatus for a dry sheet for batteries according to a first aspect includes a support plate, a roller, a heater, and a scraper. The support plate has a support surface on which an object to be stretched is placed. The relative positional relationship between the support plate and the roller is variable in a first direction along a plane parallel to the support surface. The heater is configured to heat the object to be stretched. The scraper is configured to be able to be positioned opposite the surface of the roller when stretching the object to be stretched. When stretching the object to be stretched, the height position of the tip of the scraper in a vertical direction perpendicular to the support surface is the same as the height position of the central axis of the roller in the vertical direction, or is closer to the support surface than the height position of the central axis of the roller in the vertical direction.

[0009] In the manufacturing device for a dry sheet for batteries according to the above aspect, the roller may be positioned opposite the support surface and configured to be operable at least in a vertical direction perpendicular to the support surface.

[0010] In the manufacturing apparatus for a dry sheet for batteries according to the above aspect, the heater may be disposed on the side of the support plate opposite to the support surface.

[0011] A method for producing a dry sheet for batteries according to a second aspect includes a placing step of placing an object to be stretched on a support plate, a stretching step of stretching the object to be stretched, and a peeling step of peeling the stretched object from the support plate by adjusting the temperature of the stretched object to between 35° C. and 45° C. In the stretching step, a scraper is placed opposite a roller that stretches the object to be stretched, and the vertical height position of the tip of the scraper is set to be the same as the vertical height position of the central axis of the roller or closer to the support surface than the vertical height position of the central axis of the roller.

[0012] In the stretching step of the method for producing a dry sheet for a battery according to the above aspect, the temperature of the material to be stretched may be 35°C or higher and 45°C or lower. [Effects of the Invention]

[0013] The manufacturing apparatus for a dry sheet for batteries and the manufacturing method for a dry sheet for batteries according to the above aspects are less likely to cause defects. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of a manufacturing apparatus for a dry sheet for batteries according to an embodiment of the present invention. [Figure 2] FIG. 1 is a side view of a manufacturing apparatus for a dry sheet for batteries according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present embodiment will be described in detail below with reference to the accompanying drawings. The drawings used in the following description may show characteristic portions enlarged for the sake of clarity, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present disclosure is not limited thereto. Appropriate modifications may be made within the scope of the present disclosure.

[0016] The battery dry sheet manufacturing apparatus 100 is used to manufacture battery dry sheets, which is a general term for dry sheets for positive electrodes, negative electrodes, and solid electrolyte layers.

[0017] The positive electrode dry sheet is a sheet that serves as a base for the positive electrode mixture layer. The positive electrode dry sheet contains at least a positive electrode active material. The positive electrode dry sheet is, for example, obtained by drying a paste containing a positive electrode active material, a solid electrolyte, a conductive additive, and a binder.

[0018] The positive electrode active material is not particularly limited as long as it can reversibly absorb and release, and insert and extract (intercalate and deintercalate) lithium ions, and any positive electrode active material used in known all-solid-state batteries can be used. Examples of the positive electrode active material include lithium-containing metal oxides and lithium-containing metal phosphates.

[0019] Lithium-containing metal oxides include, for example, lithium cobalt oxide (LiCoO), lithium nickel oxide (LiNiO), lithium manganese spinel (LiMnO), and lithium manganese oxides represented by the general formula: LiNi x Co y Mn z O2 (x+y+z=1), lithium vanadium compounds (LiVOPO4, Li3V2(PO4)3), olivine-type LiMPO4 (where M represents at least one element selected from Co, Ni, Mn, and Fe), and lithium titanate (Li4Ti5O 12 ) etc.

[0020] The positive electrode active material may also be lithium-free. Examples of such positive electrode active materials include non-lithium-containing metal oxides (MnO2, V2O5, etc.), non-lithium-containing metal sulfides (MoS2, etc.), and non-lithium-containing fluorides (FeF3, VF3, etc.). When using a lithium-free positive electrode active material, the negative electrode is doped with lithium ions in advance, or a lithium-ion-containing negative electrode is used.

[0021] The solid electrolyte is, for example, an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a complex hydride-based solid electrolyte, or a halide-based solid electrolyte. The solid electrolyte is, for example, a halide-based solid electrolyte.

[0022] The solid electrolyte is, for example, Li a E b G c X d ···(1). In formula (1), a satisfies 0.5 ≦ a < 6.0. b satisfies 0 < b < 2.0. c satisfies 0 ≦ c ≦ 6.0. d satisfies 0 < d ≦ 6.1.

[0023] In formula (1), E is at least one element selected from the group consisting of Al, Sc, Y, Zr, Hf, and lanthanoids. The lanthanoids are La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.

[0024] In formula (1), G is, for example, OH, BO2, BO3, BO4, B3O6, B4O7, CO3, NO3, AlO2, SiO3, SiO4, Si2O7, Si3O9, Si4O 11 , Si6O 18 , PO3, PO4, P2O7, P3O 10 , SO3, SO4, SO5, S2O3, S2O4, S2O5, S2O6, S2O7, S2O8, BF4, PF6, BOB, (COO)2, N, AlCl4, CF3SO3, CH3COO, CF3COO, OOC-(CH2)2-COO, OOC-CH2-COO, OOC-CH(OH)-CH(OH)-COO, OOC-CH(OH)-CH2-COO, C6H5SO3, OOC-CH=CH-COO, C(OH)(CH2COOH)2COO, AsO4, BiO4, CrO4, MnO4, PtF6, PtCl6, PtBr6, PtI6, SbO4, SeO4, TeO4, HCOO, O, and is at least one group selected from the group consisting of them.

[0025] In formula (1), X is a halide atom, which is at least one element selected from the group consisting of Cl, F, Br, and I.

[0026] Examples of the halide-based solid electrolyte represented by formula (1) include Li2ZrCl6, Li2ZrSO4Cl4, Li2ZrSO3Cl4, Li2ZrPO3Cl4, Li2ZrCO3Cl4, and Li2Zr((COO)2) 0.5 Cl5, Li2Zr(CH3COO) 0.2 Cl 5.8 , Li2Zr(CF3COO) 0.2 Cl 5.8 , Li2Zr(HCOO) 0.4 Cl 5.6 , Li2ZrBO2Cl5, Li2ZrBF4Cl5, Li3YSO4Cl4, Li3YCO3Cl4, Li3YBO2Cl5, Li3YBF4Cl5, Li2ZrOCl4.

[0027] The conductive additive is a carbon material. Examples of the conductive additive include carbon powder, carbon nanotubes, carbon materials, metal fine powder, a mixture of carbon materials and metal fine powder, and conductive oxides. Examples of the carbon powder include carbon black, acetylene black, and ketjen black. Examples of the metal fine powder include powder of copper, nickel, stainless steel, iron, etc.

[0028] Examples of the binder include polyvinylidene fluoride (PVDF) or its copolymer, polytetrafluoroethylene (PTFE), polyamide (PA), polyimide (PI), polyamideimide (PAI), polybenzimidazole (PBI), polyethersulfone (PES), polyacrylic acid (PA) and its copolymer, metal ion crosslinked polyacrylic acid (PA) and its copolymer, maleic anhydride grafted polypropylene (PP), maleic anhydride grafted polyethylene (PE), and mixtures thereof. Polytetrafluoroethylene (PTFE) is particularly preferred as the binder.

[0029] The negative electrode dry sheet is a sheet that serves as a base for the negative electrode composite layer. The negative electrode dry sheet contains at least a negative electrode active material. The negative electrode dry sheet is, for example, obtained by drying a paste containing the negative electrode active material, a solid electrolyte, a conductive additive, and a binder.

[0030] The negative electrode active material may be any compound capable of absorbing and releasing ions, and known active materials used in lithium ion secondary batteries can be used. Examples of the negative electrode active material include carbon materials, metals or alloys capable of reacting with lithium, composite materials of these metals or alloys with carbon materials, oxides, sulfur-modified polyacrylonitrile, metallic lithium, etc. Examples of carbon materials include natural graphite, artificial graphite, mesocarbon microbeads, mesocarbon fiber (MCF), cokes, glassy carbon, and organic compound sintered bodies. Examples of metals or alloys capable of reacting with lithium include Si, SiO x , Sn, and aluminum. The oxides are lithium titanate (Li4Ti5O 12 ), SnO2, etc.

[0031] The solid electrolyte, conductive additive, and binder contained in the negative electrode dry sheet may be the same as those contained in the positive electrode dry sheet.

[0032] The dry sheet for a solid electrolyte layer is a sheet that serves as a base for a solid electrolyte layer. The dry sheet for a solid electrolyte layer contains at least a solid electrolyte. The dry sheet for a solid electrolyte layer is, for example, obtained by drying a paste containing a solid electrolyte. The solid electrolyte is, for example, one of those described above.

[0033] FIG. 1 is a perspective view of a manufacturing apparatus 100 for a dry sheet for batteries according to this embodiment. FIG. 2 is a side view of the manufacturing apparatus 100 for a dry sheet for batteries according to this embodiment. In FIGS. 1 and 2, a direction parallel to the support surface 11A is defined as the X direction, and a direction perpendicular to the X direction is defined as the Y direction. The X direction is an example of a first direction. In addition, in FIGS. 1 and 2, a direction perpendicular to the support surface 11A is defined as the Z direction.

[0034] The battery dry sheet manufacturing apparatus 100 includes a support plate 10, a roller 20, a heater 30, and a scraper 40.

[0035] The support plate 10 has, for example, a flat plate 11, a guide 12, and a base 13. The flat plate 11 has a support surface 11A on which the object to be stretched 1 is placed. The object to be stretched 1 is a base material for a positive electrode dry sheet, a negative electrode dry sheet, or a dry sheet for a solid electrolyte layer. The object to be stretched 1 is, for example, a positive electrode composite paste, a negative electrode composite paste, or a solid electrolyte paste. The guides 12 are located at both ends of the flat plate 11 in the y direction. The guides 12 are portions that protrude in the Z direction from the support surface 11A. The guides 12 prevent the object to be stretched 1 from protruding in the y direction. The guides 12 determine the thickness of the dry sheet. The base 13 supports the flat plate 11.

[0036] The material of the support plate 10 is preferably, for example, aluminum, SUS, etc. Since halogen elements (especially Cl) contained in halide-based solid electrolytes are corrosive, it is preferable to use a material that is resistant to corrosion.

[0037] The roller 20 is positioned opposite the support surface 11A of the support plate 10. The roller 20 is pressed against the object to be stretched 1, thereby stretching the object to be stretched 1. The relative positional relationship between the roller 20 and the support plate 10 in the X direction is variable. The roller 20 may move in the X direction relative to the support plate 10, or the support plate 10 may move in the X direction relative to the roller 20. The positional relationship between the roller 20 and the support plate 10 is controlled, for example, by an actuator. The actuator has, for example, a power source (for example, a motor) that translates the roller 20 or the support plate 10, and a control unit (for example, a CPU) that controls the translation.

[0038] The roller 20 may be movable in the Z direction. The movement of the roller 20 in the Z direction is controlled, for example, by an actuator. Making the position of the roller 20 variable in the Z direction makes it easier to place the object to be stretched 1 on the support plate 10 and also makes it possible to control the thickness of the object to be stretched 1 after stretching.

[0039] The roller 20 is a cylindrical or tubular member having a central axis 21 in the Y direction. The diameter of the roller 20 is preferably, for example, 10 mm or more and 30 mm or less. The width of the roller 20 in the Y direction can be arbitrarily designed according to the size of the dry sheet for the battery.

[0040] The material of the roller 20 is preferably aluminum or SUS. These materials have high corrosion resistance.

[0041] The heater 30 is configured to heat the stretched object 1. The heater 30, for example, heats the support surface 11A and indirectly heats the stretched object 1. The heater 30 is, for example, disposed on the side opposite to the support surface 11A of the support plate 10. The heater 30 heats the stretched object 1 placed on the support surface 11A to 35°C or more and 45°C or less.

[0042] The scraper 40 is disposed at a position facing the surface of the roller 20 when stretching the stretched object 1. The position of the scraper 40 may be fixed with respect to the roller 20, or the position with respect to the roller 20 may be changeable. The scraper 40 prevents the stretched object 1 from being wound around the roller 20. The scraper 40 cleans the surface of the roller 20.

[0043] The tip 41 of the scraper 40 is close to the surface of the roller 20. The tip 41 of the scraper 40 may be in contact with the surface of the roller 20 or may be spaced apart from the surface of the roller 20.

[0044] When stretching the stretched object 1, the height position of the tip 41 of the scraper 40 in the Z direction is the same as the height position of the central axis 21 of the roller 20 in the Z direction, or is on the support surface 11A side from the height position of the central axis 21 of the roller 20 in the Z direction. When the contact point between the stretched object 1 to be stretched and the roller 20 is used as the height reference, the height H of the tip 41 satisfies 0 < H < R / 2. R is the diameter of the roller 20. By having the tip 41 of the scraper 40 at an appropriate position, the thickness variation of the dry sheet after stretching the stretched object 1 can be reduced.

[0045] The distance L between the tip 41 of the scraper 40 and the roller 20 x is such that 0 < L x Preferably satisfies the relationship of <T - s>. Here, the distance L x is the X - direction distance between the tip 41 and the roller 20 at the same height position as the tip 41. T is the dry sheet thickness standard after stretching the stretched material, and s is the dry sheet thickness standard width after stretching the stretched material. The distance L between the tip 41 and the roller 20 x When this relationship is satisfied, the tip 41 does not touch the roller 20, and it becomes easier to control the film thickness of the dry sheet within the desired film thickness range.

[0046] The manufacturing apparatus 100 for a dry sheet for a battery according to the present embodiment can heat the dry sheet when peeling the dry sheet from the support plate 10, and can suppress breakage during peeling of the dry sheet. Further, the manufacturing apparatus 100 for a dry sheet for a battery according to the present embodiment can prevent the stretched material 1 from being wound around the roller 20 by a scraper disposed at a predetermined position, and can reduce the thickness variation of the dry sheet.

[0047] Next, the manufacturing method for a dry sheet for a battery according to the present embodiment will be described. The manufacturing method for a dry sheet for a battery according to the present embodiment includes a placement step, a stretching step, and a peeling step.

[0048] In the placement step, the stretched material 1 is placed on the support plate 10. The stretched material 1 is, for example, a positive electrode composite paste, a negative electrode composite paste, or a solid electrolyte paste. The positive electrode composite paste is obtained by adding a positive electrode composite obtained by mixing a positive electrode active material, a solid electrolyte, a conductive assistant, and a binder to a solvent. The negative electrode composite paste is obtained by adding a negative electrode composite obtained by mixing a negative electrode active material, a solid electrolyte, a conductive assistant, and a binder to a solvent. The solid electrolyte paste is obtained by mixing a solid electrolyte and a binder and adding them to a solvent. The solvent is, for example, water.

[0049] In the stretching step, the object to be stretched 1 is stretched. The object to be stretched 1 is sandwiched between the roller 20 and the support plate 10 and stretched in the X direction. For example, the object to be stretched 1 is stretched in the X direction by moving the object to be stretched 1 in the X direction relative to the roller 20. The thickness of the dry sheet after stretching the object to be stretched 1 can be set, for example, by the height of the guide 12.

[0050] In the stretching process, a scraper 40 is opposed to the roller 20 that stretches the material 1 to be stretched. The height position in the Z direction of the tip 41 of the scraper 40 is the same as the height position in the Z direction of the central axis 21 of the roller 20, or is closer to the support surface 11A than the height position in the Z direction of the central axis 21 of the roller 20. The scraper 40 prevents the material 1 to be stretched from being wound around the roller 20. If the material 1 to be stretched that has wound around the roller 20 re-adheres to an unwrapped material 1 to be stretched, thickness variations may occur in the dry sheet. By positioning the tip 41 of the scraper 40 at a predetermined position, the material 1 to be stretched can be prevented from being wound around the roller 20.

[0051] The stretching speed in the stretching step is preferably, for example, 10 cm / sec or more and 16 cm / sec or less. By setting the stretching speed appropriately, it is possible to more effectively prevent the object to be stretched 1 from being wound around the roller.

[0052] In the stretching step, the temperature of the object 1 to be stretched is preferably set to 35°C or higher and 45°C or lower. Controlling the temperature in the stretching step increases the stretching efficiency of the object 1. The object 1 to be stretched is a precursor of a dry sheet for batteries, and it has been found that the stretching efficiency of dry sheets for batteries tends to be high at around 35°C.

[0053] In the peeling step, the stretched object 1 (i.e., the dry sheet for batteries) is peeled off from the support plate 10. In the peeling step, the temperature of the stretched object 1 is set to 35°C or higher and 45°C or lower. The dry sheet for batteries is easily damaged, and attempting to forcibly peel the dry sheet for batteries from the support plate 10 may result in damage to the dry sheet for batteries. When peeling the dry sheet for batteries from the support plate 10, heating the dry sheet for batteries to a predetermined temperature makes it easier to release the dry sheet for batteries, reducing damage to the dry sheet for batteries.

[0054] An all-solid-state battery can be fabricated using the dry sheets for a battery fabricated by the above procedure. First, a dry sheet for a negative electrode, a dry sheet for a positive electrode, and a dry sheet for a solid electrolyte layer are fabricated by the above procedure.

[0055] Next, the negative electrode dry sheet and the positive electrode dry sheet are stacked and pressurized so that the solid electrolyte dry sheet is sandwiched between them. External terminals are connected to the positive and negative electrodes of the pressure-molded stack. After that, the stack connected to the external terminals is housed in an exterior case, and the opening of the exterior case is heat-sealed to seal it. Through these steps, an all-solid-state battery is obtained.

[0056] The method for manufacturing a dry sheet for batteries according to this embodiment can prevent the dry sheet from being damaged during peeling because the dry sheet is heated to a predetermined temperature when peeling it off from the support plate 10. Furthermore, the method for manufacturing a dry sheet for batteries according to this embodiment uses a scraper arranged at a predetermined position to prevent the object to be stretched 1 from being wound around the roller 20, thereby reducing variations in thickness of the dry sheet.

[0057] Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible without departing from the spirit of the present disclosure. For example, although Figures 1 and 2 show an example in which the scraper 40 is disposed only in the +X direction of the roller 20, the scraper 40 may also be disposed in the -X direction of the roller 20. [Example]

[0058] "Example 1" A halide-based solid electrolyte and a fluorine-based binder were prepared to produce a solid electrolyte composite. The mass ratio of the halide-based solid electrolyte to the fluorine-based binder in the solid electrolyte layer composite was halide-based solid electrolyte:fluorine-based binder = 99.25 wt%:0.75 wt%. These were placed in a sealed zirconia container for a planetary ball mill and mixed. The sealed container was covered with a lid, which was then screwed onto the container body. The space between the lid and the container was then sealed with polyimide tape. The polyimide tape has the effect of blocking moisture.

[0059] The mixed solid electrolyte composite was used as the object to be stretched 1, and the object to be stretched 1 was stretched using the apparatus shown in Figures 1 and 2. The thickness specification of the thickness t of the dry sheet for the solid electrolyte layer after stretching the object to be stretched 1 was t≦140 μm. In addition, the specification of the thickness variation R of the dry sheet for the solid electrolyte layer after stretching the object to be stretched 1 was R≦10 μm.

[0060] The temperature of the material 1 to be stretched when the dry sheet for a solid electrolyte layer in Example 1 was stretched and peeled off was set to 40°C. The height position of the tip 41 of the scraper 40 when producing the dry sheet for a solid electrolyte layer in Example 1 was set to R / 2, where R is the diameter of the roller 20, and the diameter of the roller was set to 30 mm.

[0061] Under the above conditions, a dry sheet for a solid electrolyte layer of Example 1 was produced, and its yield was determined. The yield corresponds to the ratio of samples that were not damaged during peeling out of 20 samples produced under the same conditions. The yield of the dry sheet for a solid electrolyte layer of Example 1 was 90%.

[0062] The thickness variation of the dry sheet for the (negative electrode) solid electrolyte layer of Example 1 was also measured. The thickness variation was determined by dividing the stretched sheet into 6 equal parts in the longitudinal and transverse directions, measuring a total of 36 points within the resulting rectangle with a micrometer, and defining the difference between the maximum and minimum values ​​of the 36 numbers as the variation. The thickness variation of Example 1 was 8 μm.

[0063] "Examples 2 and 3" Examples 2 and 3 differ from Example 1 in that the temperature of the object 1 to be stretched was changed when the dry sheet for a solid electrolyte layer was stretched and when it was peeled off. The other conditions were the same as in Example 1, and the yield and thickness variation were determined.

[0064] "Examples 4 to 6" Examples 4 to 6 differ from Example 1 in that the position of the scraper was changed when stretching the dry sheet for the solid electrolyte layer. Other conditions were the same as in Example 1, and the yield and thickness variation were determined.

[0065] "Comparative Examples 1 to 3" Comparative Examples 1 to 3 differ from Example 1 in that the temperature of the object 1 to be stretched was changed when the dry sheet for a solid electrolyte layer was stretched and peeled off. The other conditions were the same as in Example 1, and the yield and thickness variation were determined.

[0066] "Comparative Example 4" Comparative Example 4 differs from Example 1 in that the position of the scraper when stretching the dry sheet for the solid electrolyte layer was changed. Other conditions were the same as in Example 1, and the yield and thickness variation were determined.

[0067] "Comparative Example 5" Comparative Example 5 differs from Example 1 in that a scraper was not used when stretching the dry sheet for a solid electrolyte layer. Other conditions were the same as in Example 1, and the yield and thickness variation were determined.

[0068] "Comparative Example 6" Comparative Example 6 differs from Example 1 in that heating with a heater was not performed when the dry sheet for a solid electrolyte layer was stretched and peeled off. The other conditions were the same as in Example 1, and the yield and thickness variation were determined.

[0069] "Comparative Example 7" Comparative Example 6 differs from Example 1 in that a scraper was not used when stretching the dry sheet for a solid electrolyte layer, and heating with a heater was not performed when stretching and peeling the dry sheet for a solid electrolyte layer. The other conditions were the same as those of Example 1, and the yield and thickness variation were determined.

[0070] The results of Examples 1 to 6 and Comparative Examples 1 to 6 are summarized in Table 1. In Table 1, R corresponds to the diameter of the roller, and the scraper position corresponds to the distance in the Z direction from the contact point between the material to be stretched and the roller during stretching.

[0071] [Table 1]

[0072] Comparing Examples 1 to 6 with Comparative Examples 1 to 6, Examples 1 to 6 had less thickness variation and a higher yield.

[0073] "Examples 8 to 11, Comparative Example 8, Reference Example 1" In Examples 8 to 11, Comparative Example 8, and Reference Example 1, the relationship between the temperature of the material to be stretched and the stretchability of the material to be stretched was investigated. Materials to be stretched were prepared under the same conditions as in Example 1, and the materials were stretched. Examples 8 to 11 and Comparative Example 8 differ only in the temperature at which the material to be stretched was stretched. Comparative Example 8 was set under the same conditions as Comparative Example 6. In Reference Example 1, the material to be stretched was stretched manually without using a device. In Examples 8 to 10, the temperature was set the same to confirm the range of variation under the same conditions. These results are summarized in Table 2 below.

[0074] [Table 2]

[0075] As shown in Table 2, in Examples 8 to 11 and Comparative Example 8, the average thickness of the material to be stretched was thinner and the stretching efficiency of the material to be stretched was higher than in Reference Example 1, which was stretched manually. The stretching efficiency of the material to be stretched was also highest at around 35°C. [Explanation of symbols]

[0076] 1 Object to be stretched 10 Support plate 11 flat plate 11A Support surface 12 Guide 13 Pedestal 20 Roller 21 Center axis 30 Heater 40 Scraper 41 Tip 100 Manufacturing equipment for dry sheets for batteries

Claims

1. A support plate, a roller, a heater, and a scraper are provided. the support plate has a support surface on which an object to be stretched is placed, a relative positional relationship between the support plate and the roller is variable in a first direction along a plane parallel to the support surface; the heater is configured to heat the object to be stretched, the scraper is configured to be disposed at a position facing the surface of the roller when the object to be stretched is stretched; a height position of the tip of the scraper in a vertical direction perpendicular to the support surface when the object to be stretched is the same as the height position of the central axis of the roller in the vertical direction, or is located closer to the support surface than the height position of the central axis of the roller in the vertical direction.

2. 2. The manufacturing device for a dry sheet for batteries according to claim 1, wherein the roller is positioned opposite to the support surface and configured to be movable at least in a vertical direction perpendicular to the support surface.

3. 2. The manufacturing apparatus for a dry sheet for batteries according to claim 1, wherein the heater is disposed on the opposite side of the support plate from the support surface.

4. a placing step of placing an object to be stretched on a support plate; a stretching step of stretching the object to be stretched; a peeling step of reducing the temperature of the stretched object to 35°C or more and 45°C or less and peeling the stretched object from the support plate, In the stretching step, a scraper is placed opposite a roller that stretches the object to be stretched, a vertical height position of the tip of the scraper being the same as a vertical height position of the central axis of the roller, or being closer to the support surface than a vertical height position of the central axis of the roller.

5. The method for producing a dry sheet for a battery according to claim 4 , wherein the temperature of the object to be stretched is set to 35° C. or higher and 45° C. or lower in the stretching step.

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