Electrode stack, method for manufacturing an electrode stack
Patent Information
- Application Number
- JP2025059402
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2026-10-14
Smart Images
Figure 2026166458000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an electrode laminate and a method for manufacturing the electrode laminate.
Background Art
[0002] Batteries such as all-solid-state batteries are manufactured, for example, by applying an electrode mixture on a positive electrode current collector to form a positive electrode active material layer, further alternately laminating a solid electrolyte layer and a negative electrode layer on the upper surface of the positive electrode active material layer on a sheet having an insulating member formed on the outer periphery of the positive electrode active material layer, and performing press molding.
[0003] In the positive electrode of the battery obtained in this manner, it is known that the positive electrode active material layer has an inclined portion that inclines so as to expand toward the positive electrode current collector, and the outer edge of the positive electrode current collector is disposed more inward than the outer edge of the positive electrode active material layer on the positive electrode current collector layer side (see, for example, Patent Document 1). When the positive electrode layer has such a configuration, if lithium ion concentration occurs near the outer edge of the boundary between the positive electrode active material layer and the solid electrolyte layer, local precipitation of lithium ions in the facing portion may occur.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of Invention
Problems to be Solved by the Invention
[0005] When the positive electrode active material layer has an inclined portion that inclines so as to expand toward the positive electrode current collector, current concentrates near the outer edge of the boundary between the positive electrode active material layer and the solid electrolyte layer, and local precipitation of lithium on the negative electrode side is a problem.
[0006] To solve the above-mentioned problems, this invention aims to suppress the concentration of current at the boundary between the positive electrode active material layer and the insulating material arranged on the outer periphery of the positive electrode of a battery, and to suppress the localized deposition of lithium on the negative electrode side. This will ultimately contribute to energy efficiency. [Means for solving the problem]
[0007] To achieve the above objective, the present invention provides the following means. [1] An electrode laminate that utilizes the deposition-dissolution reaction of metallic lithium as the reaction of the negative electrode, It comprises a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode current collector, and a negative electrode active material layer. An insulating member is arranged on the outer periphery of the positive electrode active material layer. The positive electrode active material layer has an inclined portion that is inclined such that its width narrows in the direction away from the positive electrode current collector. Between the positive electrode current collector and the positive electrode active material layer, there is a covering layer that covers the outer edge of the positive electrode active material layer. The width of the positive electrode current collector is wider than the width of the positive electrode active material layer. Between the positive electrode current collector and the positive electrode active material layer, there is an electrically insulating coating layer covering the outer edge of the positive electrode active material layer. The positive electrode current collector is an electrode laminate having a first portion facing the central part of the positive electrode active material layer and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer.
[0008] The electrode stack of the present invention has an electrically insulating coating layer covering the outer edge of the positive electrode active material layer between the positive electrode current collector and the positive electrode active material layer. This suppresses the inflow of current into the second area, that is, the positive electrode active material layer directly below the coating layer in the stacking direction of the electrode stack, and prevents current concentration at the boundary between the positive electrode active material layer and the insulating member, thereby suppressing localized lithium deposition on the negative electrode side for all-solid-state batteries.
[0009] [2] The electrode laminate according to [1], wherein the positive electrode current collector has a first portion facing a central portion of the positive electrode active material layer and having a thickness t1 in the lamination direction of the electrode laminate, and a second portion connected to an outer edge of the first portion, facing an outer edge portion of the positive electrode active material layer, and having a thickness t2 in the lamination direction that is the sum of the thickness of the positive electrode current collector and a coating layer covering the outer edge portion of the positive electrode active material layer, wherein t1 and t2 satisfy the relationship of t1<t2.
[0010] The electrode laminate of the present invention has the coating layer covering the outer edge portion of the positive electrode active material layer between the positive electrode current collector and the positive electrode active material layer, so that the thickness t2 of the second portion is larger than the thickness t1 of the first portion of the positive electrode current collector. This suppresses current inflow into the positive electrode active material layer directly below the coating layer in the lamination direction of the electrode laminate, suppresses current concentration at the boundary between the positive electrode active material layer and the insulating member, and suppresses local lithium deposition on the negative electrode side of an all-solid-state battery.
[0011] [3] The electrode laminate according to [1], wherein the second portion extends along the surface of the positive electrode active material layer that is in contact with the positive electrode current collector, to a position inside the boundary between the positive electrode active material layer and the insulating member on the solid electrolyte layer side.
[0012] The electrode laminate of the present invention can suppress current concentration at the boundary between the positive electrode active material layer and the insulating member, and can suppress local lithium deposition on the negative electrode side of an all-solid-state battery.
[0013] [4] A method for producing the electrode laminate according to any one of [1] to [3], the method comprising: forming a coating layer on the positive electrode current collector at a position facing the outer edge portion of the positive electrode active material layer; forming a plurality of insulating members at intervals on the positive electrode current collector, each insulating member having an inclined portion that inclines so as to widen toward the positive electrode current collector; forming a positive electrode active material layer between the adjacent insulating members on the positive electrode current collector to obtain a positive electrode; The process includes a step of laminating a negative electrode via a solid electrolyte layer on the side of the positive electrode active material layer and the insulating member opposite to the positive electrode current collector, The width of the positive electrode current collector is wider than the width of the positive electrode active material layer. Between the positive electrode current collector and the positive electrode active material layer, there is an electrically insulating coating layer covering the outer edge of the positive electrode active material layer. A method for manufacturing an electrode laminate, wherein the positive electrode current collector has a first portion facing the central part of the positive electrode active material layer and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer, the second portion extending along the surface of the positive electrode active material layer in contact with the positive electrode current collector, and inside the boundary between the positive electrode active material layer and the insulating member on the solid electrolyte layer side.
[0014] According to the method for manufacturing an electrode stack of the present invention, the electrode stack of the present invention can be obtained.
[0015] A method for manufacturing an electrode stack according to any one of [5][1] to [3], A process for manufacturing a positive electrode current collector having a first portion facing the central part of the positive electrode active material layer, and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer, The process of forming an electrically insulating coating layer on the positive electrode current collector at a position opposite to the outer edge of the positive electrode active material layer, so as to cover the outer edge of the positive electrode active material layer, A step of forming multiple positive electrode active material layers on a positive electrode current collector at intervals, each layer having an inclined portion that is inclined to narrow in the direction away from the positive electrode current collector, and in which the spacing on the side in contact with the positive electrode current collector and the spacing on the side not in contact with the positive electrode current collector are narrower than the width of the positive electrode current collector. The process includes forming an insulating member between adjacent positive electrode active material layers on the positive electrode current collector to obtain a positive electrode, A method for producing an electrode laminate, wherein in the step of producing the positive electrode current collector, the second portion is formed along the surface of the positive electrode active material layer that is in contact with the positive electrode current collector so as to be located inward of the boundary between the positive electrode active material layer and the insulating member on the solid electrolyte layer side.
[0016] According to the method for producing an electrode laminate of the present invention, the electrode laminate of the present invention can be obtained.
Effects of the Invention
[0017] According to the present invention, in the positive electrode of a battery, it is possible to suppress current concentration at the boundary between the positive electrode active material layer and the insulating member disposed on the outer periphery of the positive electrode active material layer, and to suppress local lithium deposition on the negative electrode side.
Brief Description of the Drawings
[0018] [Figure 1] It is a cross-sectional view showing an example of the electrode laminate according to the embodiment of the present invention. [Figure 2] It is a cross-sectional view showing another example of the electrode laminate according to the embodiment of the present invention.
Modes for Carrying Out the Invention
[0019] Hereinafter, the electrode laminate according to one embodiment of the present invention will be described with reference to the drawings.
[0020] [Electrode Laminate] Figure 1 is a cross-sectional view showing an example of the electrode laminate according to the embodiment of the present invention. The drawings used in the following description may, for the sake of clarity of features, show characteristic portions enlarged for convenience, and the dimensional ratios and the like of the respective constituent elements are not limited to those illustrated.
[0021] As shown in Figure 1, the electrode stack 1 comprises a positive electrode current collector 10, a positive electrode active material layer 20, a solid electrolyte layer 30, a negative electrode current collector 40, and a negative electrode active material layer 50. Here, the positive electrode current collector 10 is wider than the positive electrode active material layer 20. In the electrode stack 1, the positive electrode current collector 10, the positive electrode active material layer 20, the solid electrolyte layer 30, the negative electrode active material layer 50, and the negative electrode current collector 40 are stacked in this order. Between the positive electrode current collector 10 and the positive electrode active material layer 20, the electrode stack 1 has an electrically insulating coating layer 70 that covers the outer edge 20c of the positive electrode active material layer 20.
[0022] A positive electrode active material layer 20 is formed on one of the main surfaces 10a of the positive electrode current collector 10. The positive electrode active material layer 20 has an inclined portion 20a that is inclined such that its width narrows in the direction away from one main surface 10a of the positive electrode current collector 10 (towards the thickness direction of the positive electrode active material layer 20). The angle of the inclined portion 20a with respect to one main surface 10a of the positive electrode current collector 10 is not particularly limited and is adjusted according to the capacity of the positive electrode active material layer 20, the thickness of the solid electrolyte layer 30, the current density of the electrode stack 1, etc.
[0023] An insulating member 60 is arranged on the outer periphery of the positive electrode active material layer 20. The insulating member 60 has an inclined portion 60a that slopes outward toward one main surface 10a of the positive electrode current collector 10 (towards the thickness direction of the positive electrode current collector 10). The angle of the inclined portion 60a with respect to one main surface 10a of the positive electrode current collector 10 is not particularly limited and is adjusted according to the capacitance of the positive electrode active material layer 20, the thickness of the solid electrolyte layer 30, the current density of the electrode laminate 1, etc.
[0024] The positive electrode current collector 10 has a first portion 11 that is a central part of the positive electrode current collector 10, and a second portion 12 that is provided to be connected to the outer edge of the first portion 11. The first portion 11 faces the central portion 20b of the positive electrode active material layer 20. The thickness of the positive electrode current collector 10 in the stacking direction at the first portion 11 is t1. The second portion 12 faces the outer edge portion 20c of the positive electrode active material layer 20. In the second portion 12, an electrically insulating coating layer 70 is present between the positive electrode current collector 10 and the positive electrode active material layer 20. The total thickness in the stacking direction of the positive electrode current collector 10 and the electrically insulating coating layer 70 at the second portion 12 is t2. The t1 and the t2 satisfy the relationship of t1<t2. That is, in the stacking direction of the electrode laminate 1, the thickness t2 of the second portion 12 is larger than the thickness t1 of the first portion 11.
[0025] In the second portion 12, the electrically insulating coating layer 70 is disposed between the positive electrode current collector 10 and the positive electrode active material layer 20, so that electrons supplied from the positive electrode current collector 10 are limited to the range of the central portion 20b of the positive electrode active material layer 20, and ionic conduction is also limited to the vicinity of the central portion 20b of the positive electrode active material layer 20. As a result, the current distribution when reaching the solid electrolyte layer 30 is made uniform, and local current concentration at the boundary between the positive electrode active material layer 20 and the insulating member 60 is suppressed. Furthermore, in the positive electrode current collector 10, by making the thickness t2 of the second portion 12 larger than the thickness t1 of the first portion 11, current inflow to the positive electrode active material layer 20 directly below the electrically insulating coating layer 70 in the stacking direction of the electrode laminate 1 is suppressed. As a result, the current distribution when reaching the solid electrolyte layer 30 is made uniform, and local current concentration at the boundary A between the positive electrode active material layer 20 and the insulating member 60 is suppressed.
[0026] It is preferable that the second portion 12 extends along the surface 20d of the positive electrode active material layer 20 that is in contact with the positive electrode current collector 10, to a position inside the boundary A between the positive electrode active material layer 20 and the insulating member 60 on the solid electrolyte layer 30 side.
[0027] From the viewpoint of suppressing current concentration, it is preferable that the coating layer 70 extends along the surface 20d of the positive electrode active material layer 20 that is in contact with the positive electrode current collector 10, and further inward from the boundary A between the positive electrode active material layer 20 and the insulating member 60 on the solid electrolyte layer 30 side.
[0028] (positive electrode) The positive electrode current collector 10 is preferably composed of at least one material with high conductivity. Examples of highly conductive materials include metals or alloys containing at least one metallic element from silver (Ag), palladium (Pd), gold (Au), platinum (Pt), aluminum (Al), copper (Cu), chromium (Cr), and nickel (Ni), or nonmetals such as carbon (C). Considering both high conductivity and manufacturing cost, aluminum, nickel, or stainless steel are preferred. Furthermore, aluminum is less reactive with the positive electrode active material, negative electrode active material, and solid electrolyte. Therefore, using aluminum for the positive electrode current collector 10 can reduce the internal resistance of the electrode laminate 1.
[0029] Examples of the shape of the positive electrode current collector 10 include foil, plate, mesh, nonwoven fabric, and foam forms. In addition, carbon or the like may be placed on the surface of the positive electrode current collector 10 to improve adhesion with the positive electrode active material layer 20, or the surface may be roughened.
[0030] The positive electrode active material layer 20 includes at least a positive electrode active material that exchanges lithium ions and electrons. The positive electrode active material is not particularly limited as long as it is a material that can reversibly release and absorb lithium ions and perform electron transport, and known positive electrode active materials applicable to the positive electrode of an all-solid-state lithium-ion battery can be used. For example, lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium manganese oxide (LiMn2O4), solid solution oxide (Li2MnO3-LiMO2 (M=Co, Ni, etc.)), lithium-manganese-nickel-cobalt oxide (LiNi x Mn y Co zExamples include composite oxides such as O2 (x+y+z=1), olivine-type lithium phosphate oxide (LiFePO4); conductive polymers such as polyaniline and polypyrrole; sulfides such as Li2S, CuS, Li-Cu-S compounds, TiS2, FeS, MoS2, and Li-Mo-S compounds; and mixtures of sulfur and carbon. The positive electrode active material may consist of one of the above materials alone or of two or more materials.
[0031] The positive electrode active material layer 20 contains an electrolyte that exchanges lithium ions with the positive electrode active material. The electrolyte is not particularly limited as long as it has lithium ion conductivity; generally, materials used in lithium-ion batteries can be used. Examples of electrolytes include inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, and lithium-containing salts; polymer-based solid electrolytes such as polyethylene oxide; and gel-based solid electrolytes containing lithium-containing salts or lithium-ion-conductive ionic liquids. The electrolyte may be composed of one of the above materials alone, or of two or more materials. The electrolyte contained in the positive electrode active material layer 20 may be the same as or different from the electrolyte contained in the negative electrode active material layer 50 or the solid electrolyte layer 30.
[0032] The positive electrode active material layer 20 may contain a conductive additive to improve conductivity. Generally, conductive additives usable in all-solid-state lithium-ion batteries can be used as conductive additives. Examples include carbon black such as acetylene black and kecheng black; carbon fiber; vapor-phase carbon fiber; graphite powder; and carbon nanotubes. The conductive additive may consist of one of the above materials alone or two or more materials.
[0033] Furthermore, the positive electrode active material layer 20 may also include a binder that serves to bond the positive electrode active materials together and to the positive electrode current collector 10.
[0034] If the positive electrode active material layer 20 has a three-dimensional porous structure such as a mesh, nonwoven fabric, or foam, the positive electrode active material layer 20 may be provided integrally with the positive electrode current collector 10.
[0035] (solid electrolyte layer) The solid electrolyte layer 30 is positioned between the positive electrode active material layer 20 and the negative electrode active material layer 50.
[0036] The above-mentioned solid electrolyte is not particularly limited as long as it has lithium-ion conductivity and insulating properties, and materials generally used in all-solid-state lithium-ion batteries can be used. For example, inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, and lithium-containing salts, as well as polymer-based solid electrolytes such as polyethylene oxide, and gel-based solid electrolytes containing lithium-containing salts or lithium-ion conductive ionic liquids can be used. Of these, sulfide solid electrolyte materials are preferred from the viewpoint of high lithium-ion conductivity and good structural moldability and interfacial bonding properties when pressed. There are no particular restrictions on the form of the solid electrolyte material, but for example, it can be in the form of particulate matter.
[0037] The solid electrolyte layer 30 may contain an adhesive to provide mechanical strength and flexibility.
[0038] The solid electrolyte layer 30 may be in the form of a sheet having a support and a solid electrolyte held by the support. There are no particular restrictions on the form of the support, but examples include woven fabric, nonwoven fabric, mesh cloth, porous membrane, expanded sheet, punched sheet, etc. Of these forms, nonwoven fabric is preferred from the viewpoint of handling, which allows for a higher amount of solid electrolyte filling.
[0039] The above-mentioned support is preferably made of an insulating material. This improves the insulating properties of the solid electrolyte layer 30. Examples of insulating materials include resin materials such as nylon, polyester, polyethylene, polypropylene, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polyvinylidene fluoride, polyvinylidene chloride, polyvinyl chloride, polyurethane, vinylon, polybenzimidazole, polyimide, polyphenylene sulfite, polyetheretherketone, cellulose, and acrylic resins; natural fibers such as hemp, wood pulp, and cotton linters; and glass.
[0040] (Negative electrode) The negative electrode utilizes the deposition-dissolution reaction of metallic lithium and has a negative electrode active material layer 50 containing at least the negative electrode active material.
[0041] The negative electrode current collector 40 is preferably composed of at least one material with high conductivity. Examples of highly conductive materials include metals or alloys containing at least one metallic element from copper (Cu), silver (Ag), palladium (Pd), gold (Au), platinum (Pt), chromium (Cr), and nickel (Ni), or nonmetals such as carbon (C). Considering both high conductivity and manufacturing cost, nickel or stainless steel are preferred materials other than copper. Furthermore, stainless steel does not react easily with the positive electrode active material, negative electrode active material, and electrolyte. Therefore, using stainless steel in the second current collector layer can reduce the manufacturing cost of the battery.
[0042] Examples of the negative electrode current collector 40's shape include foil, plate, mesh, nonwoven fabric, and foam. Furthermore, to improve adhesion with the second active material layer, carbon or the like may be placed on the surface of the second current collector layer, or the surface may be roughened.
[0043] The negative electrode active material layer 50 contains a negative electrode active material that exchanges electrons with lithium ions. The negative electrode active material is not particularly limited as long as it is a material that can reversibly release and absorb lithium ions and transport electrons, and known negative electrode active materials applicable to the negative electrode of a lithium-ion battery can be used. For example, carbonaceous materials such as natural graphite, artificial graphite, resin carbon, carbon fiber, activated carbon, hard carbon, and soft carbon; alloy materials mainly composed of tin, tin alloys, silicon, silicon alloys, gallium, gallium alloys, indium, indium alloys, aluminum, and aluminum alloys; conductive polymers such as polyacene, polyacetylene, and polypyrrole; metallic lithium; lithium titanium composite oxide (e.g., Li4Ti5O 12 Examples of lithium alloys include Sn-Li alloy, Ag-Li alloy, Mg-Li alloy, In-Li alloy, Si-Li alloy, and Al-Li alloy. These negative electrode active materials may consist of one of the above materials alone or of two or more materials.
[0044] The negative electrode active material layer 50 may contain an electrolyte that exchanges lithium ions with the negative electrode active material. The electrolyte is not particularly limited as long as it has lithium ion conductivity; generally, materials used in lithium-ion batteries can be used. Examples of electrolytes include inorganic solid electrolytes such as sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, and lithium-containing salts; polymer-based solid electrolytes such as polyethylene oxide; and gel-based solid electrolytes containing lithium-containing salts or lithium-ion-conductive ionic liquids. The electrolyte may be composed of one of the above materials alone, or of two or more materials. The electrolyte contained in the negative electrode active material layer 50 may be the same as or different from the electrolyte contained in the positive electrode active material layer 20 or the solid electrolyte layer 30.
[0045] The negative electrode active material layer 50 may contain conductive additives and binders. There are no particular restrictions on these materials, but for example, materials similar to those used in the positive electrode active material layer 20 described above can be used.
[0046] If the negative electrode current collector 40 has a three-dimensional porous structure such as a mesh, nonwoven fabric, or foam, the negative electrode current collector 40 may be provided integrally with the negative electrode active material layer 50.
[0047] (Insulating material) The insulating material forming the insulating member 60 is not particularly limited, but examples include insulating oxides such as alumina, resins such as polyvinylidene fluoride (PVDF), and rubbers such as styrene-butadiene rubber (SBR).
[0048] (covering layer) The material forming the coating layer 70 is not particularly limited, but is preferably an insulating material. The insulating material forming the coating layer 70 may consist of either organic or inorganic materials, and may include, for example, rubber, glass; resins such as polyimide, polybenzimidazole, polyamideimide, polyetherimide, polyacetal, polyphenylene sulfide, polyetheretherketone, tetrafluoroethylene, polyamide 6 (also known as nylon 6), ultra-high molecular weight polyethylene, polyethylene, polypropylene, vinyl chloride resin, polystyrene, polyethylene terephthalate, or ABS resin; or ceramics such as alumina, zirconia, silicon nitride, aluminum nitride, mullite, steatite, magnesia, sialon, or macelite. One or more materials selected from these may be used. The coating layer 70 may further contain binders or other additives.
[0049] In the electrode laminate 1 of the present embodiment, the insulating member 60 is disposed on the outer periphery of the positive electrode active material layer 20, and the positive electrode active material layer 20 has an inclined portion 20a that is inclined such that the width thereof narrows in the direction away from the positive electrode current collector 10. The electrode laminate 1 of the present embodiment has a coating layer 70 covering the outer edge portion 20c of the positive electrode active material layer 20 between the positive electrode current collector 10 and the positive electrode active material layer 20. The positive electrode current collector 10 includes a first portion 11 facing the central portion 20b of the positive electrode active material layer 20 and having a thickness t1 in the lamination direction of the positive electrode current collector 10, and a second portion 12 connected to the outer edge of the first portion 11, facing the outer edge portion 20c of the positive electrode active material layer 20, and having a thickness t2 in the lamination direction of the positive electrode current collector 10 and the electrically insulating coating layer 70 combined, where t1 and t2 satisfy the relationship of t1<t2. Therefore, the electrode laminate 1 of the present embodiment can suppress current inflow to the positive electrode active material layer 20 directly below the coating layer 70 in the lamination direction of the electrode laminate 1, and can suppress current concentration at the boundary A between the positive electrode active material layer 20 and the insulating member 60. As a result, local lithium deposition on the negative electrode side can be suppressed.
[0050] [Method for Manufacturing Electrode Laminate] (First Embodiment) The method for manufacturing an electrode laminate of the present embodiment includes a step of forming a coating layer on a positive electrode current collector at a position facing the outer edge portion of a positive electrode active material layer (hereinafter referred to as "first step"), a step of forming a plurality of positive electrode active material layers each having an inclined portion inclined so as to expand toward the positive electrode current collector, at intervals, on the positive electrode current collector (hereinafter referred to as "second step"), a step of forming an insulating member between the adjacent positive electrode active material layers on the positive electrode current collector to obtain a positive electrode (hereinafter referred to as "third step"), and a step of laminating a negative electrode on the surface of the positive electrode active material layer and the insulating member on the side opposite to the positive electrode current collector via a solid electrolyte layer (hereinafter referred to as "fourth step").
[0051] Hereinafter, the method for manufacturing the electrode laminate of the present embodiment will be described with reference to Figure 1.
[0052] (First Step) In the first step, a coating material is applied to one main surface 10a of the positive electrode current collector 10 using a coating apparatus or the like, and the coating material is cured to form a coating layer 70 at a position facing the outer edge portion 20c of the positive electrode active material layer 20 on the one main surface 10a of the positive electrode current collector 10. As the positive electrode current collector 10, there is used one that has a first portion 11 facing the central portion 20b of the positive electrode active material layer 20 and having a thickness t1 in the stacking direction of the positive electrode current collector 10, and a second portion 12 provided continuously to the outer edge of the first portion 11, facing the outer edge portion 20c of the positive electrode active material layer 20, and having a total thickness t2 in the stacking direction of the positive electrode current collector 10 and the electrically insulating coating layer 70, wherein the second portion 12 extends along the surface of the positive electrode active material layer 20 in contact with the positive electrode current collector 10 to the inner side of the boundary A between the positive electrode active material layer 20 and the insulating member 60 on the solid electrolyte layer 30 side, and t1 and t2 satisfy the relationship of t1<t2.
[0053] (Second step) In the second step, on one main surface 10a of the positive electrode current collector 10 using a coating apparatus or the like, a positive electrode mixture containing a positive electrode active material is applied at intervals such that a plurality of positive electrode active material layers 20 each having an inclined portion 20a that inclines so as to narrow in the direction away from the one main surface 10a of the positive electrode current collector 10 are formed. At this time, the inclined portion 20a is formed so as to enter the region 20c in contact with the coating layer 70 formed in the first step.
[0054] (Third step) In the third step, an insulating material is applied on one main surface 10a of the positive electrode current collector 10, between the adjacent positive electrode active material layers formed in the second step, using a coating apparatus or the like, and the insulating material is cured to form a plurality of insulating members 60 at intervals, each insulating member 60 having an inclined portion 60a that inclines so as to narrow in the direction away from the one main surface 10a of the positive electrode current collector 10.
[0055] (Fourth step) In the fourth step, a solid electrolyte is applied to the positive electrode active material layer 20 and the side of the insulating member 60 opposite to the positive electrode current collector 10 using a coating apparatus or the like to form a solid electrolyte layer 30. A negative electrode having a negative electrode current collector 40 and a negative electrode active material layer 50 is then laminated on the side of the positive electrode active material layer 20 and the insulating member 60 opposite to the positive electrode current collector 10 via the solid electrolyte layer 30.
[0056] (Step 5) In the third step, after forming the positive electrode active material layer 20, it is preferable to pressurize the positive electrode current collector 10, the positive electrode active material layer 20, and the insulating member 60 using a pressure roller or the like. In the fifth step, a positive electrode active material layer 20 having an inclined portion 20a that slopes to narrow in the direction away from one main surface 10a of the positive electrode current collector 10 can be easily formed between adjacent insulating members 60.
[0057] (Step 6) In the sixth step, it is preferable to cut the insulating member 60 and the positive electrode current collector 10 after the fifth step. The sixth step yields an electrode laminate 1 of a predetermined size.
[0058] According to the method for manufacturing the electrode stack of this embodiment, the electrode stack 1 of the above-described embodiment can be obtained.
[0059] (Other examples) Figure 2 is a cross-sectional view showing another example of an electrode stack according to an embodiment of the present invention. In the electrode stack shown in Figure 2, the same reference numerals are used for parts that are identical to those in the electrode stack shown in Figure 1, and their descriptions are omitted. Only the differences are described.
[0060] The electrode stack 100 of this embodiment has a structure in which two electrode stacks 1 are stacked via a common positive electrode current collector 10.
[0061] The electrode stack 100 of this embodiment provides the same effects as the electrode stack 1 of the above-described embodiment. [Explanation of Symbols]
[0062] 1,100 electrode stack 10 Positive electrode current collector 20 Cathode active material layer 30 Solid electrolyte layer 40 Negative electrode current collector 50 Negative electrode active material layer 60 Insulating material 70 Covering layer
Claims
1. An electrode laminate that utilizes the deposition-dissolution reaction of metallic lithium as the reaction at the negative electrode, It comprises a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode current collector, and a negative electrode active material layer. An insulating member is arranged on the outer periphery of the positive electrode active material layer. The positive electrode active material layer has an inclined portion that is inclined such that its width narrows in the direction away from the positive electrode current collector. The width of the positive electrode current collector is wider than the width of the positive electrode active material layer. Between the positive electrode current collector and the positive electrode active material layer, there is an electrically insulating coating layer covering the outer edge of the positive electrode active material layer. The positive electrode current collector is an electrode laminate having a first portion facing the central part of the positive electrode active material layer and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer.
2. The electrode laminate according to claim 1, wherein the positive electrode current collector has a first portion facing the central part of the positive electrode active material layer and having a thickness t1 in the stacking direction of the electrode laminate, and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer, and having a thickness t2 in the stacking direction when the positive electrode current collector and the covering layer covering the outer edge of the positive electrode active material layer are combined, and t1 and t2 satisfy the relationship t1 < t2.
3. The electrode laminate according to claim 1, wherein the second portion extends along the surface of the positive electrode active material layer in contact with the positive electrode current collector, and inward from the boundary between the positive electrode active material layer and the insulating member on the solid electrolyte layer side.
4. A method for manufacturing an electrode stack according to any one of claims 1 to 3, A step of forming a coating layer on the positive electrode current collector at a position opposite to the outer edge of the positive electrode active material layer, A step of forming multiple insulating members on a positive electrode current collector, each having an inclined portion that slopes toward the positive electrode current collector, at intervals from each other, The process of forming a positive electrode active material layer between adjacent insulating members on the positive electrode current collector to obtain a positive electrode, The process includes a step of laminating a negative electrode via a solid electrolyte layer on the side of the positive electrode active material layer and the insulating member opposite to the positive electrode current collector, The width of the positive electrode current collector is wider than the width of the positive electrode active material layer. Between the positive electrode current collector and the positive electrode active material layer, there is an electrically insulating coating layer covering the outer edge of the positive electrode active material layer. A method for manufacturing an electrode laminate, wherein the positive electrode current collector has a first portion facing the central part of the positive electrode active material layer and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer, the second portion extending along the surface of the positive electrode active material layer in contact with the positive electrode current collector, and inside the boundary between the positive electrode active material layer and the insulating member on the solid electrolyte layer side.
5. A method for manufacturing an electrode stack according to any one of claims 1 to 3, A process for manufacturing a positive electrode current collector having a first portion facing the central part of the positive electrode active material layer, and a second portion provided in connection with the outer edge of the first portion and facing the outer edge of the positive electrode active material layer, The process of forming an electrically insulating coating layer on the positive electrode current collector at a position opposite to the outer edge of the positive electrode active material layer, so as to cover the outer edge of the positive electrode active material layer, A step of forming multiple positive electrode active material layers on a positive electrode current collector at intervals, each layer having an inclined portion that is inclined to narrow in the direction away from the positive electrode current collector, and in which the spacing on the side in contact with the positive electrode current collector and the spacing on the side not in contact with the positive electrode current collector are narrower than the width of the positive electrode current collector. The process includes forming an insulating member between adjacent positive electrode active material layers on the positive electrode current collector to obtain a positive electrode, A method for manufacturing an electrode laminate, wherein in the step of manufacturing the positive electrode current collector, the second portion is formed along the surface of the positive electrode active material layer that is in contact with the positive electrode current collector, and is located inside the boundary between the positive electrode active material layer and the insulating member on the solid electrolyte layer side.
Citation Information
Patent Citations
All-solid-state secondary battery
JP2022086332A