All-solid-state battery

Abstract

This all-solid-state battery comprises an electrolyte layer including a porous body and a solid electrolyte supported by the porous body. The electrolyte layer includes a first region and a second region disposed so as to surround the first region. At least a portion of the first region overlaps a positive electrode layer and a negative electrode layer. The density of the solid electrolyte in the first region is greater than the density of the solid electrolyte in the second region. Alternatively, the density of the porous body in the first region is lower than the density of the porous body in the second region.

Description

all solid state battery

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

[0002] All-solid-state batteries using solid electrolytes are known. Among such all-solid-state batteries, those having a configuration in which the solid electrolyte is supported on a porous body are known. Supporting the solid electrolyte on a porous body makes it possible to impart self-supporting or flexibility to the electrolyte layer, making it easier to handle.

[0003] In relation to the above, for example, Patent Document 1 (JP 2016-031789 A) discloses a solid electrolyte sheet which is a sheet including a nonwoven fabric and a solid electrolyte on the surface and inside of the nonwoven fabric, wherein the weight of the nonwoven fabric per square meter is 8 g or less and the thickness of the nonwoven fabric is 10 μm or more and 25 μm or less.

[0004] However, if the electrolyte layer contains a porous material, the presence of the porous material can inhibit ion conduction, potentially reducing the output of the all-solid-state battery.

[0005] Therefore, an object of the present invention is to provide a technique capable of improving ionic conductivity in an all-solid-state battery having a configuration in which a solid electrolyte is supported on a porous body.

[0006] In one aspect, an all-solid-state battery according to the present invention includes an electrolyte layer, and a positive electrode layer and a negative electrode layer arranged to sandwich the electrolyte layer in the stacking direction. The electrolyte layer includes a first region including at least a solid electrolyte, and a second region arranged to surround the first region and including the solid electrolyte and a porous body. When viewed along the stacking direction, at least a portion of the first region overlaps the positive electrode layer and the negative electrode layer. The density of the solid electrolyte in the first region is greater than the density of the solid electrolyte in the second region, and / or the density of the porous body in the first region is less than the density of the porous body in the second region.

[0007] FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery according to a first embodiment. FIG. 2 is an exploded perspective view showing an all-solid-state battery. FIG. 3 is a schematic cross-sectional view showing an all-solid-state battery 1 according to Modification 1-1. FIG. 4 is a plan view of Modification 1-1. FIG. 5 is a schematic cross-sectional view showing an all-solid-state battery according to Modification 1-2. FIG. 6 is a schematic cross-sectional view showing an all-solid-state battery according to Modification 1-3. FIG. 7 is a schematic cross-sectional view showing an all-solid-state battery according to a third embodiment. FIG. 8 is a schematic cross-sectional view showing an all-solid-state battery according to a fourth embodiment. FIG. 9 is a schematic cross-sectional view showing an all-solid-state battery according to a fifth embodiment. FIG. 10 is a plan view showing a portion of an all-solid-state battery according to a sixth embodiment. FIG. 11 is a plan view showing Modification 6-1. FIG. 12 is a plan view showing Modification 6-2.

[0008] Hereinafter, an all-solid-state battery 1 according to an embodiment of the present invention will be described with reference to the drawings.

[0009] In this specification, an "all-solid-state battery" refers to a secondary battery in which the electrolyte layer, the positive electrode layer, and the negative electrode layer are all substantially solid. Each layer may be "substantially" solid, and a small amount of liquid material may be used.

[0010] (1) First Embodiment Fig. 1 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment. Fig. 2 is an exploded perspective view showing the all-solid-state battery 1.

[0011] 1 and 2 , the all-solid-state battery 1 includes an electrolyte layer 2, a positive electrode layer 3, a negative electrode layer 4, a positive electrode current collector foil 5, and a negative electrode current collector foil 6. The electrolyte layer 2 is sandwiched between the positive electrode layer 3 and the negative electrode layer 4. The positive electrode current collector foil 5 and the negative electrode current collector foil 6 are disposed on the outer surfaces of the positive electrode layer 3 and the negative electrode layer 4, respectively. That is, in the all-solid-state battery 1, the positive electrode current collector foil 5, the positive electrode layer 3, the electrolyte layer 2, the negative electrode layer 4, and the negative electrode current collector foil 6 are stacked in this order along the stacking direction.

[0012] In the example shown in Fig. 1 , a laminated structure including an electrolyte layer 2, a positive electrode layer 3, a negative electrode layer 4, a positive electrode current collector foil 5, and a negative electrode current collector foil 6 is defined as one unit 10. In the all-solid-state battery 1, a plurality of (two) units 10 are laminated. However, the all-solid-state battery 1 does not necessarily need to include a plurality of units 10. The unit 10 may be a single unit. The configuration shown in Fig. 2 corresponds to one unit 10.

[0013] The positive electrode layer 3 is configured to absorb lithium during discharge and release lithium as lithium ions during charge. The positive electrode layer 3 is formed, for example, from a material containing a resin binder and a positive electrode active material dispersed in the resin binder. The positive electrode active material may be, for example, a lithium metal composite oxide. The thickness of the positive electrode layer 3 is, for example, 30 to 1000 μm, preferably 10 to 500 μm.

[0014] The negative electrode layer 4 is configured to occlude lithium during charging and release lithium as lithium ions during discharging. For example, the negative electrode layer 4 can be formed from a material including a resin binder and a negative electrode active material dispersed in the resin binder. Alternatively, the negative electrode layer 4 may be realized by metallic lithium that precipitates between the electrolyte layer 2 and the negative electrode current collector foil 6 during charging. That is, the all-solid-state battery 1 may be a so-called precipitation-type secondary battery. In such a precipitation-type secondary battery, there may be almost no metallic lithium present as the negative electrode layer 4 in a fully discharged state. However, at least the metallic lithium that precipitates during charging functions as the negative electrode layer 4, and therefore the all-solid-state battery 1 according to this embodiment is included.

[0015] The electrolyte layer 2 is a portion through which lithium ions are conducted during charging and discharging. The electrolyte layer 2 has electronic insulating properties and also functions as a separator that insulates the positive electrode layer 3 and the negative electrode layer 4 from each other.

[0016] The electrolyte layer 2 is a composite material including a solid electrolyte and a porous body. The solid electrolyte is filled in the pores of the porous body and is supported by the porous body.

[0017] The porous body may be, for example, a nonwoven fabric. Examples of the nonwoven fabric include polyester nonwoven fabric, polyethylene nonwoven fabric, and cellulose fiber nonwoven fabric. The thickness of the porous body is, for example, 5 to 100 μm, preferably 7 to 20 μm.

[0018] The specific material of the solid electrolyte is not particularly limited. For example, a sulfide solid electrolyte can be used as the solid electrolyte. For example, an LPS-based (e.g., Argyrodite (Li ６ P.S. ５ Cl), and LGPS systems (e.g., Li １０ GeP ２ S １２ ) materials can be mentioned.

[0019] In this embodiment, a special design is made to the structure of the electrolyte layer 2. The structure of the electrolyte layer 2 will be described in detail below.

[0020] 1 and 2, the electrolyte layer 2 has a first region 2-1 and a second region 2-2. When viewed along the stacking direction, the first region 2-1 is surrounded by the second region 2-2. In this embodiment, both the first region 2-1 and the second region 2-2 have a porous body and a solid electrolyte supported by the porous body. In each region, the pores of the porous body are filled with the solid electrolyte.

[0021] The first region 2-1 is a region where ions are mainly conducted during charging and discharging. When viewed along the stacking direction, the first region 2-1 overlaps with the positive electrode layer 3 and the negative electrode layer 4 (hereinafter, these may be collectively referred to as electrode layers).

[0022] As described above, the second region 2-2 is a region that surrounds the first region 2-1. When viewed along the stacking direction, the outer periphery of the second region 2-2 is located outside the outer periphery of the electrode layer.

[0023] Here, the density of the solid electrolyte and / or the density of the porous body differs between the first region 2-1 and the second region 2-2. Specifically, at least one of the following conditions (A) and (B) is met between the first region 2-1 and the second region 2-2: (A) The density of the solid electrolyte in the first region 2-1 is greater than the density of the solid electrolyte in the second region 2-2. (B) The density of the porous body in the first region 2-1 is less than the density of the porous body in the second region 2-2.

[0024] For example, the density of the porous body may be the same between the first region 2-1 and the second region 2-2, but the density of the solid electrolyte may be different. Alternatively, the density of the solid electrolyte may be the same between the first region 2-1 and the second region 2-2, but the density of the porous body may be different. Alternatively, the density of the solid electrolyte and the density of the porous body may both be different between the first region 2-1 and the second region 2-2.

[0025] The above is a general configuration of this embodiment.

[0026] Next, the effects of this embodiment will be described. In the following description, a high density solid electrolyte or a low density porous body may be referred to as "rich in solid electrolyte." Conversely, a high density porous body or a low density solid electrolyte may be referred to as "rich in porous body."

[0027] In this embodiment, during charge and discharge, lithium ions are conducted mainly in the first region 2-1, which is the region overlapping the electrode layer. Since the first region 2-1 is rich in solid electrolyte, ion conduction is less likely to be impeded by the porous body. In other words, even though the solid electrolyte is supported by the porous body, it is possible to suppress a decrease in ion conductivity due to the porous body.

[0028] On the other hand, solid electrolytes are typically hard and brittle. Therefore, if a solid electrolyte-rich configuration is adopted in the entire region of the electrolyte layer 2, defects such as cracks may be more likely to occur at the edges of the electrolyte layer 2. In contrast, according to this embodiment, the second region 2-2 is porous-rich, which can suppress the occurrence of cracks at the edges of the electrolyte layer 2. In other words, it is easy to use a material that is less susceptible to cracking than a solid electrolyte as the porous body. Therefore, by making the second region 2-2 porous-rich, it is possible to prevent the occurrence of cracks at the edges of the electrolyte layer 2. Furthermore, since the second region 2-2 has insulating properties and its outer peripheral edge is located outside the electrode layer, short circuits due to lithium precipitation that wraps around the edges are also prevented.

[0029] From the viewpoint of preventing cracks from occurring at the edges, it is preferable that the flexibility of the second region 2-2 be higher than that of the first region 2-1. Specifically, it is preferable that the elastic modulus of the second region 2-2 be smaller than that of the first region 2-1. By adopting such a configuration, it is possible to more reliably suppress the occurrence of cracks at the edges of the electrolyte layer 2, prevent short circuits at the edges, and improve durability.

[0030] Furthermore, if the second region 2-2 has higher flexibility than the first region 2-1, uniform surface pressure can be ensured. In order to obtain the desired charge / discharge characteristics of the all-solid-state battery 1, adjacent layers must be firmly bonded together. Therefore, the all-solid-state battery 1 is usually pressurized so as to be compressed along the stacking direction. If the second region 2-2 has higher flexibility, the presence of the second region 2-2 will not hinder the application of pressure to the first region 2-1. Therefore, it becomes easier to apply pressure to the first region 2-1 with uniform surface pressure. This makes it easier to obtain the desired battery characteristics.

[0031] Furthermore, according to this embodiment, not only the first region 2-1 but also the second region 2-2 contains a solid electrolyte. Therefore, the second region 2-2 also functions as an electrolyte layer (ion conduction function) to some extent. For example, even if a portion of the second region 2-2 unintentionally overlaps the positive electrode layer 3 and the negative electrode layer 4 due to misalignment during manufacturing, the deterioration of battery performance can be minimized.

[0032] The method for manufacturing the all-solid-state battery 1 in this embodiment is not particularly limited. For example, a free-standing film to be used as the electrolyte layer 2 can be obtained by applying a slurry containing a solid electrolyte onto a porous body, allowing the slurry to penetrate into the porous body, and drying. In this case, by using two types of slurries with different concentrations, a second region 2-2 can be formed in addition to the first region 2-1. The obtained free-standing film can be used as the electrolyte layer 2 and laminated with the positive electrode layer 3, the negative electrode layer 4, the positive electrode current collector foil 5, and the negative electrode current collector foil 6 to obtain the all-solid-state battery 1.

[0033] Next, the positional relationship between the outer peripheral ends of the first region 2-1, the positive electrode layer 3, and the negative electrode layer 4 will be described. In the example shown in FIG. 1 , when viewed along the stacking direction, the outer peripheral end of the first region 2-1 is located more inward than the outer peripheral ends of the positive electrode layer 3 and the negative electrode layer 4. The outer peripheral end of the positive electrode layer 3 is aligned with the outer peripheral end of the negative electrode layer 4. This configuration is preferable because it makes the end of the first region 2-1 less likely to crack. If the outer peripheral end of the first region 2-1 were located outside the positive electrode layer 3 and the negative electrode layer 4, the end of the first region 2-1 would not be supported in the stacking direction and would be more likely to crack. In contrast, if the outer peripheral end of the first region 2-1 were located more inward than the respective electrode layers, the end of the first region 2-1 would be less likely to crack, further improving reliability.

[0034] On the other hand, the positional relationship between the outer periphery of the first region 2-1, the positive electrode layer 3, and the negative electrode layer 4 can be changed as appropriate depending on the application, etc. Hereinafter, the positional relationship between the outer periphery will be described with reference to modified examples.

[0035] (Variation 1-1) Fig. 3 is a schematic cross-sectional view showing an all-solid-state battery 1 according to Variation 1-1. Fig. 4 is a plan view of this variation, showing the positions of the outer circumferential edges of the electrolyte layer 2, the positive electrode layer 3, and the negative electrode layer 4. In this variation, when viewed along the stacking direction, the outer circumferential edge of the negative electrode layer 4 is located outside the outer circumferential edge of the positive electrode layer 3. The outer circumferential edge of the first region 2-1 is located inside the outer circumferential edge of the positive electrode layer 3. The other points are the same as those in the configuration shown in Fig. 1.

[0036] In the all-solid-state battery 1, for example, for the purpose of preventing excessive deposition of lithium at the end, the outer peripheral edge of the negative electrode layer 4 may be disposed outside the outer peripheral edge of the positive electrode layer 3. Even in such a case, if the outer peripheral edge of the first region 2-1 is located inside the outer peripheral edge of the positive electrode layer 3, the end of the first region 2-1 is less likely to crack, and reliability can be improved.

[0037] 5 is a schematic cross-sectional view showing an all-solid-state battery 1 according to Modification 1-2. In this modification, when viewed along the stacking direction, the outer peripheral edge of the first region 2-1 coincides with the outer peripheral edge of the positive electrode layer 3. As in Modification 1-1, the outer peripheral edge of the negative electrode layer 4 is located outside the outer peripheral edge of the positive electrode layer 3.

[0038] In this modification, the end of the first region 2-1 is located on the outer side, which makes it more susceptible to cracking than in modification 1-1. However, the area of ​​the first region 2-1 is larger than in modification 1-1. Therefore, the ionic conductivity between the positive electrode layer 3 and the negative electrode layer 4 can be further increased.

[0039] (Modification 1-3) Fig. 6 is a schematic cross-sectional view showing an all-solid-state battery 1 according to Modification 1-3. In this modification, when viewed along the stacking direction, the outer peripheral edge of the first region 2-1 is located outside the outer peripheral edge of the positive electrode layer 3. The outer peripheral edge of the first region 2-1 coincides with the outer peripheral edge of the negative electrode layer 4, or is located inside the outer peripheral edge of the negative electrode layer 4. Note that Fig. 6 shows, as a specific example, a case where the outer peripheral edge of the first region 2-1 coincides with the outer peripheral edge of the negative electrode layer 4. The other configurations are the same as those of Modification 1-2.

[0040] In this modification, the outer peripheral edge of the first region 2-1 is located further outward than in modification 1-2. Therefore, the edge of the first region 2-1 is more susceptible to cracking than in modification 1-2. However, because the area of ​​the first region 2-1 is larger, the ionic conductivity between the positive electrode layer 3 and the negative electrode layer 4 can be further increased compared to modification 1-2.

[0041] (2) Second Embodiment Next, a second embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as the previously described embodiment can be adopted.

[0042] In this embodiment, no porous body is present in the first region 2-1. That is, the porous body is frame-shaped. On the other hand, a solid electrolyte is present in both the first region 2-1 and the second region 2-2. The solid electrolyte in the first region 2-1 is supported by the porous body in the second region 2-2.

[0043] In this embodiment, the density of the porous body in the first region 2-1 can be said to be zero. Therefore, condition (B) (see below) described in the first embodiment is necessarily met. (B) The density of the porous body in the first region 2-1 is smaller than the density of the porous body in the second region 2-2.

[0044] The density of the solid electrolyte in the first region 2-1 and the density of the solid electrolyte in the second region 2-2 may be the same or different.

[0045] According to this embodiment, since there is no porous body in the first region 2-1, the ionic conductivity does not decrease during charging and discharging, which is more preferable from the viewpoint of ionic conductivity.

[0046] The method for producing the electrolyte layer 2 in this embodiment is not particularly limited. For example, first, a frame-shaped porous body is prepared. Then, a slurry containing a solid electrolyte is supplied onto the porous body. Then, the slurry is filled into the pores of the porous body and the frame using an applicator or the like. Thereafter, a drying process is carried out as necessary. In this way, a free-standing membrane to be used as the electrolyte layer 2 can be obtained.

[0047] (3) Third Embodiment Next, a third embodiment will be described. Note that detailed description will be omitted for the fact that the same configuration as the previously described embodiments can be adopted.

[0048] 7 is a schematic cross-sectional view showing the all-solid-state battery 1 according to this embodiment. In this embodiment, the second region 2-2 is thicker than the first region 2-1.

[0049] Specifically, the outer peripheral edges of the positive electrode current collector foil 5 and the negative electrode current collector foil 6 are located outside the outer peripheral edges of the electrode layers (positive electrode layer 3 and negative electrode layer 4), respectively. The second region 2-2 has a thickness such that it is in contact with the positive electrode current collector foil 5 and the negative electrode current collector foil 6 in the stacking direction.

[0050] According to this embodiment, the second region 2-2 is thick, so it is possible to fill gaps in the stacking direction. That is, the outer peripheral edge of the second region 2-2 is located outside the outer peripheral edge of the electrode layer. If the thickness of the second region 2-2 were equal to or less than the thickness of the first region 2-1, spaces would be generated on both sides of the second region in the stacking direction. As a result, the second region 2-2 would be more susceptible to damage due to vibrations, etc. In contrast, according to this embodiment, the thickness of the second region 2-2 is large, so it is possible to eliminate spaces that are generated on both sides in the stacking direction. That is, the second region 2-2 is fixed from both sides in the stacking direction. This makes it possible to more reliably prevent damage to the second region 2-2 due to vibrations, etc.

[0051] (4) Fourth Embodiment Next, a fourth embodiment will be described. Note that detailed description will be omitted for the fact that the same configuration as the previously described embodiments can be adopted.

[0052] 8 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment. In this embodiment, the electrolyte layer 2 is bent between a first region 2-1 and a second region 2-2. The second region 2-2 is bonded to a side surface of the positive electrode layer 3. The second region 2-2 is also bonded to the surface of the positive electrode current collector foil 5. Specifically, the outer peripheral edge of the positive electrode current collector foil 5 is located outside the outer peripheral edge of the positive electrode layer 3. The second region 2-2 is bent so as to follow the side surface of the positive electrode layer 3 and the surface of the positive electrode current collector foil 5.

[0053] According to this embodiment, the second region 2-2 is fixed to the positive electrode layer 3 and the positive electrode current collector foil 5. This makes it possible to more reliably prevent damage to the second region 2-2 due to vibrations and the like. As a result, it is possible to improve the insulation at the end of the electrolyte layer 2 and further improve reliability.

[0054] In this embodiment, the second region 2-2 is bonded to both the positive electrode layer 3 and the positive electrode current collector foil 5. However, it is sufficient that the second region 2-2 is bonded to either the positive electrode layer 3 or the positive electrode current collector foil 5. The second region 2-2 may also be fixed to the negative electrode side instead of the positive electrode side. That is, the second region 2-2 may be bonded to at least one of the negative electrode layer 4 and the negative electrode current collector foil 6. Even when these configurations are adopted, the second region 2-2 is fixed, so that damage due to vibrations and the like can be prevented.

[0055] (5) Fifth Embodiment Next, a fifth embodiment will be described. This embodiment can be considered a modification of the fourth embodiment. Detailed description of the fact that the same configuration as the fourth embodiment can be adopted will be omitted.

[0056] 9 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment. In this embodiment, the second region 2-2 also covers the end face of the positive electrode current collector foil 5. By adopting such a configuration, the positive electrode layer 3 and the positive electrode current collector foil 5 are less likely to come into contact with the negative electrode side structure, such as the negative electrode current collector foil 6. As a result, short circuits can be more reliably prevented.

[0057] The second region 2-2 may be joined to the negative electrode side instead of the positive electrode side. That is, the second region 2-2 may be disposed so as to cover the end face of the negative electrode current collector foil 6.

[0058] (6) Sixth Embodiment Next, a sixth embodiment will be described. Note that detailed description will be omitted for the fact that the same configuration as the previously described embodiments can be adopted.

[0059] FIG. 10 is a plan view showing a portion of the all-solid-state battery 1 according to this embodiment. FIG. 10 shows the layout of the first region 2-1, the second region 2-2, the positive electrode layer 3, and the negative electrode layer 4. As shown in FIG. 10, in this embodiment, the first region 2-1 is divided into a plurality of regions. That is, the first region 2-1 has a plurality of first region elements (2-2-1, 2-1-2). When viewed along the stacking direction, each of the first region elements (2-2-1, 2-1-2) overlaps with an electrode layer (the positive electrode layer 3 and the negative electrode layer 4).

[0060] Even when the configuration of this embodiment is adopted, it is possible to prevent a decrease in ionic conductivity in each of the first region elements (2-2-1, 2-1-2), and a certain degree of effect is achieved.

[0061] (Variation 6-1) Next, a variation of this embodiment will be described. FIG. 11 is a plan view showing variation 6-1. In this variation, the first region 2-1 has a plurality of first region elements (2-1-1 to 2-1-5). Some of the plurality of first region elements (2-1-1 to 2-1-5) protrude outside the electrode layers (positive electrode layer 3 and negative electrode layer 4) in some regions. However, at least a portion of any of the plurality of first region elements (2-1-1 to 2-1-5) overlaps the electrode layers (positive electrode layer 3 and negative electrode layer 4).

[0062] In this modification, a decrease in ionic conductivity is prevented at least in the portions of the first region elements (2-1-1 to 2-1-5) that overlap with the electrode layers. Therefore, even if a configuration such as this modification is adopted, a certain degree of effect can be obtained. In other words, it is sufficient that at least a portion of the first region 2-1 overlaps with the electrode layer.

[0063] 12 is a plan view showing Modification 6-2. In this modification, the first region 2-1 is divided into four first region elements (2-1-1 to 2-1-4). Even when this configuration is adopted, it is possible to prevent a decrease in ionic conductivity in each of the first region elements (2-2-1 to 2-1-4), and a certain effect is achieved.

[0064] (7) Supplementary Notes The present invention has been described above with reference to several embodiments. The following is a summary of the relationship between the representative configurations of the present invention and their effects.

[0065] (Supplementary Note 1) An all-solid-state battery comprising: an electrolyte layer 2 including a porous body and a solid electrolyte supported by the porous body; and a cathode layer 3 and an anode layer 4 arranged to sandwich the electrolyte layer 2 in the stacking direction, wherein the electrolyte layer 2 comprises a first region 2-1 including at least the solid electrolyte; and a second region 2-2 arranged to surround the first region 2-1 and including the solid electrolyte and the porous body, wherein at least a portion of the first region 2-1 overlaps the cathode layer 3 and the anode layer 4 when viewed along the stacking direction, and wherein the density of the solid electrolyte in the first region 2-1 is greater than the density of the solid electrolyte in the second region 2-2 and / or the density of the porous body in the first region 2-1 is less than the density of the porous body in the second region 2-2.

[0066] According to this configuration, the solid electrolyte is densely present in the first region 2-1, or the porous body is sparse, so that the solid electrolyte is supported by the porous body while suppressing a decrease in ionic conductivity.

[0067] (Supplementary Note 2) The all-solid-state battery according to Supplementary Note 1, wherein, when viewed along the stacking direction, the outer peripheral edge of the first region 2-1 is located more inward than the outer peripheral edge of the negative electrode layer 4 and the outer peripheral edge of the positive electrode layer 3.

[0068] With this configuration, cracks are less likely to occur at the end of the first region 2-1.

[0069] (Supplementary Note 3) The all-solid-state battery according to Supplementary Note 1, wherein, when viewed along the stacking direction, the outer peripheral edge of the anode layer 4 is located outside the outer peripheral edge of the cathode layer 3, and the outer peripheral edge of the first region 2-1 coincides with the outer peripheral edge of the cathode layer 3.

[0070] With this configuration, the area of ​​the first region 2-1 is ensured to be large, and the ionic conductivity can be further improved.

[0071] (Supplementary Note 4) The all-solid-state battery according to Supplementary Note 1, wherein, when viewed along the stacking direction, the outer peripheral edge of the first region 2-1 is located outward from the outer peripheral edge of the positive electrode layer 3 and coincides with the outer peripheral edge of the negative electrode layer 4 or is located inward from the outer peripheral edge of the negative electrode layer 4.

[0072] With this configuration, the area of ​​the first region 2-1 can be made larger, and the ionic conductivity can be further improved.

[0073] (Supplementary Note 5) The all-solid-state battery according to any one of Supplementary Notes 1 to 4, wherein the first region does not contain a porous body.

[0074] According to this configuration, since no porous body exists in the first region 2-1, the ionic conductivity can be further improved.

[0075] (Supplementary Note 6) The all-solid-state battery according to any one of Supplementary Notes 1 to 5, wherein the second region 2-2 has higher flexibility than the first region 2-1.

[0076] With this configuration, cracks and the like are less likely to occur in the second region 2-2, thereby improving reliability.

[0077] (Supplementary Note 7) The all-solid-state battery according to any one of Supplementary Notes 1 to 6, wherein the second region 2-2 is thicker than the first region 2-1.

[0078] This configuration eliminates the gaps on both sides of the second region 2-2 in the stacking direction, thereby fixing the second region 2-2 in place. As a result, damage to the second region 2-2 due to vibrations and other factors can be more reliably prevented.

[0079] (Appendix 8) The all-solid-state battery according to any one of Appendices 1 to 7, further comprising: a positive electrode current collector foil 5 disposed on the positive electrode layer 3; and a negative electrode current collector foil 6 disposed on the negative electrode layer 4, wherein the second region 2-2 is in contact with a side surface of the positive electrode layer 3 or the positive electrode current collector foil 5, and / or is in contact with a side surface of the negative electrode layer 4 or the negative electrode current collector foil 6.

[0080] According to this configuration, the second region 2-2 can be fixed, and damage to the second region 2-2 due to the influence of vibrations or the like can be more reliably prevented.

[0081] (Supplementary Note 9) The all-solid-state battery according to Supplementary Note 8, wherein the second region 2-2 covers an end face of the positive electrode current collector foil 5 or the negative electrode current collector foil 6.

[0082] With this configuration, it is possible to more reliably prevent short circuits between the positive and negative electrodes.

[0083] (Supplementary Note 10) The all-solid-state battery according to any one of Supplementary Notes 1 to 9, wherein the first region 2-1 has a plurality of first region elements, and when viewed along the stacking direction, any of the plurality of first region elements at least partially overlaps with the positive electrode layer 3 and the negative electrode layer 4.

[0084] Even when such a configuration is adopted, the ionic conductivity can be improved in the portions where each first region element overlaps with the electrode layer, and a certain degree of effect can be achieved.

Claims

1. An electrolyte layer comprising a porous body and a solid electrolyte supported by the porous body, A positive electrode layer and a negative electrode layer are arranged so as to sandwich the electrolyte layer in the stacking direction, Equipped with, The electrolyte layer is A first region containing at least a solid electrolyte, The first region is surrounded by a second region which includes a solid electrolyte and a porous body, When viewed along the stacking direction, at least a portion of the first region overlaps with the positive electrode layer and the negative electrode layer. The density of the solid electrolyte in the first region is greater than the density of the solid electrolyte in the second region, and / or the density of the porous material in the first region is less than the density of the porous material in the second region. The second region has greater flexibility than the first region. All-solid-state battery.

2. The all-solid-state battery according to claim 1, When viewed along the stacking direction, the outer edge of the first region is located inward from the outer edge of the negative electrode layer and the outer edge of the positive electrode layer. All-solid-state battery.

3. The all-solid-state battery according to claim 1, When viewed along the stacking direction, the outer edge of the negative electrode layer is located outside the outer edge of the positive electrode layer, and the outer edge of the first region coincides with the outer edge of the positive electrode layer. All-solid-state battery.

4. The all-solid-state battery according to claim 1, When viewed along the stacking direction, the outer edge of the first region is located outside the outer edge of the positive electrode layer and coincides with the outer edge of the negative electrode layer, or is located inside the outer edge of the negative electrode layer. All-solid-state battery.

5. A solid-state battery according to claim 1 or 2, In the first region, there is no porous material. All-solid-state battery.

6. A solid-state battery according to claim 1 or 2, The second region is thicker than the first region. All-solid-state battery.

7. A solid-state battery according to claim 1 or 2, Furthermore, A positive electrode current collector foil arranged on the positive electrode layer, The negative electrode current collector foil is disposed on the negative electrode layer, The aforementioned second region is, The side surface of the positive electrode layer or in contact with the positive electrode current collector foil, and / or The side surface of the negative electrode layer or the negative electrode current collector foil in contact with it, All-solid-state battery.

8. The all-solid-state battery according to claim 7, The second region covers the end face of the positive electrode current collector foil or the negative electrode current collector foil. All-solid-state battery.

9. A solid-state battery according to claim 1 or 2, The first region has a plurality of first region elements, When viewed along the stacking direction, any of the plurality of first region elements overlaps the positive electrode layer and the negative electrode layer in at least a portion of it. All-solid-state battery.