Solid-state battery

Abstract

In one embodiment of the present application, a solid-state battery is provided. The solid-state battery is characterized by having at least one cell configuration unit along a stacking direction, the cell configuration unit having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer interposed between the positive electrode layer and the negative electrode layer, at least the solid electrolyte layer being configured to contain solid electrolyte particles, the solid electrolyte particles having a portion in which the proportion of transition metal elements with respect to all metal elements (excluding lithium) is 0.0% or more and 15% or less.

Description

Technical Field

[0001] This invention relates to a solid-state battery. Background Technology

[0002] Previously, rechargeable batteries were used for various purposes. For example, they were used as power sources for electronic devices such as smartphones and laptops.

[0003] In this type of secondary battery, liquid electrolytes, such as organic solvents, have traditionally been used as the medium for ion movement. However, secondary batteries using liquid electrolytes suffer from problems such as electrolyte leakage. Therefore, solid-state batteries, which use solid electrolytes instead of liquid electrolytes, are being developed.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2007-5279 Summary of the Invention

[0007] Solid-state batteries can employ a structure having at least one battery cell along the stacking direction. This battery cell generally comprises a positive electrode layer, a negative electrode layer, and a solid electrolyte layer between the positive and negative electrode layers. In this structure, at least the solid electrolyte layer contains solid electrolyte particles, which may contain transition metal elements as one of their constituent elements. However, if charging and discharging are performed under conditions where the proportion of transition metal elements in the solid electrolyte particles is relatively high, the following problems may arise.

[0008] Specifically, transition metal elements are generally susceptible to the potential changes of the positive and negative electrodes during charging and discharging. Therefore, when the aforementioned solid electrolyte particles are affected by these potential changes during charging and discharging, the transition metal elements, containing a large amount of them, may undergo reactions (redox reactions). Consequently, in the solid electrolyte layer located between the positive and negative electrode layers, the prescribed ion conduction pathway may be impeded, reducing ion conductivity. Furthermore, due to the reactions of the transition metal elements (redox reactions), the electron conduction pathway may become continuous via the transition metals reacting in the solid electrolyte layer between the positive and negative electrode layers. In particular, if the electron conduction pathway is continuous in the solid electrolyte layer between the positive and negative electrode layers, a short circuit may occur between the positive and negative electrodes. Such a short circuit may degrade the characteristics of the solid-state battery.

[0009] The present invention was made in view of the above circumstances. That is, the object of the present invention is to provide a solid-state battery that can appropriately suppress the degradation of battery characteristics.

[0010] To achieve the above objectives, in one embodiment of the present invention,

[0011] Provide a solid-state battery,

[0012] The battery has at least one battery unit along the stacking direction. The battery unit includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer between the positive electrode layer and the negative electrode layer.

[0013] At least the solid electrolyte layer is composed of solid electrolyte particles, wherein the solid electrolyte particles have a portion in which the proportion of transition metal elements relative to all metal elements (excluding lithium) is more than 0.0% and less than 15%.

[0014] According to one embodiment of the present invention, the degradation of battery characteristics can be appropriately suppressed. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of a solid electrolyte layer located between the electrodes of a solid battery according to one embodiment of the present invention.

[0016] Figure 2 This is a schematic cross-sectional view of a solid electrolyte layer located between the electrodes of a solid battery according to one embodiment of the present invention.

[0017] Figure 3 This is a schematic cross-sectional view of a solid electrolyte layer located between the electrodes of a solid battery according to one embodiment of the present invention. Detailed Implementation

[0018] Before describing a solid-state battery according to one embodiment of the present invention, the basic structure of a solid-state battery will be described first. In this specification, "solid-state battery" broadly refers to a battery whose constituent elements are made of solids, and narrowly refers to an all-solid-state battery whose constituent elements (especially all constituent elements) are made of solids. In a preferred embodiment, the solid-state battery of the present invention is a stacked solid-state battery in which the layers constituting the battery constituent units are stacked on top of each other, preferably such layers are made of sintered bodies. The term "solid-state battery" in this specification includes not only secondary batteries capable of repeated charging and discharging, but also primary batteries capable only of discharging. In one embodiment of the present invention, the solid-state battery is a secondary battery. The term "secondary battery" is not overly limited to this name; for example, it may also include energy storage devices.

[0019] The term "sectional view" as used in this specification refers to the state of the solid-state battery when viewed from a direction substantially perpendicular to the thickness direction based on the stacking direction of the active material layers constituting the solid-state battery. The terms "up-down direction" and "left-right direction," used directly or indirectly in this specification, correspond to the up-down and left-right directions in the figures, respectively. Unless otherwise stated, the same symbols or designations denote the same components. Location or the same meaning. In a preferred embodiment, it can be understood that the vertical direction downward (i.e., the direction of gravity) is equivalent to the "downward direction," and its opposite direction is equivalent to the "upward direction."

[0020] The "solid-state battery" of the present invention will now be described in detail. Although the description is based on the accompanying drawings as needed, the illustrations are merely schematic and illustrative for the purpose of understanding the invention, and the appearance, size ratio, etc., may differ from the actual product.

[0021] In this invention, "solid-state battery" broadly refers to a battery whose constituent elements are made of solids, and narrowly refers to an all-solid-state battery whose constituent elements (particularly preferably all battery constituent elements) are made of solids. In a preferred embodiment, the solid-state battery of this invention is a stacked solid-state battery in which the layers constituting the battery constituent units are stacked on top of each other, preferably such layers are made of sintered bodies. It should be noted that "solid-state battery" includes not only so-called "secondary batteries" that can be repeatedly charged and discharged, but also "primary batteries" that can only be discharged. According to a preferred embodiment of the invention, the "solid-state battery" is a secondary battery. The term "secondary battery" is not overly limited to this name, and may also include, for example, energy storage devices.

[0022] In this specification, "top view" refers to the shape of the object viewed from above or below along the thickness direction based on the stacking direction of the layers constituting the solid-state battery. "Cross-sectional view" refers to the shape viewed from a direction substantially perpendicular to the thickness direction based on the stacking direction of the layers constituting the solid-state battery (in short, the shape when cut along a plane parallel to the thickness direction). The terms "vertical direction" and "left-right direction" used directly or indirectly in this specification correspond to the vertical and left-right directions in the figures, respectively. Unless otherwise stated, the same symbols or designations denote the same parts. Location or the same meaning. In a preferred embodiment, it can be understood that the vertical direction downward (i.e., the direction of gravity) is equivalent to the "downward direction," and its opposite direction is equivalent to the "upward direction."

[0023] Unless otherwise stated, the various numerical ranges mentioned in this specification are intended to include both the lower and upper limits of the values ​​themselves. That is, taking the numerical range of 1 to 10 as an example, unless otherwise stated, it can be understood to include the lower limit value "1" and also include the upper limit value "10".

[0024] [Structure of solid-state batteries]

[0025] Solid-state batteries have at least a positive electrode. A solid-state battery is composed of a negative electrode layer and a solid electrolyte. Specifically, a solid-state battery is composed of a battery element containing battery constituent units, which consist of a positive electrode layer, a negative electrode layer, and a solid electrolyte in between.

[0026] In a solid-state battery, the constituent layers can be formed by sintering, with the positive electrode layer, negative electrode layer, and solid electrolyte forming a sintered layer. Preferably, the positive electrode layer, negative electrode layer, and solid electrolyte are sintered integrally with each other, thus forming a single sintered body for the battery element.

[0027] The positive electrode layer is an electrode layer comprising at least a positive electrode active material. The positive electrode layer may further comprise a solid electrolyte. For example, the positive electrode layer is composed of a sintered body comprising at least positive electrode active material particles and solid electrolyte particles. In a preferred embodiment, the positive electrode layer is composed of a sintered body substantially comprising only positive electrode active material particles and solid electrolyte particles. On the other hand, the negative electrode layer is an electrode layer comprising at least a negative electrode active material. The negative electrode layer may further comprise a solid electrolyte. For example, the negative electrode layer is composed of a sintered body comprising at least negative electrode active material particles and solid electrolyte particles. In a preferred embodiment, the negative electrode layer is composed of a sintered body substantially comprising only negative electrode active material particles and solid electrolyte particles.

[0028] Positive and negative electrode active materials are substances that participate in electron exchange in a solid-state battery. Electron exchange occurs through the movement (conduction) of ions between the positive and negative electrode layers via the solid electrolyte, thereby enabling charging and discharging. The positive and negative electrode layers are particularly preferably layers capable of intercalating or deintercalating lithium ions or sodium ions. That is, the solid-state battery is preferably an all-solid-state secondary battery in which lithium ions move between the positive and negative electrode layers via the solid electrolyte for charging and discharging.

[0029] (Positive electrode active material)

[0030] Examples of positive electrode active materials included in the positive electrode layer include at least one selected from the group consisting of lithium phosphate compounds with a NASICON-type structure, lithium phosphate compounds with an olivine-type structure, lithium-containing layered oxides, and lithium-containing oxides with a spinel-type structure. Examples of lithium phosphate compounds with a NASICON-type structure include Li3V2(PO4)3. Examples of lithium phosphate compounds with an olivine-type structure include LiFePO4 and LiMnPO4. Examples of lithium-containing layered oxides include LiCoO2 and LiCo... 1 / 3Ni 1 / 3 Mn 1 / 3 O2, etc. Examples of lithium-containing oxides with a spinel-type structure include LiMn2O4 and LiNi. 0.5 Mn 1.5 O4, etc.

[0031] In addition, as a positive electrode active material capable of intercalating and deintercalating sodium ions, at least one can be selected from the group consisting of sodium phosphate compounds having a NASICON-type structure, sodium phosphate compounds having an olivine-type structure, sodium-containing layered oxides, and sodium-containing oxides having a spinel-type structure.

[0032] (Negative electrode active material)

[0033] Examples of negative electrode active materials included in the negative electrode layer include at least one element selected from the group consisting of oxides (containing at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb, and Mo), graphite-lithium compounds, lithium alloys, lithium phosphate compounds with a NASICON-type structure, lithium phosphate compounds with an olivine-type structure, and lithium oxides with a spinel-type structure. Examples of lithium alloys include Li-Al. Examples of lithium phosphate compounds with a NASICON-type structure include Li3V2(PO4)3 and LiTi2(PO4)3. Examples of lithium phosphate compounds with an olivine-type structure include LiCuPO4. Examples of lithium oxides with a spinel-type structure include Li4Ti5O. 12 wait.

[0034] In addition, at least one of the following groups can be listed as negative electrode active materials capable of intercalating and deintercalating sodium ions: sodium phosphate compounds having a NASICON-type structure and sodium oxides having a spinel-type structure.

[0035] It should be noted that, in a preferred embodiment of the solid-state battery of the present invention, the positive electrode layer and the negative electrode layer are made of the same material.

[0036] The positive and / or negative electrode layers may contain conductive additives. Examples of conductive additives contained in the positive and negative electrode layers include at least one material from the group consisting of metals such as silver, palladium, gold, platinum, aluminum, copper, and nickel, as well as carbon.

[0037] Furthermore, the positive and / or negative electrode layers may contain sintering aids. Examples of sintering aids include at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0038] (Solid electrolyte)

[0039] Solid electrolytes are materials capable of conducting lithium ions. Especially in solid-state batteries, solid electrolytes form the battery cells, creating a layer between the positive and negative electrode layers capable of conducting lithium or sodium ions. It should be noted that the solid electrolyte only needs to be disposed between the positive and negative electrode layers. That is, the solid electrolyte can also exist around the positive and / or negative electrode layers, extending from between them. Specific examples of solid electrolytes include lithium phosphate compounds with a NASICON structure, oxides with a perovskite structure, and oxides with garnet-type or similar structures. Examples of lithium phosphate compounds with a NASICON structure include Li... x M y (PO4)3 (1≤x≤2, 1≤y≤2, M is at least one selected from the group consisting of Ti, Ge, Al, Ga and Zr). As an example of a lithium phosphate compound having a NASICON structure, Li can be cited as an example. 1.2 Al 0.2 Ti 1.8 (PO4)3, etc. As an example of oxides with a perovskite structure, La can be cited. 0.55 Li 0.35 TiO3, etc. As an example of oxides with garnet-type or similar structures, Li7La3Zr2O can be cited. 12 wait.

[0040] It should be noted that solid electrolytes capable of conducting sodium ions include, for example, sodium-phosphate compounds with a NASICON structure, oxides with a perovskite structure, and oxides with garnet-type or similar structures. Among sodium-phosphate compounds with a NASICON structure, Na... x M y (PO4)3 (1≤x≤2, 1≤y≤2, M is at least one selected from the group consisting of Ti, Ge, Al, Ga and Zr).

[0041] The solid electrolyte layer can contain sintering aids. For example, the sintering aids contained in the solid electrolyte layer can be derived from the positive electrode layer. The sintering aids that can be included in the negative electrode layer are selected from the same materials.

[0042] (terminal)

[0043] Solid-state batteries typically include terminals (e.g., external electrodes). Specifically, terminals are provided on the sides of the solid-state battery. Specifically, terminals on the positive electrode side, connected to the positive electrode layer, and terminals on the negative electrode side, connected to the negative electrode layer, are provided on the sides of the solid-state battery. The terminals of the positive electrode layer are engaged with the ends of the positive electrode layer, specifically with leads formed at the ends of the positive electrode layer. Similarly, the terminals of the negative electrode layer are engaged with the ends of the negative electrode layer, specifically with leads formed at the ends of the negative electrode layer. In a preferred embodiment, from the viewpoint of engaging with the leads of the electrode layers, the terminals preferably contain glass or glass-ceramic. Furthermore, the terminals are preferably constructed using a material with high conductivity. There are no particular limitations on the specific material of the terminals; at least one material selected from the group consisting of silver, gold, platinum, aluminum, copper, tin, and nickel can be included.

[0044] (Protective layer)

[0045] A protective layer is typically formed on the outermost side of a solid-state battery for electrical, physical, and / or chemical protection. Preferably, the material constituting the protective layer is one with excellent insulation, durability, and / or moisture resistance, and is environmentally safe.

[0046] The protective layer is a layer that covers the surface of the battery element in a way that allows the leads of each electrode layer to be individually bonded to each external electrode. Specifically, the protective layer covers the surface of the battery element in a way that allows the leads of the positive electrode layer to be bonded to the external electrode on the positive electrode side, and covers the surface of the battery element in a way that allows the leads of the negative electrode layer to be bonded to the external electrode on the negative electrode side. That is, the protective layer does not cover the entire surface of the battery element without gaps, but rather covers the battery element in a way that exposes the leads (ends of the electrode layers) of the electrode layers so that they can be bonded to the external electrodes.

[0047] [Characteristics of the solid-state battery of the present invention]

[0048] Based on the basic structure of solid-state batteries, the following describes the characteristic features of a solid-state battery according to one embodiment of the present invention.

[0049] The inventors of this application have conducted in-depth research on methods for "suppressing the generation of continuous electron conduction paths in the solid electrolyte layer located between the positive and negative electrode layers," which are the causes of reduced solid-state battery characteristics.

[0050] In particular, the inventors of this application focused on the compositional ratio of transition metal elements relative to all metal elements (excluding lithium) contained in the solid electrolyte particles of the solid electrolyte layer. As a result, this invention was proposed. Specifically, based on this focus, the inventors of this application proposed an invention having the technical concept of "at least ensuring that the compositional ratio of transition metal elements relative to all metal elements (excluding lithium) contained in the solid electrolyte particles 20I1 of the solid electrolyte layer 20 is within a specified range (more than 0.0% and less than 15%)" (see [reference]). Figure 1 It should be noted that, as mentioned above, when solid electrolyte particles contain transition metal elements, they are easily affected by the potential changes of the positive / negative electrodes during charging and discharging. Therefore, the inventors of this application have discovered that solid electrolyte layers can contain solid electrolyte particles that do not contain transition metal elements (the composition ratio of transition metal elements to all metal elements (excluding lithium) is 0.0%).

[0051] According to this technical concept, the solid electrolyte layer 20 located between electrodes 10A and 10B contains solid electrolyte particles 201 as its constituent elements, which have a relatively low proportion (more than 0.0% and less than 15%) of transition metal elements. Therefore, compared to the case where the solid electrolyte particles are composed solely of solid electrolyte particles with a relatively high proportion (e.g., greater than 15%) of transition metal elements, it has the following advantages. Specifically, even when the solid electrolyte particles 20I1 are affected by the potential changes of the positive electrode 10A / negative electrode 10B during charging and discharging, the proportion of transition metal elements in the solid electrolyte particles 20I1 that are easily affected by the potential changes of the positive electrode 10A / negative electrode 10B is relatively low (more than 0.0% and less than 15%). Therefore, the proportion of reactions (redox reactions) of the transition metal elements that are easily affected by these potential changes can be reduced. It should be noted that, from the viewpoint of further reducing the proportion of the transition metal element reaction (redox reaction), it is preferable that the proportion of the transition metal element relative to all metal elements (except lithium) contained in the solid electrolyte particles 20I1 of the solid electrolyte layer 20 is at least 1% and less than 10%.

[0052] Therefore, in the solid electrolyte layer 20 located between the positive electrode layer 10A and the negative electrode layer 10B, the situation where the prescribed ion conduction path is blocked and the ion conductivity decreases can be suppressed. Furthermore, since the proportion of the transition metal element reaction (redox reaction) that is easily affected by the potential change of the positive electrode 10A / negative electrode 10B can be reduced, the continuity of the electron conduction path via the reacted transition metal in the solid electrolyte layer 20 can be suppressed. In other words, if the proportion of the transition metal element reaction (redox reaction) can be reduced, the continuity of the electron conduction path can be blocked.

[0053] As can be seen from the above, according to the technical concept of the present invention, the solid electrolyte particles 20I1, which comprise a portion having a relatively low proportion of transition metal elements (more than 0.0% and less than 15%), contained in the solid electrolyte layer 20 located between the positive electrode layer 10A and the negative electrode layer 10B, can function appropriately not only as an "ion-conducting material" but also as an "electron conduction path blocking material." Due to the presence of these solid electrolyte particles 20I1, the continuity of electron conduction paths can be blocked, thus suppressing short circuits between the positive electrode 10A and the negative electrode 10B caused by this. As a result, the degradation of the solid-state battery's characteristics can be appropriately suppressed. In this respect, the present invention is advantageous.

[0054] The phrase "solid electrolyte particle 20I1 having a portion in which the proportion of transition metal elements to all metal elements (excluding lithium) is 0.0% or more and 15% or less" as used in this specification means that "in a single solid electrolyte particle 20I1, at least a portion has a portion in which the proportion of transition metal elements to all metal elements (excluding lithium) is 0.0% or more and 15% or less." As an example, cases where the proportion of transition metal elements to all metal elements (excluding lithium) is 0.0% or more and 15% or less in the entirety of a single solid electrolyte particle 20I1 can be listed. Furthermore, cases where the proportion of transition metal elements to all metal elements (excluding lithium) is 0.0% or more and 15% or less in a portion of a single solid electrolyte particle 20I1 can also be listed.

[0055] The following describes the means by which the technical concept of the present invention is embodied.

[0056] In one embodiment, the solid electrolyte layer 20 comprises first solid electrolyte particles 20II1 with a transition metal element composition ratio of 15% or less and second solid electrolyte particles 20II2 with a transition metal element composition ratio greater than 15%. Specifically, in this embodiment, within the main portion of the solid electrolyte layer 20 where the first solid electrolyte particles 20II1 are arranged in a matrix, the second solid electrolyte particles 20II2 are dispersed in a mutually isolated manner (see reference). Figure 2 ).

[0057] In this method, such as Figure 2 As shown, the solid electrolyte layer 20 located between electrodes 10A and 10B comprises a main portion of a solid electrolyte layer 20 in which first solid electrolyte particles 20II1 are arranged in a matrix and second solid electrolyte particles 20II2 are dispersed and arranged in a mutually isolated manner within the main portion.

[0058] The term "matrix-like" as used in this specification refers to the arrangement of the first solid electrolyte particles 20II1 in rows and columns. The term "main part of the solid electrolyte layer 20" as used in this specification refers to the main part constituting the solid electrolyte layer 20.

[0059] In this embodiment, the main portion of the solid electrolyte layer 20 is composed of first solid electrolyte particles 20II1 arranged in a matrix. The proportion of transition metal elements in these first solid electrolyte particles 20II1 is 15% or less. That is, in this embodiment, the main portion constituting the solid electrolyte layer 20 is composed of a material with a relatively low proportion of transition metal elements. Therefore, even if the first solid electrolyte particles 20II1 are affected by the potential change of the positive electrode 10A / negative electrode 10B during charging and discharging, since the proportion of transition metal elements that are easily affected by the potential change of the electrodes in the main portion constituting the solid electrolyte layer 20 is relatively low, the proportion of reactions (redox reactions) of the transition metal elements that are easily affected by the potential change can be reduced. As a result, the continuity of the electron conduction path can be blocked in the first solid electrolyte particles 20II1 by the reacted transition metal.

[0060] On the other hand, the proportion of transition metal elements in the second solid electrolyte particle 20II2 is greater than 15%. That is, the second solid electrolyte particle 20II2 is composed of a material with a relatively high proportion of transition metal elements. If the proportion of transition metal elements, which are easily affected by changes in electrode potential, is relatively high, it can be said that the proportion of transition metal element reactions (redox reactions) caused by this is higher. Therefore, it is possible for an electron conduction pathway to be formed in the second solid electrolyte particle 20II2 via the reacted transition metal.

[0061] In this respect, in this embodiment, second solid electrolyte particles 20II2 are dispersed in an isolated manner within the main portion of the solid electrolyte layer 20. Through this isolation configuration, each second solid electrolyte particle 20II2 is surrounded by first solid electrolyte particles 20II1. Specifically, each second solid electrolyte particle 20II2 that may form an electron conduction path is surrounded by a continuous first solid electrolyte particle 20II1 capable of blocking the electron conduction path. Therefore, the continuity of the electron conduction path of the second solid electrolyte particles 20II2 via the solid electrolyte layer 20 between the positive electrode 10A and the negative electrode 10B can be more appropriately suppressed. As a result, short circuits between the positive electrode 10A and the negative electrode 10B can be more appropriately suppressed, thereby more appropriately suppressing the degradation of the solid-state battery's characteristics.

[0062] In one embodiment, the solid electrolyte particle 20III can employ a core-shell structure. The core 20III2 of this core-shell structure is the portion containing a transition metal element at a proportion greater than 15%, and the shell 20III1 is the portion surrounding the core 20III2 where the transition metal element proportion is less than 15% (see reference). Figure 3 ).

[0063] In this method, such as Figure 3 As shown, a core-shell structure with a core portion 20III2 and a shell portion 20III1 is adopted. The core portion 20III2 is the part in which the proportion of transition metal elements is greater than 15%, that is, the part with a relatively high proportion of transition metal elements. The shell portion 20III1 surrounding the core portion 20III2 is the part in which the proportion of transition metal elements is less than 15%, that is, the part with a relatively low proportion of transition metal elements.

[0064] In this specification, "core" refers to the central part, or main part, of a single solid electrolyte particle. Conversely, "shell" refers to the outermost part of a single solid electrolyte particle that covers the entire surface of the core; it refers to the part outside the core.

[0065] In this embodiment, the single solid electrolyte particle 20III is configured such that the proportion of transition metal elements in its inner portion (core portion) is relatively high, while the proportion of transition metal elements in its outer shell portion (shell portion) is relatively low. With this structure, the shell portion of the single solid electrolyte particle 20III is the portion with a relatively low proportion of transition metal elements (less than 15%). Therefore, even if the solid electrolyte particle 20III is affected by the potential change of the positive electrode 10A / negative electrode 10B during charging and discharging, the proportion of the transition metal elements that are easily affected by this potential change (redox reaction) can be reduced because the shell portion of the single solid electrolyte particle 20III has a relatively low proportion of transition metal elements. Thus, the continuity of the electron conduction path can be blocked by the reacted transition metal in the shell portion (shell portion) of the solid electrolyte particle 20III.

[0066] On the other hand, the proportion of transition metal elements in the inner portion (i.e., the core portion 20III2) of a single solid electrolyte particle 20III is relatively high (less than 15%). If the proportion of transition metal elements, which are easily affected by changes in electrode potential, is relatively high, it can be said that the proportion of transition metal element reactions (redox reactions) caused by this is higher. Therefore, the electron conduction pathway may continue through the reacted transition metal to the core portion 20III2 of the solid electrolyte particle 20III.

[0067] In this respect, in this embodiment, the entire surface of the core portion 20III2 of the solid electrolyte particle 20III is surrounded by a continuous shell portion 20III1 capable of blocking the electron conduction path. Therefore, the continuity of the electron conduction path to the core portion 20III2 located inside the shell portion 20III1 of the solid electrolyte particle 20III can be prevented. As a result, when considering a single solid electrolyte particle 20III, the continuity of the electron conduction path from entering through the shell portion, passing through the core portion, and exiting through the shell portion can be prevented. Thus, even if the solid electrolyte particles 20III are arranged in a manner that allows them to contact each other between the positive electrode 10A and the negative electrode 10B, the continuity of the electron conduction path between the positive electrode 10A and the negative electrode 10B via each solid electrolyte particle 20III, i.e., via the solid electrolyte layer 20, can be appropriately suppressed. Consequently, short circuits between the positive electrode 10A and the negative electrode 10B can be more appropriately suppressed, thereby more appropriately suppressing the degradation of the solid-state battery's characteristics.

[0068] It should be noted that the present invention preferably adopts the following method.

[0069] In one embodiment, the solid electrolyte layer 20 is preferably a single layer, and a plurality of the aforementioned solid electrolyte particles 20I1 are randomly arranged within the single-layer solid electrolyte layer (see reference). Figure 1 ).

[0070] As described above, in this invention, the solid electrolyte particles 20I1 have a relatively low proportion (0.0% to 15%) of transition metal elements that are easily affected by potential changes at the positive electrode 10A / negative electrode 10B. Therefore, the proportion of reactions (redox reactions) of the transition metal elements that are easily affected by potential changes at the positive electrode 10A / negative electrode 10B can be reduced. Consequently, the continuity of electron conduction pathways can be blocked by the reacted transition metals in the solid electrolyte layer 20.

[0071] In this regard, it is advantageous to provide a plurality of solid electrolyte particles 20I1 having the above-described characteristics within a single-layer solid electrolyte layer 20, and to randomly arrange these plurality of solid electrolyte particles 20I1. Specifically, due to this random arrangement, the solid electrolyte particles 20I1 having the above-described characteristics can be distributed throughout the entire solid electrolyte layer 20. Thus, the "electron conduction path blocking function" of the solid electrolyte particles 20I1 can be exerted at any multiple locations within the solid electrolyte layer 20.

[0072] It should be noted that in this method, solid electrolyte particles 20I1 with the aforementioned characteristics are randomly arranged between the positive electrode 10A and the negative electrode 10B within a solid electrolyte layer 20 that is always composed of a single layer. However, it should be explicitly stated that this method does not involve alternating layers with a relatively low proportion of transition metal elements and layers with a relatively high proportion of transition metal elements along the stacking direction between the positive and negative electrodes. In such an alternating method, as described later, for example, a mixture of solid electrolyte particles with a relatively low proportion of transition metal elements and solid electrolyte particles with a relatively high proportion of transition metal elements is used, which, compared to the case of manufacturing a solid battery containing a single-layer solid electrolyte layer between the electrodes, results in a multi-layer solid electrolyte layer. Therefore, this is inappropriate from the viewpoint of manufacturing efficiency.

[0073] In one embodiment, preferably at least one of the positive electrode layer 10A and the negative electrode layer 10B further comprises the aforementioned solid electrolyte particles.

[0074] Specifically, it is preferable that at least one of the positive electrode layer 10A and the negative electrode layer 10B further comprises "solid electrolyte particles with a relatively low proportion (more than 0.0% and less than 15%) of transition metal elements that are easily affected by potential changes in the positive electrode 10A / negative electrode 10B". Generally, it is known that the active materials contained in the positive electrode layer 10A and the negative electrode layer 10B have low ionic and electronic conductivity. Therefore, from the viewpoint of supplementing ionic conductivity, solid electrolyte particles can be provided, and from the viewpoint of supplementing electronic conductivity, conductive additives can be provided.

[0075] In particular, when at least one of the positive electrode layer 10A and the negative electrode layer 10B contains solid electrolyte particles with a relatively low proportion of transition metal elements (more than 0.0% and less than 15%), the following advantages exist. Specifically, even when exposed to potential changes in the positive electrode 10A / negative electrode 10B during charging and discharging, the proportion of transition metal elements, which are easily affected by the potential changes in the positive electrode 10A / negative electrode 10B, in the solid electrolyte particles is relatively low (more than 0.0% and less than 15%). Therefore, the proportion of reactions (redox reactions) of transition metal elements that are easily affected by these potential changes can be reduced. Thus, compared to the case where the electrode layer contains ordinary solid electrolyte particles that do not have the above-mentioned characteristic (a low proportion of reactions (redox reactions) of transition metal elements), the obstruction of ion conduction pathways and the reduction of ion conductivity can be suppressed.

[0076] Furthermore, the solid electrolyte particles used in this invention are preferably employed in the following manner.

[0077] The solid electrolyte particles used in this invention may be composed of at least one of the following groups: lithium phosphate compounds having a NASICON-type structure, lithium compounds having a LISICON-type structure, and lithium oxides having a garnet-type structure.

[0078] Although not particularly limited, the solid electrolyte particles used in this invention are preferably composed of lithium phosphate compounds having a NASICON structure represented by Formula 1 below.

[0079] [Formula 1]

[0080] Li 1＋x Mi 2-y Mii y (PO4)3

[0081] (In the formula, 0≤x≤1, 0.0≤y≤0.3, Mi: selected from at least one of the group consisting of Al, Ga, Ge, Zr, Ca and In, Mii: selected from at least one of the group consisting of Ti, V, Co and Fe)

[0082] Although not specifically limited, x in Formula 1 above can be 0 or more and 1 or less (as described above), preferably 0.1 or more and 0.9 or less, 0.2 or more and 0.8 or less, 0.3 or more and 0.7 or less, 0.4 or more and 0.6 or less, for example, 0.5.

[0083] Although not specifically limited, y in Formula 1 above can be 0.0 or more and 0.3 or less (as described above), preferably 0.01 or more and 0.3 or less, 0.01 or more and 0.25 or less, more preferably 0.01 or more and 0.2 or less, further preferably 0.01 or more and 0.15 or less, and even more preferably 0.01 or more and 0.1 or less.

[0084] Although not specifically limited, Mi in Equation 1 above can be at least two selected from the group consisting of Al, Ga, Ge, Zr, Ca, and In. For example, Al and Ge can be selected. It should be noted that the molar ratios of the elements in the equation are not necessarily consistent; depending on the analytical method, there is a tendency for deviations. However, as long as the compositional deviation is not sufficient to cause a change in properties, the effects of this invention can be achieved.

[0085] Although there are no specific restrictions, as an example of Mii in Equation 1 above, Ti can be chosen.

[0086] Although not specifically limited, as an example of Equation 1 above, Li can be listed. 1.5 Al 0.5 Ge 1.2 Ti0.3 (PO4)3.

[0087] [Method for manufacturing a solid-state battery according to the present invention]

[0088] The following describes a method for manufacturing a solid-state battery according to one embodiment of the present invention. It should be noted that this manufacturing method is only one example, and it is explained in advance that other methods (such as screen printing) are not excluded.

[0089] A solid-state battery according to one embodiment of the present invention can be manufactured using a green sheet method. In one approach, after forming a predetermined laminate primarily by the green sheet method, a solid-state battery according to one embodiment of the present invention can finally be manufactured. It should be noted that the following description is based on this approach, but is not limited thereto; the predetermined laminate can also be formed primarily by methods such as screen printing.

[0090] (The process of forming unfired laminates)

[0091] First, a paste for a solid electrolyte layer, a paste for a positive electrode active material layer, a paste for a positive electrode current collector layer, a paste for a negative electrode active material layer, a paste for a negative electrode current collector layer, a paste for an insulating layer, and a paste for a protective layer are coated on each substrate (e.g., PET film).

[0092] Each paste can be prepared by wet mixing a specified constituent material of each layer from the group consisting of a positive electrode active material, a negative electrode active material, a conductive material, a solid electrolyte material, an insulating material, and a sintering aid, with an organic carrier in which an organic material is dissolved in a solvent. The paste for the positive electrode active material layer, for example, includes a positive electrode active material, a conductive material, a solid electrolyte material, an organic material, and a solvent. The paste for the negative electrode active material layer, for example, includes a negative electrode active material, a conductive material, a solid electrolyte material, an organic material, and a solvent. As a paste for the positive electrode current collector layer / negative electrode current collector layer, for example, at least one material selected from the group consisting of silver, palladium, gold, platinum, aluminum, copper, and nickel can be used. The paste for the solid electrolyte layer, for example, includes a solid electrolyte material, a sintering aid, an organic material, and a solvent. The paste for the protective layer, for example, includes an insulating material, an organic material, and a solvent. The paste for the insulating layer, for example, includes an insulating material, an organic material, and a solvent.

[0093] In wet mixing, a medium can be used; specifically, ball milling or adhesive milling can be used. On the other hand, wet mixing methods without a medium can be used, such as sand milling, high-pressure homogenizer method, or kneading dispersion method.

[0094] As described above, the solid electrolyte material can be a powder containing at least one compound selected from the group consisting of a lithium phosphate compound having a NASICON-type structure, a lithium compound having a LISICON-type structure, and a lithium compound having a garnet-type structure.

[0095] In particular, in this invention, a specified solid electrolyte material is preferably selected such that the final solid-state battery component, namely the solid electrolyte layer, contains solid electrolyte particles having a proportion of transition metal elements to all metal elements (excluding lithium) of 0.0% to 15%. A specified paste for the solid electrolyte layer can be prepared by wet mixing the specified solid electrolyte material, a sintering aid, and an organic carrier in which the organic material is dissolved in a solvent.

[0096] As an example, it is preferable to select at least two solid electrolyte materials. For instance, it is preferable to select at least two solid electrolyte materials such that the final solid-state battery's constituent elements, namely the solid electrolyte layer, can respectively contain solid electrolyte particles having a proportion of transition metal elements to all metal elements (excluding lithium) of 0.0% or more and 15% or less, and solid electrolyte particles having a proportion of transition metal elements to all metal elements (excluding lithium) of more than 15%. By wet mixing these at least two solid electrolyte materials, a sintering aid, and an organic carrier obtained by dissolving organic materials in a solvent, a specified paste for the solid electrolyte layer can be prepared.

[0097] As another example, it is preferable to use a two-layer solid electrolyte material (particles) so that the solid electrolyte particles contained in the solid electrolyte layer, which is the constituent element of the final solid battery, can form a core-shell structure. Specifically, it is preferable to use the above-mentioned two-layer solid electrolyte material (particles) so that the solid electrolyte particles contained in the solid electrolyte layer, which is the constituent element of the final solid battery, can form a core-shell structure (core: the part with a transition metal element composition ratio greater than 15% / shell: the part surrounding the core and with a transition metal element composition ratio of less than 15%).

[0098] Two-layer solid electrolyte materials (particles) can be obtained, for example, by the following method. As an example, a solid electrolyte material (particle) with a relatively low proportion of transition metal elements relative to all metal elements (excluding lithium) is coated onto the entire surface of the solid electrolyte material (particle) in which the transition metal element constitutes a relatively large proportion of all metal elements (excluding lithium). This yields the aforementioned two-layer solid electrolyte material.

[0099] As another example, by selecting a specified solid electrolyte material and then appropriately controlling the heat treatment conditions in subsequent firing stages, the shell portion of the solid electrolyte particles contained in the solid electrolyte layer, a constituent element of the final solid-state battery, is exposed on the entire surface of the core portion. Specifically, by selecting a specified solid electrolyte material such that the proportion of transition metal elements in the core portion of the solid electrolyte particles contained in the solid electrolyte layer, a constituent element of the final solid-state battery, is greater than 15%, and the shell portion is a portion surrounding the core portion with a transition metal element proportion of less than 15%, and then by appropriately controlling the heat treatment conditions in subsequent firing stages, the shell portion is exposed on the entire surface of the core portion.

[0100] The positive electrode active material included in the paste for the positive electrode active material layer is, for example, selected from at least one of the following groups: lithium phosphate compounds having a NASICON-type structure, lithium compounds having a LISICON-type structure, and lithium compounds having a garnet-type structure.

[0101] The insulating material included in the paste for the insulating layer may be, for example, composed of glass or ceramic materials. The insulating material included in the paste for the protective layer is preferably, for example, at least one selected from the group consisting of glass, ceramic, thermosetting resin, and photocurable resin.

[0102] The organic material contained in the paste is not particularly limited, and at least one polymeric material selected from the group consisting of polyvinyl alcohol acetal resin, cellulose resin, polyacrylic acid resin, polyurethane resin, polyvinyl acetate resin, and polyvinyl alcohol resin can be used. The solvent is not particularly limited as long as it can dissolve the aforementioned organic material; for example, toluene and / or ethanol can be used.

[0103] The negative electrode active material included in the paste used as the negative electrode active material layer can be, for example, composed of a negative electrode active material, the material included in the above-mentioned solid electrolyte paste, and a conductive material. The negative electrode active material is selected from at least one of the following groups: oxides (including at least one element selected from the group consisting of Ti, Si, Sn, Cr, Fe, Nb, and Mo), graphite-lithium compounds, lithium alloys, lithium phosphate compounds with a NASICON-type structure, lithium phosphate compounds with an olivine-type structure, and lithium oxides with a spinel-type structure.

[0104] As a sintering aid, it can be at least one selected from the group consisting of lithium oxide, sodium oxide, potassium oxide, boron oxide, silicon oxide, bismuth oxide, and phosphorus oxide.

[0105] By drying the coated paste on a heating plate heated to 30°C to 50°C, a solid electrolyte layer, a positive / negative electrode sheet, and an insulating layer sheet of a specified thickness are formed on a substrate (e.g., PET film).

[0106] Next, each sheet is peeled from the substrate. After peeling, sheets of each component of the battery cell are sequentially stacked along the lamination direction. After stacking, before subsequent stamping, a solid electrolyte layer or insulating layer can be provided to the side regions of the electrode sheets by screen printing. Next, preferably, hot pressing is performed at a specified pressure (e.g., about 50 MPa to about 100 MPa), followed by isotropic pressing at a specified pressure (e.g., about 150 MPa to about 300 MPa). This allows the formation of the specified laminate.

[0107] (Firing process)

[0108] The resulting laminate is then fired. This firing is carried out by heating in a nitrogen atmosphere at, for example, 600°C to 1000°C.

[0109] Next, terminals are formed on the resulting laminate. The terminals are configured to be electrically connected to the positive and negative electrode layers, respectively. For example, the terminals are preferably formed by sputtering or the like. Although not particularly limited, the terminals are preferably made of at least one material selected from silver, gold, platinum, aluminum, copper, tin, and nickel. Furthermore, it is preferable to form a protective layer by sputtering, spraying, or the like to a degree that does not cover the terminals.

[0110] As described above, a solid-state battery according to one embodiment of the present invention (see reference) can be suitably manufactured. Figure 1 ).

[0111] The solid-state battery obtained according to one embodiment of the present invention has the characteristic that "the composition ratio of at least the transition metal element relative to all metal elements (except lithium) contained in the solid electrolyte particles 20I1 of the solid electrolyte layer 20 is within a specified range (more than 0.0% and less than 15%)" (see reference). Figure 1 ).

[0112] Based on this characteristic, the solid electrolyte layer 20 located between electrodes 10A and 10B comprises solid electrolyte particles 20I1 with a relatively low proportion (0.0% to 15%) of transition metal elements. Therefore, compared to the case where the solid electrolyte particles are composed solely of solid electrolyte particles with a relatively high proportion (e.g., greater than 15%) of transition metal elements, even when the solid electrolyte particles 20I1 are affected by the potential changes of the positive electrode 10A / negative electrode 10B during charging and discharging, the proportion of transition metal elements in the solid electrolyte particles 20I1 that are easily affected by these potential changes is relatively low (0.0% to 15%). Therefore, the proportion of reactions (redox reactions) of the transition metal elements that are easily affected by these potential changes can be reduced.

[0113] Therefore, in the solid electrolyte layer 20 located between the positive electrode layer 10A and the negative electrode layer 10B, the situation where the prescribed ion conduction path is blocked and the ion conductivity decreases can be suppressed. Furthermore, since the proportion of the transition metal element reaction (redox reaction) that is easily affected by the potential change of the positive electrode 10A / negative electrode 10B can be reduced, the continuity of the electron conduction path via the reacted transition metal in the solid electrolyte layer 20 can be suppressed. In other words, if the proportion of the transition metal element reaction (redox reaction) can be reduced, the continuity of the electron conduction path can be blocked.

[0114] Example

[0115] The following describes embodiments related to the present invention. In these embodiments, solid-state batteries having a solid electrolyte layer were manufactured, the solid electrolyte layer comprising solid electrolyte particles having the composition shown in the following embodiments.

[0116] Specifically, firstly, a paste for a solid electrolyte layer, a paste for a positive electrode active material layer, a paste for a positive electrode current collector layer, a paste for a negative electrode active material layer, a paste for a negative electrode current collector layer, and a paste for a protective layer are coated onto each PET film.

[0117] Paste for positive electrode active material layer

[0118] The positive electrode active material (Li3V2(PO4)3), the solid electrolyte material (as shown in the examples below), the organic material (polyvinyl acetal resin), and the solvent (toluene) are used.

[0119] Paste for negative electrode active material layer

[0120] The negative electrode active material (LiTi2(PO4)3), the solid electrolyte material (as shown in the examples below), the organic material (polyvinyl acetal resin), and the solvent (toluene) are used.

[0121] Paste for positive current collector layer / Paste for negative current collector layer

[0122] aluminum

[0123] Protective layer paste

[0124] Insulating materials (glass materials), organic materials (polyvinyl acetal resin), and solvents (toluene).

[0125] Solid electrolyte layer paste

[0126] Solid electrolyte material (as shown in the examples below), sintering aid (silicon oxide), organic material (polyvinyl acetal resin), and solvent (toluene).

[0127] It should be noted that, in this embodiment, from the perspective of directly evaluating the degree of insulation as described later, a solid electrolyte particle is selected as the solid electrolyte material.

[0128] Next, the coated paste is dried on a heating plate heated to 30°C to 50°C, forming individual sheets on a PET film. Then, the sheets are peeled off from the PET film. After peeling, the sheets of each component of the battery unit are sequentially stacked along the lamination direction. After stacking, a solid electrolyte layer is screen-printed onto the side areas of the electrode sheets. Next, thermoforming is performed under a pressure of approximately 100 MPa, followed by isotropic pressure of approximately 200 MPa. This forms the desired laminate.

[0129] The resulting laminate is then fired. This firing process involves removing organic materials at 500°C in a nitrogen atmosphere containing oxygen or in the atmosphere, followed by heating at 800°C in a nitrogen atmosphere. Then, terminals are mounted on the sputtered laminate to enable electrical connections to the positive and negative electrode layers, respectively. Next, a protective layer is applied to ensure the terminals are not covered by sputtering.

[0130] As a result, various solid-state batteries were manufactured.

[0131] After manufacturing each solid-state battery, each battery was charged, and the voltage change was observed after a one-hour inactivity. The results are shown in Table 1 below (Relationship between solid electrolyte material and insulation).

[0132] [Table 1] Relationship between solid electrolyte materials and insulation properties

[0133]

[0134] [Table 2] The composition ratio of transition metal elements relative to all metal elements (excluding lithium) (%)

[0135]

[0136] As shown in Table 1, in Examples 1-4, 7-11, 15-19, 23-26, 29-31, and 33-35, the voltage change after charging the solid-state battery and stopping for 1 hour was less than 0.2V, meeting the benchmark for ensuring insulation. Under the condition of ensuring this insulation, it can be seen from Table 2 below (the composition ratio of transition metal elements to all metal elements (excluding lithium) %) that the composition ratio of transition metal elements to all metal elements (excluding lithium) is 0.0% or more and 15% or less. It should be noted that the inventors of this application have discovered that if transition metal elements are present in the solid electrolyte particles, they are easily affected by the potential changes of the positive / negative electrode during charging and discharging. Therefore, the solid electrolyte layer can contain solid electrolyte particles that do not contain transition metal elements (the composition ratio of transition metal elements to all metal elements (excluding lithium) %): 0.0%. In particular, as shown in Table 1, in Examples 1-3, 7-9, 15-18, 23-25, 29-30, and 33-34, the voltage change after charging the solid-state battery and stopping for 1 hour was less than 0.1V, which meets the benchmark for more appropriately ensuring insulation. To further ensure this insulation, as shown in Table 2 below (composition ratio of transition metal elements to all metal elements (excluding lithium) (%)), the composition ratio of transition metal elements to all metal elements (excluding lithium) is 0.5% or more and 10% or less.

[0137] On the other hand, as shown in Table 1, in Examples (corresponding to Comparative Examples) 5, 6, 12-14, 20-22, 27, 28, 32, and 36, the voltage change after charging the solid-state battery and stopping for 1 hour was 0.2V or more, which did not meet the benchmark for ensuring insulation. Without ensuring this insulation, as shown in Table 2 below, it can be seen that the proportion of transition metal elements relative to all metal elements (excluding lithium) exceeds 15%.

[0138] As can be seen from the above, if the solid electrolyte layer between the electrodes is composed of solid electrolyte particles with a relatively low proportion of transition metal elements (less than 15%) (i.e., composed of at least one solid electrolyte particle selected from the group consisting of Examples 1-4, 7-11, 15-19, 23-26, 29-31 and 33-35) or contains such solid electrolyte particles, then compared with the case where the solid electrolyte layer between the electrodes is composed only of solid electrolyte particles with a relatively high proportion of transition metal elements between the electrodes (greater than 15%), it can be seen that the proportion of the reaction (redox reaction) of the transition metal elements that are easily affected by potential changes can be reduced.

[0139] The above description illustrates one embodiment of the present invention, but only represents a typical example within the scope of the invention. Therefore, the present invention is not limited thereto, and those skilled in the art will readily understand that various modifications can be made.

[0140] Industrial availability

[0141] The solid-state battery according to one embodiment of the present invention can be used in various fields of envisioned energy storage. Although only illustrative, the solid-state battery according to one embodiment of the present invention can be applied to the following fields: electrical / information / communication fields using mobile devices, etc. (e.g., mobile phones, smartphones, laptops, and mobile devices such as digital cameras, activity meters, arm computers, and electronic paper); home / small industrial applications (e.g., power tools, golf carts, home / care / industrial robots); large industrial applications (e.g., forklifts, elevators, port cranes); transportation systems (e.g., hybrid vehicles, electric vehicles, buses, trams, electric-assisted bicycles, electric motorcycles); power system applications (e.g., various power generation, load conditioners, smart grids, home stationary energy storage systems); and IoT fields; space / deep-sea applications (e.g., space probes, underwater research vessels), etc.

[0142] Symbol Explanation

[0143] 100 battery components

[0144] 10A positive electrode layer

[0145] 10B Negative Electrode Layer

[0146] 20 Solid electrolyte layer

[0147] 20I1 refers to solid electrolyte particles containing a relatively low proportion of transition metal elements (above 0.0% and below 15%).

[0148] 20II1 First solid electrolyte particles with a transition metal element composition ratio of less than 15%.

[0149] 20II2 Second solid electrolyte particles with a transition metal element composition greater than 15%

[0150] 20III Solid Electrolyte Particles

[0151] 20III1 Shell

[0152] 20III2 core section.

Claims

1. A solid-state battery, The battery has at least one battery unit along the stacking direction. The battery unit includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer between the positive electrode layer and the negative electrode layer. The solid electrolyte layer is composed of solid electrolyte particles, wherein the solid electrolyte particles have a portion in which the proportion of a transition metal element relative to all metal elements except lithium is 0.5% or more and 15% or less, and the transition metal element is Ti or Fe.

2. The solid-state battery according to claim 1, wherein, The solid electrolyte particles serve as components that block the electron conduction path.

3. The solid-state battery according to claim 1 or 2, wherein, The solid electrolyte layer is a single layer, and multiple solid electrolyte particles are randomly arranged within this single solid electrolyte layer.

4. The solid-state battery according to claim 1 or 2, wherein, The solid electrolyte layer comprises first solid electrolyte particles in which the proportion of the transition metal element is less than 15% and second solid electrolyte particles in which the proportion of the transition metal element is greater than 15%. The second type of solid electrolyte particles are dispersed and disposed in a mutually isolated manner within the main part of the solid electrolyte layer in which the first type of solid electrolyte particles are arranged in a matrix.

5. The solid-state battery according to claim 1 or 2, wherein, The solid electrolyte particles have a core-shell structure. The core is the portion in which the proportion of the transition metal element is greater than 15%, and the shell is the portion surrounding the core in which the proportion of the transition metal element is less than 15%.

6. The solid-state battery according to claim 1 or 2, wherein, The positive electrode layer and the negative electrode layer are further comprising the solid electrolyte particles.

7. The solid-state battery according to claim 1 or 2, wherein, The solid electrolyte particles are composed of lithium phosphate compounds having a sodium superionic conductor NASICON structure represented by Formula 1 below. Li 1＋x Mi 2-y Mii y (PO4)3 Formula 1 In the formula, 0≤x≤1, 0.01≤y≤0.3, Mi: selected from at least one of the group consisting of Al, Ga, Ge, Zr, Ca and In, and Mii: selected from either Ti or Fe.

8. The solid-state battery according to claim 1, wherein, The proportion of the transition metal element is more than 0.5% and less than 10%.

9. The solid-state battery according to claim 1 or 2, wherein, The positive electrode layer and the negative electrode layer are layers capable of inserting and de-inserting lithium ions.

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