All-solid-state batteries

Abstract

The present invention provides an all-solid-state battery including: a porous sheet with an electrolyte region; and a negative electrode structure layer and a positive electrode layer stacked to be in contact with the porous sheet. The outlines of the positive electrode layer and the negative electrode structure layer are aligned. The electrolyte region broadens proceeding from the positive electrode layer side toward the negative electrode structure layer side. At the interface between the negative electrode structure layer and the electrolyte region, the edges of the electrolyte region are located farther inward than the edges of the negative electrode structure layer.

Description

[Technical Field]

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

[0002] An all-solid-state battery is a secondary battery made of solid materials, including an electrolyte layer. In an all-solid-state battery, a positive electrode and a negative electrode are provided to sandwich a solid electrolyte layer. In an all-solid-state battery, charging and discharging are generally performed by the movement of lithium ions between the positive electrode and the negative electrode. As such an all-solid-state battery, one having a structure in which a solid electrolyte is supported on a porous sheet is known. By supporting the solid electrolyte on a porous sheet, a thin but self-supporting electrolyte layer can be obtained.

[0003] A related technique is described, for example, in Patent Document 1 (JP 2021-533542 A). Patent Document 1 describes a method for producing a solid electrolyte membrane for an all-solid-state battery, including the steps of: preparing a laminate structure by sequentially stacking a first protective layer, a film-like first solid electrolyte material, a porous substrate, a film-like second solid electrolyte material, and a second protective layer; pressurizing the laminate structure to force the first and second solid electrolyte materials into the porous substrate and fill the pores of the porous substrate with the solid electrolyte material; and removing the first and second protective layers, where the pressurization is performed using a roll press method. This solid electrolyte membrane is a composite of a porous polymer material such as a nonwoven fabric and a solid electrolyte material, and therefore can be produced in a thin film form of 70 μm or less while maintaining excellent strength, which is advantageous for improving the energy density of the battery. Summary of the Invention

[0004] Incidentally, in all-solid-state batteries, excessive lithium may be deposited at the end of the negative electrode during charging.

[0005] To prevent excessive lithium deposition at the negative electrode end, it is conceivable to increase the area of ​​the negative electrode compared to the positive electrode. However, all-solid-state batteries are usually pressed with a strong force during production to achieve the desired battery function. Pressurization is performed, for example, by a roll press. If the area of ​​the negative electrode is larger than that of the positive electrode, the load is concentrated at the end of the negative electrode when pressure is applied, which may cause cracks or chips in the structure on the negative electrode side. Therefore, it has been difficult to prevent excessive lithium deposition at the negative electrode end while preventing cracks and chips during pressure application.

[0006] Therefore, an object of the present invention is to provide an all-solid-state battery that can prevent cracking or chipping of the structure on the negative electrode side and can prevent excessive deposition of lithium at the end of the negative electrode.

[0007] In one embodiment, the all-solid-state battery according to the present invention includes a porous sheet having an electrolyte region supporting a solid electrolyte, a positive electrode layer laminated on one side of the porous sheet so as to be in contact with the porous sheet, and a negative electrode structure layer laminated on the other side of the porous sheet so as to be in contact with the porous sheet. The outer shapes of the positive electrode layer and the negative electrode structure layer are aligned when viewed along the stacking direction. The electrolyte region expands in outer shape from the positive electrode layer side toward the negative electrode structure layer side. An end A of the electrolyte region at the interface between the negative electrode structure layer and the electrolyte region is located inside the end of the negative electrode structure layer when viewed along the stacking direction. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an all-solid-state battery according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram showing an all-solid-state battery according to a reference example. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an all-solid-state battery according to the second embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an all-solid-state battery according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] First embodiment 1 is a schematic cross-sectional view showing an all-solid-state battery 1 according to the first embodiment. The all-solid-state battery 1 is a secondary battery that is charged and discharged by the movement of lithium ions between a positive electrode and a negative electrode.

[0011] 1, the all-solid-state battery 1 includes a porous sheet 2, a positive electrode layer 3, a negative electrode structure layer 4, a positive electrode current collector 5, and a negative electrode current collector 6. These are stacked in the following order: positive electrode current collector 5, positive electrode layer 3, porous sheet 2, negative electrode structure layer 4, and negative electrode current collector 6.

[0012] The porous sheet 2 has an electrolyte region 7 in which a solid electrolyte is supported. By supporting the solid electrolyte on the porous sheet 2, the electrolyte layer can be handled as a thin, self-standing membrane. The electrolyte region 7 is provided in the center of the porous sheet 2. The outer periphery of the porous sheet 2 is a region in which the solid electrolyte is not supported (non-supported region 8).

[0013] The positive electrode layer 3 is provided on one surface of the porous sheet 2 in contact with the porous sheet 2. The negative electrode structure layer 4 is provided on the other surface of the porous sheet 2 in contact with the porous sheet 2. The positive electrode layer 3 and the negative electrode structure layer 4 are arranged to sandwich the electrolyte region 7 in the stacking direction.

[0014] The positive electrode layer 3 is a layer that functions as an electrode, and is configured to release lithium ions during charging and to absorb lithium during discharging.

[0015] On the other hand, the negative electrode structure layer 4 is defined as a layer provided on the negative electrode side of the porous sheet 2 in contact with the porous sheet 2. The negative electrode structure layer 4 may be the electrode (negative electrode) itself where the battery reaction proceeds during charge and discharge, but it does not have to be the negative electrode itself.

[0016] For example, in an all-solid-state battery, the anode layer may be formed directly on the electrolyte layer. In the case of an all-solid-state battery having such a configuration, the anode layer itself corresponds to the anode structure layer 4 in this embodiment.

[0017] On the other hand, in some all-solid-state batteries, the structure formed directly on the negative electrode side of the electrolyte layer is called an "anode protective layer." The anode protective layer is a structure employed, for example, in "all-precipitation type" batteries. An "all-precipitation type" all-solid-state battery is a battery configured such that, in a fully discharged state, lithium is not present on the negative electrode side as an anode active material, and upon charging, lithium ions move from the positive electrode side to the negative electrode side, resulting in the deposition of metallic lithium on the negative electrode current collector. In such batteries, if the deposited metallic lithium comes into contact with the electrolyte layer during charging, the electrolyte layer may be damaged. Therefore, to prevent damage, an anode protective layer may be provided in contact with the electrolyte layer. In such all-solid-state batteries, the anode protective layer itself may not function as an electrode, but the layer formed directly on the electrolyte layer is an anode protective layer, and therefore the anode protective layer corresponds to the anode structure layer 4 in this embodiment.

[0018] The positive electrode current collector 5 and the negative electrode current collector 6 are provided on the outside of the positive electrode layer 3 and the negative electrode structure layer 4, respectively. The positive electrode current collector 5 and the negative electrode current collector 6 are provided to electrically connect the all-solid-state battery 1 to the outside.

[0019] In this embodiment, the outer shape (outline) of the negative electrode structure layer 4 when viewed along the stacking direction is aligned with that of the positive electrode layer 3. That is, the positive electrode layer 3 and the negative electrode structure layer 4 have the same shape when viewed along the stacking direction, and are arranged so that their outer peripheral edges coincide with each other.

[0020] Additionally, in this embodiment, the electrolyte region 7 expands so that its outer shape expands from the positive electrode layer 3 side toward the negative electrode structure layer 4 side. Specifically, the electrolyte region 7 expands from the positive electrode layer 3 side toward the negative electrode structure layer 4 side so that the end faces are tapered.

[0021] Furthermore, in this embodiment, an end A of the electrolyte region 7 at the interface between the negative electrode structure layer 4 and the electrolyte region 7 is located inside the end of the negative electrode structure layer 4 when viewed along the stacking direction.

[0022] By adopting the above-described configuration, it is possible to prevent cracking and chipping of the negative electrode structure layer 4 and also to prevent excessive deposition of lithium at the edge portion. This point will be explained below with reference to a reference example.

[0023] FIG. 2 is a schematic diagram showing an all-solid-state battery according to a reference example, illustrating the state during roll pressing. In general all-solid-state batteries, the outer shape of the negative electrode is often made larger than the outer shape of the positive electrode when viewed along the stacking direction in order to prevent excessive deposition of lithium at the edges. As a result, as in the all-solid-state battery shown in FIG. 2, the edge of the structure (i.e., the negative electrode structure layer 4) provided on the negative electrode side of the electrolyte region 7 protrudes laterally beyond the edge of the positive electrode layer 3. Here, the porous sheet 2 is usually flexible. Therefore, at the edge of the negative electrode structure layer 4, the load during roll pressing is concentrated on the negative electrode structure layer 4, making it prone to cracking and chipping.

[0024] In contrast, in this embodiment, as described above, the outer shape of the positive electrode layer 3 and the outer shape of the negative electrode structure layer 4 are aligned. Therefore, the load is less likely to concentrate on the end of the negative electrode structure layer 4 during roll pressing, and cracks and chips in the negative electrode structure layer 4 can be prevented.

[0025] On the other hand, if the outer shape of the negative electrode structure layer 4 is aligned with the outer shape of the positive electrode layer 3, the positions of the ends of the negative electrode and the positive electrode will be aligned, making it easier for lithium to deposit at the ends of the negative electrode during charging.

[0026] However, in this embodiment, the electrolyte region 7 expands so that its outer shape expands from the positive electrode layer 3 side toward the negative electrode structure layer 4 side. Therefore, at the end portions, the amount of lithium ions conducted from the positive electrode side toward the negative electrode side during charging is dispersed, preventing concentrated deposition of lithium.

[0027] Furthermore, in this embodiment, at the interface between the negative electrode structure layer 4 and the electrolyte region 7, the end A of the electrolyte region 7 is located more inward than the end of the negative electrode structure layer 4. Therefore, from this perspective as well, lithium is less likely to deposit at the end of the negative electrode.

[0028] In this embodiment, as described above, the outer shapes of the positive electrode layer 3 and the negative electrode structure layer 4 are "aligned" when viewed along the stacking direction. Here, "aligned" in the present invention refers to the outer shapes being "substantially" aligned. That is, the outer shapes need only be aligned to the extent that cracks or chips do not occur in the negative electrode structure layer 4 during manufacturing. Specifically, when the area of ​​the positive electrode layer 3 is 100%, the area of ​​the negative electrode structure layer 4 is 90 to 100%, and 85% or more of the area of ​​the positive electrode layer 3 overlaps with the negative electrode structure layer 4. Preferably, when the area of ​​the positive electrode layer 3 is 100%, the area of ​​the negative electrode structure layer 4 is 95 to 100%, and 90% or more of the area of ​​the positive electrode layer 3 overlaps with the negative electrode structure layer 4. More preferably, when the area of ​​the positive electrode layer 3 is taken as 100%, the area of ​​the negative electrode structure layer 4 is 98 to 100%, and 95% or more of the area of ​​the positive electrode layer 3 overlaps with the negative electrode structure layer 4. Even more preferably, 100% of the area of ​​the positive electrode layer 3 overlaps with the negative electrode structure layer 4.

[0029] In a preferred embodiment, as shown in FIG. 1 , when the end of the electrolyte region 7 at the interface between the positive electrode layer 3 and the electrolyte region 7 is designated as end B, the distance D between end A and end B as viewed along the stacking direction is at least three times the thickness t of the porous sheet 2 in the electrolyte region 7. With this configuration, the area of ​​the portion on the negative electrode side that accepts lithium ions is sufficiently large, and the amount of lithium deposition at the negative electrode end is sufficiently reduced. This prevents concentrated lithium deposition at the negative electrode end, thereby more reliably preventing short circuits.

[0030] In the present embodiment, as shown in Fig. 1, a single laminated structure unit (hereinafter referred to as a unit) is provided, which is made up of a porous sheet 2, a positive electrode layer 3, a negative electrode structure layer 4, a negative electrode current collector 6, and a positive electrode current collector 5. However, the number of units in the all-solid-state battery 1 may be multiple. For example, the all-solid-state battery 1 may be provided as a battery pack having a configuration in which multiple stacked units are electrically connected.

[0031] Next, the materials and the like of each part constituting the all-solid-state battery 1 according to this embodiment will be described.

[0032] (porous sheet) The material constituting the porous sheet 2 is not particularly limited as long as it can support a solid electrolyte. For example, any porous material having interconnected pores can support a solid electrolyte. Examples of porous materials having interconnected pores include nonwoven fabrics, porous separators, and sheets with interconnected pores formed by lithography processing. Examples of nonwoven fabrics that can be used include polyester nonwoven fabrics, polyethylene nonwoven fabrics, and nonwoven fabrics made of cellulose fibers.

[0033] There are no particular limitations on the thickness of the porous sheet 2. For example, the thickness of the porous sheet 2 is 5 to 100 μm, and preferably 10 to 60 μm.

[0034] There is no particular limitation on the method for supporting the solid electrolyte on the porous sheet 2. For example, the solid electrolyte can be supported by preparing a slurry containing the solid electrolyte, applying the prepared slurry to the porous sheet 2, and drying it.

[0035] The method for producing the electrolyte region 7 having a tapered end surface is not particularly limited. For example, a nozzle is moved over the porous sheet 2 while supplying slurry from the nozzle to the porous sheet 2. At this time, by moving the nozzle while changing the amount of slurry supplied in a region that will become the end of the electrolyte region 7, an electrolyte region 7 having a tapered end surface can be obtained.

[0036] The content of the solid electrolyte in the electrolyte region 7 of the porous sheet 2 is not particularly limited, but is, for example, 25% by mass or more and 99% by mass or less. If the content of the solid electrolyte is 25% by mass or more, the electrolyte region 7 functions satisfactorily as the electrolyte layer of the secondary battery. On the other hand, if the content of the solid electrolyte is 99% by mass or less, the flexibility of the porous sheet 2 is sufficiently maintained, and the porous sheet 2 is less likely to be damaged during roll pressing, etc.

[0037] The solid electrolyte supported on the electrolyte region 7 may be any solid electrolyte as long as it is solid and functions as an electrolyte. For example, a sulfide solid electrolyte and an oxide solid electrolyte can be used as the solid electrolyte. Preferably, the solid electrolyte is a sulfide solid electrolyte. Examples of sulfide solid electrolytes include LPS-based (e.g., argyrodite (Li6PS5Cl)) and LGPS-based (e.g., Li 10 GeP2S 12 ) materials are included.

[0038] (positive electrode layer) The positive electrode layer 3 may be formed of a material that can release lithium ions during charging and absorb lithium ions during discharging. The positive electrode layer 3 may be formed of a material that includes, for example, 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. Examples of the lithium metal composite oxide include layered rock salt compounds such as LiCoO2, LiMnO2, LiNiO2, LiVO2, and Li(Ni-Mn-Co)O2, LiMn2O4, and LiNi 0.5 Mn 1.5 Examples of such compounds include spinel-type compounds such as LiFePO4 and LiMnPO4, olivine-type compounds such as Li2FeSiO4 and Li2MnSiO4, and Si-containing compounds such as Li4Ti5O 12 Also, the following can be used.

[0039] The thickness of the positive electrode layer 3 is not particularly limited, but is, for example, 10 to 500 μm, and preferably 50 to 200 μm.

[0040] (Negative electrode structure layer) As described above, the negative electrode structure layer 4 may be a negative electrode layer or a negative electrode protective layer, etc. The thickness of the negative electrode structure layer 4 is, for example, 1 to 100 μm, and preferably 5 to 80 μm.

[0041] The negative electrode layer may be any layer configured to absorb lithium (or precipitate lithium) during charging and release lithium ions during discharging. For example, the negative electrode layer may be formed from a material containing a resin binder and a negative electrode active material dispersed in the resin binder. Examples of the negative electrode active material that can be used include lithium metal, silicon materials, tin materials, compounds containing silicon or tin (oxides, nitrides, alloys with other metals), and carbon materials (graphite, etc.).

[0042] The negative electrode protective layer may be any layer that can protect the electrolyte region 7 from lithium metal that deposits on the negative electrode side.

[0043] For example, the negative electrode protective layer may be a layer containing one or more materials selected from the group consisting of carbon materials such as graphite and metal materials such as silver. Such a material may function as an electrode that absorbs and releases lithium ions in addition to functioning as a negative electrode protective layer.

[0044] Alternatively, the anode protective layer may be made of at least one material selected from the group consisting of lithium halides (lithium fluoride (LiF), lithium chloride (LiCl), lithium bromide (LiBr), and lithium iodide (LiI)), lithium ion conductive polymers, composite metal oxides represented by Li-MO (wherein M is one or more metal elements selected from the group consisting of Mg, Au, Al, Sn, and Zn), and Li-Ba-TiO composite oxides. These materials are particularly stable against reductive decomposition due to contact with lithium metal, and are therefore preferred from the perspective of protecting the electrolyte layer. The anode protective layer may have a configuration in which these materials are dispersed in a resin binder. The thickness of the anode protective layer is, for example, 1 to 100 μm, preferably 5 to 80 μm.

[0045] (Positive electrode current collector and negative electrode current collector) The positive electrode current collector 5 and the negative electrode current collector 6 are provided to electrically connect the all-solid-state battery 1 to an external device. The positive electrode current collector 5 and the negative electrode current collector 6 are each formed of a conductive thin film. For example, aluminum foil can be used as the positive electrode current collector 5. For example, a stainless steel thin film or a copper thin film can be used as the negative electrode current collector 6.

[0046] (Manufacturing method) There are no particular limitations on the method for manufacturing the all-solid-state battery 1 according to this embodiment. For example, the all-solid-state battery 1 can be manufactured using the method described below.

[0047] First, a slurry containing the positive electrode active material is prepared. Then, the prepared slurry is applied onto the positive electrode current collector 5 and dried. In this way, the positive electrode current collector 5 on which the positive electrode layer 3 is formed is obtained.

[0048] As described above, a slurry containing a solid electrolyte is partially applied to a porous sheet having continuous pores and then dried, thereby obtaining a porous sheet 2 having an electrolyte region 7 and a non-support region 8.

[0049] Furthermore, a slurry of the material that constitutes the negative electrode structure layer 4 is prepared, and the prepared slurry is applied onto the negative electrode current collector 6. After application, the slurry is dried. In this way, the negative electrode current collector 6 on which the negative electrode structure layer 4 is formed is obtained.

[0050] Thereafter, the positive electrode current collector 5 on which the positive electrode layer 3 is formed, the porous sheet 2 on which the electrolyte region 7 is formed, and the negative electrode current collector 6 on which the negative electrode structure layer 4 is formed are arranged so as to overlap each other. Then, pressure is applied by a roll press to obtain a laminate. At this time, as described above, in this embodiment, the outer shape of the positive electrode layer 3 and the outer shape of the negative electrode structure layer 4 are aligned, so that cracks and chips in the negative electrode structure layer 4 are prevented.

[0051] Thereafter, multiple sheets of the above-described laminate are stacked as necessary. Furthermore, a positive electrode tab and a negative electrode tab are connected to the positive electrode current collector 5 and the negative electrode current collector 6, respectively. The laminate is then housed in a laminate film made of aluminum or the like and vacuum sealed. This completes the all-solid-state battery 1.

[0052] The first embodiment has been described above. The main configurations and effects of the all-solid-state battery 1 according to this embodiment can be summarized as follows.

[0053] The all-solid-state battery 1 according to this embodiment includes a porous sheet 2 having an electrolyte region 7 supporting a solid electrolyte, a positive electrode layer 3 laminated on one side of the porous sheet 2 so as to be in contact with the porous sheet 2, and an anode structure layer 4 laminated on the other side of the porous sheet 2 so as to be in contact with the porous sheet 2. The outer shapes of the positive electrode layer 3 and the anode structure layer 4 are aligned when viewed along the stacking direction. The electrolyte region 7 expands from the positive electrode layer 3 side toward the anode structure layer 4 side. An end A of the electrolyte region 7 at the interface between the anode structure layer 4 and the electrolyte region 7 is located inside the end of the anode structure layer 4 when viewed along the stacking direction. With this configuration, the outer shapes of the positive electrode layer 3 and the anode structure layer 4 are aligned, preventing damage to the anode structure layer 4 during pressure application, such as by a roll press. Furthermore, since the electrolyte region 7 has a shape that expands from the positive electrode layer 3 side toward the negative electrode structure layer 4 side, the amount of lithium ion conduction at the negative electrode end is dispersed, preventing excessive deposition of lithium at the end. Furthermore, since the negative electrode side end (end A) of the electrolyte region 7 is located inside the end of the negative electrode structure layer 4, deposition of lithium on the end surface of the negative electrode is prevented.

[0054] In a preferred embodiment, the content of the solid electrolyte in the electrolyte region 7 is 25% by mass or more and 99% by mass or less. This configuration allows the electrolyte region 7 to fully function as an electrolyte for the secondary battery. In addition, the flexibility of the porous sheet 2 is maintained.

[0055] In a preferred embodiment, when the end of the electrolyte region 7 at the interface between the positive electrode layer 3 and the electrolyte region 7 is designated as end B, the distance D between end A and end B as viewed along the stacking direction is three times or more the thickness t of the porous sheet in the electrolyte region 7. With this configuration, the area of ​​the portion on the negative electrode side that accepts lithium ions is sufficiently wide, and the amount of lithium ions conducted at the end is sufficiently dispersed. As a result, it is possible to more reliably prevent concentrated deposition of lithium.

[0056] Second embodiment Next, a second embodiment will be described. Note that detailed description will be omitted for the fact that the same configuration as the first embodiment can be adopted.

[0057] 3 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment. In this embodiment, the non-supporting region 8 in the porous sheet 2 has a specially designed configuration. Specifically, the non-supporting region 8 has a communicating region 12 and a non-communicating region 11.

[0058] The non-communicating region 11 is a region where both sides of the porous sheet 2 in the thickness direction are not connected to each other. The non-communicating region 11 is provided at a position surrounding the electrolyte region 7 and is continuous with the electrolyte region 7.

[0059] According to this embodiment, short circuits between the positive electrode and the negative electrode caused by lithium dendrites are more reliably prevented. If communicating holes existed in the porous sheet 2 in a region outside the electrolyte region 7, lithium dendrites could grow from the edge of the negative electrode, through the communicating holes, and around the edge of the electrolyte region 7. In contrast, according to this embodiment, the non-communicating region 11 is provided outside the electrolyte region 7, so that the growth of lithium dendrites that would otherwise wrap around the edge of the electrolyte region 7 is inhibited.

[0060] The non-communicating regions 11 can be formed, for example, by blocking the communicating holes in the porous sheet 2 having the communicating holes. For example, by placing a covering material on the upper and / or lower surfaces of the porous sheet 2, the communicating holes can be blocked, thereby forming the non-communicating regions 11. Examples of the covering material that can be used include a tape material such as a polyimide film, a coating agent, and an inorganic particle material.

[0061] Alternatively, if a material that melts when heated is selected for the porous sheet 2, the communicating holes can be blocked by thermally melting part of the porous sheet 2 by heating.

[0062] Alternatively, the through holes of the porous sheet 2 can be filled with a resin material or the like to block the through holes.

[0063] On the other hand, the communicating region 12 is a region in which both sides of the porous sheet 2 are connected in the thickness direction. The communicating region 12 may or may not be present. In other words, the entire non-supporting region 8 may be the non-communicating region 11.

[0064] Third embodiment Next, a third embodiment will be described. Note that detailed description will be omitted for the points where the same configuration as in the above-described embodiments can be adopted.

[0065] 4 is a schematic cross-sectional view showing an all-solid-state battery 1 according to this embodiment. In this embodiment, the shape of the end face of the electrolyte region 7 is changed from that of the previously described embodiment. Specifically, the electrolyte region 7 expands from the positive electrode layer 3 side toward the negative electrode structure layer 4 side so that the end face has a stepped shape.

[0066] Even when the configuration of this embodiment is adopted, as in the previously described embodiments, the area of ​​the region that receives lithium ions on the negative electrode side is increased, so that it is possible to prevent lithium from being deposited at the end portions in a concentrated manner.

[0067] The electrolyte region 7 having a stepped edge surface can be obtained, for example, by the method described below. First, multiple porous sheet elements are prepared. Then, a solid electrolyte layer is disposed on each porous sheet element. In this process, solid electrolyte layers of different sizes are disposed on different porous sheet elements. These are then stacked in order of the size of the solid electrolyte layer. The resulting stack is integrated by pressing or the like. This allows the solid electrolyte to penetrate each porous sheet element, resulting in a porous sheet 2 having an electrolyte region 7 having a stepped edge surface as a whole.

[0068] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0069] This application claims priority based on Japanese Patent Application No. 2022-112193, filed with the Japan Patent Office on July 13, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. A porous sheet having an electrolyte region provided in a central portion and supporting a solid electrolyte, and a non-supporting region provided in an outer periphery and not supporting a solid electrolyte; a positive electrode layer laminated on one surface of the porous sheet so as to be in contact with the porous sheet; a negative electrode structure layer laminated on the other surface of the porous sheet so as to be in contact with the porous sheet, the outer shape of the positive electrode layer and the outer shape of the negative electrode structure layer are aligned when viewed along the stacking direction; the electrolyte region expands so that its outer shape expands from the positive electrode layer side toward the negative electrode structure layer side, an end A of the electrolyte region at the interface between the negative electrode structure layer and the electrolyte region is located more inward than an end of the negative electrode structure layer when viewed along the stacking direction; All-solid-state battery.

2. The all-solid-state battery according to claim 1, the non-supporting region has a non-communicating region where both sides of the porous sheet in the thickness direction are not connected to each other, The non-communicating region is provided at a position surrounding the electrolyte region and is continuous with the electrolyte region. All-solid-state battery.

3. The all-solid-state battery according to claim 1 or 2, the electrolyte region expands from the positive electrode layer side toward the negative electrode structure layer side so that the end surface has a stepped shape; All-solid-state battery.

4. The all-solid-state battery according to claim 1 or 2, the electrolyte region extends from the positive electrode layer side toward the negative electrode structure layer side so that the end surface thereof is tapered; All-solid-state battery.

5. The all-solid-state battery according to claim 1 or 2, The content of the solid electrolyte in the electrolyte region is 25% by mass or more and 99% by mass or less. All-solid-state battery.

6. The all-solid-state battery according to claim 1 or 2, an end portion of the electrolyte region at the interface between the positive electrode layer and the electrolyte region is defined as end portion B; A distance D between the end A and the end B when viewed along the stacking direction is three times or more the thickness t of the porous sheet in the electrolyte region. All-solid-state battery.

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