All-solid-state battery

Abstract

The problem to be solved by the present invention is to provide an all-solid-state battery capable of ensuring insulating properties even when a tab line extending from a negative electrode collector of each unit structure is aggregated to function as a battery, and the spatial distance between the tab line and a positive electrode collector is shortened due to the bending of the tab line. In order to solve the problem, the present invention provides an all-solid-state battery comprising an electrode body in which a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector are laminated in this order, the end portion of the positive electrode layer being provided with a first insulating material, and the end portion of the negative electrode layer being provided with a second insulating material. A second insulating material is provided between the negative electrode current collector and the solid electrolyte layer and in a portion facing an end portion of the solid electrolyte layer and an end portion of the first insulating material.

Description

Technical Field

[0001] The invention relates to an all-solid-state battery. Background Art

[0002] In recent years, in order to ensure sustainable and advanced energy that is affordable and reliable to many people, research and development related to secondary batteries that contribute to energy efficiency has been carried out. As a secondary battery, lithium metal batteries with high energy density have attracted attention.

[0003] Lithium metal batteries are secondary batteries that use lithium metal as the negative electrode and can be high-capacity batteries. Among them, so-called all-solid lithium metal batteries that are fully solid by replacing the electrolyte with a solid electrolyte layer have attracted attention due to their excellent safety. For example, an all-solid lithium metal battery has a monomer structure comprising a negative electrode, a positive electrode, and a solid electrolyte layer composed of lithium metal.

[0004] Figure 5 This is a cross-sectional view showing the structure of a conventional all-solid-state battery. Figure 5 The all-solid-state battery 1 shown in the figure comprises: a negative electrode, formed by a negative electrode collector 2a and a lithium metal layer (negative electrode layer) 3a, or a negative electrode collector 2b and a lithium metal layer (negative electrode layer) 3b; a positive electrode, formed by a positive electrode collector 4 and a positive electrode active material layer (positive electrode layer) 5a or 5b; and solid electrolyte layers 6a and 6b, adjacent to the positive electrode active material layer (positive electrode layer) 5a or 5b. Figure 5 The all-solid battery 1 shown in the figure has an intermediate layer 7a between the lithium metal layer (negative electrode layer) 3a and the solid electrolyte layer 6a, and an intermediate layer 7b between the lithium metal layer (negative electrode layer) 3b and the solid electrolyte layer 6b. In addition, first insulating materials 8a and 8c are respectively arranged at both ends of the positive electrode active material layer (positive electrode layer) 5a, and first insulating materials 8b and 8d are respectively arranged at both ends of the positive electrode active material layer 5b. In addition, L in the figure represents the stacking direction of the layers constituting the all-solid battery 1.

[0005] The all-solid-state battery has an electrode body formed by stacking multiple monomer structures, and the tab wires extending from the negative electrode collectors of each monomer structure are gathered to function as a battery. In addition, when the tab wires are gathered, the tab wires extending from the electrode body will bend, and the tab wires far from the gathering part will bend particularly greatly. As a result, the spatial distance between the tab wire and the positive electrode collector becomes shorter, and there is a concern that the insulation distance cannot be ensured.

[0006] Patent document 1 discloses an all-solid-state battery, in which an electrode body is stacked in sequence with a positive electrode collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode collector foil, the positive electrode layer is arranged and stacked closer to the inside than the solid electrolyte layer and the negative electrode layer, and an insulating layer is arranged on the surface of the positive electrode collector foil on the positive electrode layer side and at least on the portion opposite to the ends of the solid electrolyte layer and the negative electrode layer.

[0007] The insulating layer used in the all-solid-state battery described in Patent Document 1 is a ceramic layer bonded to the positive electrode collector foil via an adhesive layer, and the following effects are expected: the high-hardness ceramic layer is used to suppress damage to the insulating layer by metal foreign matter and thus suppress short circuits, and if a short circuit occurs, the high resistance of the ceramic layer is used to suppress heat generation in the short-circuit portion.

[0008] However, since the insulating layer described in Patent Document 1 includes a ceramic layer, it is not assumed that the insulating layer itself is bent for use.

[0009] [Prior Technical Literature]

[0010] (Patent Document)

[0011] Patent Document 1: Japanese Patent Application Publication No. 2022-104116 Summary of the invention

[0012] [Problems to be solved by the invention]

[0013] The object of the present invention is to provide an all-solid-state battery that can ensure insulation even when the tab wires extending from the negative electrode collectors of each single structure are assembled to function as a battery and the spatial distance between the tab wires and the positive electrode collector becomes shorter due to the bending of the tab wires.

[0014] [Technical means to solve the problem]

[0015] The inventors of the present invention have been actively exploring to achieve the above-mentioned purpose. Then, it was found that if in a fully solid-state battery including an electrode body stacked in sequence with a positive electrode collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode collector, the end of the positive electrode layer is provided with a first insulating material, and the portion between the negative electrode collector and the solid electrolyte layer and opposite to the end of the solid electrolyte layer and the end of the first insulating material is provided with a second insulating material, and the creepage distance from the surface of the negative electrode layer side of the negative electrode collector to the surface of the positive electrode layer side of the positive electrode collector is greater than the straight-line distance from the same starting point to the end, then the insulation can be ensured by the creepage distance, thereby completing the present invention.

[0016] That is, the present invention includes the following aspects. [1]

[0018] An all-solid-state battery comprises an electrode body in which a positive electrode collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode collector are sequentially stacked, and

[0019] The positive electrode current collector includes a first insulating material on a surface on the positive electrode layer side and adjacent to an end of the positive electrode layer.

[0020] The solid electrolyte layer is arranged in contact with the positive electrode layer and the first insulating material.

[0021] A second insulating material is provided between the negative electrode current collector and the solid electrolyte layer and at a portion facing an end of the solid electrolyte layer and an end of the first insulating material.

[0022] The second insulating material is arranged in contact with the solid electrolyte layer so that a creepage distance from a surface of the negative electrode current collector on the negative electrode layer side to a surface of the positive electrode current collector on the positive electrode layer side is greater than a straight line distance between the same start and end points. [2]

[0024] The all-solid-state battery according to aspect [1], wherein the thickness of the first insulating material in the stacking direction of the electrode body decreases as the distance from the end adjacent to the positive electrode layer in the extending direction of the electrode body increases. [3]

[0026] In the all-solid-state battery according to aspect [1] or [2], the second insulating material is arranged so as to overlap with an end portion of the negative electrode layer in the extending direction of the electrode body. [4]

[0028] The all-solid-state battery according to aspect [3], wherein the second insulating material is arranged so that at least a portion of it abuts against the negative electrode current collector. [5]

[0030] The all-solid-state battery according to aspect [1] or [2], wherein the electrode body comprises an intermediate layer between the solid electrolyte layer and the negative electrode layer,

[0031] In the extension direction of the electrode body, the end of the intermediate layer is arranged at approximately the same position as the end of the negative electrode layer or the end of the second insulating material, or is arranged inside than the end of the negative electrode layer or the end of the second insulating material. [6]

[0033] The all-solid-state battery according to aspect [5], wherein the second insulating material is arranged so that at least a portion of it abuts against the intermediate layer. [7]

[0035] In the all-solid-state battery according to aspect [1] or [2], an end portion of the solid electrolyte layer is located at substantially the same position as an end portion of the first insulating material in the extension direction of the electrode body. [8]

[0037] The all-solid-state battery according to aspect [1] or [2], wherein the second insulating material is a laminate including an adhesive layer and an insulating layer,

[0038] The adhesive layer is disposed on the negative electrode collector side.

[0039] The insulating layer is disposed on the solid electrolyte layer side. [9]

[0041] The all-solid-state battery according to aspect [8], wherein the adhesive layer is an acrylic adhesive layer,

[0042] The insulating layer includes polyethylene.

[0043] (Effects of the Invention)

[0044] According to the present invention, an all-solid-state battery capable of ensuring insulation can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a part of a cross-sectional view showing the structure of the all-solid-state battery according to the first embodiment.

[0046] Figure 2 It is a part of a cross-sectional view showing the structure of an all-solid-state battery according to a second embodiment.

[0047] Figure 3 It is a part of a cross-sectional view showing the structure of an all-solid-state battery according to a third embodiment.

[0048] Figure 4 It is a part of a cross-sectional view showing the structure of an all-solid-state battery according to a fourth embodiment.

[0049] Figure 5 This is a cross-sectional view showing the structure of a conventional all-solid-state battery. DETAILED DESCRIPTION

[0050] Hereinafter, embodiments will be described with reference to the drawings.

[0051] <First embodiment>

[0052] The all-solid-state battery of the present disclosure will be described with reference to an all-solid-state battery 11 as one embodiment.

[0053] The all-solid-state battery disclosed herein comprises an electrode body in which a positive electrode current collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode current collector are sequentially stacked. The positive electrode current collector has a first insulating material adjacent to an end of the positive electrode layer on a surface on the positive electrode layer side, and the solid electrolyte layer is arranged in a manner of abutting the positive electrode layer and the first insulating material.

[0054] The all-solid-state battery disclosed herein is also provided with a second insulating material between the negative electrode collector and the solid electrolyte layer and in a portion opposite to the end of the solid electrolyte layer and the end of the first insulating material. The second insulating material is arranged in contact with the solid electrolyte layer in such a way that the creepage distance from the surface of the negative electrode collector on the negative electrode layer side to the surface of the positive electrode collector on the positive electrode layer side is greater than the straight-line distance from the same start to end.

[0055] The all-solid-state battery disclosed herein has a first insulating material at the end of the positive electrode layer, and has a second insulating material between the negative electrode collector and the solid electrolyte layer and in a portion opposite to the end of the solid electrolyte layer and the end of the first insulating material, in such a way that the creepage distance from the surface of the negative electrode layer side of the negative electrode collector to the surface of the positive electrode layer side of the positive electrode collector is greater than the straight-line distance from the same starting and ending points. Therefore, insulation can be ensured by the creepage distance.

[0056] More specifically, even when the tab wires extending from the negative electrode collectors of each single structure are assembled to function as a battery, the creepage distance can be ensured and insulation can be guaranteed because the spatial distance between the tab wire and the positive electrode collector is shortened due to the bending of the tab wire.

[0057] Figure 1 It is a part of a cross-sectional view showing the structure of the all-solid-state battery 11 according to the first embodiment. Figure 1 An end portion of a single body structure of the all-solid-state battery 11 is shown. Figure 1 The all-solid-state battery 11 shown in the figure comprises: a positive electrode, formed by a positive electrode collector 140 and a positive electrode active material layer (positive electrode layer) 15a or 15b; solid electrolyte layers 16a and 16b, adjacent to the positive electrode active material layer (positive electrode layer) 15a or 15b; and a negative electrode, formed by a lithium metal layer (negative electrode layer) 13a and a negative electrode collector 12a, or a lithium metal layer (negative electrode layer) 13b and a negative electrode collector 12b.

[0058] Figure 1 The all-solid-state battery 11 shown in the figure has an intermediate layer 17a between the lithium metal layer (negative electrode layer) 13a and the solid electrolyte layer 16a, and an intermediate layer 17b between the lithium metal layer (negative electrode layer) 13b and the solid electrolyte layer 16b. In addition, a first insulating material 18c is arranged at the end of the positive electrode active material layer (positive electrode layer) 15a, and a first insulating material 18d is arranged at the end of the positive electrode active material layer (positive electrode layer) 15b.

[0059] exist Figure 1 In the all-solid battery 11 of the first embodiment shown in , the ends of the intermediate layers 17a and 17b are arranged inside the ends of the lithium metal layers (negative electrode layers) 13a and 13b in the extending direction of the electrode body.

[0060] Figure 1 The all-solid-state battery 11 shown in the figure has first insulating materials 18c and 18d at the ends of the positive electrode layers 15a and 15b, respectively, and has a second insulating material 19a between the negative electrode collector 12a and the solid electrolyte layer 16a, and in the portion opposite to the end of the solid electrolyte layer 16a and the end of the first insulating material 18c, in such a way that the creepage distance from the surface of the negative electrode collector 12a on the negative electrode layer 13a side to the surface of the positive electrode collector 140 on the positive electrode layer 15a side is greater than the straight-line distance between the same starting and ending points (in the figure, indicated by the arrow b).

[0061] More specifically, the second insulating material 19a of the all-solid-state battery 11 of the first embodiment is arranged so that a portion of the surface overlaps with the end of the negative electrode layer 13a in the extending direction of the electrode body of the all-solid-state battery 11, and the negative electrode layer 13a is covered with the overlapping portion, and is arranged in contact with the negative electrode collector 12a without contacting the end of the intermediate layer 17a. Figure 1 Except for the portion indicated by arrow a in FIG. 1 , the portion contacts the solid electrolyte layer 16 a .

[0062] That is, in Figure 1 In the all-solid battery 11 shown in FIG. 1 , a portion of a surface of the second insulating material 19a is in contact with the negative electrode layer 13a in the extending direction of the electrode body, and the remaining portion is in contact with the negative electrode collector 12a. The surface opposite to the surface in contact with the negative electrode layer 13a and the negative electrode collector 12a is configured as follows: Figure 1 The portion indicated by arrow a in FIG. 1 is in a state where it protrudes from the end of the solid electrolyte layer 16 a and partially contacts the solid electrolyte layer 16 a .

[0063] Thus, even when the all-solid-state battery 11 is used as a battery by gathering the tab wires extending from the negative electrode current collector 12a, the space distance between the tab wires and the positive electrode current collector 140 is shortened due to the bending of the tab wires. However, due to the presence of the second insulating material 19a in the arrow a portion extending from the end of the solid electrolyte layer 16a, the creepage distance from the surface of the negative electrode layer 13a side of the negative electrode current collector 12a to the surface of the positive electrode layer 15a side of the positive electrode current collector 140 is increased due to the presence of the second insulating material 19a. Thus, the creepage distance of the all-solid-state battery 11 is ensured, and the insulation can be guaranteed.

[0064] In addition, since the second insulating material 19a has a portion indicated by an arrow a extending from the end of the solid electrolyte layer 16a, even if the tab wires extending from the negative electrode collector 12a are bent and stress is concentrated on the bent portion when they are gathered together to function as a battery, the mechanical strength is improved due to the presence of the second insulating material 19a, thereby suppressing breakage of the tab wire.

[0065] In addition, in the all-solid-state battery of the present disclosure, the distance ( Figure 1 The arrow a) in FIG. 1 is not particularly limited. As long as the end of the second insulating material is located outside the end of the solid electrolyte in the extending direction of the electrode body, the above-mentioned effect of the present invention can be enjoyed.

[0066] <Second embodiment>

[0067] A portion of a cross-sectional view showing the structure of the all-solid-state battery 12 according to the second embodiment is shown in FIG. Figure 2 . Figure 2 An end portion of a single body structure of the all-solid-state battery 12 is shown. Figure 2 The all-solid-state battery 12 shown in the figure comprises: a positive electrode formed by a positive electrode collector 24 and a positive electrode active material layer (positive electrode layer) 25a or 25b; solid electrolyte layers 26a and 26b adjacent to the positive electrode active material layer (positive electrode layer) 25a or 25b; and a negative electrode formed by a lithium metal layer (negative electrode layer) 23a and a negative electrode collector 22a, or a lithium metal layer (negative electrode layer) 23b and a negative electrode collector 22b.

[0068] Figure 2 The all-solid battery 12 shown in the figure has an intermediate layer 27a between the lithium metal layer (negative electrode layer) 23a and the solid electrolyte layer 26a, and an intermediate layer 27b between the lithium metal layer (negative electrode layer) 23b and the solid electrolyte layer 26b. In addition, a first insulating material 28c is arranged at the end of the positive electrode active material layer (positive electrode layer) 25a, and a first insulating material 28d is arranged at the end of the positive electrode active material layer (positive electrode layer) 25b.

[0069] exist Figure 2 In the all-solid battery 12 of the second embodiment shown in , the ends of the intermediate layers 27a and 27b are arranged at substantially the same positions as the ends of the lithium metal layers (negative electrode layers) 23a and 23b in the extending direction of the electrode body.

[0070] Figure 2The all-solid-state battery 12 shown in the figure has first insulating materials 28c and 28d at the ends of the positive electrode layers 25a and 25b, respectively, and has a second insulating material 29a between the negative electrode collector 22a and the solid electrolyte layer 26a, and in the portion opposite to the end of the solid electrolyte layer 26a and the end of the first insulating material 28c, in such a way that the creepage distance from the surface of the negative electrode collector 22a on the negative electrode layer 23a side to the surface of the positive electrode collector 24 on the positive electrode layer 25a side is greater than the straight-line distance between the same starting and ending points.

[0071] In more detail, the second insulating material 29a of the all-solid battery 12 of the second embodiment is arranged in contact with the negative electrode current collector 22a in a state where the portion overlapping with the negative electrode layer 23a and the intermediate layer 27a does not exist in the extension direction of the electrode body of the all-solid battery 12. The other surface of the second insulating material 29a is in contact with the solid electrolyte layer 26a.

[0072] That is, in Figure 2 In the all-solid-state battery 12 shown in the figure, the second insulating material 29a has an entire surface in contact with the negative electrode collector 22a in the extension direction of the electrode body, and the surface opposite to the surface in contact with the negative electrode collector 22a is configured to extend from the end of the solid electrolyte layer 26a and partially contact with the solid electrolyte layer 26a.

[0073] Therefore, the all-solid-state battery 12 is similar to the above-mentioned embodiment. For example, even when the tab wires extending from the negative electrode collector 22a are gathered together to function as a battery, if the tab wires are bent, the creepage distance can be ensured to ensure insulation, and the breakage of the tab wires can be suppressed by improving the mechanical strength.

[0074] <Third Embodiment>

[0075] A portion of a cross-sectional view showing the structure of the all-solid-state battery 13 according to the third embodiment is shown in FIG. Figure 3 . Figure 3 An end portion of a single body structure of the all-solid-state battery 13 is shown. Figure 3 The all-solid-state battery 13 shown in the figure comprises: a positive electrode, formed by a positive electrode collector 34 and a positive electrode active material layer (positive electrode layer) 35a or 35b; solid electrolyte layers 36a and 36b, adjacent to the positive electrode active material layer (positive electrode layer) 35a or 35b; and a negative electrode, formed by a lithium metal layer (negative electrode layer) 33a and a negative electrode collector 32a, or a lithium metal layer (negative electrode layer) 33b and a negative electrode collector 32b.

[0076] Figure 3The all-solid battery 13 shown in the figure has an intermediate layer 37a between the lithium metal layer (negative electrode layer) 33a and the solid electrolyte layer 36a, and an intermediate layer 37b between the lithium metal layer (negative electrode layer) 33b and the solid electrolyte layer 36b. In addition, a first insulating material 38c is arranged at the end of the positive electrode active material layer (positive electrode layer) 35a, and a first insulating material 38d is arranged at the end of the positive electrode active material layer (positive electrode layer) 35b.

[0077] exist Figure 3 In the all-solid battery 13 of the third embodiment shown in , the ends of the intermediate layers 37a and 37b are arranged at substantially the same positions as the ends of the lithium metal layers (negative electrode layers) 33a and 33b in the extending direction of the electrode body.

[0078] Figure 3 The all-solid-state battery 13 shown in the figure has first insulating materials 38c and 38d at the ends of the positive electrode layers 35a and 35b, respectively, and has a second insulating material 39a between the negative electrode collector 32a and the solid electrolyte layer 36a, and in the portion opposite to the end of the solid electrolyte layer 36a and the end of the first insulating material 38c, in such a way that the creepage distance from the surface of the negative electrode collector 32a on the negative electrode layer 33a side to the surface of the positive electrode collector 34 on the positive electrode layer 35a side is greater than the straight-line distance between the same starting and ending points.

[0079] In more detail, the second insulating material 39a of the all-solid battery 13 of the third embodiment is arranged in contact with the negative electrode current collector 32a in a state where the portion overlapping with the negative electrode layer 33a and the intermediate layer 37a does not exist in the extension direction of the electrode body of the all-solid battery 13. The other surface of the second insulating material 39a is in contact with the solid electrolyte layer 36a.

[0080] That is, in Figure 3 In the all-solid-state battery 13 shown in the figure, the second insulating material 39a has one surface that is entirely in contact with the intermediate layer 37a in the extension direction of the electrode body, and the surface opposite to the surface in contact with the intermediate layer 37a is configured to extend from the end of the solid electrolyte layer 36a and partially in contact with the solid electrolyte layer 36a.

[0081] Therefore, the all-solid-state battery 13 is similar to the above-mentioned embodiment. For example, even when the tab wires extending from the negative electrode collector 32a are assembled to function as a battery, if the tab wires are bent, the creepage distance can be ensured to ensure insulation, and the breakage of the tab wires can be suppressed by improving the mechanical strength.

[0082] <Fourth embodiment>

[0083] A portion of a cross-sectional view showing the structure of the all-solid-state battery 14 according to the fourth embodiment is shown in FIG. Figure 4 . Figure 4 An end portion of a single body structure of the all-solid-state battery 14 is shown. Figure 4 The all-solid-state battery 14 shown in the figure comprises: a positive electrode, formed by a positive electrode collector 44 and a positive electrode active material layer (positive electrode layer) 45a or 45b; solid electrolyte layers 46a and 46b, adjacent to the positive electrode active material layer (positive electrode layer) 45a or 45b; and a negative electrode, formed by a lithium metal layer (negative electrode layer) 43a and a negative electrode collector 42a, or a lithium metal layer (negative electrode layer) 43b and a negative electrode collector 42b.

[0084] Figure 4 The all-solid battery 14 shown in the figure has an intermediate layer 47a between the lithium metal layer (negative electrode layer) 43a and the solid electrolyte layer 46a, and an intermediate layer 47b between the lithium metal layer (negative electrode layer) 43b and the solid electrolyte layer 46b. In addition, a first insulating material 48c is arranged at the end of the positive electrode active material layer (positive electrode layer) 45b.

[0085] exist Figure 4 In the all-solid-state battery 14 of the first embodiment shown in , the end of the intermediate layer 47a is arranged inside the end of the lithium metal layer (negative electrode layer) 43a in the extending direction of the electrode body.

[0086] In the all-solid battery 14 of the fourth embodiment, the first insulating material 48c increases as the distance ( Figure 4 The arrow c in the figure becomes larger, while the stacking direction of the electrode body ( Figure 4 That is, the first insulating material 48c is formed in the stacking direction ( Figure 4 The arrow L in the figure has an inclined shape, and the inclined portion becomes a gap.

[0087] Figure 4 The all-solid-state battery 14 shown in the figure has a first insulating material 48c at the end of the positive electrode layer 45a, and has a second insulating material 49a between the negative electrode collector 42a and the solid electrolyte layer 46a, and in a portion opposite to the end of the solid electrolyte layer 46a and the end of the first insulating material 48c, in such a way that the creepage distance from the surface of the negative electrode collector 42a on the negative electrode layer 43a side to the surface of the positive electrode collector 44 on the positive electrode layer 45a side is greater than the straight-line distance between the same starting and ending points.

[0088] In more detail, the second insulating material 49a of the all-solid-state battery 14 of the fourth embodiment is similar to the above-mentioned first embodiment. In the extension direction of the electrode body of the all-solid-state battery 14, a portion of one surface abuts against the negative electrode layer 43a, and the remaining portion abuts against the negative electrode collector 42a, and the surface opposite to the surface abutting against the negative electrode layer 43a and the negative electrode collector 42a is configured as: extending from the end of the solid electrolyte layer 46a, it partially abuts against the solid electrolyte layer 16a.

[0089] That is, in Figure 4 In the all-solid battery 14 shown in the figure, a portion of one surface of the second insulating material 49a is in contact with the negative electrode layer 43a in the extension direction of the electrode body, and the remaining portion is in contact with the negative electrode collector 42a, and the surface opposite to the surface in contact with the negative electrode layer 43a and the negative electrode collector 42a is configured as: extending from the end of the solid electrolyte layer 46a, and partially in contact with the solid electrolyte layer 46a.

[0090] In addition, Figure 4 In the all-solid battery 14 shown in FIG, the second insulating material 49a is a laminate including an adhesive layer 491 and an insulating layer 492. The adhesive layer 491 is arranged to abut against the negative electrode collector 42a, and the insulating layer 492 is arranged to abut against the solid electrolyte layer 46a.

[0091] Therefore, the all-solid-state battery 14 is similar to the above-mentioned embodiment. For example, even when the tab wires extending from the negative electrode collector 42a are gathered together to function as a battery, if the tab wires are bent, the creepage distance can be ensured to ensure insulation, and the breakage of the tab wires can be suppressed by improving the mechanical strength.

[0092] In particular, in the all-solid battery 14 of the fourth embodiment, the first insulating material 48c is formed in the stacking direction ( Figure 4 The second insulating material 49a has an inclined shape as indicated by the arrow L in FIG. 1 , and a gap is formed in the inclined portion. Furthermore, since the second insulating material 49a is disposed in the gap region, the generation of pressure caused by the presence of the second insulating material 49a can be suppressed when the electrode body is pressed or laminated.

[0093] Hereinafter, each structure of the all-solid-state battery of the present disclosure will be described.

[0094] [positive electrode]

[0095] The positive electrode of the all-solid battery of the present disclosure includes a positive electrode current collector and a positive electrode layer. In the all-solid battery of the present disclosure, the positive electrode layer abuts against the positive electrode current collector.

[0096] (Positive electrode collector)

[0097] The positive electrode collector used in the all-solid battery disclosed herein is configured in a manner of abutting against the positive electrode layer and has the function of collecting current from the positive electrode layer. The material of the positive electrode collector is not particularly limited as long as it can collect current from the positive electrode layer. Examples of the material of the positive electrode collector include aluminum, aluminum alloy, stainless steel, nickel, iron, and titanium, among which at least one selected from the group consisting of aluminum, aluminum alloy, and stainless steel is preferred.

[0098] The shape of the positive electrode collector is not particularly limited, and for example, a foil shape, a plate shape, etc. can be cited. In addition, the thickness of the positive electrode collector is not particularly limited, and can be the same as that used in the positive electrode of a general all-solid battery. The thickness of the positive electrode collector can also be, for example, in the range of 0.1 μm or more and 1 mm or less.

[0099] (Positive electrode layer)

[0100] The positive electrode layer is a layer containing at least a positive electrode active material. The positive electrode active material contained in the positive electrode layer is not particularly limited as long as it is a material used in the positive electrode layer of a general all-solid-state battery. As the positive electrode active material, for example, if it is a lithium-ion battery, layered active materials containing lithium, spinel-type active materials, olivine-type active materials, etc. can be listed. Specific examples of positive electrode active materials include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), LiNi p Mn q Co r O2(p+q+r=1), LiNi p Al q Co r O2 (p + q + r = 1), lithium manganate (LiMn2O4), Li 1+x Mn 2-x-y M y Heterogeneous element represented by O4 (x+y=2, M is selected from at least one of Al, Mg, Co, Fe, Ni and Zn) substituted Li-Mn spinel, lithium titanate (oxide containing Li and Ti), lithium metal phosphate (LiMPO4, M is selected from at least one of Fe, Mn, Co and Ni), etc.

[0101] The content of the positive electrode active material in the positive electrode layer may be, for example, in the range of 50 mass % to 99 mass %. The surface of the positive electrode active material may be coated with an oxide layer such as a lithium niobate layer, a lithium titanate layer or lithium phosphate.

[0102] The positive electrode layer may also arbitrarily include a solid electrolyte described later for the purpose of improving lithium ion conductivity. In addition, the positive electrode layer may also arbitrarily include an adhesive or a conductive aid, etc. As these substances, substances commonly used in all-solid batteries may be used.

[0103] The thickness of the positive electrode layer is not particularly limited and can be appropriately set according to the desired battery performance. The thickness of the positive electrode layer may be, for example, in the range of 0.1 μm to 1 mm.

[0104] In the case where the all-solid battery disclosed herein has an intermediate layer described later, the positive electrode layer preferably has an area equal to that of the intermediate layer on the stacking surface. Thus, the energy density of the all-solid battery can be increased. The area of ​​the positive electrode layer in the all-solid battery disclosed herein can be, for example, 100% at most, 90% to 100%, or 80% to 90% relative to the area of ​​the intermediate layer.

[0105] The method for producing the positive electrode layer is not particularly limited and can be produced by a known method. The positive electrode layer can be produced, for example, by mixing materials constituting the positive electrode layer with a solvent to form a slurry, applying the slurry on the positive electrode collector, and drying the slurry.

[0106] [Solid electrolyte layer]

[0107] The solid electrolyte layer is a layer containing a solid electrolyte and is arranged so as to be in contact with the positive electrode layer and the first insulating material.

[0108] As the material of the solid electrolyte, as long as it has lithium ion conductivity and insulation, it is not particularly limited. As the material of the solid electrolyte, the material commonly used in the all-solid lithium ion battery can be used, for example, sulfide solid electrolyte materials, oxide solid electrolyte materials, halide solid electrolytes, inorganic solid electrolytes such as lithium salts, solid electrolytes of polymer systems such as polyethylene oxide, and gel-based solid electrolytes containing lithium salts or lithium ion conductive ionic liquids can be listed. Among these, from the perspective of high conductivity of lithium ions and good structural formability and interface bonding under compression, sulfide solid electrolyte materials are preferably used.

[0109] The form of the solid electrolyte material is not particularly limited, and may be, for example, in a particle form. In addition, in the solid electrolyte layer of the all-solid battery disclosed herein, the content of the solid electrolyte is not particularly limited. The content of the solid electrolyte may be, for example, in the range of 50 mass % to 99 mass %.

[0110] The solid electrolyte layer may also contain a binder as desired. In addition, a binder may be contained as desired for the purpose of imparting mechanical strength and flexibility. As these substances, substances commonly used in all-solid batteries may be used.

[0111] The solid electrolyte layer may be arranged so that an end portion thereof is located at substantially the same position as an end portion of the first insulating material in the extending direction of the electrode body of the all-solid-state battery of the present disclosure.

[0112] Since the solid electrolyte layer of the electrode body of this shape does not protrude from the end surface of the electrode body, it is possible to suppress the occurrence of cracks in the solid electrolyte layer when pressure such as roll pressing is applied during the production process of the electrode body.

[0113] The method for producing the solid electrolyte layer is not particularly limited, and the solid electrolyte layer can be produced by a known method. The solid electrolyte layer can be produced, for example, by mixing the material constituting the solid electrolyte layer with a solvent to form a slurry, applying the slurry on a substrate, and drying the slurry.

[0114] [negative electrode]

[0115] The negative electrode of the all-solid battery of the present disclosure includes a negative electrode current collector and a negative electrode layer. In the all-solid battery of the present disclosure, the negative electrode layer abuts against the negative electrode current collector.

[0116] (Negative electrode current collector)

[0117] The negative electrode collector used in the all-solid battery disclosed in the present invention is configured in a manner of abutting against the negative electrode layer, and has the function of collecting electricity for the negative electrode layer. The material of the negative electrode collector is not particularly limited as long as it can collect electricity for the negative electrode layer, and is preferably composed of a material with high electrical conductivity. As a material with high electrical conductivity, for example, a metal containing at least one metal element selected from the group consisting of silver, palladium, gold (, platinum, aluminum, copper and nickel, or an alloy such as a stainless steel material, or a non-metal such as carbon (C) can be listed.

[0118] Among these highly conductive materials, if the manufacturing cost is considered in addition to the conductivity, it is preferred to use at least one selected from the group consisting of copper, stainless steel (SUS) and nickel. In particular, stainless steel materials are not easy to react with negative electrode active materials, positive electrode active materials and solid electrolytes, so if stainless steel materials are used as the material of the negative electrode collector, the internal resistance of the all-solid battery can be reduced.

[0119] The shape of the negative electrode collector is not particularly limited, and for example, foil, plate, mesh, nonwoven fabric, foam, etc. can be listed. In addition, for the negative electrode collector, a carbon layer can be configured on the surface for the purpose of improving the adhesion with the negative electrode layer, and the surface can also be roughened.

[0120] The thickness of the negative electrode current collector is not particularly limited, and may be the same as that used in the negative electrode of a general all-solid-state battery. The thickness of the negative electrode current collector may be, for example, in the range of 0.1 μm to 1 mm.

[0121] (Negative electrode layer)

[0122] The negative electrode layer is a layer containing a negative electrode active material that accepts electrons with lithium ions. The negative electrode active material contained in the negative electrode layer is not particularly limited as long as it is a material used in the negative electrode layer of a general all-solid-state battery. It is preferred to use a material with high electronic conductivity so that lithium ions can be reversibly released and retained, and electrons can be easily transported. As such a negative electrode active material, for example, silicon-based active materials such as silicon and silicon alloys, or carbon-based active materials such as graphite and hard carbon, various oxide-based active materials such as lithium titanate, lithium-based active materials such as metallic lithium and lithium alloys, etc. can be listed. The negative electrode active material can be used alone or in combination of two or more.

[0123] In the all-solid battery of the present disclosure, the negative electrode layer may also be a single metal lithium or a lithium metal alloy or a mixture thereof. Since the electrical capacity per unit weight of the negative electrode layer composed of a single lithium metal or a lithium metal alloy or a mixture thereof is large, a high-capacity all-solid battery can be realized.

[0124] The content of the negative electrode active material in the negative electrode layer may be, for example, in the range of 30% by mass to 100% by mass.

[0125] The negative electrode layer may also contain the above-mentioned solid electrolyte arbitrarily for the purpose of improving lithium ion conductivity. In addition, the negative electrode layer may also contain a binder or a conductive aid, etc. arbitrarily. As these substances, substances commonly used in all-solid batteries can be used.

[0126] The thickness of the negative electrode layer is not particularly limited and can be appropriately set according to the desired battery performance. The thickness of the negative electrode layer may be, for example, in the range of 0.1 μm to 1 mm.

[0127] The method for producing the negative electrode layer is not particularly limited and can be produced by a known method. The negative electrode layer can be produced, for example, by mixing materials constituting the negative electrode layer with a solvent to form a slurry, applying the slurry on the negative electrode collector, and drying the slurry.

[0128] [Middle layer]

[0129] In the case where the all-solid battery of the present disclosure is provided with an intermediate layer, the intermediate layer is provided between the solid electrolyte and the negative electrode layer. In the case where the negative electrode layer of the all-solid battery of the present disclosure is a layer of a single metal lithium or lithium metal alloy or a mixture thereof, by providing an intermediate layer between the solid electrolyte layer and the negative electrode layer, the uneven precipitation of dendrites at the interface between the solid electrolyte layer and the negative electrode layer can be suppressed, and the interface adhesion can be improved.

[0130] The middle layer is a layer with both electronic conductivity and ion conductivity. Since the middle layer has ion conductivity, for example, lithium ions can pass through it. Therefore, as the all-solid-state battery is repeatedly charged and discharged, the lithium ions (Li + ) will pass through the intermediate layer. Due to the presence of the intermediate layer, lithium metal can be uniformly precipitated between the intermediate layer and the negative electrode layer. In addition, when the intermediate layer has the flexibility to follow the volume changes of each layer accompanying the charge and discharge, even when the all-solid battery is repeatedly charged and discharged, the interface adhesion can be maintained, and the durability of the all-solid battery can be improved.

[0131] In the extension direction of the electrode body of the all-solid-state battery disclosed herein, the end of the intermediate layer can be arranged at a position substantially the same as the end of the negative electrode layer or the end of the second insulating material, or can be arranged further inward than the end of the negative electrode layer or the end of the second insulating material. Thus, the effect of arranging the intermediate layer can be fully presented.

[0132] The material constituting the intermediate layer is not particularly limited, and the intermediate layer may contain, for example, amorphous carbon, metal nanoparticles, and a binder as a binding material.

[0133] Amorphous carbon, unlike graphite, does not react with lithium metal to form an alloy, so the formation of dendrites can be suppressed, and the cycle characteristics of all-solid-state batteries can be improved.

[0134] Examples of amorphous carbon include carbon blacks such as acetylene black, furnace black, and Ketjen black, coke, activated carbon, etc. Amorphous carbon may be graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), carbon nanotubes (CNT), fullerene, or graphene.

[0135] By including metal nanoparticles in the middle layer, the electronic conductivity of the middle layer can be improved, and as a result, lithium metal can be precipitated more uniformly. The metal nanoparticles are not particularly limited, and examples thereof include metal nanoparticles such as tin, silicon, zinc, magnesium, gold, platinum, palladium, silver, aluminum, bismuth, and antimony.

[0136] The binder contained in the intermediate layer maintains the structure of the intermediate layer and improves the adhesion between the particles constituting the intermediate layer and between the intermediate layer and the solid electrolyte layer. The binder is not particularly limited, and substances commonly used in all-solid batteries can be used.

[0137] [First insulating material]

[0138] The first insulating material is disposed on the surface of the positive electrode layer side of the positive electrode collector in a manner adjacent to the end of the positive electrode layer. By disposing the insulating material of the first insulating material at the end of the positive electrode layer, it is possible to avoid the contact between the tab wire and the positive terminal due to the bending of the tab wire when the tab wire extending from the negative electrode collector of each single structure is assembled to function as a battery, thereby suppressing short circuits, suppressing the generation of cracks caused by volume changes accompanying repeated charging and discharging, and suppressing short circuits caused by cracks.

[0139] The shape of the first insulating material is not particularly limited as long as it is disposed at the end of the positive electrode layer. The size of the first insulating material is not particularly limited as long as it has a thickness less than the thickness of the positive electrode layer in the stacking direction of the electrode body and abuts against a part or all of the end surface of the positive electrode layer in the extending direction of the electrode body and is disposed at the end of the positive electrode layer.

[0140] The material of the first insulating material is not particularly limited as long as it exhibits insulating properties, and may be a so-called insulator other than a semiconductor or a conductor. The material of the first insulating material can be appropriately selected depending on the properties to be added to the insulating property.

[0141] Examples of the material of the first insulating material include polypropylene, alumina, anodized aluminum, boehmite, zirconium oxide, aluminum nitride, and silicon nitride.

[0142] Optionally, in the first insulating material, as the distance from the end adjacent to the positive electrode layer increases in the extending direction of the electrode body of the all-solid-state battery disclosed in the present invention, the thickness in the stacking direction of the electrode body decreases. Figure 4 The inclined shape shown in FIG. 1 has a gap formed in the inclined portion. Furthermore, since the second insulating material of the present disclosure can be arranged in the gap region, the generation of pressure can be suppressed when the electrode body is pressed or laminated.

[0143] The method for producing the first insulating material is not particularly limited, and the first insulating material may be produced by, for example, applying a slurry containing a material of the first insulating material onto a positive electrode current collector having a positive electrode layer formed thereon, and drying the slurry.

[0144] [Second insulating material]

[0145] The second insulating material is disposed between the negative electrode collector and the solid electrolyte layer and at a portion opposite to the end of the solid electrolyte layer and the end of the first insulating material. In addition, the second insulating material is disposed in contact with the solid electrolyte layer in such a manner that a creepage distance from the surface of the negative electrode collector on the negative electrode layer side to the surface of the positive electrode collector on the positive electrode layer side is greater than a straight line distance from the same start to end.

[0146] The all-solid-state battery disclosed in the present invention has the above-mentioned structure. Even when the tab wires extending from the negative electrode collectors of each single structure are gathered together to function as a battery, the spatial distance between the tab wires and the positive electrode collector becomes shorter due to the bending of the tab wires. The creepage distance from the surface on the negative electrode layer side of the negative electrode collector to the surface on the positive electrode layer side of the positive electrode collector is large, thereby ensuring insulation.

[0147] The second insulating material may also be a laminate including an adhesive layer and an insulating layer. Optionally, the adhesive layer is disposed on the negative electrode collector side, and the insulating layer is disposed on the solid electrolyte layer side. Since the second insulating material is in this state, it can be attached to a desired position of the electrode body by means of the adhesive layer. For example, the second insulating material may also be in the form of a tape having a release paper on the adhesive layer side.

[0148] In the case where the second insulating material is a laminate including an adhesive layer and an insulating layer, the material of the adhesive layer is not particularly limited and may be formed of a known material. Among them, since it is a material that does not easily cause an electrochemical reaction during charge and discharge, an acrylic adhesive layer is preferably used. In addition, the material of the insulating layer is not particularly limited and may be formed of a known material. Among them, since it is a material that does not easily cause an electrochemical reaction during charge and discharge, a material containing polyethylene is preferably used.

[0149] The manufacturing method of the second insulating material is not particularly limited, and it can be manufactured, for example, by applying a slurry containing a material for an adhesive layer on a substrate with a release paper and drying the slurry to form an adhesive layer, and applying a slurry containing a material for an insulating layer on the formed adhesive layer and drying the slurry to manufacture the second insulating material.

[0150] <Method for manufacturing all-solid-state battery>

[0151] The manufacturing method of the all-solid-state battery disclosed in the present invention is not particularly limited, and a known method can be used. For example, the negative electrode layer, the intermediate layer, the solid electrolyte layer and the positive electrode layer are stacked in sequence, and a first insulating material is formed at both ends of the positive electrode layer. Afterwards, the second insulating material is attached to the desired position with a desired size, thereby making a monomer structure. In addition, after making a monomer structure, multiple layers can also be stacked and then arbitrarily pressed to integrate.

[0152] As mentioned above, although the preferred embodiment of the present invention has been described, the present invention is not limited to the above-mentioned embodiment, and modifications or improvements within the scope that can achieve the object of the present invention are included in the present invention.

[0153] Reference numerals

[0154] 1, 11, 12, 13, 14 All-solid-state batteries

[0155] 2a, 2b, 12a, 12b, 22a, 22b, 32a, 32b, 42a negative electrode collector

[0156] 3a, 3b, 13a, 13b, 23a, 23b, 33a, 33b, 43a lithium metal layer (negative electrode layer)

[0157] 40, 140, 240, 340, 440 positive electrode collector

[0158] 5a, 5b, 15a, 15b, 25a, 25b, 35a, 35b, 45a positive electrode active material layer (positive electrode layer)

[0159] 6a, 6b, 16a, 16b, 26a, 26b, 36a, 36b, 46a solid electrolyte layer

[0160] 7a, 7b, 17a, 17b, 27a, 27b, 37a, 37b, 47a middle layer

[0161] 8a, 8b, 8c, 8d, 18c, 18d, 28c, 28d, 38c, 38d, 48c first insulating material

[0162] 19a, 19b, 29a, 29b, 39a, 39b, 49a second insulating material

[0163] 491 adhesive layer

[0164] 492 insulation layer

[0165] L electrode stacking direction

[0166] a) A region of the second insulating material extending from the solid electrolyte layer (a region that contributes to the creepage distance from the surface of the negative electrode current collector on the negative electrode layer side to the surface of the positive electrode current collector on the positive electrode layer side)

[0167] b The straight-line distance from the surface of the negative electrode current collector on the negative electrode layer side to the surface of the positive electrode current collector on the positive electrode layer side

[0168] c The distance from the end of the first insulating material adjacent to the positive electrode active material layer (positive electrode layer) in the extending direction of the electrode body

Claims

1. An all-solid-state battery, comprising an electrode body in which a positive electrode collector, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode collector are sequentially stacked, and The positive electrode current collector includes a first insulating material on a surface on the positive electrode layer side and adjacent to an end of the positive electrode layer. The solid electrolyte layer is arranged in contact with the positive electrode layer and the first insulating material. A second insulating material is provided between the negative electrode current collector and the solid electrolyte layer and at a portion facing an end of the solid electrolyte layer and an end of the first insulating material. The second insulating material is arranged in contact with the solid electrolyte layer so that a creepage distance from a surface of the negative electrode current collector on the negative electrode layer side to a surface of the positive electrode current collector on the positive electrode layer side is greater than a straight line distance between the same start and end points.

2. The all-solid-state battery according to claim 1, wherein: The first insulating material has a thickness in the stacking direction of the electrode body that decreases as the distance from the end portion adjacent to the positive electrode layer in the extending direction of the electrode body increases.

3. The all-solid-state battery according to claim 1 or 2, wherein: The second insulating material is arranged so as to overlap with an end portion of the negative electrode layer in an extending direction of the electrode body.

4. The all-solid-state battery according to claim 3, wherein: The second insulating material is disposed so that at least a portion thereof contacts the negative electrode current collector.

5. The all-solid-state battery according to claim 1 or 2, wherein: The electrode body includes an intermediate layer between the solid electrolyte layer and the negative electrode layer. In the extending direction of the electrode body, the end of the intermediate layer is arranged at substantially the same position as the end of the negative electrode layer or the end of the second insulating material, or is arranged inside the end of the negative electrode layer or the end of the second insulating material.

6. The all-solid-state battery according to claim 5, wherein: The second insulating material is arranged so that at least a portion thereof abuts against the intermediate layer.

7. The all-solid-state battery according to claim 1 or 2, wherein: An end portion of the solid electrolyte layer is located at substantially the same position as an end portion of the first insulating material in the extending direction of the electrode body.

8. The all-solid-state battery according to claim 1 or 2, wherein: The second insulating material is a laminate including an adhesive layer and an insulating layer. The adhesive layer is disposed on the negative electrode collector side. The insulating layer is disposed on the solid electrolyte layer side.

9. The all-solid-state battery according to claim 8, wherein: The aforementioned adhesive layer is an acrylic adhesive layer, The insulating layer includes polyethylene.

Images