Method for manufacturing electrode laminate

Abstract

To provide a method for manufacturing an electrode laminate that can reduce wrinkles on an electrode laminate.SOLUTION: A method for manufacturing an electrode laminate includes: (a) providing a preliminary electrode laminate 100 having a first electrode active material layer 111, a solid electrolyte layer 120, a second electrode active material layer 112, a first collector layer 131, a second electrode active material layer 112, a solid electrolyte layer 120, and a first electrode active material layer 111, in this order; and (b) subjecting the preliminary electrode laminate 100 to flat pressing at a temperature of 120-160°C.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing an electrode laminate.

Background Art

[0002] When manufacturing an electrode laminate, in order to increase the density of the electrode active material layer contained in the electrode laminate, it is known to press the electrode laminate by roll pressing. When the electrode laminate is pressed by roll pressing, wrinkles and distortions may occur in the electrode laminate. In order to obtain an electrode laminate with less wrinkles and distortions, the following electrode sheet, method for manufacturing an all-solid-state battery, and method for manufacturing a sheet electrode have been disclosed.

[0003] Patent Document 1 discloses an electrode sheet having a metal foil and a coated portion and an uncoated portion disposed on the metal foil, wherein the coated portion has at least an electrode composite layer containing an active material, the uncoated portion does not have the electrode composite layer, when the electrode sheet is viewed in plan in the thickness direction, and the direction from the end of the coated portion to the end of the uncoated portion is defined as the first direction and the direction orthogonal to the first direction is defined as the second direction, the uncoated portion has a notch extending in the second direction. According to the electrode sheet of Patent Document 1, it is said that an electrode sheet capable of suppressing the occurrence of wrinkles in the uncoated portion, or an electrode sheet in which the occurrence of the wrinkles is suppressed can be provided.

[0004] Patent Document 2 discloses a method for manufacturing an all-solid-state battery, comprising the steps of preparing a laminate in which a positive electrode, a solid electrolyte layer, and a negative electrode are laminated in this order, a first pressing step of roll pressing the laminate from one direction, and a second pressing step of roll pressing the laminate after the first pressing step from a direction orthogonal to the one direction. According to the method for manufacturing an all-solid-state battery of Patent Document 2, it is said that the occurrence of electrode undulations can be suppressed and the battery resistance of the all-solid-state battery can be reduced.

[0005] In Patent Document 3, the amount of curvature after roll pressing of a sheet electrode obtained by coating and drying an electrode active material on the surface of a current collector sheet is measured, the strain difference in the width direction of the sheet electrode is calculated using an arithmetic expression represented by a predetermined formula, the temperature correction conditions are obtained from the correlation between the temperature tensile characteristics of the current collector sheet and the strain difference obtained in advance, and the strain of the sheet electrode is corrected under the obtained temperature correction conditions. A method for manufacturing a sheet electrode is disclosed. According to the method for manufacturing a sheet electrode of Patent Document 3, by performing strain correction of the sheet electrode under appropriate temperature correction conditions, problems such as undulations and curvature on the surface of the sheet electrode are eliminated, and a flat sheet electrode without strain is obtained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the roll pressing process of the electrode laminate, the electrode laminate is pressurized and stretched by roll pressing, and since the strain stress of the current collector layer is greater than the strain stress of the electrode active material layer, the electrode active material layer is pulled by the current collector layer, thereby causing wrinkles.

[0008] In particular, in the manufacture of a solid battery including a solid electrolyte as an electrolyte layer, compared with a liquid battery including an electrolyte solution in the electrolyte layer, it is necessary to roll press the electrode laminate at a high pressure, and since the overall design of the electrode laminate has low rigidity, the problem of wrinkles caused by roll pressing is prominent.

[0009] Therefore, an object of the present disclosure is to provide a method for manufacturing an electrode laminate capable of reducing wrinkles in the electrode laminate.

Means for Solving the Problem

[0010] The present disclosure achieves the above object by the following means.

[0011] 〈Aspect 1〉 A method for manufacturing an electrode laminate, including the following method: (a) Providing a preliminary electrode laminate having a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, a first current collector layer, a second electrode active material layer, a solid electrolyte layer, and a first electrode active material layer in this order, and (b) Planar pressing the above preliminary electrode laminate at a temperature of 120 to 160°C. 〈Aspect 2〉 Between step (a) and step (b), (a-2) Sandwiching both sides of the above preliminary electrode laminate with metal plates, and roll-pressing the preliminary electrode laminate sandwiched with the metal plates at a pressure of 1.0 ton / cm or more. The method for manufacturing an electrode laminate according to Aspect 1, further including this. 〈Aspect 3〉 After step (b), (c) Connecting a second current collector layer to the first electrode active material layer of the above electrode laminate. The method for manufacturing an electrode laminate according to Aspect 1 or 2, further including this. 〈Aspect 4〉 The method for manufacturing an electrode laminate according to any one of Aspects 1 to 3, wherein the above metal plate is a stainless steel plate having a thickness of 10 to 1000 μm. 〈Aspect 5〉 The method for manufacturing an electrode laminate according to any one of Aspects 1 to 4, wherein the above first current collector layer contains aluminum. 〈Aspect 6〉 The method for manufacturing an electrode laminate according to any one of Aspects 1 to 5, wherein the thickness of the above preliminary electrode laminate is 100 to 300 μm.

Advantages of the Invention

[0012] According to the method for manufacturing an electrode laminate of the present disclosure, wrinkles in the electrode laminate can be reduced.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited to the following embodiments and can be variously modified and implemented within the scope of the gist of the present disclosure. Also, in the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0015] Regarding the present disclosure, "composite material" means a composition that can constitute a positive electrode active material layer or the like as it is or by further containing other components. Also, regarding the present disclosure, "composite material slurry" means a slurry that contains a dispersion medium in addition to the "composite material" and can form a positive electrode active material layer or the like by coating and drying.

[0016] 《Method for Manufacturing an Electrode Laminate》 The method for manufacturing an electrode laminate of the present disclosure is (a) providing a preliminary electrode laminate having a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, a first current collector layer, a second electrode active material layer, a solid electrolyte layer, and a first electrode active material layer in this order, and (b) performing planar pressing on the above preliminary electrode laminate at a temperature of 120 to 160°C. including.

[0017] According to the method for manufacturing an electrode laminate of the present disclosure, wrinkles in the electrode laminate can be reduced.

[0018] When pressure is applied to the electrode laminate, for example, by roll pressing, the electrode laminate expands. Since the strain stress of the first current collector layer in the electrode laminate is greater than that of the electrode active material layer, the electrode active material layer is pulled by the first current collector layer, thereby causing wrinkles. Although not limited to theory, it is presumed that when flat pressing is performed on the electrode laminate, the strain stress of the first current collector layer is relaxed, thereby reducing wrinkles.

[0019] FIG. 1 is a schematic diagram showing one aspect of the method for manufacturing the electrode laminate of the present disclosure, but is not limited to this case.

[0020] The method for manufacturing the electrode laminate of the present disclosure first provides, in step (a), a preliminary electrode laminate 100 having a first electrode active material layer 111, a solid electrolyte layer 120, a second electrode active material layer 112, a first current collector layer 131, a second electrode active material layer 112, a solid electrolyte layer 120, and a first electrode active material layer 111 in this order (FIG. 1A). As a method for producing the preliminary electrode laminate 100, for example, the solid electrolyte layer 120 formed on the base material is superposed on and pressed against each surface of the second electrode active material layer 112 formed on both surfaces of the first current collector layer 131, the solid electrolyte layer 120 is transferred to the surface of the second electrode active material layer 112, the base material in contact with the solid electrolyte layer 120 is peeled off, the solid electrolyte layer 120 is laminated on the second electrode active material layer 112, and then the first electrode active material layer 111 formed on the base material is superposed on and pressed against each surface of the solid electrolyte layer 120 laminated on both surfaces of the second electrode active material layer 112, the first electrode active material layer 111 is transferred to the surface of the solid electrolyte layer 120, the base material in contact with the first electrode active material layer 111 is peeled off, the first electrode active material layer 111 is laminated on the solid electrolyte layer 120, and the preliminary electrode laminate 100 can be obtained. The preliminary electrode laminate 100 may be subjected to a pressure treatment such as roll pressing. Next, in step (b), the preliminary electrode laminate 100 is flat pressed at a pressure P at a temperature of 120 to 160°C (FIG. 1B). By flat pressing at a temperature of 120 to 160°C, the strain stress of the first current collector layer 131 is relaxed, thereby reducing wrinkles in the electrode laminate.

[0021] The manufacturing method of the electrode laminate of the present disclosure may further include, between step (a) and step (b), (a-2) sandwiching both sides of the above-mentioned preliminary electrode laminate with metal plates, and roll-pressing the preliminary electrode laminate sandwiched between the metal plates at a pressure of 1.0 ton / cm or more. It may further include.

[0022] FIG. 2 is a schematic diagram showing one embodiment of the manufacturing method of the electrode laminate of the present disclosure, but is not limited to this case.

[0023] In the method of the electrode laminate of the present disclosure shown in FIG. 2, first, in step (a), a preliminary electrode laminate 100 is provided (FIG. 2A). Next, in step (a-2), both sides of the preliminary electrode laminate 100 are sandwiched with metal plates 140, and the preliminary electrode laminate 100 sandwiched between the metal plates 140 is roll-pressed at a pressure P' of 1.0 ton / cm or more (FIG. 2B). Then, in step (c), the preliminary electrode laminate 100 is flat-pressed at a pressure P at a temperature of 120 to 160°C (FIG. 2C). By flat-pressing at a temperature of 120 to 160°C, the strain stress of the first current collector layer 131 is relaxed, thereby reducing the wrinkles of the electrode laminate. In particular, by sandwiching the preliminary electrode laminate with metal plates and roll-pressing the preliminary electrode laminate sandwiched between the metal plates at a high pressure of 1.0 ton / cm or more, wrinkles immediately after roll-pressing can be suppressed, and a densified electrode laminate can be obtained.

[0024] After step (b), the manufacturing method of the electrode laminate of the present disclosure may further include (c) connecting a second current collector layer to the first electrode active material layer of the electrode laminate. It may further include.

[0025] In the above-described FIG. 1, after step (b), as step (c), the second current collector layer 132 may be connected to the first electrode active material layer 111 of the electrode laminate 101. As a method of connecting the second current collector layer 132, for example, the second current collector layer is overlapped and pressed on each surface of the first electrode active material layer 111, and the second current collector layer 132 is laminated on the first electrode active material layer 111, whereby the second current collector layer 132 can be connected.

[0026] 〈Flat press〉 The flat press is not particularly limited, and a known flat press machine can be used. The temperature of the flat press is 120 to 160°C. From the viewpoint of reducing wrinkles in the electrode laminate, the temperature of the flat press may be 120°C or higher, 130°C or higher, or 140°C or higher, and may also be 160°C or lower, 150°C or lower, or 140°C or lower. Here, the temperature of the flat press can be adjusted to a predetermined temperature, for example, by heating the pressure surface of the flat press machine.

[0027] The pressure (pressing pressure) of the flat press is not particularly limited, and may be 1 MPa or higher, 2 MPa or higher, or 5 MPa or higher, and may also be 30 MPa or lower, 20 MPa or lower, 10 MPa or lower, or 7 MPa or lower.

[0028] The time of the flat press is not particularly limited, and from the viewpoint of reducing wrinkles in the electrode laminate, it may be 1 min or longer, 3 min or longer, or 5 min or longer, and may also be 30 min or shorter, 20 min or shorter, 10 min or shorter, or 5 min or shorter.

[0029] 〈Roll press〉 The roll press is not particularly limited, and a known roll press machine can be used. The temperature of the roll press is not particularly limited, and may be 100°C or higher, 140°C or higher, or 160°C or higher, and may also be 240°C or lower, 200°C or lower, 180°C or lower. Here, the temperature of the roll press can be adjusted to a predetermined temperature, for example, by heating the roll of the roll press machine.

[0030] The linear pressure of the roll press is not particularly limited, but from the perspective of increasing the density of the electrode active material layer, it may be 1 ton / cm or more, 2 ton / cm or more, or 4 ton / cm or more, and may also be 30 ton / cm or less, 20 ton / cm or less, or 10 ton / cm or less.

[0031] 《Manufacturing Method of Electrode Laminate: Each Component》 Hereinafter, each component of the manufacturing method of the electrode laminate of the present disclosure will be described.

[0032] 〈Preliminary Electrode Laminate〉 The preliminary electrode laminate has a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, a first current collector layer, a second electrode active material layer, a solid electrolyte layer, and a first electrode active material layer in this order.

[0033] The thickness of the preliminary electrode laminate is not particularly limited, but is preferably 100 to 300 μm. The thickness of the preliminary electrode laminate is not particularly limited, and may be 100 μm or more, 120 μm or more, 140 μm or more, or 160 μm or more, and may also be 300 μm or less, 250 μm or less, 200 μm or less, or 150 μm or less. When the thickness of the preliminary electrode laminate is small, the rigidity of the preliminary electrode laminate becomes small, and the problem of wrinkles when pressing the preliminary electrode laminate becomes more prominent, and reduction of wrinkles is desired.

[0034] 〈First Current Collector Layer〉 The material used for the first current collector layer is not particularly limited, but those that can be used as the current collector of the battery can be appropriately adopted. Examples of the material used for the first current collector layer include, but are not limited to, Cu, Ni, Cr, Au, Pt, Ag, Al, Fe, Ti, Zn, Co, stainless steel, etc. Also, the first current collector layer may have some coating layer on its surface for the purpose of adjusting the resistance or the like. Further, the first current collector layer may be a metal foil or a substrate on which the above metal is plated or vapor-deposited. The first current collector layer is not particularly limited, but preferably contains aluminum.

[0035] The shape of the first current collector layer is not particularly limited, and examples thereof include a foil shape, a plate shape, a mesh shape, and the like. Among these, a foil shape is preferable.

[0036] The thickness of the first current collector layer is not particularly limited, but it may be 0.1 μm or more, or 1 μm or more, and may also be 100 μm or less, 50 μm or less, 30 μm or less, or 20 μm or less.

[0037] 〈Second current collector layer〉 The material used for the second current collector layer is not particularly limited, and those that can be used as a current collector of the battery can be appropriately adopted. For the second current collector layer, reference can be made to the description of the above “〈First current collector layer〉”.

[0038] 〈First electrode active material layer〉 The first electrode active material layer contains at least an electrode active material, and may further optionally contain a solid electrolyte, a conductive assistant, a binder, and the like. The first 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 first electrode active material layer may be appropriately determined according to the target battery performance. For example, taking the whole of the first electrode active material layer (the whole solid content) as 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.

[0039] The first electrode active material layer may be a positive electrode active material layer or a negative electrode active material layer. When the first electrode active material layer is a positive electrode active material layer, the electrode active material is a positive electrode active material, and when the first electrode active material layer is a negative electrode active material layer, the electrode active material is a negative electrode active material. The first electrode active material layer is not particularly limited, but is preferably a positive electrode active material layer.

[0040] (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 heteroatom-substituted Li-Mn spinel having a composition represented by the formula, but is not limited thereto.

[0041] The positive electrode active material is not particularly limited, but may have a coating layer. The coating layer is a layer containing a substance having lithium ion conduction performance, low reactivity with the positive electrode active material and the solid electrolyte, and capable of maintaining 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, Li4Ti5O 12 , Li3PO4, Li-Ti-Al-F-based materials, etc., but are not limited thereto.

[0042] The shape of the positive electrode active material is not particularly limited as long as it is a general shape as the positive electrode active material of the battery. The positive electrode active material may be, for example, in the form of particles. The positive electrode active material may be primary particles or secondary particles in which a plurality of primary particles are aggregated. The average particle diameter D 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.

[0043] (Negative electrode active material) As the negative electrode active material, various materials having a potential (charge-discharge potential) for occluding and releasing lithium ions that is lower than that of the positive electrode active material of the present disclosure can be employed. The material of the negative electrode active material is not particularly limited, and may be metallic lithium, or may be 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 alloy-based negative electrode active materials, carbon materials, or lithium titanate (Li4Ti5O 12 ) and the like, but are not limited thereto.

[0044] The alloy-based negative electrode active material is not particularly limited, and examples thereof include Si alloy-based negative electrode active materials or Sn alloy-based negative electrode active materials. The Si alloy-based negative electrode active material includes silicon, silicon oxide, silicon carbide, silicon nitride, or a solid solution thereof. Further, the Si alloy-based negative electrode active material can contain metal elements other than silicon, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Sn, Ti, etc. The Sn alloy-based negative electrode active material includes tin, tin oxide, tin nitride, or a solid solution thereof. Further, the Sn alloy-based negative electrode active material can contain metal elements other than tin, such as Fe, Co, Sb, Bi, Pb, Ni, Cu, Zn, Ge, In, Ti, Si, etc.

[0045] The carbon material is not particularly limited, and examples thereof include hard carbon, soft carbon, graphite, etc.

[0046] The shape of the negative electrode active material is not particularly limited. The negative electrode active material may be, for example, particulate, or may be sheet-shaped. The negative electrode active material may be primary particles, or may be secondary particles in which a plurality of primary particles are aggregated. 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. Note that 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.

[0047] (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.

[0048] 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.

[0049] Examples of the oxide solid electrolyte include, but are not limited to, Li7La3Zr2O 12 , 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., but are not limited thereto.

[0050] The sulfide solid electrolyte and the oxide solid electrolyte may be glass or crystallized glass (glass ceramics).

[0051] Examples of the polymer electrolyte include, but are not limited to, polyethylene oxide (PEO), polypropylene oxide (PPO), and copolymers thereof.

[0052] (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), conductive carbon, 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, and only one type may be used alone, or two or more types may be used in combination.

[0053] (Binder) The binder is not particularly limited. The binder may be, for example, materials 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, and only one type may be used alone, or two or more types may be used in combination.

[0054] The shape of the first electrode active material layer is not particularly limited, and may be, for example, a sheet-like electrode active material layer having a substantially flat surface. The thickness of the first electrode active material layer is not particularly limited, and may be, for example, 0.1 μm or more, 1 μm or more, or 10 μm or more, and may also be 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, or 80 μm or less.

[0055] The first electrode active material layer can be manufactured by applying known methods. For example, the first electrode active material layer can be easily formed by molding an electrode mixture containing the above various components in a dry or wet manner, etc.

[0056] 〈Second Electrode Active Material Layer〉 Regarding the second electrode active material layer, reference can be made to the description of the above “〈First Electrode Active Material Layer〉”.

[0057] Note that the first electrode active material layer and the second electrode active material layer have opposite polarities to each other. That is, if the first electrode active material layer is a positive electrode active material layer, the second electrode active material layer is a negative electrode active material layer. Similarly, if the first electrode active material layer is a negative electrode active material layer, the second electrode active material layer is a positive electrode active material layer.

[0058] 〈Solid Electrolyte Layer〉 The solid electrolyte layer contains at least a solid electrolyte, and may contain a conductive assistant, a binder, etc. as required.

[0059] Regarding the solid electrolyte, the conductive assistant, and the binder, reference can be made to the description of the above “〈First Electrode Active Material Layer〉”.

[0060] The thickness of the solid electrolyte layer is not particularly limited, but for example, it may be 0.1 μm or more, 1 μm or more, or 10 μm or more, and may also be 300 μm or less, 200 μm or less, 150 μm or less, 100 μm or less, or 80 μm or less.

[0061] The solid electrolyte layer can be easily formed, for example, by molding a solid electrolyte mixture containing the above solid electrolyte and binder, etc. in a dry or wet manner, etc.

[0062] 〈Metal Plate〉 The metal plate is not particularly limited, but it may be a stainless steel (SUS) plate having a thickness of 10 to 1000 μm.

[0063] The material of the metal plate is not particularly limited, and for example, a stainless steel plate (SUS) or an iron plate (Fe) can be used. From the perspective of the rigidity of the metal plate, a stainless steel plate (SUS) is preferred.

[0064] The thickness of the metal plate is not particularly limited. From the perspective of suppressing wrinkles in the electrode laminate immediately after roll pressing, it may be 10 μm or more, 50 μm or more, or 100 μm or more. From the perspective of workability, it may be 1000 μm or less, 800 μm or less, 600 μm or less, or 400 μm or less.

[0065] The usage mode of the metal plate is not particularly limited. For example, one metal plate may be arranged on each of the upper and lower surfaces of the preliminary electrode laminate to sandwich the preliminary electrode laminate, or two metal plates may be arranged on each side to sandwich the preliminary electrode laminate, or two or more metal plates may be arranged to sandwich the preliminary electrode laminate.

[0066] 《Solid Battery》 The solid battery of the present disclosure may include an electrode laminate obtained by the manufacturing method of the present disclosure.

[0067] Regarding the present disclosure, "solid battery" means a battery that uses at least a solid electrolyte as an electrolyte. Therefore, the solid battery may use a combination of a solid electrolyte and a liquid electrolyte as the electrolyte. Further, the solid battery of the present disclosure may be an all-solid battery, that is, a battery that uses only a solid electrolyte as the electrolyte.

[0068] The above electrode laminate may be used as a solid battery, or a positive electrode current collector layer and / or a negative electrode current collector layer may be provided as necessary and laminated and encapsulated to form a solid battery. The solid battery is not particularly limited. For example, it may be constrained by a constraint pressure of 5 MPa.

[0069] Examples of the shape of the solid battery include, but are not limited to, coin type, laminate type, cylindrical type, and rectangular type.

Examples

[0070] 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.

[0071] <<Production Example 1>> Production of Preliminary Electrode Laminate A1 <Production of the First Electrode Active Material Layer and the Solid Electrolyte Layer> On one side of an aluminum foil (film thickness: 15 μm) as a base material, a positive electrode composite material containing LiNi 0.8 (CoAl) 0.2 O2 was applied, dried, and a first electrode active material layer formed on one side of the base material was obtained. Similarly, on one side of an aluminum foil (film thickness: 15 μm) as another substrate, a solid electrolyte composite material was applied, dried, and a solid electrolyte layer formed on one side of the base material was obtained.

[0072] <Production of the Second Electrode Active Material Layer> On both sides of a carbon-coated aluminum foil (film thickness: 17 μm) as the first current collector layer, a negative electrode composite material containing Li4Ti5O 12 was applied, dried, and a second electrode active material layer formed on both sides of the first current collector layer was obtained.

[0073] <Production of the Preliminary Electrode Laminate> On the respective surfaces of the second electrode active material layers formed on both sides of the first current collector layer, the solid electrolyte layers were respectively superposed and pressed at a pressing pressure of 20 kN to transfer the solid electrolyte layers to the surfaces of the second electrode active material layers, and the base materials in contact with the solid electrolyte layers were peeled off to laminate the solid electrolyte layers on the second electrode active material layers. Next, on the respective surfaces of the solid electrolyte layers laminated on both sides of the second electrode active material layer, the first electrode active material layers were respectively superposed and pressed at a pressing pressure of 20 kN to transfer the first electrode active material layers to the surfaces of the solid electrolyte layers, and the base materials in contact with the first electrode active material layers were peeled off to laminate the first electrode active material layers on the solid electrolyte layers, thereby producing a preliminary electrode laminate. The preliminary electrode laminate had the first electrode active material layer, the solid electrolyte layer, the second electrode active material layer, the first current collector layer, the second electrode active material layer, the solid electrolyte layer, and the first electrode active material layer laminated in this order. The thickness of the preliminary electrode laminate A1 was 180 μm.

[0074] Example 1 <Production of Preliminary Electrode Laminate B1 by Roll Pressing> Two stainless steel (SUS) plates (thickness: 50 μm) were used to sandwich both sides of the preliminary electrode laminate A1 produced in Production Example 1, and roll pressing was performed under the conditions of a temperature of 170°C and a linear pressure of 4.5 ton / cm. Subsequently, the SUS plates on both sides were removed to obtain the preliminary electrode laminate B1 after the roll pressing process.

[0075] <Production of Electrode Laminate C1 by Flat Pressing> The preliminary electrode laminate B1 after the roll pressing process was pressed with a flat press under the conditions of a temperature of 140°C, a pressing pressure of 5 MPa, and a holding time of 5 minutes to obtain the electrode laminate C1.

[0076] <Measurement of Wrinkle Height and Wrinkle Period Length of Electrode Laminate C1> The wrinkle height and wrinkle period length of the electrode laminate C1 were measured with a height and flatness measuring instrument HM-1000 (manufactured by Keyence Corporation). The wrinkle height of the electrode laminate C1 was 0.057 mm, and the wrinkle period length was 15 mm. Here, the wrinkle height is the difference between the maximum value and the minimum value of the amplitude due to wrinkles in the measurement area, and the wrinkle period length is the length from the minimum value of the wrinkle height to the next minimum value in the measurement area.

[0077] Example 2 <Production of Preliminary Electrode Laminate B2 by Roll Pressing> One stainless steel (SUS) plate (thickness: 100 μm) was used to sandwich both sides of the preliminary electrode laminate A1 produced in Production Example 1, and roll pressing was performed under the conditions of a temperature of 170°C and a linear pressure of 4.5 ton / cm. Subsequently, the SUS plates on both sides were removed to obtain the preliminary electrode laminate B2 after the roll pressing process.

[0078] <Production of Electrode Laminate C2 by Flat Pressing> The preliminary electrode laminate B2 after the roll pressing process was pressed with a flat press under the conditions of a temperature of 140°C, a pressing pressure of 5 MPa, and a holding time of 5 minutes to obtain the electrode laminate C2.

[0079] <Measurement of wrinkle height and wrinkle periodic length of electrode laminate C2> The wrinkle height and wrinkle periodic length of the electrode laminate C2 were measured in the same manner as in Example 1. The wrinkle height and wrinkle periodic length of the electrode laminate C2 were as shown in Table 1.

[0080] <<Comparative Example 1>> <Fabrication of electrode laminate c1 and measurement of wrinkle height and wrinkle periodic length of electrode laminate c1> The preliminary electrode laminate B1 that had only undergone the roll pressing process of Example 1 was used as the electrode laminate c1. The wrinkle height and wrinkle periodic length of the electrode laminate c1 were measured in the same manner as in Example 1. The wrinkle height and wrinkle periodic length of the electrode laminate c1 were as shown in Table 1.

[0081] <<Comparative Example 2>> <Fabrication of electrode laminate c2 and measurement of wrinkle height and wrinkle periodic length of electrode laminate c2> The preliminary electrode laminate B2 that had only undergone the roll pressing process of Example 2 was used as the electrode laminate c2. The wrinkle height and wrinkle periodic length of the electrode laminate c2 were measured in the same manner as in Example 1. The wrinkle height and wrinkle periodic length of the electrode laminate b were as shown in Table 1.

[0082]

Table 1

[0083] From Examples 1 and 2 and Comparative Examples 1 and 2, it was confirmed that by performing the planar pressing process, the wrinkle height of the electrode laminate becomes smaller and the wrinkle periodic length of the electrode laminate becomes larger, that is, the wrinkles of the electrode laminate are reduced.

[0084] When only roll pressing is performed at a linear pressure of 4.5 ton / cm as in Comparative Examples 1 and 2, the electrode laminate elongates, and the strain stress of the aluminum foil in the electrode laminate is greater than the strain stress of the electrode active material layer. Therefore, it is presumed that the electrode active material layer is pulled by the aluminum foil, thereby causing wrinkles. On the other hand, in Examples 1 and 2, flat pressing was performed after high-pressure pressing, and the strain stress of the aluminum foil was relaxed, thereby presuming that wrinkles were reduced.

[0085] 《Reference Example 1》 A preliminary electrode active material layer A2 was prepared in the same manner as in Production Example 1, except that a nickel foil (thickness 15 μm) was used instead of the aluminum foil with a carbon coating (thickness 17 μm) as the first current collector layer. The thickness of the preliminary electrode laminate was 180 μm. Next, one stainless steel (SUS) plate (thickness 100 μm) was used to sandwich both sides of the preliminary electrode laminate A2, and roll pressing was performed under the conditions of a temperature of 170°C and a linear pressure of 4.5 ton / cm. The SUS plates on both sides were removed to obtain a preliminary electrode laminate B3 after the roll pressing treatment. The preliminary electrode laminate B3 that had only undergone the roll pressing treatment was used as the electrode laminate C3. The wrinkle height and wrinkle period length of the electrode laminate C3 were measured with a laser microscope (Keyence VK-X3000, manufactured by Keyence Corporation). The wrinkle height and wrinkle period length of the electrode laminate C3 were as shown in Table 2.

[0086] 《Reference Example 2》 A preliminary electrode laminate A3 was prepared in the same manner as in Production Example 1, except that the thickness of the preliminary laminate was 370 μm. Next, one stainless steel (SUS) plate (thickness 100 μm) was used to sandwich both sides of the preliminary electrode laminate A3, and roll pressing was performed under the conditions of a temperature of 170°C and a linear pressure of 4.5 ton / cm. The SUS plates on both sides were removed to obtain a preliminary electrode laminate B4 after the roll pressing treatment. The preliminary electrode laminate B4 that had only undergone the roll pressing treatment was used as the electrode laminate C4. The wrinkle height and wrinkle period length of the electrode laminate C4 were measured with a laser microscope (Keyence VK-X3000, manufactured by Keyence Corporation). The wrinkle height and wrinkle period length of the electrode laminate C4 were as shown in Table 2.

[0087]

Table 2

[0088] In the electrode laminate C3, only roll press treatment was performed using a nickel foil instead of an aluminum foil as the first current collector layer. When the first current collector layer is a nickel foil, since the rigidity of the foil is greater than that of the aluminum foil, the elongation of the foil is reduced, the strain stress of the foil is reduced, and thus the wrinkles of the electrode laminate were few even after the roll press treatment. In the electrode laminate C4, a thick pre-electrode laminate was examined. When the thickness of the pre-electrode laminate is large, the rigidity of the electrode active material layer also becomes large, the elongation of the foil becomes small, the strain stress of the foil becomes small, and thus the wrinkles of the electrode laminate were few even after the roll press treatment. From the above, when the design of the entire electrode laminate is such that the rigidity is high, the influence of wrinkles can be suppressed. In other words, for example, in the case of a design that makes the electrode laminate thinner or when applying aluminum as the current collector, that is, when the design of the entire electrode laminate has low rigidity, it is presumed that the influence of wrinkles is significant.

[0089] Although the preferred embodiments of the method for manufacturing the electrode laminate of the present disclosure have been described, those skilled in the art will understand that changes can be made without departing from the scope of the claims.

Explanation of Reference Numerals

[0090] 100 Pre-electrode laminate 101 Electrode laminate 111 First electrode active material layer 112 Second electrode active material layer 120 Solid electrolyte layer 131 First current collector layer 132 Second current collector layer 140 Metal plate

Claims

1. A method for manufacturing an electrode laminate, comprising the following method: (a) providing a preliminary electrode laminate having a first electrode active material layer, a solid electrolyte layer, a second electrode active material layer, a first current collector layer, a second electrode active material layer, a solid electrolyte layer, and a first electrode active material layer in this order, and (b) performing planar pressing on the preliminary electrode laminate at a temperature of 120 to 160 °C.

2. Between step (a) and step (b), (a-2) sandwiching both surfaces of the preliminary electrode laminate with metal plates, and performing roll pressing on the preliminary electrode laminate sandwiched with the metal plates at a pressure of 1.0 ton / cm or more. The method for manufacturing an electrode laminate according to claim 1, further comprising this.

3. After step (b), (c) connecting a second current collector layer to the first electrode active material layer of the electrode laminate. The method for manufacturing an electrode laminate according to claim 1, further comprising this.

4. The method for manufacturing an electrode laminate according to claim 1, wherein the metal plate is a stainless steel plate having a thickness of 10 to 1000 μm.

5. The method for manufacturing an electrode laminate according to claim 1, wherein the first current collector layer contains aluminum.

6. The method for manufacturing an electrode laminate according to any one of claims 1 to 5, wherein the thickness of the preliminary electrode laminate is 100 to 300 μm.

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