All-solid-state battery and method for manufacturing an all-solid-state battery

Abstract

To provide an all-solid-state battery and a method for manufacturing the same that can more effectively suppress localized deposition of lithium. [Solution] In the all-solid-state battery 1, in the ZY cross-section, the Y-direction dimension of the positive electrode active material layer 15 increases toward the positive electrode current collector 11. The solid electrolyte layer 30 covers the Y-direction outer end of the positive electrode active material layer 15. The surface 16 of the positive electrode active material layer 15 that contacts the solid electrolyte layer 30 has a first inclined portion 18 that slopes outward in the Y-direction toward the positive electrode current collector 11. The surface 31 of the solid electrolyte layer 30 opposite to the surface that contacts the positive electrode active material layer 15 has a second inclined portion 32 that slopes outward in the Y-direction toward the positive electrode current collector 11. The end of the second inclined portion 32 toward the negative electrode layer 20 is located further outward in the Y-direction than the end of the first inclined portion 18 toward the negative electrode layer 20.

Description

Technical Field

[0001] The present invention relates to an all-solid-state battery and a method for manufacturing the all-solid-state battery.

Background Art

[0002] In recent years, research and development on secondary batteries that contribute to energy efficiency have been carried out to ensure that more people can gain access to affordable, reliable, sustainable and advanced energy.

[0003] Among secondary batteries, all-solid-state batteries using a solid electrolyte as the electrolyte are particularly attracting attention because they are excellent in high safety due to the nonflammable nature of the solid electrolyte and high energy density. As all-solid-state batteries, all-solid-state batteries having a stacked structure in which a plurality of electrodes (positive electrode layers and negative electrode layers) are alternately stacked with solid electrolyte layers interposed therebetween have been studied (for example, Patent Document 1).

[0004] The all-solid-state battery of Patent Document 1 includes a positive electrode for all-solid-state batteries in which a positive electrode active material layer is formed on a positive electrode current collector, a negative electrode for all-solid-state batteries in which a negative electrode active material layer is formed on a negative electrode current collector, a solid electrolyte layer disposed between the positive electrode for all-solid-state batteries and the negative electrode for all-solid-state batteries, and an insulating member provided on the outer periphery of the positive electrode active material layer. The positive electrode active material layer has an inclined portion that is inclined so as to expand in the direction away from the positive electrode current collector. The negative electrode active material layer contains metallic lithium or a lithium alloy.

[0005] According to the all-solid-state battery of Patent Document 1, it is possible to suppress current concentration at the boundary between the positive electrode active material layer and the insulating member in the positive electrode of the all-solid-state battery, and suppress local precipitation of lithium on the negative electrode side containing metallic lithium or a lithium alloy.

[0006] When manufacturing the all-solid-state battery of Patent Document 1, the insulating member is disposed on the current collector foil that serves as the positive electrode current collector, and then the positive electrode active material layer is disposed so as to overlap with the insulating member.

Prior Art Documents

Patent Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2024-145930 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, if the insulating material is placed before the positive electrode active material layer, it becomes difficult to position the positive electrode active material layer. Therefore, there is room for improvement in the positional accuracy of the positive electrode active material layer in the manufacturing method of the all-solid-state battery described above. In addition, if the positive electrode active material layer is not positioned correctly, current concentration may occur, potentially leading to localized deposition of lithium.

[0009] This invention aims to provide an all-solid-state battery and a method for manufacturing the same that can more effectively suppress the localized deposition of lithium, thereby contributing to improved energy efficiency. [Means for solving the problem]

[0010] (1) The present invention relates to an all-solid-state battery comprising: a positive electrode layer including a positive electrode current collector and a positive electrode active material layer; a negative electrode layer including at least a negative electrode current collector; and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, wherein the direction in which the positive electrode layer and the negative electrode layer are stacked via the solid electrolyte layer is defined as the stacking direction, one of the directions perpendicular to the stacking direction is defined as the first direction, the direction perpendicular to the stacking direction and the first direction is defined as the second direction, and the direction of the second direction that moves away from the center of the second direction of the all-solid-state battery is defined as the outward direction of the second direction, the positive electrode current collector has a tab portion extending in the first direction, and the stacking direction and the second direction The present invention relates to an all-solid-state battery wherein, in orthogonal cross-sections, the second dimension of the positive electrode active material layer increases toward the positive electrode current collector, the solid electrolyte layer covers the outer end of the positive electrode active material layer toward the second direction, the surface of the positive electrode active material layer in contact with the solid electrolyte layer has a first inclined portion that slopes outward toward the second direction toward the positive electrode current collector, the surface of the solid electrolyte layer opposite to the surface in contact with the positive electrode active material layer has a second inclined portion that slopes outward toward the second direction toward the positive electrode current collector, and the end of the second inclined portion toward the negative electrode layer is located further outward toward the second direction than the end of the first inclined portion toward the negative electrode layer.

[0011] According to the all-solid-state battery described in (1), the solid electrolyte layer and the negative electrode layer can be positioned outside the region that overlaps with the positive electrode active material layer in the stacking direction. Lithium ions released from the first inclined portion move linearly and reach the portion of the negative electrode layer that is not aligned with the positive electrode active material layer in the stacking direction, via the solid electrolyte layer. This makes it possible to suppress the local deposition of lithium at the edge of the region of the negative electrode layer that overlaps with the positive electrode active material layer in the stacking direction.

[0012] Furthermore, with this configuration, the positive electrode active material layer can be placed on the positive electrode current collector before the solid electrolyte layer during the manufacturing of the all-solid-state battery. This makes it easier to ensure the positional accuracy of the positive electrode active material layer, thereby suppressing localized deposition of lithium caused by misalignment of the positive electrode active material layer.

[0013] Therefore, it is possible to provide an all-solid-state battery that can more effectively suppress localized deposition of lithium.

[0014] (2) In the all-solid-state battery described in (1) above, an insulating member is provided which is arranged around the positive electrode active material layer, and in a cross section perpendicular to the stacking direction and the second direction, the insulating member may cover the second inclined portion.

[0015] In the all-solid-state battery described in (2), the insulating material blocks the lithium ion migration path, thereby blocking the path of lithium ions released from the first inclined portion toward the vicinity of the second outer end of the negative electrode layer. This makes it possible to suppress the concentration and deposition of lithium near the end of the negative electrode layer.

[0016] (3) In the all-solid-state battery described in (1) or (2) above, the negative electrode layer side end of the second inclined portion may be located further outward in the second direction than the positive electrode current collector side end of the first inclined portion.

[0017] According to the all-solid-state battery described in (3), it is possible to suppress lithium ions released from the first inclined portion from hitting the edge (or insulating material) of the solid electrolyte layer when they move along the stacking direction. This makes the flow of lithium ions between the positive electrode active material layer and the negative electrode layer smoother.

[0018] (4) In the all-solid-state battery described in (2) or (3) above, in a cross section perpendicular to the stacking direction and the second direction, when the region between adjacent positive electrode current collectors and the negative electrode layer is divided into two equal parts in the stacking direction, one of the regions may have the following characteristics: a region in which the insulating member and the solid electrolyte layer overlap in the stacking direction; a region in which the solid electrolyte layer is arranged without overlapping with either the positive electrode active material layer or the insulating member in the stacking direction; and a region in which the positive electrode active material layer and the solid electrolyte layer overlap in the stacking direction.

[0019] In the all-solid-state battery described in (4), a region is provided in which the positive electrode active material layer and the solid electrolyte layer overlap in the stacking direction, making it easier to deposit lithium in the negative electrode layer. Furthermore, a region is provided in which the positive electrode active material layer and the insulating material are arranged without overlapping in the stacking direction, allowing lithium to be deposited to some extent outside the second direction end of the portion of the negative electrode layer that overlaps with the positive electrode active material layer in the stacking direction. This makes it possible to suppress localized lithium deposition at the second direction end of the portion of the negative electrode layer that overlaps with the positive electrode active material layer in the stacking direction. Moreover, a region is provided in which the insulating material and the solid electrolyte layer overlap in the stacking direction, which makes it possible to suppress localized lithium deposition at the second direction end of the negative electrode layer.

[0020] Furthermore, by positioning the solid electrolyte layer to cover the edges of the positive electrode active material layer, it is possible to suppress the formation of gaps between the edges of the positive electrode active material layer and the solid electrolyte layer during the manufacturing of all-solid-state batteries.

[0021] Furthermore, even if a gap is formed at the negative electrode layer side of the boundary between the solid electrolyte layer and the insulating material when the insulating material is coated, this gap is formed in a position that does not overlap with the positive electrode active material layer in the stacking direction. This makes it possible to suppress the occurrence of cracks caused by uneven reaction during charging.

[0022] (5) In any one of the all-solid-state batteries described in (1) to (4) above, the ratio of the length in the second direction between the end of the second inclined portion on the negative electrode layer side and the end of the first inclined portion on the positive electrode active material layer side to the dimension of the first inclined portion in the second direction, in a cross section perpendicular to the stacking direction and the second direction, may be 0.01 or more and 5000 or less.

[0023] According to such a configuration, by setting the size of the solid electrolyte layer to a certain value or more, it is possible to favorably secure a path for lithium ions to reach the negative electrode layer from the first inclined portion via the solid electrolyte layer. Further, by setting the size of the solid electrolyte layer to a certain value or less, it is possible to suppress the generation of a solid electrolyte layer that does not contribute to the conduction of lithium ions.

[0024] (6) In the all-solid-state battery according to any one of the above (2) to (5), in a cross section orthogonal to the stacking direction and the second direction, a ratio of a length in the second direction between the end of the second inclined portion on the negative electrode layer side and the end of the first inclined portion on the positive electrode active material layer side to the dimension of the second inclined portion in the second direction may be 0.01 or more and 5000 or less.

[0025] According to the all-solid-state battery described in (6), the occurrence of short circuits can be favorably suppressed by arranging the insulating member to have a size of a certain value or more. Further, by setting the size of the insulating member to a certain value or less, it is possible to favorably secure a path for lithium ions to reach the negative electrode layer from the first inclined portion via the solid electrolyte layer.

[0026] (7) In the all-solid-state battery according to any one of the above (1) to (6), in a cross section orthogonal to the stacking direction and the second direction, the negative electrode layer may be provided at a portion of the negative electrode layer that overlaps the second inclined portion in the stacking direction, and may have a negative electrode inclined portion that inclines toward the positive electrode current collector side as it goes outward in the second direction.

[0027] According to the all-solid-state battery described in (7), the insulating member and a part of the solid electrolyte layer located closer to the negative electrode layer than the end of the positive electrode active material layer on the negative electrode layer side can be arranged side by side in the second direction. Therefore, by pressing the laminate of the positive electrode layer with the insulating member and the solid electrolyte layer, it is possible to increase the density of the part of the solid electrolyte layer that is located closer to the negative electrode layer than the end of the positive electrode active material layer on the negative electrode layer side.

[0028] (8) The method for manufacturing an all-solid-state battery of the present invention is the method for manufacturing an all-solid-state battery described in (1) to (7) above, comprising the steps of forming the positive electrode active material layer on the positive electrode current collector and forming the solid electrolyte layer so as to extend from the positive electrode active material layer to the positive electrode current collector.

[0029] According to the method for manufacturing an all-solid-state battery described in (8), a first inclined portion can be formed in the positive electrode active material layer, and the first inclined portion can be covered with a solid electrolyte layer. Furthermore, when forming the positive electrode active material layer on the positive electrode current collector, it is possible to suppress the constraint on the formation work of the positive electrode current collector by other components. This makes it possible to improve the positional accuracy of the positive electrode current collector. In addition, it is possible to improve the workability when forming the positive electrode active material layer.

[0030] (9) The method for manufacturing an all-solid-state battery of the present invention is the method for manufacturing an all-solid-state battery according to (2) to (8) above, comprising the steps of: forming the positive electrode active material layer on the positive electrode current collector; forming the solid electrolyte layer so as to extend from the positive electrode active material layer to the positive electrode current collector; and forming the insulating member so as to extend from the positive electrode current collector to the solid electrolyte layer.

[0031] According to the method for manufacturing an all-solid-state battery described in (9), a second inclined portion can be formed in the solid electrolyte layer, and the second inclined portion can be covered with an insulating member. Furthermore, since the positive electrode active material layer is formed before the insulating member, the positive electrode active material layer can be formed on the positive electrode current collector without being obstructed by the insulating member. This improves the positional accuracy of the positive electrode current collector. It also improves the workability when forming the positive electrode active material layer. [Effects of the Invention]

[0032] According to the present invention, it is possible to provide an all-solid-state battery and a method for manufacturing the same that can more effectively suppress the localized deposition of lithium. [Brief explanation of the drawing]

[0033] [Figure 1] This is a plan view of the all-solid-state battery according to the embodiment, viewed in the stacking direction. [Figure 2] This is a side view of the all-solid-state battery according to the embodiment, viewed from a second direction. [Figure 3] This is a cross-sectional view of an all-solid-state battery along the line III-III in Figure 1. [Figure 4] This figure corresponds to Figure 3 and shows an all-solid-state battery according to a modified example. [Modes for carrying out the invention]

[0034] The following describes an embodiment of the all-solid-state battery 1 of the present invention. The type of all-solid-state battery 1 is not particularly limited, but for example, it is an all-solid-state lithium battery that uses lithium ions as a charge transfer medium. As shown in Figures 1 to 3, the all-solid-state battery 1 has a structure in which a positive electrode layer 10 and a negative electrode layer 20 are stacked via a solid electrolyte layer 30.

[0035] In this specification, the direction in which the positive electrode layer 10 and the negative electrode layer 20 are stacked via the solid electrolyte layer 30 is defined as the "Z direction". The Z direction corresponds to the stacking direction. The direction perpendicular to the Z direction from which the extension portion described later extends is defined as the "X direction". The X direction corresponds to the first direction. The direction perpendicular to the Z direction and the X direction is defined as the "Y direction". The Y direction corresponds to the second direction. One side of the Z direction is defined as the "Z+ direction", and the opposite side of the Z+ direction is defined as the "Z- direction". One side of the X direction is defined as the "X+ direction", and the opposite side of the X+ direction is defined as the "X- direction". One side of the Y direction is defined as the "Y+ direction", and the opposite side of the Y+ direction is defined as the "Y- direction". The direction in the Y direction that moves away from the center of the all-solid-state battery 1 in the Y direction is defined as the "Y direction outside". The Y direction outside corresponds to the second direction outside. Note that the Y direction outside is indicated as "Yo" in the drawings.

[0036] "Negative electrode side" means the direction towards the nearest negative electrode layer 20 when viewed from the point being described. "Positive electrode current collector side" means the direction towards the nearest positive electrode current collector 11 when viewed from the point being described.

[0037] Furthermore, the drawings may be schematically simplified to illustrate the content of the invention, and the ratios of the dimensions of the depicted components or between components may not match the ratios of those dimensions described in the specification. In addition, components described in the specification may be omitted in the drawings, or their number may be omitted. Moreover, the terms used in this invention to specify shapes, geometric conditions, and their degree, such as "straight line," "parallel," "orthogonal," "identical," and "flush," as well as values ​​of length and angle, should not be interpreted strictly, but rather to include a range that allows for the expectation of similar functionality.

[0038] (All-solid-state battery) The all-solid-state battery 1 comprises, for example, a positive electrode layer 10 including a positive electrode current collector 11 and a positive electrode active material layer 15, a negative electrode layer 20 including at least a negative electrode current collector 21, and a solid electrolyte layer 30 disposed between the positive electrode layer 10 and the negative electrode layer 20. More specifically, it comprises one positive electrode layer 10, two negative electrode layers 20, two solid electrolyte layers 30, and one positive electrode layer 10. However, the number of layers of the positive electrode layer 10, negative electrode layer 20, and solid electrolyte layer 30 is not particularly limited.

[0039] (Positive electrode layer) One positive electrode layer 10 includes, for example, one positive electrode current collector 11 and two positive electrode active material layers 15 provided sandwiching the positive electrode current collector 11 in the Z direction.

[0040] The positive electrode current collector 11 is provided adjacent to the positive electrode active material layer 15. The positive electrode current collector 11 is formed of a current collector. Examples of current collectors include aluminum, copper, nickel, vanadium, iron, titanium, stainless steel, gold, platinum, and carbon. The positive electrode current collector 11 is formed of aluminum, for example. Examples of the shape of the positive electrode current collector 11 include foil, plate, mesh, nonwoven fabric, and foam. The positive electrode current collector 11 has a positive electrode portion 12 and a positive electrode tab portion 13.

[0041] The positive electrode portion 12 overlaps with the adjacent positive electrode active material layer 15 in the Z direction. The shape of the positive electrode portion 12 in the Z direction is, for example, rectangular with its longer side extending along the X direction.

[0042] The positive electrode tab portion 13 extends from the positive electrode portion 12 in the X direction, and more specifically, in the X+ direction. The Y-direction dimension of the positive electrode tab portion 13 is smaller than the Y-direction dimension of the positive electrode portion 12. The shape of the positive electrode tab portion 13 when viewed in the Z direction is, for example, a roughly rectangular shape with its longer side extending along the X direction.

[0043] The positive electrode active material layer 15 contains a positive electrode active material. Examples of positive electrode active materials include transition metal chalcogenides such as titanium disulfide, molybdenum disulfide, and niobium selenide, and transition metal oxides such as lithium nickelate (LiNiO2), lithium manganeseate (LiMnO2, LiMn2O4), and lithium cobaltate (LiCoO2). The positive electrode active material layer 15 may further contain a solid electrolyte, a conductive additive, a binder, etc. The positive electrode active material may be a ternary lithium nickel cobalt manganese composite oxide (NCM) system material or a lithium nickel cobalt aluminum oxide (NCA) system material, which are commonly used in lithium-ion batteries.

[0044] The shape of the positive electrode active material layer 15 when viewed in the Z direction is, for example, rectangular with its longer side extending along the X direction.

[0045] (solid electrolyte layer) The solid electrolyte layer 30 is, for example, a single layer. The solid electrolyte layer 30 may be provided in two or more layers stacked on top of each other. The solid electrolyte layer 30 contains a solid electrolyte material. Examples of the solid electrolyte material include sulfide solid electrolyte materials and oxide solid electrolyte materials.

[0046] (Negative electrode layer) One negative electrode layer 20 includes, for example, one negative electrode current collector 21 and one negative electrode active material layer 25.

[0047] The negative electrode current collector 21 is provided adjacent to the negative electrode active material layer 25. The negative electrode current collector 21 is not particularly limited, but is made of copper, for example. The shape of the negative electrode current collector 21 can be, for example, foil-like, plate-like, mesh-like, non-woven fabric-like, or foam-like. The negative electrode current collector 21 has a negative electrode portion 22 and a negative electrode tab portion 23.

[0048] The negative electrode portion 22 overlaps with the adjacent negative electrode active material layer 25 in the Z direction. The shape of the negative electrode portion 22 in the Z direction is, for example, a roughly rectangular shape with its longer side extending along the X direction.

[0049] The negative electrode tab portion 23 extends from the negative electrode portion 22 in the X direction, and more specifically, in the X- direction. The Y-direction dimension of the negative electrode tab portion 23 is smaller than the Y-direction dimension of the negative electrode portion 22. The shape of the negative electrode tab portion 23 in a Z-direction view is, for example, a roughly rectangular shape with its long side extending along the X direction. An insulating tape T is placed at the base end of the negative electrode tab portion 23. This suppresses the occurrence of short circuits caused by contact between the negative electrode tab portion 23 and other parts.

[0050] The negative electrode active material layer 25 contains a negative electrode active material. Examples of negative electrode active materials include lithium metal, lithium alloy, silicon (Si), silicon alloys and other silicon-based active materials, lithium titanate (Li4Ti5O 12Examples include lithium transition metal oxides such as ), transition metal oxides such as TiO2, Nb2O3 and WO3, metal sulfides, metal nitrides, carbon materials such as graphite, soft carbon and hard carbon, and metallic indium. The negative electrode active material layer 25 is preferably composed of lithium metal. The negative electrode active material layer 25 may further contain a solid electrolyte, a conductive additive, a binder, etc.

[0051] The negative electrode active material layer 25 has a shape that is, for example, a flat plate with its surface extending along the X and Y directions. The shape of the negative electrode active material layer 25 when viewed in the Z direction has a shape that is, for example, a rectangle with its longer side extending along the X direction.

[0052] (Insulating material) Furthermore, the all-solid-state battery 1 may also include, for example, a plurality of insulating members 40 arranged around the positive electrode active material layer 15.

[0053] The insulating member 40 has non-electron conductivity and non-ionic conductivity. The insulating member 40 includes an insulating material. Examples of insulating materials include insulating oxides such as alumina, resins such as polyvinylidene fluoride (PVDF), and rubbers such as styrene-butadiene rubber (SBR). The insulating member 40 is preferably formed of alumina. The shape of the insulating member 40 in the Z direction is, for example, a rectangular frame shape.

[0054] (Middle class) Furthermore, the all-solid-state battery 1 may include, for example, multiple intermediate layers 50 provided between the negative electrode layer 20 and the solid electrolyte layer 30.

[0055] The intermediate layer 50 includes, for example, a metal that can be alloyed with lithium and carbon. Examples of metals that can be alloyed with lithium include Mg, Zn, Al, In, Si, Ge, Sn, Ag, Au, Pt, Pd, Pb, Sb, Mn, and Bi. The shape of the intermediate layer 50 is, for example, a substantially rectangular plate with its surface extending in the X and Y directions.

[0056] The intermediate layer 50 is formed to be more flexible than the negative electrode layer 20 and the solid electrolyte layer 30. Therefore, the intermediate layer 50 adheres well to both the negative electrode layer 20 and the solid electrolyte layer 30. The intermediate layer 50 helps to suppress delamination between the negative electrode layer 20 and the solid electrolyte layer 30.

[0057] (Composition of the positive electrode active material layer and its surrounding area) Here, the configuration of the positive electrode active material layer and its surroundings in a cross-section perpendicular to the Z and Y directions (sometimes referred to as a "ZY cross-section") will be explained with reference to Figure 3. Figure 3 is a ZY cross-section passing through the center in the Y direction of the all-solid-state battery 1.

[0058] As shown in Figure 3, in the ZY cross-section, the Y-direction dimension of the positive electrode active material layer 15 increases toward the positive electrode current collector 11. The solid electrolyte layer 30 covers the Y-direction outer end of the positive electrode active material layer 15. The surface 16 of the positive electrode active material layer 15 that contacts the solid electrolyte layer 30 has a first inclined portion 18 that slopes outward in the Y-direction toward the positive electrode current collector 11. The surface 31 of the solid electrolyte layer 30 opposite to the surface that contacts the positive electrode active material layer 15 has a second inclined portion 32 that slopes outward in the Y-direction toward the positive electrode current collector 11. The end 32a of the second inclined portion 32 toward the negative electrode layer 20 is located further outward in the Y-direction than the end 18a of the first inclined portion 18 toward the negative electrode layer 20.

[0059] The positive electrode active material layer 15 has a roughly trapezoidal shape, for example, tapering towards the negative electrode layer 20. The end of the first inclined portion 18 on the negative electrode layer 20 side, 18a, is in contact with the solid electrolyte layer 30, and the end of the first inclined portion 18 on the positive electrode current collector 11 side, 18b, is in contact with the positive electrode current collector 11.

[0060] The solid electrolyte layer 30 covers the first inclined portion 18, and more specifically, covers the entire first inclined portion 18. The solid electrolyte layer 30 covers the entire positive electrode active material layer 15. The solid electrolyte layer 30 extends from the solid electrolyte layer 30 to the positive electrode current collector 11. The solid electrolyte layer 30 is in contact with the positive electrode active material layer 15 and the positive electrode current collector 11. The positive electrode current collector 11 is in contact with both the positive electrode active material layer 15 and the solid electrolyte layer 30. The solid electrolyte layer 30 is in contact with the positive electrode active material layer 15 in the Y direction. The end 32a of the second inclined portion 32 on the negative electrode layer 20 side is in contact with the intermediate layer 50, and the end 32b of the second inclined portion 32 on the positive electrode current collector 11 side is in contact with the positive electrode current collector 11.

[0061] It is preferable that the insulating member 40 covers the second inclined portion 32.

[0062] The end 18a of the first inclined portion 18 on the negative electrode layer 20 side is preferably located outward in the Y direction than the end 32a of the portion of the second inclined portion 32 that contacts the insulating member 40 on the negative electrode layer 20 side. The insulating member 40 covers, for example, the entire second inclined portion 32. The surface of the insulating member 40 that contacts the second inclined portion 32 has a third inclined portion 41 that inclins outward in the Y direction as it approaches the positive electrode current collector 11 side. The end 34a of the portion 34 of the second inclined portion 32 that contacts the insulating member 40 on the negative electrode layer 20 side coincides, for example, with the end 32a of the second inclined portion 32 on the negative electrode layer 20 side. The end 34b of the portion 34 of the second inclined portion 32 that contacts the insulating member 40 on the positive electrode current collector 11 side coincides, for example, with the end 32b of the second inclined portion 32 on the positive electrode current collector 11 side. The surface of the insulating member 40 facing the negative electrode layer 20 is flush with, for example, the portion of the solid electrolyte layer 30 facing the negative electrode layer 20 where the second inclined portion 32 is not provided. This makes it possible to make the stress acting on the interface between the solid electrolyte layer 30 and the positive electrode active material layer 15 more uniform when the all-solid-state battery 1 is in use. This makes it possible to suppress the occurrence of localized reactions at the interface between the solid electrolyte layer 30 and the positive electrode active material layer 15.

[0063] It is preferable that the end 32a of the second inclined portion 32 on the negative electrode layer 20 side is located outward in the Y direction than the end 18b of the first inclined portion 18 on the positive electrode current collector 11 side.

[0064] In the ZY cross-section, when the region between adjacent positive electrode current collectors 11 and negative electrode layer 20 is divided into two equal parts in the X direction, one of the regions forms: region A1 (sometimes simply called "region A1") where the insulating member 40 and the solid electrolyte layer 30 overlap in the Z direction; region A2 (sometimes simply called "region A2") where the solid electrolyte layer 30 is positioned without overlapping with either the positive electrode active material layer 15 or the insulating member 40 in the Z direction; and region A3 (sometimes simply called "region A3") where the positive electrode active material layer 15 and the solid electrolyte layer 30 overlap in the Z direction. Note that in region A1, the solid electrolyte layer 30 does not overlap with the positive electrode active material layer 15 in the Z direction. In region A3, the solid electrolyte layer 30 does not overlap with the insulating member 40 in the Z direction.

[0065] In the ZY cross-section, it is preferable that the ratio of the area of ​​the solid electrolyte layer 30 that overlaps with the positive electrode current collector 11 in the Y direction to the area of ​​the positive electrode active material layer 15 is between 0.01 and 5000.

[0066] In the ZY cross-section, it is preferable that the ratio of the area of ​​the portion of the insulating member 40 that overlaps with the positive electrode current collector 11 in the Y direction to the area of ​​the positive electrode active material layer 15 is between 0.01 and 5000.

[0067] Preferably, the position in the Z-direction of the end of the first inclined portion 18 on the negative electrode layer 20 side is the same as the position in the Z-direction of the end 32a of the second inclined portion 32 on the negative electrode layer 20 side, or is closer to the positive electrode current collector 11 than the position in the Z-direction of the end 32a of the second inclined portion 32 on the negative electrode layer 20 side.

[0068] The position in the Z direction of the end portion 16a on the negative electrode layer 20 side of the surface 16 of the positive electrode active material layer 15 that contacts the solid electrolyte layer 30 is preferably the same as the position in the Z direction of the end portion 34a on the negative electrode layer 20 side of the portion 34 of the solid electrolyte layer 30 that contacts the insulating member 40, or it is preferably on the positive electrode current collector 11 side than the position in the Z direction of the end portion 34b on the negative electrode layer 20 side of the portion 34 of the solid electrolyte layer 30 that contacts the insulating member 40.

[0069] The outer edge of the negative electrode active material layer 25 in the Y direction is located further out in the Y direction than, for example, the outer edge of the positive electrode active material layer 15 in the Y direction. The outer edge of the insulating member 40 in the Y direction is located further out in the Y direction than, for example, the outer edge of the negative electrode active material layer 25 in the Y direction.

[0070] Furthermore, in the Z-direction view, it is preferable that the area of ​​the negative electrode layer 20 is larger than the area of ​​the positive electrode active material layer 15. With this configuration, the area of ​​the portion of the negative electrode layer 20 that is not aligned with the positive electrode active material layer 15 in the Z-direction can be increased, making it easier to increase the area of ​​the region in the negative electrode layer 20 where lithium can be deposited.

[0071] Furthermore, in a view in the Z direction, it is preferable that the entire portion of the negative electrode current collector 21 excluding the negative electrode tab portion 23 (in other words, the negative electrode portion 22) is positioned inside the outer contour line of the insulating member 40. With this configuration, when lithium is deposited near the end of the negative electrode layer 20 in a direction perpendicular to the Z direction, the deposited lithium can be easily protected by the insulating member 40. This suppresses lithium shedding, thereby improving cycle characteristics.

[0072] (Manufacturing method for all-solid-state batteries) Next, a method for manufacturing the all-solid-state battery 1 according to this embodiment will be described.

[0073] A method for manufacturing an all-solid-state battery according to this embodiment includes, for example, a positive electrode active material layer formation step, a solid electrolyte layer formation step, an insulating member formation step, a positive electrode side pressing step, a positive electrode side cutting step, a negative electrode active material layer formation step, an intermediate layer formation step, a negative electrode side cutting step, a negative electrode side pressing step, a lamination step, and an integrated pressing step.

[0074] (Cathode active material layer formation process) A positive electrode active material layer 15 is formed on the positive electrode current collector 11. More specifically, an aluminum foil to be used as the positive electrode current collector 11 is prepared. The aluminum foil is, for example, in a long shape. A slurry for the positive electrode active material layer 15 is applied to the aluminum foil, for example, using an intermittent coating device, and dried. Multiple portions of the slurry for the positive electrode active material layer are applied, for example, at intervals in the Y direction. This results in a positive electrode assembly in which multiple positive electrode active material layers 15 are laminated on a connected positive electrode current collector 11. Furthermore, when applying the slurry for the positive electrode active material layer, the viscosity of the slurry and the coating speed can be appropriately adjusted to form a first inclined portion 18 at each end of the positive electrode active material layer 15 in the Y direction.

[0075] (Solid electrolyte layer formation process) Next, a solid electrolyte layer 30 is formed so as to extend from the positive electrode active material layer 15 to the positive electrode current collector 11. More specifically, a slurry for the solid electrolyte layer, which will become the solid electrolyte layer 30, is applied to the positive electrode assembly using, for example, an intermittent coating device and dried. At this time, the slurry for the solid electrolyte layer is applied so as to extend from the positive electrode active material layer 15 to the positive electrode current collector 11. The slurry for the solid electrolyte layer is applied so as to form second inclined portions 32 at each end of the solid electrolyte layer 30 in the Y direction. This gives a positive electrode assembly with the solid electrolyte layer 30 stacked on top. The solid electrolyte layer 30 is in contact with the positive electrode active material layer 15 in the Y direction and covers the first inclined portion 18. Furthermore, when applying the slurry for the solid electrolyte layer, the viscosity of the slurry and the coating speed can be appropriately adjusted to form the second inclined portions 32 at each end of the solid electrolyte layer 30 in the Y direction.

[0076] (Insulating material formation process) Next, an insulating member 40 is formed so as to extend from the positive electrode current collector 11 to the solid electrolyte layer 30. More specifically, the insulating material that will become the insulating member 40 is applied to the positive electrode current collector 11 and cured, for example, using an intermittent coating device. At this time, the insulating material is applied so as to surround the solid electrolyte layer 30. The insulating material is applied so that a part of the insulating material overlaps with the peripheral edge of the solid electrolyte layer. This gives a positive electrode connector with an insulating member 40 on which the solid electrolyte layer 30 is laminated. The insulating member 40 is in contact with the solid electrolyte layer 30 in the Y direction and covers the second inclined portion 32. In addition, a third inclined portion 41 is formed in the part of the insulating member 40 that overlaps with the second inclined portion 32 of the solid electrolyte layer 30. The insulating member 40 may be applied, for example, by spraying.

[0077] (Positive electrode side pressing process) Next, the positive electrode assembly with an insulating member 40 on which the solid electrolyte layer 30 is laminated is pressed, for example, by a roll press device. At this time, the temperature is, for example, room temperature or 25°C to 100°C, and the pressure is, for example, 500 MPa to 1200 MPa. This integrates the positive electrode active material layer 15, the solid electrolyte layer 30, and the insulating member 40, and also increases the density of the solid electrolyte layer 30. Furthermore, the first inclined portion 18, the second inclined portion 32, and the third inclined portion 41 can be enlarged or made more linear, respectively.

[0078] The positive electrode active material layer 15 is more easily rolled than the solid electrolyte layer 30. Because the solid electrolyte layer 30 and the positive electrode active material layer 15 are in contact in the Y direction, the solid electrolyte layer 30 is suitably rolled in accordance with the positive electrode active material layer 15. In addition, the gap between the positive electrode active material layer 15 and the insulating member 40 is suitably filled by the solid electrolyte layer 30.

[0079] Furthermore, since the surface of the insulating member 40 on the negative electrode layer 20 side and the surface of the solid electrolyte layer 30 on the negative electrode layer 20 side where the second inclined portion 32 is not formed are flush, the pressure during pressing, as described later, can be applied more evenly to the solid electrolyte layer 30 compared to the case where the solid electrolyte layer 30 is placed on the positive electrode active material layer 15 and the solid electrolyte layer 30 which are arranged side by side in the Y direction. This makes it possible to suppress cracking of the solid electrolyte layer 30 during pressing.

[0080] (Positive electrode cutting process) Next, the positive electrode connector with the insulating member 40, on which the solid electrolyte layer 30 is laminated, is cut along the Y direction, for example, using a rotary cutter. The portion of the positive electrode current collector 11 that will become the positive electrode tab portion 13 is cut into the desired shape. This results in a laminate of the solid electrolyte layer 30 and the positive electrode layer 10 with the insulating member 40.

[0081] (Negative electrode active material layer formation process) Furthermore, a slurry for the negative electrode active material layer 25 is applied to the copper foil that will become the negative electrode current collector 21, for example, using an intermittent coating apparatus. The copper foil is, for example, in a long shape. This results in a negative electrode assembly in which multiple negative electrode active material layers 25 are laminated on the copper foil that will become the negative electrode current collector 21.

[0082] (Intermediate layer formation process) Next, an intermediate layer 50 is formed on the negative electrode assembly. The intermediate layer 50 is transferred onto the negative electrode active material layer 25, for example, using an intermediate layer transfer sheet. This results in a negative electrode assembly with the intermediate layer 50 laminated on top. The intermediate layer transfer sheet can be obtained, for example, by dispersing the materials constituting the intermediate layer 50 in a solvent, applying the resulting slurry to a support sheet, and drying it.

[0083] (Negative electrode side pressing process) Next, the negative electrode assembly with the intermediate layer 50 laminated on it is pressed, for example, by a roll press device. At this time, the temperature is, for example, room temperature or 25°C to 100°C, and the pressure is, for example, 500 MPa to 1200 MPa. As a result, the negative electrode current collector 21, the negative electrode active material layer 25, and the intermediate layer 50 are integrated into one unit.

[0084] (Negative electrode cutting process) Next, the negative electrode assembly with the intermediate layer 50 laminated on it is cut along the second direction, for example, using a rotary cutter. The portion of the positive electrode current collector 11 that will become the positive electrode tab portion 13 is cut into the desired shape. This gives a laminate of the intermediate layer 50 and the negative electrode layer 20. In addition, insulating tape T may be attached to the base end of the negative electrode tab portion 23.

[0085] (Lamination process) Next, a laminate of the solid electrolyte layer 30 and the positive electrode layer 10 with an insulating member 40 is laminated, and a laminate of the intermediate layer 50 and the negative electrode layer 20 is laminated. At this time, the laminate of the intermediate layer 50 and the negative electrode layer 20 is performed on both sides of the laminate of the solid electrolyte layer 30 and the positive electrode layer 10 with an insulating member 40. As a result, the all-solid-state battery 1 has a structure in which each layer is laminated symmetrically on both sides in the Z direction, as shown in Figures 1 to 3.

[0086] (Integrated pressing process) Next, the laminate of the solid electrolyte layer 30 and the positive electrode layer 10 with the insulating member 40, and the laminate of the intermediate layer 50 and the negative electrode layer 20 are pressed, for example, by a roll press device. At this time, the temperature is, for example, room temperature or 25°C to 100°C, and the pressure is, for example, 200 MPa to 800 MPa. As a result, the positive electrode layer 10, the negative electrode layer 20, the solid electrolyte layer 30, and the intermediate layer 50 are integrated, and the solid electrolyte layer 30 is further densened. In addition, the first inclined portion 18, the second inclined portion 32, and the third inclined portion 41 can be enlarged or made more linear, respectively.

[0087] The positive electrode pressing process and the integrated pressing process correspond to the processes of stacking and pressing the positive electrode current collector, the positive electrode active material layer, and the solid electrolyte layer, respectively.

[0088] Based on the above, an all-solid-state battery 1 as shown in Figure 1 can be obtained.

[0089] The manufacturing method for the all-solid-state battery 1 is not limited to the manufacturing method described above. For example, the positive electrode layer 10 does not necessarily have to be obtained by cutting a positive electrode connector, and may be obtained by laminating one positive electrode active material layer 15 on one positive electrode current collector 11. The same applies to the negative electrode layer 20.

[0090] (Effects according to the embodiment) According to the above embodiment, the following effects can be obtained.

[0091] In the all-solid-state battery 1 of the above embodiment, in the ZY cross-section, the Y-direction dimension of the positive electrode active material layer 15 increases toward the positive electrode current collector 11. The solid electrolyte layer 30 covers the Y-direction outer end of the positive electrode active material layer 15. The surface 16 of the positive electrode active material layer 15 that contacts the solid electrolyte layer 30 has a first inclined portion 18 that slopes outward in the Y-direction toward the positive electrode current collector 11. The surface 31 of the solid electrolyte layer 30 opposite to the surface that contacts the positive electrode active material layer 15 has a second inclined portion 32 that slopes outward in the Y-direction toward the positive electrode current collector 11. The end 32a of the second inclined portion 32 toward the negative electrode layer 20 is located further outward in the Y-direction than the end 18a of the first inclined portion 18 toward the negative electrode layer 20.

[0092] With this configuration, the solid electrolyte layer 30 and the negative electrode layer 20 can be positioned outside the region that overlaps with the positive electrode active material layer 15 in the Z direction. Lithium ions released from the first inclined portion 18 move linearly and reach the portion of the negative electrode layer 20 that is not aligned with the positive electrode active material layer 15 in the Z direction, via the solid electrolyte layer 30. This makes it possible to suppress the localized deposition of lithium at the edge of the region of the negative electrode layer 20 that overlaps with the positive electrode active material layer 15 in the Z direction.

[0093] Furthermore, with this configuration, during the manufacturing of the all-solid-state battery 1, the positive electrode active material layer 15 can be placed on the positive electrode current collector 11 before the solid electrolyte layer 30. This makes it easier to ensure the positional accuracy of the positive electrode active material layer 15, thereby suppressing localized deposition of lithium caused by displacement of the positive electrode active material layer 15.

[0094] Therefore, it is possible to provide an all-solid-state battery 1 that can more effectively suppress localized deposition of lithium.

[0095] Furthermore, because the Y-direction dimension of the positive electrode active material layer 15 increases towards the positive electrode current collector 11, the Y-direction outer end of the positive electrode active material layer 15 on the negative electrode layer 20 side can be moved away from the Y-direction end of the all-solid-state battery 1, thereby ensuring adequate insulation.

[0096] In the above embodiment, the all-solid-state battery 1 is preferably equipped with an insulating member 40, and the insulating member 40 covers the second inclined portion 32.

[0097] With this configuration, the insulating member 40 blocks the lithium ion migration path, thereby blocking the path of lithium ions released from the first inclined portion 18 toward the vicinity of the outer end of the negative electrode layer 20 in the Y direction. This makes it possible to suppress the concentration and deposition of lithium near the end of the negative electrode layer 20.

[0098] Furthermore, when the laminate of the positive electrode layer 10 with the insulating member 40 and the solid electrolyte layer 30 is pressed, the solid electrolyte layer 30 tends to stretch in the Y direction, following the rolling of the positive electrode active material layer 15. However, with this configuration, the rolling of the solid electrolyte layer 30 in the Y direction is suppressed by the insulating member 40. As a result, the solid electrolyte layer 30 can be compressed, and therefore the density of the solid electrolyte layer 30 can be increased compared to a configuration without the insulating member 40.

[0099] Furthermore, since the end of the first inclined portion 18 on the negative electrode layer 20 side is located outward in the Y direction from the end of the second inclined portion 32 on the negative electrode layer 20 side that contacts the insulating member 40, the insulating member 40 can be prevented from being placed on the path through which lithium ions released from the first inclined portion 18 reach the negative electrode layer 20. As a result, even in the all-solid-state battery 1 equipped with the insulating member 40, localized deposition of lithium can be effectively suppressed.

[0100] In the all-solid-state battery 1 of the above embodiment, it is preferable that the end 32a of the second inclined portion 32 on the negative electrode layer 20 side is located outward in the Y direction than the end 18b of the first inclined portion 18 on the positive electrode current collector 11 side.

[0101] With this configuration, it is possible to suppress lithium ions released from the first inclined portion 18 from hitting the edge of the solid electrolyte layer 30 (or the insulating member 40) when they move along the Z direction. This makes the flow of lithium ions between the positive electrode active material layer 15 and the negative electrode layer 20 smoother.

[0102] In the all-solid-state battery 1 of the above embodiment, when the region between adjacent positive electrode current collectors 11 and negative electrode layer 20 is divided into two equal parts in the X direction in the ZY cross-section, one of the regions has a region A1 in which the insulating member 40 and the solid electrolyte layer 30 overlap in the Z direction, a region A2 in which the solid electrolyte layer 30 is arranged without overlapping with either the positive electrode active material layer 15 or the insulating member 40 in the Z direction, and a region A3 in which the positive electrode active material layer 15 and the solid electrolyte layer 30 overlap in the Z direction.

[0103] With this configuration, the presence of region A3 makes it easier to deposit lithium in the negative electrode layer 20. Furthermore, the presence of region A2 allows lithium to be deposited to some extent outside the Y-direction end of the portion of the negative electrode layer 20 that overlaps with the positive electrode active material layer 15 in the Z-direction. This suppresses localized lithium deposition at the Y-direction end of the portion of the negative electrode layer 20 that overlaps with the positive electrode active material layer 15 in the Z-direction. Moreover, the presence of region A1 suppresses localized lithium deposition at the Y-direction end of the negative electrode layer 20.

[0104] Furthermore, by arranging the solid electrolyte layer 30 to cover the edges of the positive electrode active material layer 15, it is possible to suppress the formation of gaps between the edges of the positive electrode active material layer 15 and the solid electrolyte layer 30 during the manufacturing of the all-solid-state battery 1.

[0105] Furthermore, even if a gap is formed at the negative electrode layer 20 side of the boundary between the solid electrolyte layer 30 and the insulating member 40 when the insulating member 40 is coated, this gap is formed in a position that does not overlap with the positive electrode active material layer 15 in the Z direction. This makes it possible to suppress the occurrence of cracks caused by uneven reaction during charging.

[0106] In the all-solid-state battery 1 of the above embodiment, it is preferable that the ratio of the length in the Y direction between the end of the second inclined portion 32 on the negative electrode layer 20 side and the end of the first inclined portion 18 on the positive electrode active material layer 15 side, in the ZY cross-section, to the Y-direction dimension of the first inclined portion 18 is 0.01 or more and 5000 or less.

[0107] With this configuration, by setting the size of the solid electrolyte layer 30 to a certain level or greater, a suitable path for lithium ions to reach the negative electrode layer 20 from the first inclined portion 18 through the solid electrolyte layer 30 can be secured. Furthermore, by setting the size of the solid electrolyte layer 30 to a certain level or less, it is possible to suppress the occurrence of solid electrolyte layers 30 that do not contribute to the conduction of lithium ions.

[0108] In the all-solid-state battery 1 of the above embodiment, it is preferable that the ratio of the length in the Y direction between the end of the second inclined portion 32 on the negative electrode layer 20 side and the end of the first inclined portion 18 on the positive electrode active material layer 15 side, in the ZY cross-section, to the Y-direction dimension of the second inclined portion 32 is 0.01 or more and 5000 or less.

[0109] With this configuration, by arranging the insulating members 40 to be of a certain size or larger, the occurrence of short circuits can be suitably suppressed. Furthermore, by making the insulating members 40 smaller than a certain size, a suitable path can be secured for lithium ions to reach the negative electrode layer 20 from the first inclined portion 18 through the solid electrolyte layer 30.

[0110] In the all-solid-state battery 1 of the above embodiment, it is preferable that the position in the Z direction of the end 18a of the first inclined portion 18 on the negative electrode layer 20 side is the same as the position in the Z direction of the end 32a of the second inclined portion 32 on the negative electrode layer 20 side, or is closer to the positive electrode current collector 11 than the position in the Z direction of the end 32a of the second inclined portion 32 on the negative electrode layer 20 side.

[0111] With this configuration, the insulating member 40 and a portion of the solid electrolyte layer 30 that is located on the negative electrode layer 20 side of the positive electrode active material layer 15 can be aligned in the Y direction. Therefore, by pressing the laminate of the positive electrode layer 10 with the insulating member 40 and the solid electrolyte layer 30, the density of a portion of the solid electrolyte layer 30 that is located on the negative electrode layer 20 side of the positive electrode active material layer 15 can be increased.

[0112] The manufacturing method of the all-solid-state battery 1 of the above embodiment includes the steps of forming a positive electrode active material layer 15 on a positive electrode current collector 11 and forming a solid electrolyte layer 30 extending from the positive electrode active material layer 15 to the positive electrode current collector 11.

[0113] According to this manufacturing method, a first inclined portion 18 can be formed in the positive electrode active material layer 15, and the first inclined portion 18 can be covered with a solid electrolyte layer 30. Furthermore, when forming the positive electrode active material layer 15 on the positive electrode current collector 11, it is possible to suppress the constraint on the formation work of the positive electrode current collector 11 by other components. This makes it possible to improve the positional accuracy of the positive electrode current collector 11. In addition, it is possible to improve the workability when forming the positive electrode active material layer 15.

[0114] The manufacturing method for the all-solid-state battery 1 of the above embodiment includes the steps of forming a positive electrode active material layer 15 on a positive electrode current collector 11, forming a solid electrolyte layer 30 extending from the positive electrode active material layer 15 to the positive electrode current collector 11, and forming an insulating member 40 extending from the positive electrode current collector 11 to the solid electrolyte layer 30.

[0115] According to this manufacturing method, a second inclined portion 32 can be formed in the solid electrolyte layer 30, and the second inclined portion 32 can be covered with an insulating member 40. Furthermore, since the positive electrode active material layer 15 is formed before the insulating member 40, the positive electrode active material layer 15 can be formed on the positive electrode current collector 11 without being hindered by the insulating member 40. This improves the positional accuracy of the positive electrode current collector 11. It also improves the workability when forming the positive electrode active material layer 15.

[0116] (Modified examples of the embodiment) A modified example of the all-solid-state battery 1 will be described with reference to Figure 4. Components similar to those in the all-solid-state battery 1 according to the embodiment may be denoted by the same reference numerals and their descriptions may be omitted.

[0117] As shown in Figure 4, the all-solid-state battery 200 does not have an insulating member 40.

[0118] In the ZY cross-section, the negative electrode current collector 21 has a fourth inclined portion 24 provided in the portion of the negative electrode current collector 21 that overlaps with the second inclined portion 32 in the Z direction, and which inclins toward the positive electrode current collector 11 as it extends outward in the Y direction. The fourth inclined portion 24 (more specifically, the entire fourth inclined portion 24) is located outside the region that overlaps with the positive electrode active material layer 15 in the Z direction. The fourth inclined portion 24 extends substantially parallel to the direction in which the second inclined portion 32 extends.

[0119] In the ZY cross-section, the negative electrode active material layer 25 has a fifth inclined portion 26 provided in the portion of the negative electrode active material layer 25 that overlaps with the second inclined portion 32 in the Z direction, and which inclins toward the positive electrode current collector 11 as it extends outward in the Z direction. The fifth inclined portion 26 is adjacent to the fourth inclined portion 24. The fifth inclined portion 26 (more specifically, the entire fifth inclined portion 26) is located outside the region that overlaps with the positive electrode active material layer 15 in the Z direction. The fifth inclined portion 26 extends substantially parallel to the direction in which the second inclined portion 32 extends.

[0120] The fourth inclined portion 24 and the fifth inclined portion 26 are collectively referred to as the "negative electrode inclined portion 28". The negative electrode layer 20 has a negative electrode inclined portion 28 which is provided in the portion of the negative electrode layer 20 that overlaps with the second inclined portion 32 in the Z direction and is inclined toward the positive electrode current collector 11 as it extends outward in the Y direction.

[0121] In the ZY cross-section, the intermediate layer 50 has a sixth inclined portion 51 provided in the portion of the intermediate layer 50 that overlaps with the second inclined portion 32 in the Z direction, and which inclins toward the positive electrode current collector 11 as it extends outward in the Y direction. The sixth inclined portion 51 is adjacent to the fifth inclined portion 26. The sixth inclined portion 51 (more specifically, the entire sixth inclined portion 51) is located outside the region that overlaps with the positive electrode active material layer 15 in the Z direction. The sixth inclined portion 51 extends substantially parallel to the direction in which the second inclined portion 32 extends.

[0122] In the ZY section, the first inclined portion 18, the second inclined portion 32, the third inclined portion 41, the fourth inclined portion 24, and the fifth inclined portion 26 overlap in a direction perpendicular to the direction in which the first inclined portion 18 extends.

[0123] With this configuration, lithium ions released from the first inclined portion 18 can move linearly and reach the negative electrode inclined portion 28 via the solid electrolyte layer 30 and the sixth inclined portion 51 of the intermediate layer 50. This allows lithium to be deposited appropriately even in the portion of the negative electrode layer 20 that is not aligned with the positive electrode active material layer 15 in the Z direction. As a result, lithium can be dispersed and deposited in the negative electrode layer 20, thereby suppressing localized deposition of lithium.

[0124] The present invention is not limited to the configuration of the above embodiments, and can be modified and applied as appropriate without altering the essence of the invention. Furthermore, a combination of two or more of the desirable configurations described in the above embodiments also constitutes the present invention. [Explanation of Symbols]

[0125] 1,200: All-solid-state battery, 10: Positive electrode layer, 11: Positive electrode current collector, 15: Positive electrode active material layer, 13: Positive electrode tab section (tab section), 18: First inclined section, 21: Negative electrode current collector, 20: Negative electrode layer, 28: Negative electrode inclined section, 30: Solid electrolyte layer, 32: Second inclined section, 40: Insulating material.

Claims

1. A solid-state battery comprising: a positive electrode layer including a positive electrode current collector and a positive electrode active material layer; a negative electrode layer including at least a negative electrode current collector; and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, If we define the direction in which the positive electrode layer and the negative electrode layer are stacked via the solid electrolyte layer as the stacking direction, one of the directions perpendicular to the stacking direction as the first direction, the direction perpendicular to both the stacking direction and the first direction as the second direction, and the direction of the second direction that moves away from the center of the second direction of the all-solid-state battery as the outer direction of the second direction, then The positive electrode current collector has a tab portion extending in the first direction, In a cross-section perpendicular to the stacking direction and the second direction, The second dimension of the positive electrode active material layer increases toward the positive electrode current collector side. The solid electrolyte layer covers the outer end of the positive electrode active material layer in the second direction, The surface of the positive electrode active material layer that contacts the solid electrolyte layer has a first inclined portion that slopes outward in the second direction as it approaches the positive electrode current collector. The surface of the solid electrolyte layer opposite to the surface in contact with the positive electrode active material layer has a second inclined portion that slopes outward in the second direction as it approaches the positive electrode current collector. A solid-state battery wherein the end of the second inclined portion on the negative electrode layer side is located outward in the second direction than the end of the first inclined portion on the negative electrode layer side.

2. The positive electrode active material layer is provided with an insulating member arranged around it, In a cross-section perpendicular to the stacking direction and the second direction, The all-solid-state battery according to claim 1, wherein the insulating member covers the second inclined portion.

3. The all-solid-state battery according to claim 1 or 2, wherein the end of the second inclined portion on the negative electrode layer side is located outward in the second direction than the end of the first inclined portion on the positive electrode current collector side.

4. In a cross section perpendicular to the stacking direction and the second direction, when the region between adjacent positive electrode current collectors and the negative electrode layer is divided into two equal parts in the stacking direction, one of the regions includes a region where the insulating member and the solid electrolyte layer overlap in the stacking direction, a region where the solid electrolyte layer is arranged without overlapping with either the positive electrode active material layer or the insulating member in the stacking direction, and a region where the positive electrode active material layer and the solid electrolyte layer overlap in the stacking direction, as described in claim 2.

5. In a cross-section perpendicular to the stacking direction and the second direction, The all-solid-state battery according to claim 1 or 2, wherein the ratio of the length in the second direction between the end of the second inclined portion on the negative electrode layer side and the end of the first inclined portion on the positive electrode active material layer side to the dimension of the first inclined portion in the second direction is 0.01 or more and 5000 or less.

6. In a cross-section perpendicular to the stacking direction and the second direction, The all-solid-state battery according to claim 2, wherein the ratio of the length in the second direction between the end of the second inclined portion on the negative electrode layer side and the end of the first inclined portion on the positive electrode active material layer side to the second dimension of the second inclined portion is 0.01 or more and 5000 or less.

7. In a cross-section perpendicular to the stacking direction and the second direction, The all-solid-state battery according to claim 1, wherein the negative electrode layer is provided in a portion of the negative electrode layer that overlaps with the second inclined portion in the stacking direction, and has a negative electrode inclined portion that inclins toward the positive electrode current collector side as it moves outward in the second direction.

8. A method for manufacturing an all-solid-state battery according to claim 1, The process of forming the positive electrode active material layer on the positive electrode current collector, A step of forming the solid electrolyte layer so as to extend from the positive electrode active material layer to the positive electrode current collector, A method for manufacturing an all-solid-state battery, including [the specified component].

9. A method for manufacturing an all-solid-state battery according to claim 2, The process of forming the positive electrode active material layer on the positive electrode current collector, A step of forming the solid electrolyte layer so as to extend from the positive electrode active material layer to the positive electrode current collector, A step of forming the insulating member so as to extend from the positive electrode current collector to the solid electrolyte layer, A method for manufacturing an all-solid-state battery, including [the specified component].

Images