All-solid battery and manufacturing method of the all-solid battery

Abstract

To provide an all-solid battery capable of suppressing damage at a neighbor of an outer periphery of an electrode layer by an electric charging and discharging.SOLUTION: The present invention discloses an all-solid battery having: a first collector; a first electrode layer; a solid electrolyte layer; a second electrode layer; and a second collector in this order. The first electrode layer contains a first active material layer, and the second electrode layer contains a second active material layer of which volume is changed in a charging and a discharging. In the case where the all-solid battery is viewed in a plan view from a thickness direction, an area of the second electrode layer is larger than an area of the first electrode layer, and a first surface on the solid electrolyte layer side of the first electrode layer includes an inside region and an outside region arranged on outside of the inside region and including an end part. In the thickness direction, the all-solid battery includes the solid electrolyte layer, and a low elastic ratio member of which an elastic ratio is lower than that of a space (i) or the second electrode layer and the solid electrolyte layer (ii) between the outside region and the second electrode layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an all-solid-state battery and a method for manufacturing an all-solid-state battery. [Background technology]

[0002] An all-solid-state battery is a battery that has a solid electrolyte layer between a positive electrode layer and a negative electrode layer, and has the advantage that it is easier to simplify safety devices compared to liquid batteries that have an electrolyte solution containing a flammable organic solvent.

[0003] An all-solid-state battery is manufactured by sandwiching a solid electrolyte layer between a positive electrode and a negative electrode and bonding them under pressure in the thickness direction. Patent Document 1 discloses an all-solid-state battery including a solid electrolyte layer, one electrode and the other electrode sandwiching the solid electrolyte layer, and a first current collector sandwiching the one electrode together with the solid electrolyte layer, in which an end of the one electrode is inclined toward the first current collector, and an edge of the end of the other electrode on the solid electrolyte layer side is disposed between an edge of the end of the one electrode on the solid electrolyte layer side and an edge of the end of the one electrode on the first current collector side in a plan view. In Patent Document 1, by inclining one electrode toward the first current collector side, pressure is not directly applied even when pressed from the first current collector side, thereby reducing stress concentration on the solid electrolyte layer during pressure bonding. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-062579 A Summary of the Invention [Problem to be solved by the invention]

[0005] In some cases, an active material that changes in volume during charging and discharging is used in the electrode layers of an all-solid-state battery. The inventors of the present application have found a new problem in that when the active material contained in one electrode layer expands during charging and discharging, stress is concentrated near the outer periphery of the other opposing electrode layer, which may cause damage.

[0006] The present disclosure has been made in consideration of the above problems, and has as its main object to provide an all-solid-state battery capable of suppressing damage to the vicinity of the outer periphery of an electrode layer caused by charging and discharging. [Means for solving the problem]

[0007] [1] An all-solid-state battery having, in this order, a first current collector, a first electrode layer, a solid electrolyte layer, a second electrode layer, and a second current collector, the first electrode layer includes a first active material; the second electrode layer includes a second active material that changes in volume during charging and discharging; When the all-solid-state battery is viewed in a plan view from a thickness direction, an area of ​​the second electrode layer is larger than an area of ​​the first electrode layer, a first surface of the first electrode layer facing the solid electrolyte layer has an inner region and an outer region disposed outside the inner region and including an end portion; an all-solid-state battery having, between the outer region and the second electrode layer in the thickness direction, the solid electrolyte layer, and (i) a space, or (ii) a low elastic modulus member having an elastic modulus lower than those of the second electrode layer and the solid electrolyte layer.

[0008] [2] The all-solid-state battery according to [1], wherein a thickness of the first electrode layer decreases from a boundary between the inner region and the outer region toward the end portion.

[0009] [3] The all-solid-state battery according to [1] or [2], wherein the space is disposed between the outer region and the solid electrolyte layer in the thickness direction.

[0010] [4] The all-solid-state battery according to [1] or [2], wherein the low elastic modulus member is disposed between the outer region and the solid electrolyte layer in the thickness direction.

[0011] [5] the solid electrolyte layer is disposed to cover the inner region and the outer region; The all-solid-state battery according to [1] or [2], wherein the space is disposed between the solid electrolyte layer covering the outer region and the second electrode layer in the thickness direction.

[0012] [6] the solid electrolyte layer is disposed to cover the inner region and the outer region; The all-solid-state battery according to [1] or [2], wherein the low elastic modulus member is disposed between the solid electrolyte layer covering the outer region and the second electrode layer in the thickness direction.

[0013] [7] the solid electrolyte layer has, from the first electrode layer side, a first solid electrolyte layer and a second solid electrolyte layer, the first solid electrolyte layer is disposed to cover the inner region and the outer region; the second solid electrolyte layer is disposed in contact with the second electrode layer, The all-solid-state battery according to [1] or [2], wherein the space is disposed between a first solid electrolyte layer covering the outer region and the second solid electrolyte layer in the thickness direction.

[0014] [8] the solid electrolyte layer has, from the first electrode layer side, a first solid electrolyte layer and a second solid electrolyte layer, the first solid electrolyte layer is disposed to cover the inner region and the outer region; the second solid electrolyte layer is disposed in contact with the second electrode layer, The all-solid-state battery according to [1] or [2], wherein the low elastic modulus member is disposed between a first solid electrolyte layer covering the outer region and the second solid electrolyte layer in the thickness direction.

[0015] [9] The all-solid-state battery according to any one of [1] to [8], wherein the second electrode layer is a negative electrode active material layer and contains an alloy-based active material as the second active material.

[0016]

[10] A method for producing an all-solid-state battery according to any one of [1] to [9], a first laminate preparation step of preparing a first laminate having the first current collector and the first electrode layer; a second laminate preparation step of preparing a second laminate having the second current collector and the second electrode layer; a first laminate pressure molding step of pressure molding the first laminate; a lamination step of laminating the first laminate and the second laminate with the solid electrolyte layer interposed therebetween after the first laminate pressure molding step, a first laminate pressure molding step of performing isostatic pressing to reduce a thickness of the first electrode layer from a boundary between the inner region and the outer region toward the end portion.

[0017]

[11] The method for producing an all-solid-state battery according to

[10] , wherein the isostatic pressing is performed without placing a support plate on a surface of the first laminate on the side of the first electrode layer. Effect of the Invention

[0018] The present disclosure has an effect of providing an all-solid-state battery capable of suppressing damage to the vicinity of the outer periphery of the electrode layer due to charging and discharging. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example (first embodiment) of an all-solid-state battery according to the present disclosure. [Diagram 2] FIG. 4 is a schematic cross-sectional view showing another example (second embodiment) of the all-solid-state battery according to the present disclosure. [Diagram 3]FIG. 4 is a schematic cross-sectional view showing another example (third embodiment) of the all-solid-state battery according to the present disclosure. [Figure 4] FIG. 2 is a schematic cross-sectional view showing another example (stacked battery) of the all-solid-state battery according to the present disclosure. [Diagram 5] FIG. 2 is a schematic cross-sectional view showing an example of a method for producing the all-solid-state battery according to the first embodiment of the present disclosure. [Figure 6] FIG. 4 is a schematic cross-sectional view showing an example of a method for producing an all-solid-state battery according to a second embodiment of the present disclosure. [Figure 7] FIG. 11 is a schematic cross-sectional view showing an example of a method for producing an all-solid-state battery according to a third embodiment of the present disclosure. [Figure 8] 1 is a schematic cross-sectional view showing an example of a method for producing an all-solid-state battery (laminated battery) in the present disclosure. FIG. [Figure 9] 1 is a schematic cross-sectional view showing an example of a method for producing an all-solid-state battery (laminated battery) in the present disclosure. FIG. [Figure 10] FIG. 1 is a schematic cross-sectional view showing an example of a conventional all-solid-state battery. [Figure 11] 3 is a schematic cross-sectional view of a battery after a charge-discharge test in an example and a comparative example. FIG. [Figure 12] 13 shows the results of comparing the coulombic efficiency at each charging rate in an embodiment and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present disclosure will be described in detail below with reference to the drawings. The drawings are merely examples, and the size and shape of each part may be exaggerated to facilitate understanding.

[0021] A. All-solid-state battery 1(a) and 1(b) are schematic cross-sectional views showing an example of an all-solid-state battery according to the present disclosure. As shown in FIG. 1(a) and FIG. 1(b), an all-solid-state battery 10A has a thickness direction D T1, the all-solid-state battery 10A includes, in this order, a first current collector 1, a first electrode layer 2, a solid electrolyte layer 3, a second electrode layer 4, and a second current collector 5. Although not specifically shown, the all-solid-state battery 10A may include an exterior body and a restraining member, which will be described later.

[0022] In the present disclosure, the first electrode layer 2 includes a first active material, and the second electrode layer 4 includes a second active material that changes in volume during charging and discharging. Also, as shown in FIG. 1(a) and FIG. 1(b), the all-solid-state battery 10A is arranged in a thickness direction D T When viewed from above, the area of ​​the second electrode layer 4 is larger than the area of ​​the first electrode layer 2. In the present disclosure, the first surface S21 of the first electrode layer 2 on the side of the solid electrolyte layer 3 has an inner region R1 and an outer region R2 that is disposed outside the inner region R1 and includes an end E2, and T The semiconductor device is characterized in that, between the outer region R2 of the first surface S21 and the second electrode layer 4 (within the dotted line frame), there is a solid electrolyte layer 3, and (i) a space 30, or (ii) a low elastic modulus member 40 having an elastic modulus lower than those of the second electrode layer and the solid electrolyte layer.

[0023] In the all-solid-state battery 10A shown in FIG. 1(a) and FIG. 1(b), the thickness of the first electrode layer 2 decreases from the boundary B between the inner region R1 and the outer region R2 toward the end E2. As shown in FIG. 1(a), T 1(b), a space 30 may be formed between the outer region R2 on the first surface S21 of the first electrode layer 2 and the solid electrolyte layer 3. Meanwhile, a low elastic modulus member 40 may be disposed between the outer region R2 on the first surface S21 of the first electrode layer 2 and the solid electrolyte layer 3.

[0024] FIG. 10(a) is a schematic cross-sectional view showing an example of a conventional all-solid-state battery. Conventionally, in order to achieve high battery performance, as in the conventional all-solid-state battery 50A shown in FIG. 10(a), it has been considered important that the first electrode layer 52, the solid electrolyte layer 53, and the second electrode layer 54 are in good contact with each other up to the end of each layer. However, if the second electrode layer 54 contains an active material that changes in volume during charging and discharging, when the all-solid-state battery 50 is applied with a restraining pressure P in the thickness direction by the restraining member 60, and the second electrode layer 54 expands during charging and discharging (arrow in FIG. 10), stress is concentrated near the outer periphery of the first electrode layer 52, and damage may occur near the outer periphery of the first electrode layer 52.

[0025] FIG. 10(b) is a schematic cross-sectional view showing another example of a conventional all-solid-state battery. Depending on the manufacturing method of the conventional all-solid-state battery, as in the all-solid-state battery 50B shown in FIG. 10(b), the end of the first electrode layer 52 may droop toward the solid electrolyte layer 53. In such an all-solid-state battery 50B, when the second electrode layer 54 expands during charging and discharging, stress is concentrated near the outer periphery of the first electrode layer 52, and bending stress is generated near the outer periphery of the first electrode layer 52, so that the outer periphery of the first electrode layer 52 is more likely to be damaged. In addition, in FIG. 10(a) and FIG. 10(b), 51 indicates a first current collector, and 55 indicates a second current collector.

[0026] It should be noted that the above-mentioned Patent Document 1 aims to reduce stress concentration on the solid electrolyte layer during pressure bonding, and does not mention the problem of damage to the outer periphery of one electrode layer due to expansion of the other electrode during charging and discharging.

[0027] In contrast, the all-solid-state battery of the present disclosure has a thickness direction D TEven if the second electrode layer 4 expands when a confining pressure is applied to the first electrode layer 2, the space 30 or the low elastic modulus member 40, in addition to the solid electrolyte layer 3, is provided between the outer peripheral region R2 of the first electrode layer 2 and the second electrode layer 4, so that excessive stress concentration near the outer periphery of the first electrode layer 2 (the first electrode layer at the position overlapping with the outer region in the thickness direction and in the vicinity thereof) can be suppressed, and damage near the outer periphery of the first electrode layer 2 can be suppressed. This makes it possible to prevent the ion conduction path and the electron conduction path near the outer periphery of the first electrode layer 2 from being blocked, thereby suppressing a decrease in capacity.

[0028] 1. Structure of all-solid-state batteries The all-solid-state battery according to the present disclosure has a first current collector, a first electrode layer, a solid electrolyte layer, a second electrode layer, and a second current collector.

[0029] As shown in FIG. 1, the all-solid-state battery according to the present disclosure has a thickness direction D T When viewed from above, the area of ​​the second electrode layer 4 is larger than the area of ​​the first electrode layer 2. In other words, the end surface S2t of the first electrode layer 2 is located inside the end surface S4t of the second electrode layer 4. The ratio (A4 / A2) of the area (A4) of the second electrode layer 4 to the area (A2) of the first electrode layer 2 is, for example, larger than 1.0, may be 1.1 or more, or may be 1.2 or more. On the other hand, the ratio (A4 / A2) is, for example, 1.5 or less, may be 1.4 or less, or may be 1.3 or less. When the area of ​​the second electrode layer 4 is larger than the area of ​​the first electrode layer 2, stress is likely to concentrate near the outer periphery of the first electrode layer due to the expansion of the second electrode layer. On the other hand, in the present disclosure, since a solid electrolyte layer and a space or a low elastic modulus member are provided between the outer region of the first electrode layer and the second electrode layer in the thickness direction, excessive stress concentration near the outer periphery of the first electrode layer 2 can be suppressed, and damage near the outer periphery of the electrode layer due to charging and discharging can be suppressed. Furthermore, when the second electrode layer is a negative electrode active material layer, by having the above ratio (A4 / A2), for example, lithium deposition at the end of the second electrode layer can be suppressed, and a short circuit can be suppressed.

[0030] In the all-solid-state battery of the present disclosure, the first surface S21 of the first electrode layer 2 on the side of the solid electrolyte layer 3 has an inner region R1 and an outer region R2 disposed outside the inner region R1 and including an end E2. The all-solid-state battery of the present disclosure has, for example, a second surface S22 which is the surface of the first electrode layer 2 on the side of the first current collector 1. The all-solid-state battery may further have an end surface S2t connecting the first surface S21 and the second surface S22. In this case, the end surface E2 of the first surface S21 is a side where the end surface S2t intersects with the first surface S21.

[0031] The all-solid-state battery of the present disclosure may have a solid electrolyte layer and a space between the outer region of the first electrode layer and the second electrode layer in the thickness direction. On the other hand, the solid electrolyte layer and a low elastic modulus member may be provided between the outer region of the first electrode layer and the second electrode layer. By disposing the low elastic modulus member, stress concentration near the outer periphery of the first electrode layer due to expansion and contraction of the second electrode layer is prevented, and excessive deformation is suppressed, so that vibrations and the like are absorbed and damage due to external impact can be prevented. The elastic modulus of the low elastic modulus member may be lower than the elastic modulus of the second electrode layer and the elastic modulus of the solid electrolyte layer, and is preferably lower than any of the first electrode layer, the solid electrolyte layer, and the second electrode layer.

[0032] The low elastic modulus member may be any member having an elastic modulus lower than those of the second electrode layer and the solid electrolyte layer, and examples thereof include rubber (elastomer), urethane, resin sponge, plastic, and other resin materials.

[0033] In the present disclosure, as shown in FIG. 1(a) and FIG. 1(b), it is preferable that the thickness of the first electrode layer 2 decreases from the boundary B between the inner region R1 and the outer region R2 toward the end E2. In other words, it is preferable that the outer region R2 of the first surface S21 of the first electrode layer 2 has an inclined surface that inclines toward the first current collector 1. This makes it possible to further suppress the concentration of stress near the outer periphery of the first electrode layer 2. It is preferable that the outer region R2 of the first surface of the first electrode layer 2 is an inclined surface having a curvature. On the other hand, it is not limited to an inclined surface having a curvature, and may be an inclined surface with one angle, or may have inclined surfaces with multiple angles.

[0034] In the present disclosure, the density of the first electrode layer at a position overlapping with the outer region in the thickness direction is preferably higher than the density of the first electrode layer at a position overlapping with the inner region in the thickness direction. Such a density difference is generated, for example, by performing isostatic pressing, which will be described later. In addition, the impact resistance is improved by having a high density of the first electrode layer at a position overlapping with the outer region in the thickness direction.

[0035] 1(a) and 1(b), the second surface S22 is preferably flat over its entirety. Since the second surface S22 is flat over its entirety, no gap is generated between the first electrode layer 2 and the restraint plate in the thickness direction, and bending stress near the outer periphery of the first electrode layer 2 due to expansion of the second electrode layer 4 is suppressed, so that damage to the first electrode layer 2 can be further suppressed.

[0036] The all-solid-state battery according to the present disclosure may be exemplified as a first embodiment illustrated in FIG. 1(a) and FIG. 1(b), a second embodiment illustrated in FIG. 2(a) and FIG. 2(b), and a third embodiment illustrated in FIG. 3(a) and FIG. 3(b), depending on the position of the space or the low modulus of elasticity member.

[0037] (1) First embodiment As shown in Figures 1(a) and 1(b), in the all-solid-state battery 10A in the first embodiment, the thickness of the first electrode layer 2 decreases from the boundary B between the inner region R1 and the outer region R2 toward the end E2. T 1(b), a space 30 is provided between the outer region R2 and the solid electrolyte layer 3. On the other hand, in the all-solid-state battery 10A shown in FIG.

[0038] In the all-solid-state battery of this embodiment, even if the second electrode layer 4 expands under a confining pressure applied in the thickness direction, the pressure acting on the vicinity of the periphery of the first electrode layer caused by the volume change of the second active material can be reduced because of the space or the low elasticity member, and excessive stress concentration on the vicinity of the periphery of the first electrode layer 2 can be suppressed. Therefore, damage to the vicinity of the periphery of the first electrode layer can be suppressed. In this embodiment, as shown in FIG. 1(a) and FIG. 1(b), the outer region R2 and the solid electrolyte layer 3 are usually arranged apart from each other.

[0039] In this embodiment, in a cross-sectional view in the thickness direction, the ratio (H1 / W1) of the distance (H1 in FIG. 1) between the end E2 and the solid electrolyte layer 3 to the width (W1 in FIG. 1) of the outer region R2 is, for example, 1 / 50 or more, and may be 1 / 10 or more. On the other hand, the ratio (H1 / W1) is, for example, 1 or less, and may be 1 / 5 or less. Specifically, the H1 is, for example, 40 μm or more and 100 μm or less, and the W1 is, for example, 400 μm or more and 500 μm or less. Note that, when the thickness of the first electrode layer 2 is reduced from the boundary between the inner region and the outer region toward the end by isostatic pressing as described later, the ratio (H1 / W1) is influenced by the ratio of the width and thickness of the first electrode layer.

[0040] In this embodiment, in a plan view of the all-solid-state battery, the area of ​​the solid electrolyte layer 3 is preferably the same as or larger than the second electrode layer 4. That is, the end face S3t of the solid electrolyte layer 3 is preferably at the same position as the end face S4t of the second electrode layer 4 or is located outside the end face S4t. This is because the entire surface of the second electrode layer is in contact with the solid electrolyte layer 3, thereby making it possible to suppress the deposition of Li at the end of the second electrode layer.

[0041] (2) Second embodiment 2(a) and 2(b) are schematic cross-sectional views showing another example of the all-solid-state battery of the present disclosure. In the all-solid-state battery 10B shown in FIG. 2(a) and FIG. 2(b), the thickness of the first electrode layer 2 decreases from the boundary B between the inner region R1 and the outer region R2 toward the end E2. In addition, the solid electrolyte layer 3 is disposed so as to cover the inner region R1 and the outer region R2 on the first surface S21 of the first electrode layer 2. That is, the solid electrolyte layer 3 is disposed so as to follow the first electrode layer 2. The all-solid-state battery 10B shown in FIG. 2(a) has a thickness direction D T 2(b), there is a space between the solid electrolyte layer 3 covering the outer region R2 and the second electrode layer 4. On the other hand, in the all-solid-state battery 10B shown in FIG. 2(b), a low elastic modulus member 40 is disposed between the solid electrolyte layer 3 covering the outer region R2 and the second electrode layer 4.

[0042] The all-solid-state battery 10B in this embodiment has the space 30 or the low elastic modulus member 40, and for the reasons described above, it is possible to suppress excessive stress concentration near the outer periphery of the first electrode layer 2. Therefore, it is possible to suppress cracking of the first electrode layer. In this embodiment, it is also possible to suppress cracking near the outer periphery of the solid electrolyte layer. Therefore, it is possible to suppress internal short circuits.

[0043] In this embodiment, the surface (outer region R3) of the solid electrolyte layer 3 on the second electrode layer side covering the outer region R2 is preferably an inclined surface having a curvature. On the other hand, it is not limited to an inclined surface having a curvature, and may be an inclined surface with one angle or may have an inclined surface with multiple angles. This makes it possible to further suppress the concentration of stress near the outer periphery of the solid electrolyte layer and near the outer periphery of the first electrode layer. The outer region R3 of the solid electrolyte layer 3 is preferably an inclined surface having a curvature. On the other hand, it is not limited to an inclined surface having a curvature, and may be an inclined surface with one angle or may have an inclined surface with multiple angles. In this embodiment, the outer region R3 is usually arranged away from the second electrode layer 4.

[0044] In this embodiment, the solid electrolyte layer 3 has, for example, a first surface S31 and a second surface S32 facing each other, and an end surface S3t connecting the first surface S31 and the second surface S32. The first surface S31 is the surface of the solid electrolyte layer 3 facing the second electrode layer 4, and the second surface S32 is the surface of the solid electrolyte layer 3 facing the first electrode layer 2. In this embodiment, the first surface S31 of the solid electrolyte layer 3 includes an outer region R3 which includes the end E3.

[0045] In this embodiment, in a cross-sectional view in the thickness direction, the ratio (H2 / W2) of the distance (H2 in FIG. 2) between the end E3 and the second electrode layer 4 to the width (W2 in FIG. 2) of the outer region R3 of the solid electrolyte layer 3 is, for example, 1 / 50 or more, and may be 1 / 10 or more. Meanwhile, the ratio (H2 / W2) is, for example, 1 or less, and may be 1 / 5 or less. Specifically, H2 is, for example, 40 μm or more and 100 μm or less, and W2 is, for example, 400 μm or more and 500 μm or less.

[0046] (3) Third embodiment 3(a) and 3(b) are schematic cross-sectional views showing another example of the all-solid-state battery of the present disclosure. In the all-solid-state battery 10C shown in FIG. 3(a) and FIG. 3(b), the thickness of the first electrode layer 2 decreases from the boundary B between the inner region R1 and the outer region R2 toward the end E2. In addition, the solid electrolyte layer 3 has a first solid electrolyte layer 31 and a second solid electrolyte layer 32 from the first electrode layer 2 side, and the first solid electrolyte layer 31 is arranged so as to cover the inner region R1 and the outer region R2 on the first surface S21 of the first electrode layer 2. That is, the first solid electrolyte layer 31 is arranged so as to follow the first electrode layer 2. On the other hand, the second solid electrolyte layer 32 is arranged so as to be in contact with the second electrode layer 4. In the all-solid-state battery 10C shown in FIG. 3(a), a space is formed between the first solid electrolyte layer 31 covering the outer region R2 and the second solid electrolyte layer 32 in the thickness direction. On the other hand, in the all-solid-state battery 10C shown in FIG. 3(b), the low elastic modulus member 40 is disposed between the first solid electrolyte layer 31 covering the outer region R2 and the second solid electrolyte layer 32 in the thickness direction.

[0047] The all-solid-state battery 10C in this embodiment has the space 30 or the low elastic modulus member 40, and for the reasons described above, it is possible to suppress excessive stress concentration near the outer periphery of the first electrode layer 2. Therefore, it is possible to suppress cracking of the first electrode layer. In this embodiment, it is also possible to suppress cracking near the outer periphery of the solid electrolyte layer. Therefore, it is possible to suppress internal short circuits.

[0048] In this embodiment, the surface (outer region R31) of the first solid electrolyte layer 31 on the second electrode layer 4 side covering the outer region R2 is preferably an inclined surface having a curvature. On the other hand, it is not limited to an inclined surface having a curvature, and may be an inclined surface with one angle or may have an inclined surface with multiple angles. This makes it possible to further suppress the concentration of stress near the outer periphery of the first solid electrolyte layer and near the outer periphery of the first electrode layer. In this embodiment, the outer region R31 is usually disposed away from the second solid electrolyte layer 32. The shape of the first electrode layer 2 in this embodiment may be the same as that of the first embodiment.

[0049] In this embodiment, the first solid electrolyte layer 31 has, for example, a first surface S311 and a second surface S312 facing each other, and an end surface S31t connecting the first surface S311 and the second surface S312. The first surface S311 is the surface of the first solid electrolyte layer 31 facing the second electrode layer 4, and the second surface S312 is the surface of the first solid electrolyte layer 31 facing the first electrode layer 2. In this embodiment, the first surface S311 of the first solid electrolyte layer 31 includes an outer region R31 which includes the end E31.

[0050] In this embodiment, in a cross-sectional view in the thickness direction, the ratio (H3 / W3) of the distance (H3 in FIG. 3) between the end E31 and the second solid electrolyte layer 32 to the width (W3 in FIG. 3) of the outer region R31 of the first solid electrolyte layer 31 is, for example, 1 / 50 or more, and may be 1 / 10 or more. Meanwhile, the ratio (H3 / W3) is, for example, 1 or less, and may be 1 / 5 or less. Specifically, H3 is, for example, 40 μm or more and 100 μm or less, and W3 is, for example, 400 μm or more and 500 μm or less.

[0051] In this embodiment, in a plan view of the all-solid-state battery, the area of ​​the second solid electrolyte layer 32 is preferably the same as or larger than the area of ​​the second electrode layer 4. That is, the end face S32t of the second solid electrolyte layer 32 is preferably at the same position as the end face S4t of the second electrode layer 4 or is located outside the end face S4t. This is because the entire surface of the second electrode layer is in contact with the second solid electrolyte layer 32, thereby making it possible to suppress the deposition of Li in the vicinity of the end of the second electrode layer.

[0052] 2. Components of solid-state batteries In the present disclosure, the first current collector and the first electrode layer may be a positive current collector and a positive active material layer, respectively. In this case, the second current collector and the second electrode layer are a negative current collector and a negative active material layer, respectively. Conversely, the first current collector and the first electrode layer may be a negative current collector and a negative active material layer, respectively. In this case, the second current collector and the second electrode layer are a positive current collector and a positive active material layer, respectively.

[0053] (1)Second electrode layer In the present disclosure, the second electrode layer includes a second active material that changes in volume during charging and discharging. The second active material is preferably an active material that expands in volume upon charging and contracts in volume upon discharging. On the other hand, the second active material may be an active material that expands in volume upon discharging and contracts in volume upon charging. The active material that changes in volume during charging and discharging has a volume expansion rate during charging or discharging of, for example, 105% or more, or may be 110% or more, 150% or more, or may be 200% or more.

[0054] When the second electrode layer is a negative electrode active material layer, examples of the second active material (negative electrode active material) include alloy-based active materials (e.g., Si-based active materials, Sn-based active materials) containing metals capable of forming alloys with lithium, such as Sn and Si, carbon active materials, metallic lithium (Li), etc. Among these, alloy-based active materials are preferred because they have a large volume expansion coefficient.

[0055] The Si-based active material is an active material containing the Si element. Examples of the Si-based active material include simple Si, Si alloys, and Si oxides. The Si alloy preferably contains the Si element as a main component. The ratio of the Si element in the Si alloy may be, for example, 50 mol% or more, 70 mol% or more, or 90 mol% or more. Examples of the Si alloy include Si-Al alloys, Si-Sn alloys, Si-In alloys, Si-Ag alloys, Si-Pb alloys, Si-Sb alloys, Si-Bi alloys, Si-Mg alloys, Si-Ca alloys, Si-Ge alloys, and Si-Pb alloys. The Si alloy may be a two-component alloy or a multi-component alloy of three or more components. Examples of the Si oxide include SiO.

[0056] The Sn-based active material is an active material containing Sn element. Examples of the Sn-based active material include simple Sn and Sn alloys. The Sn alloy preferably contains Sn element as a main component. The ratio of Sn element in the Sn alloy may be, for example, 50 mol% or more, 70 mol% or more, or 90 mol% or more.

[0057] Examples of the carbon active material include mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon.

[0058] These negative electrode active materials may be used alone, or two or more kinds of negative electrode active materials may be used in combination.

[0059] The shape of the negative electrode active material may be, for example, particulate. The average particle size (D50) of the negative electrode active material is, for example, 10 nm or more, and may be 100 nm or more. On the other hand, the average particle size (D50) of the negative electrode active material is, for example, 50 μm or less, and may be 20 μm or less. The average particle size (D50) can be calculated, for example, from measurements using a laser diffraction particle size distribution meter or a scanning electron microscope (SEM).

[0060] When the second electrode layer is a positive electrode active material layer, examples of the second active material (positive electrode active material) include lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-iron composite oxide, LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 Examples of the positive electrode active material include lithium-nickel-cobalt composite oxides such as O2, lithium-metal phosphate compounds, and lithium-transition metal sulfate compounds. These positive electrode active materials may be used alone or in combination of two or more.

[0061] The second electrode layer may further contain at least one of a conductive material, a solid electrolyte, and a binder. Examples of the conductive material include carbon materials. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Examples of the binder include a rubber-based binder and a fluoride-based binder.

[0062] (2) First electrode layer The first electrode layer includes a first active material. When the first electrode layer is a positive electrode active material layer, the first active material (positive electrode active material) included in the first electrode layer is not particularly limited. That is, in addition to the positive electrode active material exemplified as the second active material described above, a conventionally known active material can be used.

[0063] When the first electrode layer is a negative electrode active material layer, the first active material (negative electrode active material) contained in the first electrode layer is not particularly limited. That is, in addition to the negative electrode active materials exemplified as the second active material described above, conventionally known active materials can be used.

[0064] The first electrode layer may further contain at least one of a conductive material, a solid electrolyte, and a binder. The conductive material, the solid electrolyte, and the binder may be the same as those described above.

[0065] (3) First current collector and second current collector The negative electrode current collector collects the current from the negative electrode active material layer. Examples of the material for the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include a foil shape. The negative electrode current collector may have a carbon coating layer on the surface on the negative electrode active material layer side.

[0066] The positive electrode current collector collects the current from the positive electrode active material layer. Examples of the material for the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of the shape of the positive electrode current collector include a foil shape. The positive electrode current collector may have a carbon coating layer on the surface on the positive electrode active material layer side.

[0067] (4) Solid electrolyte layer The solid electrolyte layer is disposed between the first electrode layer and the second electrode layer and contains at least a solid electrolyte. The type of the solid electrolyte is the same as that described above. As shown in Figures 1 and 2, the solid electrolyte layer may have a single-layer structure, or as shown in Figure 3, it may have a multi-layer structure in which multiple layers are stacked.

[0068] (5) All-solid-state battery In addition, the all-solid-state battery may have one, two, or three or more power generating units each composed of a first electrode layer, a solid electrolyte layer, and a second electrode layer. When the all-solid-state battery has a plurality of power generating units, they may be connected in parallel or in series.

[0069] FIG. 4 is a schematic cross-sectional view illustrating an all-solid-state battery according to the present disclosure. The all-solid-state battery 10D shown in FIG. 4 includes four electrode laminates 11 (11A, 11B, 11C, and 11D). The electrode laminate 11A includes a first current collector 1, a power generating element 12A (a first electrode layer 2, a solid electrolyte layer 3, and a second electrode layer 4), and a second current collector 5, in this order. The electrode laminate 11B includes a first current collector 1, a power generating element 12B (a first electrode layer 2, a solid electrolyte layer 3, and a second electrode layer 4), and a second current collector 5, in this order. On the other hand, the electrode laminate 11C includes a first current collector 1, a power generating element 12C (a first electrode layer 2, a solid electrolyte layer 3, and a second electrode layer 4), and a second current collector 5, in this order. Moreover, laminate 11D has, in this order, a first current collector 1, a power generating element 12D (first electrode layer 2, solid electrolyte layer 3, and second electrode layer 4), and a second current collector 5. Electrode laminate 11A and electrode laminate 11B share one first current collector 1, electrode laminate 11B and electrode laminate 11C share one second current collector 5, and electrode laminate 11C and electrode laminate 11D share one first current collector 1. These laminates 11A to 11D are connected in parallel with each other.

[0070] The all-solid-state battery according to the present disclosure generally has an exterior body that covers an electrode stack including a first current collector, a first electrode layer, a solid electrolyte layer, a second electrode layer, and a second current collector. The exterior body may be a laminate-type exterior body or a case-type exterior body.

[0071] The all-solid-state battery in the present disclosure preferably includes a restraining member. The restraining member is a member that applies a restraining pressure to the electrode laminate in the thickness direction. The configuration of the restraining member is not particularly limited, and a known configuration can be adopted. By applying the restraining pressure, a good ion conduction path and an electron conduction path are formed. The restraining pressure is, for example, 0.1 MPa or more, may be 1 MPa or more, or may be 5 MPa or more. On the other hand, the restraining pressure is, for example, 100 MPa or less, may be 50 MPa or less, or may be 20 MPa or less.

[0072] The all-solid-state battery in the present disclosure is typically a lithium-ion secondary battery. Examples of applications of the all-solid-state battery include power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, it is preferable to use the all-solid-state battery as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The all-solid-state battery in the present disclosure may also be used as a power source for moving objects other than vehicles (e.g., railways, ships, and aircraft), and may also be used as a power source for electrical products such as information processing devices.

[0073] B. Manufacturing method of all-solid-state batteries The manufacturing method of the all-solid-state battery in the present disclosure is the manufacturing method of the all-solid-state battery described above, comprising: a first laminate preparation step of preparing a first laminate having the first current collector and the first electrode layer; a second laminate preparation step of preparing a second laminate having the second current collector and the second electrode layer; a first laminate pressure molding step of performing pressure molding on the first laminate; and a lamination step of stacking the first laminate and the second laminate with the solid electrolyte layer interposed therebetween after the first laminate pressure molding step, in which isostatic pressing is performed to reduce the thickness of the first electrode layer from the boundary between the inner region and the outer region toward the end portion.

[0074] According to the present disclosure, the first laminate pressure molding step performs isostatic pressing to reduce the thickness of the first electrode layer from the boundary between the inner region and the outer region toward the end, thereby obtaining an all-solid-state battery capable of suppressing damage to the vicinity of the outer periphery of the first electrode layer due to charging and discharging.

[0075] Hereinafter, each step of the method for producing an all-solid-state battery according to the present disclosure will be described in detail with reference to Fig. 5. Fig. 5 is a schematic cross-sectional view showing an example of the method for producing the all-solid-state battery according to the first embodiment described above.

[0076] 1. First laminate preparation process This step is a step of preparing a first laminate having a first current collector and a first electrode layer. As shown in Fig. 5(a), a first laminate 51A has a first current collector 1 and a first electrode layer 2. As shown in Figs. 6 and 7 described later, the first laminate may have a solid electrolyte layer on the surface of the first electrode layer opposite to the first current collector.

[0077] The first laminate is produced, for example, by forming a first electrode layer on a first current collector 1. For example, a method for forming the first electrode layer includes a method (coating method) in which a slurry for forming the first electrode layer is applied and dried. Furthermore, a solid electrolyte layer may be formed on the first electrode layer. For example, a method for forming the solid electrolyte layer includes a method (transfer method) in which a sheet in which a solid electrolyte layer is formed on a metal foil is used to transfer the solid electrolyte layer onto the first electrode layer.

[0078] 2. Second laminate preparation process This step is a step of preparing a second laminate having a second current collector and a second electrode layer. As shown in Fig. 5(b), the second laminate 52A has a second current collector 4 and a second electrode layer 5. As shown in Fig. 5(b), the second electrode layer 4 may have a solid electrolyte layer 3 on the surface opposite to the first current collector 5. The method of forming the second electrode layer and the solid electrolyte layer is the same as the method of forming the first electrode layer and the solid electrolyte layer described above.

[0079] 3. First laminate pressure molding process This step is a step of performing pressure molding on the first laminate, and is a step of reducing the thickness of the first electrode layer from the boundary between the inner region and the outer region toward the end by performing isostatic pressing.

[0080] In this step, as shown in FIG. 5(c), it is preferable to perform isostatic pressing without arranging a support plate on the surface of the first laminate 51A on the first electrode layer 2 side. The "surface of the first laminate on the first electrode layer side" refers to the surface of the first laminate located on the first electrode layer side with the first current collector as a reference. By such isostatic pressing, a slope is provided in the outer region of the surface (first surface) of the first electrode layer opposite the first current collector on which the support plate is not arranged. That is, the thickness of the first electrode layer can be easily reduced from the boundary between the inner region and the outer region of the first surface toward the end. The support plate is not particularly limited as long as it is a member having a higher rigidity than the first laminate. On the other hand, it is preferable to arrange a support plate 15 on the first current collector 1 side of the first laminate 51A. By isostatic pressing, the surface of the first laminate on which the support plate is arranged on the first current collector side becomes flat.

[0081] Examples of the pressure medium for the isostatic press include liquids such as water and oil, and powders. It is more preferable to use a liquid as the pressure medium. The pressure in the isostatic press is not particularly limited, but can be, for example, 10 to 1000 MPa, preferably 100 to 500 MPa. The pressurizing time is not particularly limited, but can be, for example, 1 to 120 minutes, preferably 5 to 30 minutes. Furthermore, the temperature of the pressure medium during pressurization is also not particularly limited, but can be, for example, 20 to 200°C, preferably 50 to 100°C.

[0082] 5(c), the first laminate 51A is preferably isostatically pressed in a state in which it is sealed together with the support plate 15 by the laminate film 16 and is isolated from the external atmosphere. Furthermore, release films for preventing adhesion may be disposed between the first laminate and the support and between the support and the laminate film.

[0083] 4.Lamination process This step is a step of laminating the first and second laminates with a solid electrolyte layer interposed therebetween after the first laminate pressure molding step. As shown in FIG. 5(b), when the second laminate 52A has a solid electrolyte layer 3, the first and second laminates 51A and 52A are opposed to each other with the solid electrolyte layer 3 of the second laminate interposed therebetween and laminated (FIG. 5(d)). When the first laminate has a solid electrolyte layer, the first and second laminates are opposed to each other with the solid electrolyte layer of the first laminate interposed therebetween and laminated. This produces an all-solid-state battery 10A. When producing an all-solid-state battery in which a low elastic modulus member is disposed, the first and second laminates are laminated in the lamination step with the low elastic modulus member interposed between them.

[0084] 5. Other embodiments Fig. 6 is a schematic cross-sectional view showing an example of a method for manufacturing the all-solid-state battery of the second embodiment described above. As shown in Fig. 6(a), a first laminate 51B is prepared, which has a first current collector 1 and a first electrode layer 2, and further has a solid electrolyte layer 3 on the surface of the first electrode layer 2 opposite to the first current collector 1. Also, as shown in Fig. 6(b), a second laminate 52B is prepared, which has a second current collector 5 and a second electrode layer 4.

[0085] Next, as shown in FIG. 6(c), in the first laminate pressure molding step, a support plate 15 is placed on the first current collector 1 side of the first laminate 51B, and isostatic pressing is performed without placing a support plate on the surface of the first laminate 51 on the first electrode layer 2 side (the surface of the solid electrolyte layer). By isostatic pressing, the surface of the first laminate on the first current collector side on which the support plate is placed becomes flat. On the other hand, the surfaces of the first electrode layer 2 and the solid electrolyte layer 3 on which the support plate is not placed are provided with an inclination in the outer region. That is, the thickness of the first electrode layer can be easily reduced from the boundary between the inner region and the outer region of the first surface of the first electrode layer toward the end.

[0086] 6(d), in a stacking step, the first stack 51B and the second stack 52B are stacked with the solid electrolyte layer 3 of the first stack 51B interposed therebetween, thereby producing the all-solid-state battery 10B of the second embodiment.

[0087] Fig. 7 shows an example of a method for manufacturing the all-solid-state battery of the third embodiment described above. First, as shown in Fig. 7(a), a first laminate 51C is prepared, which has a first current collector 1 and a first electrode layer 2, and further has a first solid electrolyte layer 31 on the surface of the first electrode layer 2 opposite to the first current collector 1. Also, as shown in Fig. 7(b), a second laminate 52C is prepared, which has a second current collector 5 and a second electrode layer 4, and further has a second solid electrolyte layer 32 on the surface of the second electrode layer 4 opposite to the second current collector 5.

[0088] Next, as shown in FIG. 7(c), in the first laminate pressure molding step, a support plate 15 is placed on the first current collector 1 side of the first laminate 51C, and isostatic pressing is performed without placing a support plate on the surface of the first laminate 51C on the first electrode layer 2 side (the surface of the first solid electrolyte layer). By isostatic pressing, the surface of the first laminate on the first current collector side on which the support plate is placed becomes flat. On the other hand, the surfaces of the first electrode layer 2 and the first solid electrolyte layer 31 on which the support plate is not placed are provided with an inclination in the outer region. That is, the thickness of the first electrode layer can be easily reduced from the boundary between the inner region and the outer region of the first surface of the first electrode layer toward the end.

[0089] 7(d), in a stacking step, the first stack 51C and the second stack 52C are stacked, facing each other with the first solid electrolyte layer 31 of the first stack 51C and the second solid electrolyte layer 32 of the second stack 52C interposed therebetween, thereby producing the all-solid-state battery 10C of the third embodiment.

[0090] 8 is a schematic cross-sectional view showing an example of a method for manufacturing an all-solid-state battery when the all-solid-state battery is a laminated battery. First, as shown in FIG. 8(a), a first laminate 51D having a first current collector 1 and a first electrode layer 2 formed on both sides of the first current collector 1 is prepared. Also, as shown in FIG. 8(b), a second laminate 52D having a second current collector 5 and a second electrode layer 4 and a solid electrolyte layer 3 formed on both sides of the second current collector 5 is prepared.

[0091] 8(c), in the first laminate pressure molding step, isostatic pressing is performed without placing support plates on both sides of the first laminate 51D (the faces of the first electrode layer 2). As a result, the outer regions of the first faces of the first electrode layer 2 on both sides of the first laminate 51D are inclined.

[0092] Next, as shown in Fig. 9, in a lamination step, a first laminate 51D is placed on both sides of a second laminate 52D. Furthermore, a third laminate 53D having a solid electrolyte layer 3, a second electrode layer 4, and a second current collector 5 is placed and laminated on each of the first laminates 51D. At this time, the third laminate 53D is placed and laminated such that the solid electrolyte 3 faces the first laminate 51D. In this way, an all-solid-state battery 10D of the fourth embodiment is manufactured.

[0093] The present disclosure is not limited to the above-described embodiment. The above-described embodiment is merely an example, and any configuration that is substantially the same as the technical idea described in the claims of the present disclosure and that exhibits similar effects is included in the technical scope of the present disclosure. EXAMPLES

[0094] [Preparation of evaluation cell] (Example) First, LiNi 0.5 Co 0.2 Mn 0.3 A slurry for the positive electrode active material layer was prepared by dispersing O2, an argyrodite-type sulfide solid electrolyte, a conductive additive, and a binder in a solvent. The slurry for the positive electrode active material was applied to a positive electrode current collector foil and dried to produce a positive electrode sheet having a positive electrode current collector (first current collector) and a positive electrode active material layer (first electrode layer). Next, a slurry for the negative electrode active material layer was prepared by dispersing silicon, an argyrodite-type sulfide solid electrolyte, a conductive additive, and a binder in a solvent. The slurry for the negative electrode active material layer was applied to a negative electrode current collector foil and dried to produce a negative electrode sheet having a negative electrode current collector (second current collector) and a negative electrode active material layer (second electrode layer).

[0095] Next, a slurry was prepared by dispersing the argyrodite-type solid electrolyte and a binder in a solvent, and the slurry was applied to a metal foil and dried to produce a first solid electrolyte sheet having a first solid electrolyte layer and a metal foil. A second solid electrolyte sheet having a second solid electrolyte layer and a metal foil was produced in a similar manner.

[0096] Next, the positive electrode sheet, the negative electrode sheet, the first solid electrolyte sheet, and the second solid electrolyte sheet were each cut to a predetermined size. At this time, the area of ​​the negative electrode sheet was made larger than the area of ​​the positive electrode sheet. The areas of the first solid electrolyte sheet and the second solid electrolyte sheet were made larger than the areas of both the cut positive electrode sheet and the cut negative electrode sheet.

[0097] Next, the positive electrode sheet and the first solid electrolyte sheet were stacked so that the positive electrode active material layer and the first solid electrolyte layer faced each other to obtain a first laminate. This first laminate was placed on a stainless steel plate, and vacuum-sealed with an aluminum laminate film together with the stainless steel plate as a support plate. At this time, the positive electrode sheet side was placed on the stainless steel plate side. The vacuum-sealed first laminate was subjected to a warm isostatic pressing (WIP) process (first laminate pressure molding process). Thereafter, the aluminum laminate film was opened to remove the first laminate, and the metal foil on the solid electrolyte layer side was peeled off. As a result, the solid electrolyte layer was transferred, and a highly filled positive electrode active material layer was obtained.

[0098] Furthermore, the second solid electrolyte layer of the second solid electrolyte sheet was placed opposite the negative electrode active material layer of the negative electrode sheet and bonded by roll press, and then the metal foil on the second solid electrolyte layer side was peeled off to obtain a second laminate having the negative electrode current collector, the negative electrode active material layer, and the second solid electrolyte layer.

[0099] The first and second solid electrolyte layers of the first and second laminates were stacked so that they faced each other, and the current collecting tabs were vacuum sealed with a laminate film to produce an all-solid-state battery. The all-solid-state battery was restrained with a flat restraining jig to apply a predetermined surface pressure.

[0100] (Comparative Example) An all-solid-state battery was produced in the same manner as in the example, except that in the first laminate pressure molding step, the solid electrolyte sheet was placed on the stainless steel plate side.

[0101] [Charge / discharge test] The all-solid-state batteries manufactured in the Examples and Comparative Examples were charged and discharged under predetermined conditions for conditioning, and then a charge and discharge test was carried out at 60° C. and a voltage range of 2.5 to 4.35 V. The charge rates were 1C, 2C, 3C, 4C, 5C, and 6C (CC charge), and the discharge rate was 0.1C (CCCV discharge, cutoff rate 0.1C), and the ratio of the discharge capacity (CCCV capacity) to the charge capacity (CC capacity) was calculated as the coulombic efficiency.

[0102] The results of comparing the coulombic efficiency at each charging rate of the Example and the Comparative Example are shown in Figure 12. It was confirmed that the coulombic efficiency of the Example was higher than that of the Comparative Example at each charging rate. When a short circuit occurs, the current caused by the short circuit flows more during charging, decreasing the coulombic efficiency, so this result shows that the Example is able to suppress short circuits.

[0103] The cross-sectional shape of the all-solid-state battery before the charge-discharge test was observed by SEM. In the all-solid-state battery of the example, it was confirmed that the outer region of the first surface of the positive electrode active material layer (first electrode layer) and the surface of the first solid electrolyte layer covering this outer region on the second solid electrolyte layer side were inclined. It was also confirmed that there was a space between the first solid electrolyte layer covering the outer region of the first surface of the positive electrode active material layer (first electrode layer) and the second solid electrolyte layer. On the other hand, in the all-solid-state battery of the comparative example, it was confirmed that the surfaces of the positive electrode active material layer (first electrode layer) and the first solid electrolyte layer on the second solid electrolyte layer side were not inclined, and the outer region of the surface of the first electrode layer on the first current collector side was inclined.

[0104] The cross-sectional shape of the battery after the charge-discharge test was observed by SEM. Schematic diagrams of the observed cross-sectional shapes are shown in Fig. 11(a) and Fig. 11(b). As shown in Fig. 11(a), in the battery of the example, no significant cracks were observed in the positive electrode active material layer (first electrode layer 2) and the solid electrolyte layer 3. On the other hand, as shown in Fig. 11(b), in the battery of the comparative example, obvious cracks were observed near the outer periphery of the positive electrode active material layer (first electrode layer 52) and the solid electrolyte layer 53 (first solid electrolyte layer 531 and second solid electrolyte layer 532). [Explanation of symbols]

[0105] 1 ... First current collector 2...First electrode layer 3...Solid electrolyte layer 31...first solid electrolyte layer 32...Second solid electrolyte layer 4...Second electrode layer 5...Second current collector 10…All-solid-state battery

Claims

1. An all-solid-state battery having, in this order, a first current collector, a first electrode layer, a solid electrolyte layer, a second electrode layer, and a second current collector, the first electrode layer includes a first active material; the second electrode layer includes a second active material that changes in volume during charging and discharging; When the all-solid-state battery is viewed in a planar view from a thickness direction, an area of ​​the second electrode layer is larger than an area of ​​the first electrode layer, a first surface of the first electrode layer facing the solid electrolyte layer has an inner region and an outer region disposed outside the inner region and including an end portion; an outer region and a second electrode layer in the thickness direction; and a low elastic modulus member having an elastic modulus lower than those of the second electrode layer and the solid electrolyte layer.

2. 2. The all-solid-state battery according to claim 1, wherein a thickness of the first electrode layer decreases from a boundary between the inner region and the outer region toward the end portion.

3. The all-solid-state battery according to claim 1 , wherein the space is disposed between the outer region and the solid electrolyte layer in the thickness direction.

4. The all-solid-state battery according to claim 1 , wherein the low elastic modulus member is disposed between the outer region and the solid electrolyte layer in the thickness direction.

5. the solid electrolyte layer is disposed to cover the inner region and the outer region; 2 . The all-solid-state battery according to claim 1 , wherein the space is disposed in the thickness direction between the solid electrolyte layer covering the outer region and the second electrode layer.

6. the solid electrolyte layer is disposed to cover the inner region and the outer region; 2 . The all-solid-state battery according to claim 1 , wherein the low elastic modulus member is disposed between the solid electrolyte layer covering the outer region and the second electrode layer in the thickness direction.

7. the solid electrolyte layer has, from the first electrode layer side, a first solid electrolyte layer and a second solid electrolyte layer, the first solid electrolyte layer is disposed to cover the inner region and the outer region; the second solid electrolyte layer is disposed in contact with the second electrode layer, 2 . The all-solid-state battery according to claim 1 , wherein the space is disposed in the thickness direction between a first solid electrolyte layer covering the outer region and the second solid electrolyte layer.

8. the solid electrolyte layer has, from the first electrode layer side, a first solid electrolyte layer and a second solid electrolyte layer, the first solid electrolyte layer is disposed to cover the inner region and the outer region; the second solid electrolyte layer is disposed in contact with the second electrode layer, 2. The all-solid-state battery according to claim 1, wherein the low elastic modulus member is disposed between a first solid electrolyte layer covering the outer region and the second solid electrolyte layer in the thickness direction.

9. The all-solid-state battery according to claim 1 , wherein the second electrode layer is a negative electrode active material layer and contains an alloy-based active material as the second active material.

10. A method for producing an all-solid-state battery according to any one of claims 1 to 9, comprising: a first laminate preparation step of preparing a first laminate having the first current collector and the first electrode layer; a second stack preparation step of preparing a second stack having the second current collector and the second electrode layer; a first laminate pressure molding step of pressure molding the first laminate; a lamination step of laminating the first laminate and the second laminate with the solid electrolyte layer interposed therebetween after the first laminate pressure molding step, a first laminate pressure molding step of isostatically pressing the first electrode layer to reduce a thickness from a boundary between the inner region and the outer region toward the end portion.

11. The method for producing an all-solid-state battery according to claim 10 , wherein the isostatic pressing is performed without disposing a support plate on a surface of the first laminate on a side of the first electrode layer.

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