All-solid-state batteries

Abstract

To provide an all-solid-state battery, in which a negative electrode current collector foil extension portion that connects a negative electrode current collector foil to a negative electrode tab is less likely to short-circuit with a positive electrode current collector foil.SOLUTION: An all-solid-state battery includes an electrode laminate in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order. An edge of the positive electrode layer is located inward of edges of the solid electrolyte layer and the negative electrode layer. The positive electrode current collector foil has a positive electrode current collector foil extension portion coupled to a positive electrode tab. The negative electrode current collector foil has a negative electrode current collector foil extension portion coupled to a negative electrode tab. An insulating frame is disposed at an outer edge of the positive electrode layer. A flexible insulating tape is attached to a surface of the negative electrode current collector foil extension portion on a side of the positive electrode layer, at a distance from the negative electrode layer, and an edge of the solid electrolyte layer on a side of the negative electrode current collector foil extension portion is positioned opposite the insulating tape.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] In recent years, research and development into secondary batteries that contribute to energy efficiency has been conducted to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. Among secondary batteries, all-solid-state batteries with a laminated structure in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are stacked in this order have attracted particular attention due to their superior safety (the solid electrolyte is non-flammable) and higher energy density. Known configurations of all-solid-state batteries with this laminated structure include connecting the positive electrode current collector foil and the positive electrode tab with an extension of the positive electrode current collector foil, and connecting the negative electrode current collector foil and the negative electrode tab with an extension of the negative electrode current collector foil. For all-solid-state batteries with this configuration, the placement of a ceramic layer or a buffer material on the surface of the extension of the current collector foil has been considered to prevent damage to the extended portions of the positive electrode current collector foil or the negative electrode current collector foil due to external load or stress concentration (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-104116 [Patent Document 2] Japanese Patent Application Publication No. 2023-39756 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in secondary batteries, increasing capacity and preventing short circuits between the positive and negative electrodes are key challenges. All-solid-state lithium batteries have been investigated as high-capacity all-solid-state batteries. These batteries use lithium ions as a charge transfer medium, depositing lithium from the positive electrode layer onto the negative electrode layer during charging and absorbing it into the positive electrode layer during discharging. In all-solid-state lithium batteries, the thickness of the negative electrode layer changes during charging and discharging. Therefore, in all-solid-state lithium batteries, the positive electrode current collector foil extension and the negative electrode current collector foil extension are preferably deformable in response to changes in the thickness of the negative electrode layer. However, deformation of the negative electrode current collector foil extension in response to changes in the thickness of the negative electrode layer can lead to a short circuit between the negative electrode current collector foil extension and the positive electrode current collector foil. Furthermore, if the negative electrode current collector foil extension and the positive electrode current collector foil are positioned close to each other due to manufacturing variations, external vibrations can cause a short circuit between the negative electrode current collector foil extension and the positive electrode current collector foil.

[0005] The present invention has been made in view of the above circumstances, and has an object to provide an all-solid-state battery in which a short circuit is less likely to occur between an extension portion of a negative electrode current collector foil that connects the negative electrode current collector foil and a negative electrode tab and the positive electrode current collector foil. [Means for solving the problem]

[0006] The present inventors have discovered that in an all-solid-state battery including an electrode laminate in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order, the positive electrode current collector foil has a positive electrode current collector foil extension connected to a positive electrode tab, and the negative electrode current collector foil has a negative electrode current collector foil extension connected to a negative electrode tab, it is possible to solve the above-mentioned problems by arranging an insulating frame on the outer edge of the positive electrode layer and attaching flexible insulating tape to the surface of the negative electrode current collector foil extension facing the positive electrode layer, with a gap between it and the negative electrode layer, so that the end of the solid electrolyte layer on the negative electrode current collector foil extension side is positioned opposite the insulating tape, and have completed the present invention.

[0007] (1) An all-solid-state battery including an electrode laminate in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order, an end of the positive electrode layer is located more inward than ends of the solid electrolyte layer and the negative electrode layer, the positive electrode current collector foil has a positive electrode current collector foil extension connected to a positive electrode tab, the negative electrode current collector foil has a negative electrode current collector foil extension connected to a negative electrode tab, an insulating frame is disposed on an outer edge of the positive electrode layer, a flexible insulating tape is affixed to a surface of the negative electrode current collector foil extension facing the positive electrode layer with a gap therebetween, and an end of the solid electrolyte layer on the negative electrode current collector foil extension side is located opposite the insulating tape.

[0008] In the all-solid-state battery (1), flexible insulating tape is attached to the extension of the negative electrode current collector foil, making it difficult for the extension and the positive electrode current collector foil to short-circuit. The insulating tape is flexible and can follow the deformation of the extension of the negative electrode current collector foil. Therefore, the extension of the negative electrode current collector foil is easily deformed in response to changes in the thickness of the negative electrode layer due to charging and discharging, and the insulating tape is not easily peeled off even when the extension of the negative electrode current collector foil deforms. The flexible insulating tape is attached to the extension of the negative electrode current collector foil with a gap between it and the negative electrode layer, so the insulating tape does not ride up onto the negative electrode layer when attached to the extension of the negative electrode current collector foil. Furthermore, because the end of the solid electrolyte layer on the side of the extension of the negative electrode current collector foil faces the insulating tape, even if there is a gap between the insulating tape and the negative electrode layer or if the extension of the negative electrode current collector foil deforms toward the positive electrode layer, the extension of the negative electrode current collector foil and the positive electrode current collector foil are unlikely to short-circuit. Furthermore, since an insulating frame is disposed on the outer edge of the positive electrode layer, even if the extension of the positive electrode current collector foil is deformed, the extension of the positive electrode current collector foil and the negative electrode current collector foil are less likely to short-circuit.

[0009] (2) The all-solid-state battery according to (1), wherein the solid electrolyte layer is divided into two or more layers, and an end of at least one of the solid electrolyte layers on the side of the negative electrode current collector foil extension is located at approximately the same position as an end of the insulating frame.

[0010] According to the all-solid-state battery of (2), at least one of the solid electrolyte layers is supported by the insulating frame, thereby improving the strength of the solid electrolyte layer.

[0011] (3) The all-solid-state battery according to (1) or (2), wherein the insulating tape has an extension that extends beyond the position of an outer edge of the insulating frame, and the length of the extension is equal to or greater than the total thickness of the solid electrolyte layer, the positive electrode layer, and the positive electrode current collector foil.

[0012] In the all-solid-state battery of (3), the length of the extended portion of the insulating tape is within the above range, so that when the extended portion of the negative electrode current collector foil is bent toward the positive electrode layer, a short circuit is less likely to occur between the extended portion of the negative electrode current collector foil and the positive electrode current collector foil.

[0013] (4) The all-solid-state battery according to any one of (1) to (4), wherein the thickness of the insulating tape is smaller than the distance between the negative electrode current collector foil extension and the solid electrolyte layer.

[0014] In the all-solid-state battery (4), the insulating tape and the solid electrolyte layer face each other with a gap therebetween, so the insulating tape is unlikely to be pressed by the solid electrolyte layer, causing the insulating tape to peel off from the extended portion of the negative electrode current collector foil.

[0015] (5) The all-solid-state battery according to (1), wherein an end of the solid electrolyte layer on the side of the extension portion of the negative electrode current collector foil is located near an end of the insulating frame.

[0016] In the all-solid-state battery of (5), the end of the solid electrolyte layer is located near the end of the insulating frame. Therefore, even if the extension of the negative electrode current collector foil is deformed toward the positive electrode layer, the extension of the negative electrode current collector foil and the positive electrode current collector foil are less likely to short-circuit.

[0017] (6) The all-solid-state battery according to (2), wherein the solid electrolyte layer is divided into a cathode-side solid electrolyte layer disposed on the cathode layer side, an anode-side solid electrolyte layer disposed on the anode layer side, and a central solid electrolyte layer disposed between the cathode-side solid electrolyte layer and the anode-side solid electrolyte layer, an end of the cathode-side solid electrolyte layer on the anode current collector foil extension side is positioned substantially flush with an end of the insulating frame, an end of the central solid electrolyte layer on the anode current collector foil extension side is positioned more inward than an end of the cathode-side solid electrolyte layer, and an end of the anode-side solid electrolyte layer on the anode current collector foil extension side is positioned more inward than an end of the central solid electrolyte layer.

[0018] (7) An all-solid-state battery including an electrode laminate in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order, the positive electrode current collector foil has a positive electrode current collector foil extension connected to a positive electrode tab, the negative electrode current collector foil has a negative electrode current collector foil extension connected to a negative electrode tab, an insulating frame is arranged on an outer edge of the positive electrode layer, a flexible insulating tape is affixed to a surface of the negative electrode current collector foil extension facing the positive electrode layer with a gap therebetween, an end of the positive electrode layer on the negative electrode current collector foil extension side is located more inward than ends of the solid electrolyte layer and the negative electrode layer, and an end of the solid electrolyte layer on the negative electrode current collector foil extension side is located opposite the insulating tape, and a thickness of the insulating tape is smaller than a distance between the negative electrode current collector foil extension and the solid electrolyte layer.

[0019] According to the all-solid-state battery (7), flexible insulating tape is attached to the extension of the negative electrode current collector foil, making it difficult for a short circuit to occur between the extension of the negative electrode current collector foil and the positive electrode current collector foil. The insulating tape is flexible and can follow the deformation of the extension of the negative electrode current collector foil. Therefore, the extension of the negative electrode current collector foil is easily deformed in response to changes in the thickness of the negative electrode layer due to charging and discharging, and the insulating tape is not easily peeled off even when the extension of the negative electrode current collector foil deforms. The flexible insulating tape is attached to the extension of the negative electrode current collector foil with a gap between it and the negative electrode layer, so the insulating tape does not ride up on the negative electrode layer when attached to the extension of the negative electrode current collector foil. Furthermore, because the end of the solid electrolyte layer on the side of the extension of the negative electrode current collector foil faces the insulating tape, even if there is a gap between the insulating tape and the negative electrode layer or if the extension of the negative electrode current collector foil deforms toward the positive electrode layer, a short circuit between the extension of the negative electrode current collector foil and the positive electrode current collector foil is difficult to occur. Furthermore, since the insulating tape is thin and does not come into contact with the solid electrolyte layer, the insulating tape is unlikely to cause the solid electrolyte layer and the negative electrode layer to peel off.Furthermore, since an insulating frame is disposed on the outer edge of the positive electrode layer, a short circuit is unlikely to occur between the positive electrode current collector foil extension and the negative electrode current collector foil even if the positive electrode current collector foil extension is deformed. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide an all-solid-state battery in which a short circuit is unlikely to occur between the positive electrode current collector foil and an extension portion of the negative electrode current collector foil that connects the negative electrode current collector foil and the negative electrode tab. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a plan view showing an all-solid-state battery according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 3 is an enlarged view of a main part of FIG. 2. [Figure 5] FIG. 5 is a plan view of the negative electrode current collector foil shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are merely examples of the present invention, and the present invention is not limited to the following.

[0023] Fig. 1 is a plan view showing an all-solid-state battery according to one embodiment of the present invention, Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1, Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1, Fig. 4 is an enlarged view of a main part of Fig. 2, and Fig. 5 is a plan view of the negative electrode current collector foil shown in Fig. 4.

[0024] As shown in FIGS. 1 to 5 , the all-solid-state battery 100 includes a positive electrode 10, a negative electrode 20, and a solid electrolyte layer 30 laminated between the positive electrode 10 and the negative electrode 20. The negative electrode 20 and the solid electrolyte layer 30 are laminated so as to sandwich one positive electrode 10. An intermediate layer 40 is disposed between the negative electrode 20 and the solid electrolyte layer 30. The positive electrode 10 includes a positive electrode current collector foil 11 and a positive electrode layer 12 laminated on both surfaces of the positive electrode current collector foil 11. The negative electrode 20 includes a negative electrode current collector foil 21 and a negative electrode layer 22 laminated on the positive electrode 10 side of the negative electrode current collector foil 21. The all-solid-state battery 100 includes an electrode laminate in which the positive electrode layer 12, the solid electrolyte layer 30, the negative electrode layer 22, and the negative electrode current collector foil 21 are laminated in this order on both surfaces of the positive electrode current collector foil 11.

[0025] The positive current collector foil 11 has a positive current collector foil extension 11a that connects to the positive electrode tab 15. The positive current collector foil extension 11a does not have a positive electrode layer 12 formed thereon. The negative current collector foil 21 has a negative current collector foil extension 21a that connects to the negative electrode tab 25. The negative current collector foil extension 21a does not have a negative electrode layer 22 laminated thereon. The positive current collector foil extension 11a and the negative current collector foil extension 21a extend in opposite directions.

[0026] An insulating frame 13 is disposed on the outer edge of the positive electrode layer 12. The insulating frame 13a on the positive electrode current collector foil extension 11a side is wider than the insulating frame 13b on the negative electrode current collector foil extension 21a side. The width of the insulating frame 13a on the positive electrode current collector foil extension 11a side may be greater than the total thickness of the positive electrode layer 12, the solid electrolyte layer 30, the intermediate layer 40, and the negative electrode 20. If the width of the insulating frame 13a is greater than the total thickness, even if the positive electrode current collector foil extension 11a is deformed, a short circuit between the positive electrode current collector foil extension 11a and the negative electrode current collector foil 21 is unlikely to occur. The width of the insulating frame 13a may be equal to or less than twice the total thickness. The width of the insulating frame 13b on the negative electrode current collector foil extension 21a side (L1 in FIG. 4) is, for example, within a range of 2.0 mm to 4.0 mm.

[0027] A flexible insulating tape 50 is attached to the surface of the negative electrode current collector foil extension 21a on the positive electrode 10 side, with a gap between it and the negative electrode layer 22. The insulating tape 50 is a strip-shaped body attached to the edge of the negative electrode layer 22 as shown in FIG. 5. The insulating tape 50 has an extension 51 that extends beyond the outer edge of the insulating frame 13b. The length of the extension 51 (L in FIG. 4) may be equal to or greater than the total thickness of the solid electrolyte layer 30, the positive electrode layer 12, and the positive electrode current collector foil 11. When the length of the extension 51 is equal to or greater than the total thickness, a short circuit is less likely to occur between the negative electrode current collector foil extension 21a and the positive electrode current collector foil 11 when the negative electrode current collector foil extension 21a is bent toward the positive electrode 10.

[0028] The solid electrolyte layer 30 is divided into three layers: a cathode-side solid electrolyte layer 31 disposed on the cathode layer 12 side; an anode-side solid electrolyte layer 33 disposed on the anode layer 22 side; and a central solid electrolyte layer 32 disposed between the cathode-side solid electrolyte layer 31 and the anode-side solid electrolyte layer 33. The cathode-side solid electrolyte layer 31 functions to improve adhesion between the cathode layer 12 and the central solid electrolyte layer 32. The anode-side solid electrolyte layer 33 functions to improve adhesion between the anode layer 22 and the central solid electrolyte layer 32. The cathode-side solid electrolyte layer 31 and the anode-side solid electrolyte layer 33 are thinner than the central solid electrolyte layer 32. The ends of the cathode-side solid electrolyte layer 31 and the central solid electrolyte layer 32 on the anode current collector foil extension 21a side are located at approximately the same position as the end of the insulating frame 13b. Support by the insulating frame 13b improves the strength of the solid electrolyte layer 30.

[0029] As shown in FIG. 4 , the positions of the ends of the components on the side of the negative current collector foil extension 21a are as follows: The end of the positive electrode layer 12 is located more inward than the ends of the solid electrolyte layer 30 and the negative electrode layer 22 (on the opposite side to the negative electrode tab 25). The end of the positive electrode side solid electrolyte layer 31 is located substantially flush with the end of the insulating frame 13b. The end of the central solid electrolyte layer 32 is located more inward than the end of the positive electrode side solid electrolyte layer 31. The end of the negative electrode side solid electrolyte layer 33 is located more inward than the end of the central solid electrolyte layer 32. The end of the intermediate layer 40 is located between the end of the negative electrode side solid electrolyte layer 33 and the end of the central solid electrolyte layer 32. The end of the negative electrode layer 22 is located between the end of the intermediate layer 40 and the end of the central solid electrolyte layer 32. The relationship between the length of the negative electrode layer 22 from one end of the positive electrode layer 12 to the other end (see FIG. 4 ) and the width of the insulating frame 13b (see FIG. 4 ) is not particularly limited. For example, the ratio of L2 to L1 may be within a range of 0.3 to 0.6. The gap between the negative electrode layer 22 and the insulating tape 50 (see FIG. 4 ) is within a range of 0.5 to 1.0 mm. If the insulating tape 50 runs over the negative electrode layer 22 due to variations in application of the insulating tape 50 to the negative electrode current collector foil extension 21a, damage to the negative electrode layer 22 or density variations may occur. For this reason, in this embodiment, a gap is provided between the negative electrode layer 22 and the insulating tape 50. However, providing a gap between the negative electrode layer 22 and the insulating tape 50 may cause a short circuit between the negative electrode current collector foil extension 21a and the positive electrode current collector foil 11 when the negative electrode current collector foil extension 21a is bent toward the positive electrode 10. For this reason, the end of the central solid electrolyte layer 32 is positioned to face the insulating tape 50. This makes it less likely that a short circuit will occur between the negative electrode current collector foil extension 21a and the positive electrode current collector foil 11, even if the negative electrode current collector foil extension 21a is bent toward the positive electrode 10.

[0030] The insulating tape 50 and the solid electrolyte layer 30 (central solid electrolyte layer 32) face each other with a gap therebetween. That is, the thickness of the insulating tape 50 is smaller than the distance between the negative electrode current collector foil extension 21a and the central solid electrolyte layer 32 (the total thickness of the negative electrode layer 22, the intermediate layer 40, and the negative electrode solid electrolyte layer 33). Because the insulating tape 50 is thin and the insulating tape 50 and the solid electrolyte layer 30 face each other with a gap therebetween, the insulating tape 50 is unlikely to press against the solid electrolyte layer 30, causing the solid electrolyte layer 30 and the negative electrode layer 22 to peel off from each other. The thickness of the insulating tape 50 is preferably within a range of 0.5 to 0.8 times the distance between the negative electrode current collector foil extension 21a and the central solid electrolyte layer 32.

[0031] Examples of materials for the positive electrode current collector foil 11, the positive electrode layer 12, the positive electrode tab 15, the negative electrode current collector foil 21, the negative electrode layer 22, the negative electrode tab 25, the solid electrolyte layer 30, the intermediate layer 40, and the insulating tape will be described using the case where the all-solid-state battery 100 is an all-solid-state lithium battery that uses lithium ions as a charge transfer medium.

[0032] There are no particular limitations on the material or shape of the positive electrode current collector foil 11, as long as it has the function of collecting current from the positive electrode 10. Examples of materials for the positive electrode current collector foil 11 include aluminum, aluminum alloys, stainless steel, nickel, iron, and titanium, and among these, aluminum, aluminum alloys, and stainless steel are preferred. Examples of the shape of the positive electrode current collector foil 11 include foil and plate shapes.

[0033] The positive electrode layer 12 contains at least one type of positive electrode active material. There are no particular limitations on the positive electrode active material, and any material that is used in the positive electrode layers of general solid-state secondary batteries can be used. For example, a layered active material containing lithium, a spinel-type active material, an olivine-type active material, etc. can be used. Specific examples of the positive electrode active material include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), and LiNi p Mn q Co r O2(p+q+r=1), LiNi p Al q Co rO2 (p+q+r=1), lithium manganese oxide (LiMn2O4), Li 1+x Mn 2-x-y Examples include heteroelement-substituted Li-Mn spinel represented by MO4 (x+y=2, M=at least one selected from Al, Mg, Co, Fe, Ni, and Zn), lithium titanate (oxide containing Li and Ti), and lithium metal phosphate (LiMPO4, M=at least one selected from Fe, Mn, Co, and Ni).

[0034] The positive electrode layer 12 may optionally contain a solid electrolyte in order to improve lithium ion conductivity. It may also optionally contain a conductive additive in order to improve conductivity. Furthermore, it may also optionally contain a binder in order to achieve flexibility. There are no particular restrictions on the solid electrolyte, conductive additive, and binder, and those used in the positive electrode layers of general all-solid-state lithium batteries may be used.

[0035] The material of the positive electrode tab 15 may be the same as or different from the material of the positive electrode current collector foil 11. The positive electrode tab 15 may be integrally connected to the positive electrode current collector foil 11.

[0036] There are no particular limitations on the material or shape of the negative electrode current collector foil 21 as long as it has the function of collecting current from the negative electrode 20. Examples of materials for the negative electrode current collector foil 21 include nickel, copper, and stainless steel. Examples of shapes for the negative electrode current collector foil 21 include foil and plate shapes.

[0037] The material and shape of the anode layer 22 are not particularly limited as long as it has the function of densely depositing lithium ions. A metallic lithium layer or a layer of a metal that forms an alloy with lithium can be used as the anode layer 22. Examples of metals that form an alloy with lithium include Mg, Si, Au, Ag, In, Ge, Sn, Pb, Al, and Zn. The metal that forms the anode layer 22 may be in the form of a powder or a thin film. By using the anode 20 having this anode layer 22, a uniform lithium deposit layer can be formed on the surface of the anode layer 22.

[0038] The material of the negative electrode tab 25 may be the same as the material of the negative electrode current collector foil 21, or may be different from the material of the negative electrode current collector foil 21.

[0039] The solid electrolyte layer 30 is divided into three layers: a positive electrode-side solid electrolyte layer 31, a central solid electrolyte layer 32, and a negative electrode-side solid electrolyte layer 33. The positive electrode-side solid electrolyte layer 31, the central solid electrolyte layer 32, and the negative electrode-side solid electrolyte layer 33 each contain a solid electrolyte. The solid electrolytes contained in the positive electrode-side solid electrolyte layer 31, the central solid electrolyte layer 32, and the negative electrode-side solid electrolyte layer 33 may be the same or different.

[0040] The solid electrolyte is not particularly limited as long as it has lithium ion conductivity, and examples thereof include sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, and halide solid electrolytes. Examples of sulfide solid electrolytes include Li2S-P2S5 and Li2S-P2S5-LiI. The sulfide solid electrolyte may have an argyrodite-type crystal structure. Examples of oxide solid electrolytes include NASICON-type oxides, garnet-type oxides, and perovskite-type oxides. Examples of NASICON-type oxides include oxides containing Li, Al, Ti, P, and O (e.g., Li 1.5 Al 0.5 Ti 1.5 Examples of garnet-type oxides include oxides containing Li, La, Zr, and O (e.g., LiLaZrO 12 Examples of perovskite oxides include oxides containing Li, La, Ti, and O (for example, LiLaTiO3).

[0041] The solid electrolyte layer 30 may contain a binder. There are no particular restrictions on the binder, and any binder that is used in the solid electrolyte layer of a general solid secondary battery can be used.

[0042] In order to improve adhesion to the positive electrode layer 12, the positive electrode side solid electrolyte layer 31 may have a higher binder content than the central solid electrolyte layer 32. In order to improve adhesion to the negative electrode layer 22, the negative electrode side solid electrolyte layer 33 may have a higher binder content than the central solid electrolyte layer 32.

[0043] The intermediate layer 40 may be, for example, one that improves the uniformity of lithium ions deposited in the anode layer 22 of the anode 20. The intermediate layer 40 may be a layer that has electronic conductivity and has voids through which lithium ions can pass. The intermediate layer 40 may contain a material that has lithium metal conductivity and a material that has electronic conductivity. As the material that has lithium metal conductivity, for example, amorphous carbon particles can be used. Examples of amorphous carbon particles include carbon blacks such as acetylene black, furnace black, and ketjen black, coke, activated carbon, CNTs (carbon nanotubes), fullerenes, and graphene. As the material that has electronic conductivity, for example, a metal can be used. The metal may be in the form of particles. Examples of metals include Ag, Au, Pt, Pd, Si, Al, Bi, Sn, Zn, Ga, and In.

[0044] The insulating tape 50 has an insulating resin layer and an adhesive layer. There are no particular restrictions on the material of the insulating resin layer as long as it is flexible. For example, vinyl tape, cellophane tape, or polyimide tape can be used as the insulating tape 50.

[0045] In the all-solid-state battery 100 of this embodiment configured as described above, the flexible insulating tape 50 is attached to the negative electrode current collector foil extension 21a, making it difficult for a short circuit to occur between the negative electrode current collector foil extension 21a and the positive electrode current collector foil 11. The insulating tape 50 is flexible and can follow the deformation of the negative electrode current collector foil extension 21a. Therefore, the negative electrode current collector foil extension 21a is easily deformed in response to changes in the thickness of the negative electrode layer 22 due to charge and discharge, and the insulating tape 50 is unlikely to peel off even if the negative electrode current collector foil extension 21a deforms. Because the flexible insulating tape 50 is attached to the negative electrode current collector foil extension 21a with a gap between it and the negative electrode layer 22, the insulating tape 50 does not ride up on the negative electrode layer 22 when attaching the insulating tape 50 to the negative electrode current collector foil extension 21a. Furthermore, the end of the solid electrolyte layer 30 on the negative electrode current collector foil extension 21a side is positioned opposite the insulating tape 50, so there is a gap between the insulating tape 50 and the negative electrode layer 22, and even if the negative electrode current collector foil extension 21a deforms toward the positive electrode layer 12, the negative electrode current collector foil extension 21a and the positive electrode current collector foil 11 are less likely to short-circuit. Furthermore, because the insulating frame 13 is disposed on the outer edge of the positive electrode layer 12, even if the positive electrode current collector foil extension 11a deforms, the positive electrode current collector foil extension 11a and the negative electrode current collector foil 21 are less likely to short-circuit.

[0046] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the present embodiment, the solid electrolyte layer 30 is divided into three layers, but the solid electrolyte layer 30 may be a single layer. Furthermore, in the present embodiment, the insulating tape 50 and the solid electrolyte layer 30 (the central insulating base material) face each other with a gap therebetween, but the insulating tape 50 and the solid electrolyte layer 30 may be in contact with each other. Furthermore, in the present embodiment, the thickness of the insulating tape 50 is set to be smaller than the distance between the negative electrode current collector foil extension 21a and the solid electrolyte layer 30, but the thickness of the insulating tape 50 may be set to be larger than this distance so that the insulating tape 50 is crushed by the solid electrolyte layer 30. [Explanation of symbols]

[0047] 10 positive electrode 11 Positive electrode current collector foil 11a Positive electrode current collecting foil extension 12 Positive electrode layer 13 Insulation frame 15 Positive electrode tab 20 negative electrode 21 Negative electrode current collecting foil 21a Negative current collector foil extension 22 negative electrode layer 25 Negative electrode tab 30 Solid electrolyte layer 31 Positive electrode solid electrolyte layer 32 Central insulating substrate 33 Negative electrode side solid electrolyte layer 40 Middle Class 50 Electrical Tape 100 solid state battery

Claims

1. an electrode laminate in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order; an end of the positive electrode layer is located inside ends of the solid electrolyte layer and the negative electrode layer; the positive electrode current collector foil has a positive electrode current collector foil extension portion connected to a positive electrode tab, the negative electrode current collector foil has a negative electrode current collector foil extension connected to a negative electrode tab, an insulating frame is disposed on the outer edge of the positive electrode layer; a flexible insulating tape is attached to a surface of the negative electrode current collector foil extension on the positive electrode layer side with a gap between the tape and the negative electrode layer; an end of the solid electrolyte layer on the negative electrode current collector foil extension side is positioned opposite the insulating tape.

2. 2. The all-solid-state battery according to claim 1, wherein the solid electrolyte layer is divided into two or more layers, and an end of at least one of the solid electrolyte layers on the side of the negative electrode current collector foil extension portion is located at approximately the same position as an end of the insulating frame.

3. 2. The all-solid-state battery according to claim 1, wherein the insulating tape has an extension that extends beyond the position of an outer edge of the insulating frame, and the length of the extension is equal to or greater than the total thickness of the solid electrolyte layer, the positive electrode layer, and the positive electrode current collector foil.

4. 2. The all-solid-state battery according to claim 1, wherein the thickness of the insulating tape is smaller than the distance between the negative electrode current collector foil extension and the solid electrolyte layer.

5. 2. The all-solid-state battery according to claim 1, wherein an end of the solid electrolyte layer on the side of the negative electrode current collector foil extension is located near an end of the insulating frame.

6. the solid electrolyte layer is divided into a cathode-side solid electrolyte layer disposed on the cathode layer side, an anode-side solid electrolyte layer disposed on the anode layer side, and a central solid electrolyte layer disposed between the cathode-side solid electrolyte layer and the anode-side solid electrolyte layer, an end of the positive electrode-side solid electrolyte layer on the side of the negative electrode current collector foil extension portion is located at substantially the same position as an end of the insulating frame; an end portion of the central solid electrolyte layer on the side of the negative electrode current collector foil extension portion is located more inward than an end portion of the positive electrode solid electrolyte layer; 3. The all-solid-state battery according to claim 2, wherein an end of the negative electrode-side solid electrolyte layer on the negative electrode current collector foil extension side is located more inward than an end of the central solid electrolyte layer.

7. an electrode laminate in which a positive electrode current collector foil, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative electrode current collector foil are laminated in this order; the positive electrode current collector foil has a positive electrode current collector foil extension portion connected to a positive electrode tab, the negative electrode current collector foil has a negative electrode current collector foil extension connected to a negative electrode tab, an insulating frame is disposed on the outer edge of the positive electrode layer; a flexible insulating tape is attached to a surface of the negative electrode current collector foil extension on the positive electrode layer side with a gap between the tape and the negative electrode layer; an end of the positive electrode layer on the side of the negative electrode current collector foil extension is located inside ends of the solid electrolyte layer and the negative electrode layer, an end of the solid electrolyte layer on the side of the extension portion of the negative electrode current collector foil is located opposite the insulating tape; a thickness of the insulating tape is smaller than a distance between the negative electrode current collector foil extension and the solid electrolyte layer.

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