Method for inspecting long coated sheet

Abstract

To provide a method for inspecting a long coated sheet capable of determining whether or not moisture content of a product portion is good.SOLUTION: A method for inspecting a long coated sheet 100 having a long sheet substrate 110 in a roll form and an electrode active material layer and / or a solid electrolyte layer 120 coated on the long sheet substrate 110, includes the steps of: (i) measuring a starting end moisture content at a starting end position located at a predetermined starting end distance from a coating starting end and comparing it with a starting end standard value; (ii) measuring a terminal end moisture content at a terminal end position located at a predetermined terminal end distance from a coating terminal end and comparing it with a terminal end standard value; and (iii) determining that the long coated sheet between the starting end position and the terminal end position is an acceptable product when the starting end moisture content is smaller than the starting end standard value and the terminal end moisture content is smaller than the terminal end standard value.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a method for inspecting a long coated sheet.

Background Art

[0002] A solid battery is a secondary battery containing a solid electrolyte as an electrolyte, and has attracted attention because it has higher safety compared to a liquid battery using an electrolyte solution as an electrolyte. In a solid battery, the solid electrolyte may be included not only in the solid electrolyte layer but also in the electrode active material layer. For example, in the manufacture of a solid battery, from the viewpoint of production efficiency, an electrode active material layer and a solid electrolyte layer are coated on a long sheet base material to produce a long coated sheet. However, if moisture is present in the long coated sheet, the solid electrolyte contained in the solid electrolyte layer and the electrode active material layer may react with the moisture, thereby reducing the ionic conductivity of the solid electrolyte. Therefore, the following manufacturing method of an all-solid-state battery has been disclosed.

[0003] For example, Patent Document 1 discloses a method for manufacturing an all-solid-state battery having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, the method including: a first step of manufacturing the positive electrode layer, the negative electrode layer, and the solid electrolyte layer; a dehydration step of subjecting at least one of the positive electrode layer, the negative electrode layer, and the solid electrolyte layer containing a solid electrolyte to a dehydration treatment of the solid electrolyte; and a lamination step of disposing the solid electrolyte layer between the positive electrode layer and the negative electrode layer. According to the method for manufacturing an all-solid-state battery of Patent Document 1, it is said that a method and an apparatus for storing a solid electrolyte capable of suppressing deterioration of the solid electrolyte, and an all-solid-state battery with suppressed performance degradation can be manufactured.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the manufacture of a solid-state battery, since the solid electrolyte deteriorates due to reaction with moisture, it is necessary to inspect the moisture content of a long coated sheet in which a solid electrolyte layer and an electrode active material layer are coated on a long sheet substrate. However, when actually inspecting the moisture content of a long coated sheet containing a solid electrolyte, if a full inspection is performed, there is a risk of taking time, and if a sampling inspection is performed, there is a risk of variation depending on the inspection location.

[0006] Therefore, an object of the present disclosure is to provide an inspection method for a long coated sheet capable of determining whether the moisture content of a product portion is good or bad.

Means for Solving the Problems

[0007] The present disclosure achieves the above object by the following means.

[0008] <Aspect 1> An inspection method for a long coated sheet having a long sheet substrate formed in a roll shape and an electrode active material layer and / or a solid electrolyte layer coated on the long sheet substrate, the method including the following: (i) Measuring a first start moisture content at a first start position located at a position of a first start predetermined distance from the coating start end and comparing it with a first start standard value; (ii) Measuring a first end moisture content at a first end position located at a position of a first end predetermined distance from the coating end and comparing it with a first end standard value; and (iii) When the first start moisture content is less than the first start standard value and the first end moisture content is less than the first end standard value, regarding the long coated sheet between the first start position and the first end position as a qualified product. <Aspect 2> The method according to Aspect 1, wherein the electrode active material layer and / or the solid electrolyte layer contains a sulfide solid electrolyte. <Aspect 3> The method according to aspect 1 or 2, wherein the predetermined distance from the first start end is greater than the predetermined distance from the first end end. <Aspect 4> When the water content at the first start end is greater than the first start end standard value, measuring the water content at a second start end position farther from the coating start end than the first start end position and comparing it with the second start end standard value, The method according to any one of aspects 1 to 3, further comprising: <Aspect 5> When the water content at the first end end is greater than the first end end standard value, measuring the water content at a second end end position farther from the coating end end than the first end end position and comparing it with the second end end standard value, The method according to any one of aspects 1 to 4, further comprising: <Aspect 6> A method for manufacturing a battery, comprising the method according to any one of aspects 1 to 5.

Effect of the Invention

[0009] According to the inspection method of the long coating sheet of the present disclosure, it is possible to determine whether the water content of the product part is good or bad.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present disclosure. In the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0012] Regarding the present disclosure, "composite material" means a composition that can form an electrode active material layer or the like as it is or by further containing other components.

[0013] 《Inspection Method for Long Coated Sheet》 The inspection method for the long coated sheet of the present disclosure is an inspection method for a long coated sheet having a long sheet substrate in a roll shape and an electrode active material layer and / or a solid electrolyte layer coated on the long sheet substrate, the method including the following: (i) Measuring the first starting moisture content at a first starting position located at a predetermined distance from the coating start end from the coating start end, and comparing it with the first starting standard value; (ii) Measuring the first ending moisture content at a first ending position located at a predetermined distance from the coating end from the coating end, and comparing it with the first ending standard value; and (iii) When the first starting moisture content is less than the first starting standard value and the first ending moisture content is less than the first ending standard value, regarding the long coated sheet between the first starting position and the first ending position as a qualified product.

[0014] According to the inspection method for the long coated sheet of the present disclosure, it is possible to determine the quality of the moisture content of the product part.

[0015] The present inventors measured the moisture content at each position from the coating start end to the coating end of the long coated sheet during the production of the long coated sheet, and found that when a graph was created with the moisture content on the vertical axis and the measurement position on the horizontal axis, a downwardly convex curve relationship (specifically, for example, FIG. 1) was obtained. Although not limited to theory, when the first starting moisture content at the first starting position located at a predetermined distance from the coating start end and the first ending moisture content at the first ending position located at a predetermined distance from the coating end are smaller than the standard values, from the relationship between the moisture content and the measurement position, it is predicted that the moisture content of the long coated sheet between the first starting position and the first ending position will be smaller than the standard value, whereby it is possible to determine the quality of the moisture content of the product part from the moisture content of the locations other than the product part.

[0016] FIG. 2 is a schematic diagram showing one aspect of the inspection method for the long coated sheet of the present disclosure, but is not limited to this case.

[0017] The long coated sheet 100 is obtained by coating an electrode active material layer and / or a solid electrolyte layer 120 on a long sheet base material 110. In the inspection method of the long coated sheet 100, first, at the first start position 121a located at a position of a first start predetermined distance 120b from the coating start end 120a, the first start moisture content is measured and compared with the first start standard value. Next, at the first end position 121c located at a position of a first end predetermined distance 120d from the coating end 120c, the first end moisture content is measured and compared with the first end standard value. Then, when the first start moisture content is less than the first start standard value and the first end moisture content is less than the first end standard value, the long coated sheet between the first start position 121a and the first end position 121c is regarded as a qualified product. According to the inspection method of the long coated sheet of the present disclosure, from the moisture content at locations other than the product parts such as the first start position 121a and the first end position 121c, it is possible to determine the quality of the moisture content of the product part such as the long coated sheet between the first start position 121a and the first end position 121c.

[0018] Note that due to the influence of the bobbin moisture and the long sheet base material moisture, the moisture content of the long coated sheet tends to increase on the coating start end side. Therefore, the first start predetermined distance 120b is not particularly limited, but may be larger than the first end predetermined distance 120d. Here, regarding the influence of the long sheet base material moisture, since the coating start end of the long coated sheet base material before coating is on the outer circumference of the roll, moisture is likely to be adsorbed on the foil surface, thereby causing the moisture content of the long coated sheet to tend to increase.

[0019] The inspection method of the long coated sheet of the present disclosure may further include, when the first start moisture content is greater than the first start standard value, measuring the second start moisture content at a second start position farther from the coating start end than the first start position and comparing it with the second start standard value.

[0020] In the above-mentioned FIG. 2, when the first starting moisture content at the first starting position 121a is greater than the first starting standard value, the second starting moisture content at the second starting position 122a, which is farther from the coating starting end 120a than the first starting position 121a, is measured. Next, the second starting moisture content is compared with the second starting standard value. When the moisture content at the first starting position 121a is greater than the starting standard value, for example, the inspection position is moved to the center side of the long coating sheet until the moisture content becomes less than the starting standard value, that is, to a position farther from the coating starting end 120a than the first starting position 121a. From the relationship between the moisture content and the measurement position described above, it is possible to determine the product part of the qualified product, that is, the product part of the long sheet where the moisture content is less than the standard value. The second starting standard value is not particularly limited, but it is preferably the same as the first starting standard value.

[0021] Further, the inspection method of the long coating sheet of the present disclosure may further include measuring the second ending moisture content at the second ending position, which is farther from the coating ending end than the first ending position, when the first ending moisture content is greater than the first ending standard value, and comparing it with the second ending standard value.

[0022] In the above-mentioned FIG. 2, when the first ending moisture content at the first ending position 121c is greater than the first ending standard value, the second ending moisture content at the second ending position 122c, which is farther from the coating ending end 120c than the first ending position 121c, is measured. Next, the second ending moisture content is compared with the second ending standard value. When the moisture content at the first ending position 121c is greater than the starting standard value, for example, the inspection position is moved to the center side of the long coating sheet until the moisture content becomes less than the ending standard value, that is, to a position farther from the coating ending end 120c than the first ending position 121c. From the relationship between the moisture content and the measurement position described above, it is possible to determine the product part of the qualified product, that is, the product part of the long sheet where the moisture content is less than the standard value. The second ending standard value is not particularly limited, but it is preferably the same as the first ending standard value.

[0023] 〈Method for Measuring Moisture Content〉 The moisture content of the long coated sheet can be measured using a Karl Fischer apparatus (Karl Fischer apparatus CA-310 and moisture vaporizer VA-300 manufactured by Nitto Seiko). Specifically, the positive electrode active material layer is heated to 200 °C with the moisture vaporizer VA-300, and the moisture generated by the heating is measured by the Karl Fischer apparatus CA-310 to determine the moisture content.

[0024] 《Inspection Method for Long Coated Sheet: Each Component》 Hereinafter, each component of the inspection method for the long coated sheet will be described.

[0025] 〈Long Coated Sheet〉 The long coated sheet has a long sheet base material in a roll shape and an electrode active material layer and / or a solid electrolyte layer coated on the long sheet base material.

[0026] 〈Long Sheet Base Material〉 The material used for the long sheet base material is not particularly limited, but materials that can be used as the positive electrode current collector or negative electrode current collector of the battery can be appropriately adopted. Examples of the material used for the long sheet base material include, but are not limited to, Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, etc. Further, the long sheet base material may have some coating layer on its surface for the purpose of adjusting the resistance or the like. Also, the long sheet base material may be a metal foil or a material in which the above metals are plated or vapor-deposited on the base material.

[0027] The shape of the long sheet base material is not particularly limited, and examples thereof include a foil shape, a plate shape, or a mesh shape. Among these, a foil shape is preferable.

[0028] The thickness of the long sheet base material is not particularly limited, but it may be 0.1 μm or more, or 1 μm or more, and may be 1 mm or less, or 100 μm or less.

[0029] 〈Electrode Active Material Layer〉 The electrode active material layer contains an electrode active material and may further optionally contain a solid electrolyte, a conductive assistant, a binder, etc. The electrode active material layer is not particularly limited, but preferably contains a sulfide solid electrolyte. The electrode active material layer may also contain various additives. The content of each of the electrode active material, solid electrolyte, conductive assistant, binder, etc. in the electrode active material layer may be appropriately determined according to the intended battery performance. For example, assuming the total of the electrode active material layer (total solid content) is 100% by mass, the content of the electrode active material may be 40% by mass or more, 50% by mass or more, 60% by mass or more, and may also be 100% by mass or less, or 90% by mass or less.

[0030] The electrode active material contained in the electrode active material layer may be a positive electrode active material or a negative electrode active material.

[0031] (Positive electrode active material) The material of the positive electrode active material is not particularly limited as long as it can occlude and release lithium ions. Examples of the positive electrode active material include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganate (LiMn2O4), lithium nickel cobalt manganate (NCM: LiCO 1 / 3 Ni 1 / 3 Mn 1 / 3 O2), lithium nickel cobalt aluminate (LiNi 0.8 (CoAl) 0.2 O2), Li 1+x Mn 2-x-y M y O4 (M is one or more metal elements selected from Al, Mg, Co, Fe, Ni, and Zn), such as hetero-element substituted Li-Mn spinel with a composition represented by this, but is not limited thereto.

[0032] The positive electrode active material is not particularly limited, but may have a coating layer. The coating layer is a layer containing a material that has lithium ion conduction performance, low reactivity with the positive electrode active material and the solid electrolyte, and can maintain the form of the coating layer without flowing even when in contact with the active material and the solid electrolyte. Specific examples of the material constituting the coating layer include, in addition to LiNbO3, Li4Ti5O12 Examples include, but are not limited to, Li3PO4, Li-Ti-Al-F-based materials, etc.

[0033] The shape of the positive electrode active material is not particularly limited. The positive electrode active material may be, for example, particulate. The positive electrode active material may be primary particles or secondary particles aggregated from a plurality of primary particles. The average particle diameter D of the positive electrode active material 50 may be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and may also be 500 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. The average particle diameter D 50 is the particle diameter (median diameter) at the integrated value of 50% in the volume-based particle size distribution determined by the laser diffraction / scattering method.

[0034] (Negative electrode active material) As the negative electrode active material, various substances having a potential (charge / discharge potential) for occluding and releasing lithium ions that is lower than that of the above positive electrode active material can be adopted. The material of the negative electrode active material is not particularly limited and may be metallic lithium or a material capable of occluding and releasing metal ions such as lithium ions. Examples of materials capable of occluding and releasing metal ions such as lithium ions include, but are not limited to, alloy-based negative electrode active materials, carbon materials, or lithium titanate (Li4Ti5O 12 ), etc.

[0035] The alloy-based negative electrode active material is not particularly limited and examples include Si alloy-based negative electrode active materials or Sn alloy-based negative electrode active materials, etc. Si alloy-based negative electrode active materials include silicon, silicon oxides, silicon carbides, silicon nitrides, or solid solutions thereof, etc. Further, Si alloy-based negative electrode active materials can contain metal elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. Sn alloy-based negative electrode active materials include tin, tin oxides, tin nitrides, or solid solutions thereof, etc. Further, Sn alloy-based negative electrode active materials can contain metal elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0036] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, and the like.

[0037] The shape of the negative electrode active material is not particularly limited. The negative electrode active material may be, for example, particulate or sheet-like. The negative electrode active material may be primary particles or secondary particles formed by aggregation of a plurality of primary particles. The average particle diameter D of the negative electrode active material 50 may be, for example, 1 nm or more, 5 nm or more, or 10 nm or more, and may also be 500 μm or less, 100 μm or less, 50 μm or less, or 30 μm or less. The average particle diameter D 50 is the particle diameter (median diameter) at 50% of the integrated value in the volume-based particle size distribution determined by the laser diffraction / scattering method.

[0038] (Solid electrolyte) The material of the solid electrolyte is not particularly limited, and may be, for example, a sulfide solid electrolyte, an oxide solid electrolyte, a polymer electrolyte, or the like.

[0039] Examples of the sulfide solid electrolyte include, but are not limited to, sulfide-based amorphous solid electrolytes, sulfide-based crystalline solid electrolytes, or argyrodite-type solid electrolytes. Specific examples of the sulfide solid electrolyte include Li2S-P2S5 systems (Li7P3S 11 , Li3PS4, Li8P2S9, etc.), Li2S-SiS2, LiI-Li2S-SiS2, LiI-Li2S-P2S5, LiI-LiBr-Li2S-P2S5, Li2S-P2S5-GeS2 (Li 13 GeP3S 16 , Li 10 GeP2S 12 , etc.), LiI-Li2S-P2O5, LiI-Li3PO4-P2S5, Li 7-x PS 6-x Cl x , etc.; or combinations thereof can be mentioned, but are not limited thereto.

[0040] Examples of the oxide solid electrolyte include Li7La3Zr2O12 , Li 7-x La3Zr 1-x Nb x O 12 , Li 7-3x La3Zr2Al x O 12 , Li 3x La 2 / 3-x TiO3, Li 1+x Al x Ti 2-x (PO4)3, Li 1+x Al x Ge 2-x (PO4)3, Li3PO4, or Li 3+x PO 4-x N x (LiPON), etc. are exemplified, but not limited thereto.

[0041] The sulfide solid electrolyte and the oxide solid electrolyte may be glass or crystallized glass (glass ceramics).

[0042] Examples of the polymer electrolyte include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

[0043] (Conductive aid) The conductive aid is not particularly limited. The conductive aid may be, for example, vapor-grown carbon fiber (VGCF), acetylene black (AB), ketjen black (KB), carbon nanotube (CNT), carbon nanofiber (CNF), etc., but is not limited thereto. The conductive aid may be, for example, particulate or fibrous, and its size is not particularly limited. The conductive aid is not particularly limited, but only one kind may be used alone, or two or more kinds may be used in combination.

[0044] (Binder) The binder is not particularly limited. The binder may be, for example, a material such as polyvinylidene fluoride (PVdF), butadiene rubber (BR), polytetrafluoroethylene (PTFE), styrene-butadiene rubber (SBR), etc., but is not limited thereto. The binder is not particularly limited, but only one type may be used alone, or two or more types may be used in combination.

[0045] The shape of the electrode active material layer is not particularly limited, but may be, for example, a sheet-like electrode active material layer having a substantially flat surface. The thickness of the electrode active material layer is not particularly limited, but may be, for example, 0.1 μm or more, 1 μm or more, or 10 μm or more, and may also be 2 mm or less, 1 mm or less, or 500 μm or less.

[0046] The electrode active material layer can be manufactured by applying known methods. For example, the electrode active material layer can be easily formed by molding the electrode mixture containing the above various components in a dry or wet manner.

[0047] 〈Solid electrolyte layer〉 The solid electrolyte layer contains a solid electrolyte and may further optionally contain a conductive aid, a binder, etc. The solid electrolyte layer is not particularly limited, but preferably contains a sulfide solid electrolyte.

[0048] Regarding the solid electrolyte, the conductive aid, and the binder, reference can be made to the description in the above “〈Electrode active material layer〉”.

[0049] The thickness of the solid electrolyte layer is not particularly limited, but may be, for example, 0.1 μm or more, 1 μm or more, or 10 μm or more, and may also be 2 mm or less, 1 mm or less, or 500 μm or less.

[0050] The solid electrolyte layer can be easily formed, for example, by molding a solid electrolyte mixture containing the above-mentioned solid electrolyte and binder, etc. in a dry or wet manner.

[0051] 《Method for manufacturing a battery》 The method for manufacturing a battery according to the present disclosure may include the method for inspecting a long sheet according to the present disclosure.

[0052] According to the method for manufacturing a battery of the present disclosure, a battery can be manufactured from a member having a moisture content smaller than the standard value.

[0053] 〈Battery〉 The battery is not particularly limited, but may be a liquid-based battery containing an electrolytic solution as the electrolyte layer, or may be a solid battery having a solid electrolyte layer as the electrolyte layer. In the present disclosure, "solid battery" means a battery using at least a solid electrolyte as the electrolyte. Therefore, the solid battery may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. Further, the battery may be an all-solid battery, that is, a battery using only a solid electrolyte as the electrolyte.

[0054] Specifically, as a method for manufacturing a battery, for example, a solid electrolyte layer formed on a long sheet base material is superposed on the surface of a negative electrode active material layer formed on a negative electrode current collector as a long sheet base material, pressed, the solid electrolyte layer is transferred to the surface of the negative electrode active material layer, the long sheet base material in contact with the solid electrolyte layer is peeled off, the solid electrolyte layer is laminated on the negative electrode active material layer, and then, a positive electrode active material layer formed on the long sheet base material is superposed on the surface of the solid electrolyte layer laminated on the negative electrode active material layer, pressed, the positive electrode active material layer is transferred to the surface of the solid electrolyte layer, the long sheet base material in contact with the positive electrode active material layer is peeled off, and the positive electrode active material layer can be laminated on the solid electrolyte layer, but it is not limited to this case.

[0055] The above laminate may be used as a battery, or a positive electrode current collector layer and / or a negative electrode current collector layer may be provided on a laminate in which a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer are laminated, and the laminate may be laminated and sealed to form a battery. The battery is not particularly limited, but may be constrained, for example, with a constraint pressure of 5 MPa.

Examples

[0056] The present disclosure will be described in more detail with reference to the following examples, but the scope of the present disclosure is not limited to these examples.

[0057] 〈Moisture content of the solid electrolyte layer〉 The moisture content of the solid electrolyte layer was measured using a Karl Fischer apparatus (Karl Fischer apparatus CA-310 and moisture vaporizer VA-300 manufactured by Nitto Seiko). Specifically, the solid electrolyte layer was heated to 200 °C by the moisture vaporizer VA-300, and the moisture generated by the heating was measured by the Karl Fischer apparatus CA-310 to determine the moisture content.

[0058] 《Example 1》 A long coated sheet having a long sheet base material formed in a roll shape and a solid electrolyte layer coated on the long sheet base material was inspected. Here, the solid electrolyte layer is a solid electrolyte layer containing a sulfide solid electrolyte. The first start standard value and the first end standard value were set to 500 ppm. Example 1 will be described with reference to FIG. 2.

[0059] 〈Comparison between the first start moisture content and the first start standard value〉 The first start moisture content was measured at the first start position 121a located at a position of a first start predetermined distance 120b from the coating start end 120a. The first start moisture content was 382 ppm. Since the first start moisture content was 328 ppm and the first start standard value was 500 ppm, the first start moisture content was smaller than the first start standard value.

[0060] 〈Comparison between the first end moisture content and the first end standard value〉 The first end moisture content was measured at the first end position 121c located at a position of a first end predetermined distance 120d from the coating end 120c. The first end moisture content was 266 ppm. Since the first end moisture content was 266 ppm and the first end standard value was 500 ppm, the first end moisture content was smaller than the first end standard value.

[0061] 〈Inspection results of the long coated sheet and the moisture content〉 Since the moisture content at the first starting end is less than the first starting-end standard value and the moisture content at the first ending end is less than the first ending-end standard value, the long coated sheet between the first starting position 121a and the first ending position 121c was regarded as a qualified product. Here, when measuring the moisture content at four locations of the long coated sheet between the first starting position 121a and the first ending position 121c, it was 197 ppm, 231 ppm, 212 ppm, and 225 ppm, all of which were less than 500 ppm of the first starting-end standard value and the first ending-end standard value. Also, the moisture content at the coating starting end 120a was 1143 ppm, and the moisture content at the coating ending end 120c was 524 ppm, both of which were greater than 500 ppm of the first starting-end standard value and the first ending-end standard value. From the above, it was confirmed that it is possible to determine the quality of the moisture content of a product part such as the long coated sheet between the first starting position 121a and the first ending position 121c from the moisture content at locations other than the product parts such as the first starting position 121a and the first ending position 121c.

[0062] 《Example 2》 An inspection was carried out on a long coated sheet having a roll-shaped long sheet substrate and a solid electrolyte layer coated on the long sheet substrate. Here, the solid electrolyte layer is a solid electrolyte layer containing a sulfide solid electrolyte. The first starting-end standard value, the second starting-end standard value, and the first ending-end standard value were set at 500 ppm. Example 2 will be described with reference to FIG. 2.

[0063] 〈Comparison between the moisture content at the first starting end and the first starting-end standard value〉 The moisture content at the first starting position 121a, which is at a position of a first starting-end predetermined distance 120b from the coating starting end 120a, was measured. The moisture content at the first starting end was 723 ppm. Since the moisture content at the first starting end was 723 ppm and the first starting-end standard value was 500 ppm, the moisture content at the first starting end was greater than the first starting-end standard value.

[0064] 〈Comparison between the moisture content at the second starting end and the second starting-end standard value〉 Since the first starting moisture content was greater than the first starting standard value, the second starting moisture content at the second starting position 122a, which is farther from the coating start end 120a than the first starting position 121a, was measured. The second starting moisture content was 382 ppm. Since the second starting moisture content was 328 ppm and the second starting standard value was 500 ppm, the second starting moisture content was less than the second starting standard value.

[0065] 〈Comparison between the first ending moisture content and the first ending standard value〉 The first ending moisture content was measured at the first ending position 121c, which is at a position of a first ending predetermined distance 120d from the coating end 120c. The first ending moisture content was 266 ppm. Since the first ending moisture content was 266 ppm and the first ending standard value was 500 ppm, the first ending moisture content was less than the first ending standard value.

[0066] 〈Inspection results of the long coating sheet and the moisture content〉 Since the second starting moisture content was less than the second starting standard value and the first ending moisture content was less than the first ending standard value, the long coating sheet between the second starting position 122a and the first ending position 121c was regarded as a qualified product. Here, when the moisture contents at four locations of the long coating sheet between the second starting position 122a and the first ending position 121c were actually measured, they were 197 ppm, 231 ppm, 212 ppm, and 225 ppm, all of which were less than 500 ppm of the first starting standard value, the second starting standard value, and the first ending standard value. Also, the moisture content at the coating start end 120a was 1143 ppm, and the moisture content at the coating end 120c was 524 ppm, both of which were greater than 500 ppm of the first starting standard value, the second starting standard value, the first ending standard value, and the second ending standard value. From the above, it was confirmed that the quality of the moisture content of the product part such as the long coating sheet between the second starting position 122a and the first ending position 121c can be determined from the moisture contents at locations other than the product parts such as the second starting position 122a and the first ending position 121c.

[0067] Although the preferred embodiments of the inspection method for the long coating sheet of the present disclosure have been described, those skilled in the art understand that changes can be made without departing from the scope of the claims.

Explanation of Signs

[0068] 100 Long coating sheet 110 Long sheet substrate 120 Electrode active material layer and / or solid electrolyte layer 120a Coating start end 120b First start end predetermined distance 121a First start position 122a Second start position 120c Coating end 120d First end predetermined distance 121c First end position 122c Second end position

Claims

1. A method for inspecting a long coated sheet having a long sheet base material formed in a roll shape and an electrode active material layer and / or a solid electrolyte layer coated on the long sheet base material, the method including the following: (i) Measuring a first starting moisture content at a first starting position located at a first starting predetermined distance from the coating start end and comparing it with a first starting standard value; (ii) Measuring a first ending moisture content at a first ending position located at a first ending predetermined distance from the coating end and comparing it with a first ending standard value; and (iii) When the first starting moisture content is less than the first starting standard value and the first ending moisture content is less than the first ending standard value, regarding the long coated sheet between the first starting position and the first ending position as a qualified product.

2. The method according to Claim 1, wherein the electrode active material layer and / or the solid electrolyte layer contains a sulfide solid electrolyte.

3. The method according to Claim 1, wherein the first starting predetermined distance is also greater than the first ending predetermined distance.

4. The method according to Claim 1, further including, when the first starting moisture content is greater than the first starting standard value, measuring a second starting moisture content at a second starting position farther from the coating start end than the first starting position and comparing it with a second starting standard value.

5. The method according to Claim 1, further including, when the first ending moisture content is greater than the first ending standard value, measuring a second ending moisture content at a second ending position farther from the coating end than the first ending position and comparing it with a second ending standard value.

6. A method for manufacturing a battery, including the method according to any one of Claims 1 to 5.

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