Solid-state battery and method for manufacturing solid-state battery

Abstract

A solid-state battery in which the occurrence of a short circuit is suppressed is provided.SOLUTION: The solid-state battery of the present disclosure includes an electrode body, a current collector tab connected to the electrode body, and a protective material. The electrode assembly includes a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector, which are stacked in a stacking direction. The solid electrolyte layer has a support including a plurality of fibers made of a material different from that of the protective material. The support protrudes from an end of the solid electrolyte layer. The protective material is connected to the support body and disposed on the end surface.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to solid-state batteries and methods for manufacturing solid-state batteries. [Background technology]

[0002] Solid-state batteries are known as lithium-ion secondary batteries that are excellent in safety.

[0003] Patent Document 1 discloses an all-solid-state battery (hereinafter also referred to as a "solid-state battery"). The solid-state battery includes an electrode body and a current collecting tab connected to the electrode body. The electrode body includes a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector. The electrode body includes a first side surface portion, a second side surface portion facing the first side surface portion, and a third side surface portion connecting the first side surface portion and the second side surface portion. In the first side surface portion, the first active material layer, the solid electrolyte layer, and the second active material layer are flush with each other. A protective member is disposed on the first side surface portion. The protective member covers the side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer. In the third side surface portion, the first active material layer, the solid electrolyte layer, and the second active material layer are flush with each other. A specific fastening member is disposed on the third side surface portion. The binding member covers the side surfaces of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer. Resin is disclosed as the material for the protection member and the binding member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2024-11688 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the solid-state battery disclosed in Patent Document 1, the materials of the protective member and the fastening member are different from the material of the electrode assembly. In other words, the thermal expansion coefficients of the protective member and the fastening member are different from the thermal expansion coefficient of the electrode assembly. Therefore, repeated charging and discharging may reduce the adhesive strength of the protective member and the fastening member to the electrode assembly. If at least one of the protective member and the fastening member peels off from the electrode assembly, a short circuit may occur between the positive and negative electrodes of the electrode assembly.

[0006] The present disclosure has been made in consideration of the above circumstances. An object of one embodiment of the present disclosure is to provide a solid-state battery in which the occurrence of short circuits is suppressed, and a method for manufacturing the solid-state battery. [Means for solving the problem]

[0007] The means for solving the above problems include the following embodiments.

[0008] <1> The solid-state battery of the first embodiment comprises: The battery includes an electrode body, a current collecting tab connected to the electrode body, and a protective material, the electrode body has a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector, which are stacked along a stacking direction; the solid electrolyte layer has a support including a plurality of fibers made of a material different from that of the protective material, the support protrudes from an end surface of the solid electrolyte layer, The solid-state battery is configured such that the protective material is connected to the support and disposed on the end surface.

[0009] The term "solid electrolyte layer" refers to a layer containing a solid electrolyte but not containing an active material (i.e., at least one of a positive electrode active material and a negative electrode active material). The term "positive electrode active material layer" refers to a layer containing a positive electrode active material. The term "negative electrode active material layer" refers to a layer containing a negative electrode active material. The term "support" refers to an insulator having multiple pores that provides mechanical strength to the solid electrolyte layer and does not conduct electricity. The term "pores of the support" refers to holes in which a solid electrolyte is disposed and holds the solid electrolyte. The portion of the support protruding from the end face of the solid electrolyte layer may be a fiber aggregate or a single fiber (hereinafter also referred to as "fluff"). The fiber aggregate may be, for example, a part of a nonwoven fabric or a mesh sheet. The term "fluff" refers to a fiber protruding from the end face of the solid electrolyte layer and having a total length from the end face of the solid electrolyte layer of 0.5 mm or less. The number of fluffs protruding from the end face of the solid electrolyte layer needs to be at least one, and preferably multiple from the viewpoint of suppressing the occurrence of short circuits in the solid-state battery. The "protective material" is an insulator that is in a solid state at the operating temperature of a solid-state battery (for example, 120°C or less) and does not conduct electricity. The layered structure of the "electrode body" includes a monopolar structure and a bipolar structure.

[0010] In the first embodiment, the protective material is connected to the support and disposed on the end surface of the solid electrolyte layer. This results in a larger contact area between the protective material and the electrode assembly than when the protective material is connected to the support and not disposed on the end surface of the solid electrolyte layer. Therefore, even when the solid battery is repeatedly charged and discharged, the adhesive strength of the protective material to the electrode assembly is less likely to decrease. In other words, the protective material is less likely to peel off from the electrode assembly. As a result, the solid battery of the first embodiment is less likely to have a short circuit.

[0011] <2> The solid-state battery of the second embodiment is the electrode body includes a plurality of unit electrode bodies stacked along the stacking direction, the unit electrode body includes the positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector, the protective material is connected to the support and disposed on the end surface of the adjacent solid electrolyte layer between two adjacent unit electrode bodies, <1> The solid-state battery is described in

[0012] The laminated structure of the "unit electrode body" includes a monopolar structure and a bipolar structure.

[0013] In the second embodiment, the protective material is connected to the support and disposed on the end surfaces of the adjacent solid electrolyte layers between two adjacent unit electrode bodies. In other words, the positive electrode active material layer or the negative electrode active material layer disposed between the adjacent solid electrolyte layers between two adjacent unit electrode bodies is likely to be reliably covered by the protective material. This more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. Additionally, the protective material more reliably prevents electrical contact between at least one of the positive electrode active material layer and the negative electrode active material layer and the exterior body of the solid battery. As a result, the occurrence of short circuits is more effectively suppressed in the solid battery of the second embodiment.

[0014] <3> The solid-state battery of the third embodiment comprises: the unit electrode body is formed by stacking the positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector in this order along the stacking direction, the protective material is connected to the support and disposed on the end surface of the adjacent solid electrolyte layer within the unit electrode body; <2> 1. The fixed battery according to claim 1.

[0015] In a third aspect, the laminated structure of the electrode assembly is configured such that a plurality of unit electrode assemblies having a monopolar structure are connected in parallel. In the third aspect, the protective material is connected to the support and disposed on the end surface of the adjacent solid electrolyte layer within the unit electrode assembly. In other words, the positive electrode active material layer or the negative electrode active material layer disposed between adjacent solid electrolyte layers within the unit electrode assembly is likely to be reliably covered by the protective material. This more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. In addition, the protective material more reliably prevents electrical contact between at least one of the positive electrode active material layer and the negative electrode active material layer and the exterior body of the solid battery. As a result, the occurrence of short circuits is more suppressed in the solid battery of the third aspect.

[0016] <4> The solid-state battery of the fourth aspect is the protective material is disposed to cover at least one end surface of the positive electrode active material layer and the negative electrode active material layer; <1> ~ <3> The solid-state battery according to any one of the above items.

[0017] This allows the protective material to more reliably prevent electrical contact between the positive electrode active material layer and the negative electrode active material layer. In addition, the protective material more reliably prevents electrical contact between at least one of the positive electrode active material layer and the negative electrode active material layer and the exterior body of the solid-state battery. As a result, the occurrence of short circuits is further suppressed in the solid-state battery of the fourth aspect.

[0018] <5> The solid-state battery of the fifth aspect is The electrode body A first side portion; a second side surface portion facing the first side surface portion; a third side surface portion connecting the first side surface portion and the second side surface portion; a fourth side surface portion connecting the first side surface portion and the second side surface portion and facing the third side surface portion; and the current collecting tab protrudes from at least one of the third side surface portion and the fourth side surface portion, the protective material is disposed to cover the first side surface portion and the second side surface portion; <1> ~ <4> The solid-state battery according to any one of the above items.

[0019] The "side surface of the electrode body" refers to a surface of the electrode body whose normal direction intersects with the normal direction (stacking direction) of the main surface of the electrode body. The "main surface" refers to a surface whose normal direction is parallel to the stacking direction.

[0020] In a fifth aspect, the protective material is disposed to cover the first side surface portion and the second side surface portion. This allows the protective material to more reliably prevent electrical contact between the positive electrode active material layer and the negative electrode active material layer than when the protective material is not disposed to cover the first side surface portion and the second side surface portion. The protective material more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer on the first side surface portion and the second side surface portion and the exterior body of the solid-state battery. As a result, the occurrence of a short circuit is more suppressed in the solid-state battery of the fifth aspect.

[0021] <6> The solid-state battery of the sixth aspect is The electrode body A first side portion; a second side surface portion facing the first side surface portion; a third side surface portion connecting the first side surface portion and the second side surface portion; a fourth side surface portion connecting the first side surface portion and the second side surface portion and facing the third side surface portion; and the current collecting tab protrudes from at least one of the third side surface portion and the fourth side surface portion, the protective material is disposed on the third side surface portion and the fourth side surface portion so as to be connected to the current collecting tab; <1> ~ <5> The solid-state battery according to any one of the above items.

[0022] In the sixth aspect, the protective material is arranged by being joined to the current collecting tab at the third side surface portion and the fourth side surface portion. In other words, the positive electrode active material layer or the negative electrode active material layer arranged between the solid electrolyte layer and the current collecting tab is likely to be reliably covered by the protective material. As a result, the protective material more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. The protective material more reliably prevents electrical contact between at least one of the positive electrode active material layer and the negative electrode active material layer and the exterior body of the solid battery. As a result, the solid battery of the sixth aspect is more suppressed from short-circuiting.

[0023] <7> The seventh aspect of the solid-state battery is The support is a nonwoven fabric. <1> ~ <6> The solid-state battery according to any one of the above items.

[0024] "Nonwoven fabric" refers to a sheet-like material in which fibers are bonded or intertwined without being woven, and refers to a flat fiber assembly that has a predetermined level of structural strength obtained by physical and / or chemical methods other than weaving, knitting, and papermaking (JIS L0222:2022). The fiber assembly has multiple pores. The nonwoven fabric contains a resin.

[0025] The solid state battery of the seventh embodiment has more satisfactory battery performance than when the support is not a nonwoven fabric.

[0026] <8> The method for producing a solid-state battery according to an eighth embodiment includes the steps of: preparing an electrode assembly having a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector stacked along a stacking direction, wherein the solid electrolyte layer has a support including a plurality of fibers, and the support protrudes from an end face of the solid electrolyte layer; forming a protective material connected to the support on the end surface; and In the method for manufacturing a solid-state battery, the material of the fiber and the material of the protective material are different.

[0027] The method for manufacturing a solid state battery according to the eighth embodiment can manufacture a solid state battery in which the occurrence of short circuits is suppressed. [Effects of the Invention]

[0028] According to the embodiments of the present disclosure, a solid-state battery in which the occurrence of a short circuit is suppressed and a method for manufacturing the solid-state battery are provided. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view of a solid state battery according to a first embodiment. [Figure 2] FIG. 2 is a front view of the electrode body according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a front view of an electrode body according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view taken along line XI-XI in FIG. [Figure 7] FIG. 7 is a cross-sectional view taken along line XII-XII in FIG. [Figure 8] FIG. 8 is a cross-sectional view of an example of an electrode body having a laminated structure in which a plurality of unit electrode bodies having a bipolar structure are connected in series. DETAILED DESCRIPTION OF THE INVENTION

[0030] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved.

[0031] Hereinafter, embodiments of the solid-state battery and the method for manufacturing the solid-state battery according to the present disclosure will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters, and description thereof will not be repeated.

[0032] (1) First embodiment (1.1) Solid state battery 1, the solid state battery 1A according to the first embodiment includes an electrode assembly 10, a plurality of positive electrode current collector tabs 21 (an example of current collector tabs), a plurality of negative electrode current collector tabs 22 (an example of current collector tabs), a protective material 30A (see FIG. 2), a positive electrode terminal 41, a negative electrode terminal 42, and an exterior body 50. The electrode assembly 10 is a rectangular parallelepiped object.

[0033] In the first embodiment, the longitudinal direction of the main surface S10 of the electrode body 10 is defined as the X-axis direction. The lateral direction of the main surface S10 of the electrode body 10 is defined as the Y-axis direction. The thickness direction of the electrode body 10 is defined as the Z-axis direction. The X-axis, Y-axis, and Z-axis are each perpendicular to one another. The Z-axis direction is an example of a stacking direction. Note that these directions do not limit the orientation of the solid-state battery of the present disclosure during use.

[0034] The positive electrode terminal 41, the multiple positive electrode current collector tabs 21, the electrode assembly 10, the multiple negative electrode current collector tabs 22, and the negative electrode terminal 42 are arranged in this order along the positive direction of the X-axis. The multiple positive electrode current collector tabs 21 electrically connect the positive electrode terminal 41 and the electrode assembly 10. The multiple negative electrode current collector tabs 22 electrically connect the negative electrode terminal 42 and the electrode assembly 10. A protective material 30A is attached to the side of the electrode assembly 10. An outer casing 50 covers the electrode assembly 10, the multiple positive electrode current collector tabs 21, the multiple negative electrode current collector tabs 22, and the protective material 30A. The electrode assembly 10, the positive electrode current collector tabs 21, the negative electrode current collector tabs 22, and the protective material 30A are sealed by the positive electrode terminal 41, the negative electrode terminal 42, and the outer casing 50.

[0035] (1.1.1) Electrode body The electrode body 10 functions as a power generating element of the solid state battery 1A.

[0036] The electrode body 10 is a rectangular parallelepiped. As shown in FIG. 2, the electrode body 10 has a first side surface portion S10A, a second side surface portion S10B, a third side surface portion S10C, and a fourth side surface portion S10D. The second side surface portion S10B faces the first side surface portion S10A in the Y-axis direction. The third side surface portion S10C connects the first side surface portion S10A and the second side surface portion S10B. The fourth side surface portion S10D connects the first side surface portion S10A and the second side surface portion S10B. The fourth side surface portion S10D faces the third side surface portion S10C in the X-axis direction.

[0037] Each of the first side surface portion S10A, the second side surface portion S10B, the third side surface portion S10C and the fourth side surface portion S10D may be a surface without a step (i.e., a flat surface) or a surface with a step (i.e., a stepped surface).

[0038] The length L1 (thickness) of the electrode body 10 in the Z-axis direction (see FIGS. 3 and 4) is not particularly limited, and is, for example, 18.5 mm.

[0039] 3 and 4, the electrode assembly 10 includes a plurality of unit electrode bodies 10U. The plurality of unit electrode bodies 10U are stacked along the Z-axis direction. The plurality of unit electrode bodies 10U are connected in parallel.

[0040] The unit electrode body 10U has a monopolar layer structure. Specifically, the unit electrode body 10U has two solid electrolyte layers 11, two positive electrode active material layers 12, two negative electrode active material layers 13, two positive electrode current collectors 14, and one negative electrode current collector 15. The positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layer 11, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layer 11, the positive electrode active material layer 12, and the positive electrode current collector 14 are layered in this order along the Z-axis direction.

[0041] (1.1.1.1) Solid electrolyte layer The solid electrolyte layer 11 includes a support 110 and a solid electrolyte 111. The solid electrolyte 111 is disposed on the support 110. More specifically, the solid electrolyte 111 is filled inside the support 110. The solid electrolyte 111 covers the support 110. The support 110 includes a plurality of fibers. The plurality of fibers are made of a material different from that of the protective material 30A.

[0042] The support 110 protrudes from the end surface S11 of the solid electrolyte layer 11. In the first embodiment, a plurality of individual fibers P110 (also referred to as "fluff P110") protrude from the end surface S11 of the solid electrolyte layer 11, as shown in Figures 3 and 4. The fluff P110 originates from fibers contained in the support 110.

[0043] The plurality of feathers P110 may be arranged irregularly or regularly. The number of feathers P110 is not particularly limited. When the support 110 is observed from a direction parallel to the end surface S11 of the solid electrolyte layer 11 (for example, the Z-axis direction), the number of feathers P110 may be 10 or more per mm. The shape of the feathers P110 may extend linearly in a specific direction, or may extend while curving in a specific direction.

[0044] The length L2 (see FIGS. 3 and 4) of the feathers P110 in the direction perpendicular to the end surface S11 of the solid electrolyte layer 11 is not particularly limited and may be 0.05 mm to 0.5 mm. In FIG. 3, L2 indicates the length of the feathers P110 in the X-axis direction. In FIG. 4, L2 indicates the length of the feathers P110 in the Y-axis direction.

[0045] The end surface S11 from which the plurality of fluffs P110 protrude may be, for example, a sheared surface formed by shearing the support 110 under specific conditions. A shearing tool (for example, scissors or a round blade) may be used to shear the support 110.

[0046] (1.1.1.1.1) Support The support 110 holds the solid electrolyte 111. The support 110 and the solid electrolyte 111 prevent electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13.

[0047] The support 110 may include a plurality of fibers, and may be made of a plurality of fibers. The support 110 has a plurality of pores. The pores of the support 110 are filled with a solid electrolyte 111.

[0048] The pore size of the support 110 is not particularly limited, and may be 1 μm to 15 μm from the viewpoint of further reducing the battery resistance of the solid state battery 1A, etc. The pore size of the support 110 is measured by the bubble point method (JIS K 3832).

[0049] The basis weight of the support 110 is not particularly limited, and is set to 0.10 mg / cm from the viewpoint of further reducing the battery resistance of the solid state battery 1A. 2 ~0.80mg / cm 2 The basis weight of the support 110 can be obtained by cutting out a sheet of a certain area from the support 110 and calculating the mass per area of ​​the cut-out sheet.

[0050] The porosity of the support 110 is not particularly limited, and may be 30% to 95%, or 30% to 70%, from the viewpoint of further reducing the battery resistance of the solid state battery 1A. The "porosity" refers to the volume of voids inside the support 110 relative to the total volume of the support 110. The porosity of the support 110 is obtained by calculating the volume of voids from the difference between the actual volume of the support 110 and the volume calculated from the specific gravity of the material, and then calculating the ratio of voids to the actual volume of the support 110.

[0051] The length (thickness) of support 110 in the Z direction is not particularly limited, and may be 10 μm to 30 μm, or may be 10 μm to 15 μm. The thickness of support 110 is measured using a bench micrometer.

[0052] Examples of the support 110 include a nonwoven fabric and a mesh sheet. The support 110 is preferably a nonwoven fabric. The support 110 is more preferably made of a single sheet of nonwoven fabric.

[0053] The term "mesh sheet" refers to a woven fabric that contains a plurality of resin fibers and has pores between the resin fibers.

[0054] The nonwoven fabric is not particularly limited, and examples thereof include meltblown nonwoven fabric, spunbond nonwoven fabric, carded nonwoven fabric, parallel nonwoven fabric, cross nonwoven fabric, random nonwoven fabric, spunlaid nonwoven fabric, flash-spun nonwoven fabric, chemically bonded nonwoven fabric, hydroentangled nonwoven fabric, needle-punched nonwoven fabric, stitch-bonded nonwoven fabric, thermally bonded nonwoven fabric, burst fiber nonwoven fabric, tow-spread nonwoven fabric, and film-split nonwoven fabric. Among these, the type of nonwoven fabric is preferably a meltblown nonwoven fabric. Meltblown nonwoven fabrics are made of ultrafine fibers (for example, fiber diameters of 1 μm to 6 μm). Therefore, even if the basis weight of a meltblown nonwoven fabric is low, the number of fibers contained in the nonwoven fabric is large. As a result, it is easy to obtain a nonwoven fabric whose pore size, basis weight, and porosity are each within the above ranges.

[0055] Nonwoven fabrics are made of fibers. The diameter and length of the fibers are not particularly limited. The fibers may be long or short. The cross-sectional shape of the fibers is not particularly limited, and may be circular, elliptical, irregular, or the like.

[0056] Examples of fiber materials include resins, glass, etc. Examples of resins include polyester-based resins (e.g., polyethylene terephthalate (PET)), polyolefin-based resins (e.g., polyethylene (PE) or polypropylene (PP)), and polyamide-based resins (e.g., nylon or aramid).

[0057] The mesh sheet is made of fibers, and examples of the fibers of the mesh sheet include the same fibers as those exemplified as the fibers of the nonwoven fabric.

[0058] (1.1.1.1.2) Solid electrolyte The solid electrolyte 111 is not particularly limited and may be an aggregate of a plurality of particles. The particle size is not particularly limited as long as it is a particle size that can penetrate into the pores of the support 110, and may be 0.05 μm to 3.0 μm. The particle size is preferably smaller than the thickness of the support 110. The ratio of the total volume of the solid electrolyte 111 to the total volume of voids in the support 110 may be 50 vol% or more, 70 vol% or more, or even 90 vol%. The particle size can be obtained by observing the cross section of the solid electrolyte layer 11 with a scanning electron microscope (SEM), randomly selecting particles, and measuring the average particle size.

[0059] The solid electrolyte 111 preferably includes one selected from the group consisting of a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte. The solid electrolyte 111 may be a known solid electrolyte.

[0060] (1.1.1.1.3) Binder The solid electrolyte layer may further include a binder. The binder may be used for bonding between solid electrolyte layers. The binder may be used for bonding between the solid electrolyte 111 and the positive electrode active material layer 12 or the negative electrode active material layer 13. Examples of the binder include a vinyl halide resin (e.g., polyvinylidene fluoride (PVdF)), rubbers (e.g., acrylate butadiene rubber (ABR), styrene-butadiene rubber (SBR), etc.), and a polyolefin resin (e.g., polyethylene (PE), polypropylene (PP), etc.).

[0061] (1.1.1.2) Positive electrode active material layer The positive electrode active material layer 12 contains a positive electrode active material. The positive electrode active material layer 12 may contain at least one of a positive electrode solid electrolyte, a conductive additive, and a binder, as necessary.

[0062] The positive electrode active material preferably contains a lithium composite oxide. The lithium composite oxide may contain at least one element selected from the group consisting of F, Cl, N, S, Br, and I. The lithium composite oxide may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc. The lithium composite oxide may have an O2-type structure in which the transition metal, oxygen, and lithium are primarily arranged. The positive electrode active material may be a known positive electrode active material.

[0063] Examples of the solid electrolyte for the positive electrode include the same solid electrolytes as those exemplified as the solid electrolyte contained in the solid electrolyte layer.

[0064] Examples of conductive additives include carbon materials (e.g., carbon black, carbon nanotubes, graphite, or carbon fluoride), metal materials (e.g., aluminum powder or conductive whiskers), or conductive polymer materials (e.g., polyaniline, polypyrrole, or polythiophene).

[0065] Examples of the binder include the same binders as those exemplified as the binder contained in the solid electrolyte layer.

[0066] (1.1.1.3) Negative electrode active material layer The negative electrode active material layer 13 contains a negative electrode active material. The negative electrode active material layer 13 may contain at least one of a negative electrode solid electrolyte, a conductive additive, and a binder, as necessary.

[0067] Examples of the negative electrode active material include a Li-based active material (e.g., metallic lithium), a carbon-based active material (e.g., graphite), an oxide-based active material (e.g., lithium titanate), or a Si-based active material (e.g., elemental Si).

[0068] Examples of the solid electrolyte for the negative electrode include the same solid electrolytes as those exemplified as the solid electrolyte for the positive electrode that can be used in the positive electrode active material layer.

[0069] Examples of the conductive additive that can be used in the negative electrode active material layer include the same ones as those exemplified as the conductive additive that can be used in the positive electrode active material layer.

[0070] Examples of binders that can be used in the negative electrode active material layer include the same binders as those exemplified as binders that can be used in the positive electrode active material layer.

[0071] (1.1.1.4) Positive electrode current collector The positive electrode current collector 14 collects current from the positive electrode active material layer 12. The material of the positive electrode current collector is not particularly limited, and examples thereof include stainless steel, aluminum, copper, nickel, iron, titanium, and carbon. The positive electrode current collector may be an aluminum alloy foil or an aluminum foil. The aluminum alloy foil and the aluminum foil may be manufactured using powder. The positive electrode current collector may have a foil or mesh shape, for example. The positive electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on its surface.

[0072] (1.1.1.5) Negative electrode current collector The negative electrode current collector 15 collects current from the negative electrode active material layer 13. The material of the negative electrode current collector is not particularly limited, and examples thereof include stainless steel, aluminum, copper, nickel, iron, titanium, and carbon. The negative electrode current collector may be a copper foil. The negative electrode current collector may have a foil or mesh shape, for example. The negative electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on its surface.

[0073] (1.1.2) Positive and negative electrode current collecting tabs The positive electrode current collector tab 21 electrically connects the positive electrode current collector 14 and the positive electrode terminal 41. The positive electrode current collector tab 21 is connected to the positive electrode current collector 14. As shown in FIGS. 2 and 3 , the positive electrode current collector tab 21 protrudes in the negative direction of the X-axis from the third side surface portion S10C. More specifically, in the first embodiment, a bundle including a plurality of positive electrode current collector tabs 21 is electrically connected to the positive electrode terminal 41. It is preferable that the positive electrode current collector tab 21 is formed continuously from the positive electrode current collector 14.

[0074] The negative electrode current collector tab 22 electrically connects the negative electrode current collector 15 and the negative electrode terminal 42. The negative electrode current collector tab 22 is connected to the negative electrode current collector 15. As shown in FIGS. 2 and 3 , the negative electrode current collector tab 22 protrudes in the positive direction of the X-axis from the fourth side surface portion S10D. More specifically, in the first embodiment, a bundle including a plurality of negative electrode current collector tabs 22 is electrically connected to the negative electrode terminal 42. It is preferable that the negative electrode current collector tab 22 is formed continuously from the positive electrode current collector 14.

[0075] The material of the negative electrode current collector tab and the positive electrode current collector tab is not particularly limited, and may be a metal (for example, aluminum, stainless steel (SUS), nickel, or the like).

[0076] (1.1.3) Protective materials The protective material 30A prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13.

[0077] The protective material 30A is connected to the fluff P110 and disposed on the side surface of the electrode body 10 (i.e., the side surface portions S10A to S10D). As shown in FIG. 3, the protective material 30A is connected to the fluff P110 and disposed on the end surface S11 of the adjacent solid electrolyte layer 11 within the unit electrode body 10U in the third side surface portion S10C and the fourth side surface portion S10D and between two adjacent unit electrode bodies 10U. As shown in FIG. 4, the protective material 30A is disposed so as to cover the end surface S12 of the positive electrode active material layer 12 and the end surface S13 of the negative electrode active material layer 13 in the first side surface portion S10A and the second side surface portion S10B. As shown in FIG. 3, the protective material 30A is disposed so as to cover the end surface S13 of the negative electrode active material layer 13 in the third side surface portion S10C. The protective material 30A is disposed so as to cover the end surface S12 of the positive electrode active material layer 12 in the fourth side surface portion S10D.

[0078] In the first embodiment, the protective material 30A is not arranged so as to be connected to either the positive electrode current collector tab 21 or the negative electrode current collector tab 22 on the third side surface portion S10C or the fourth side surface portion S10D.

[0079] In the third side surface portion S10C and the fourth side surface portion S10D, the length L3 (see FIG. 3) of the protective material 30A in the X-axis direction is not particularly limited and may be 0.02 mm to 0.20 mm. In the first side surface portion S10A and the second side surface portion S10B, the length L4 (see FIG. 4) of the protective material 30A in the Y-axis direction is not particularly limited and may be 0.02 mm to 1.00 mm.

[0080] The protective material 30A may be a solidified resin composition. The resin composition is different from the material of the fibers contained in the support 110. The resin composition may be a known resin composition (e.g., a thermoplastic resin composition, a thermosetting resin composition, a photocurable resin composition, etc.) as long as it is a resin composition that is in a solid state at the operating temperature of the solid-state battery 1A (e.g., 120°C or lower). The resin composition includes a known resin (e.g., a thermoplastic resin, a thermosetting resin, a photocurable resin, etc.). The resin composition may further include a polymerization initiator, a curing agent, etc., as necessary.

[0081] The surface energy of the material of the protective material 30A (for example, a resin composition) is preferably greater than the surface energy of the material of the support 110. This makes it less likely that the unsolidified portion of the protective material 30A will be repelled by the support 110 (specifically, the fluff P110) than if the surface energy of the material of the protective material 30A is smaller than the surface energy of the material of the support 110. As a result, the protective material 30A adheres more firmly to the fluff P110.

[0082] "Surface energy" refers to Gibbs free energy. Surface energy can be calculated from surface tension. Surface tension is the Gibbs free energy per unit area on the surface of a material.

[0083] (1.1.4) Negative and positive terminals The positive electrode terminal 41 and the negative electrode terminal 42 are used to conduct electricity generated in the electrode body to the outside of the solid state battery 1A. The positive electrode terminal 41 and the negative electrode terminal 42 are rectangular parallelepiped objects. Examples of materials for the positive electrode terminal 41 and the negative electrode terminal 42 include metals (e.g., aluminum, stainless steel (SUS), nickel, etc.).

[0084] (1.1.5) Exterior body The exterior body 50 covers the electrode body 10 and seals the electrode body 10 together with the positive terminal 41 and the negative terminal 42. In the first embodiment, the exterior body 50 is a metal container. The exterior body 50 is a rectangular parallelepiped (i.e., square). The exterior body 50 has a first wall facing the third side surface portion S10C of the electrode body 10 and a second wall facing the fourth side surface portion S10D of the electrode body 10. The first wall has one through-hole. As shown in FIG. 1 , the positive terminal 31 is exposed from the through-hole of the first wall. The second wall has one through-hole similar to the first wall. The negative terminal 32 is exposed from the through-hole of the second wall. The material of the exterior body 50 is metal (e.g., aluminum, copper, stainless steel (SUS), nickel, etc.). The exterior body 50 may have an electrical insulator on the surface (inner peripheral wall) facing the electrode body 10 to prevent electrical connection with the electrode body 10. The electrical insulator may be a layered material or a bag.

[0085] (1.1.6) Purpose Applications of the solid-state battery 1A include power sources for electric devices (e.g., vehicles, electronic devices, or electricity storage devices). Examples of vehicles include electric four-wheeled vehicles, electric two-wheeled vehicles, gasoline-powered automobiles, and diesel-powered automobiles. Examples of electric four-wheeled vehicles include electric vehicles (BEVs), plug-in hybrid vehicles (PHEVs), and hybrid electric vehicles (BEVs). Examples of electric two-wheeled vehicles include electric motorcycles and electrically assisted bicycles. Examples of electronic devices include handheld devices (e.g., smartphones, tablet computers, and audio players), portable devices (e.g., notebook computers and compact disc (CD) players), and mobile devices (e.g., power tools and commercial video cameras). Among these, the solid-state battery 1A is preferably used as a power source for driving hybrid automobiles, plug-in hybrid automobiles, or electric automobiles.

[0086] (1.2) Manufacturing method of solid-state battery The manufacturing method of the solid-state battery of the first embodiment is a method for manufacturing a solid-state battery 1A. The manufacturing method includes a preparation step, a current collecting tab connecting step, a lamination step, a protective material forming step, a connecting step, and a sealing step. The preparation step, current collecting tab connecting step, lamination step, protective material forming step, connecting step, and sealing step are performed in this order.

[0087] (1.2.1) Preparation process In the preparation step, an electrode assembly 10 is prepared, to which a positive electrode current collector tab 21 and a negative electrode current collector tab 22 are connected. The solid electrolyte layer 11 of the electrode assembly 10 has a support 110 including a plurality of fibers. The support 110 protrudes from an end surface S11 of the solid electrolyte layer 11. In the first embodiment, a plurality of fluffs P110 protrude from the end surface S11 of the solid electrolyte layer 11, as shown in FIGS. 3 and 4 .

[0088] The method for preparing the electrode assembly 10 is not particularly limited, and may include the first method, the second method, or the like.

[0089] (1.2.1.1) First method The first method includes a solid electrolyte sheet preparation step and a unit electrode body formation step, which are carried out in this order.

[0090] In the solid electrolyte sheet preparation step, a solid electrolyte sheet is prepared. The solid electrolyte sheet is a raw material for the solid electrolyte layer 11. An end face of the solid electrolyte sheet corresponds to the end face S11 of the solid electrolyte layer 11.

[0091] A method for preparing a solid electrolyte sheet may be, for example, a method in which a support sheet, which is the raw material of the support 110, is sheared to form a plurality of fluffs P110 on the sheared surface to obtain the support 110, and a solid electrolyte paste is applied to the entire support 110 obtained and dried to form a solid electrolyte sheet. A shearing tool (e.g., scissors) is used to shear the support sheet. The solid electrolyte paste contains a solid electrolyte 111 and a known dispersion medium, and may also contain a binder as necessary. The application method, drying method, and arrangement method may be known methods.

[0092] In the unit electrode body formation process, the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte sheet, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte sheet, the positive electrode active material layer 12, and the positive electrode current collector 14 are stacked in this order along the Z-axis direction to form the unit electrode body 10U.

[0093] There are no particular limitations on the methods for forming the positive electrode current collector 14, the positive electrode active material layer 12, the negative electrode active material layer 13, and the negative electrode current collector 15, and any known methods may be used. There are also no particular limitations on the lamination method, and any known methods may be used.

[0094] (1.2.1.2) Second method The second method includes a unit electrode sheet preparation step and a cutting step, which are carried out in this order.

[0095] In the unit electrode sheet preparation step, a unit electrode sheet is prepared. The unit electrode sheet is similar to the unit electrode 10U except that it is larger in size than the unit electrode 10U.

[0096] The unit electrode sheets may be prepared by a known method.

[0097] In the cutting step, the unit electrode sheet is sheared so that a plurality of fluffs P110 are formed on the end surface S11 of the solid electrolyte layer 11 that constitutes the sheared surface, to form the unit electrode body 10U. A shearing tool (for example, a round blade) is used to shear the unit electrode sheet.

[0098] (1.2.2) Current collecting tab connection process In the current collecting tab connecting step, a positive electrode current collecting tab 21 is connected to the positive electrode current collector 14 of the unit electrode body 10U, and a negative electrode current collecting tab 22 is connected to the negative electrode current collector 15 of the unit electrode body 10U. This results in a unit electrode body 10U in which the positive electrode current collecting tab 21 and the negative electrode current collecting tab 22 are connected (hereinafter also referred to as a "unit electrode body with current collecting tabs").

[0099] The positive electrode current collecting tab 21 and the negative electrode current collecting tab 22 may be connected by any known method.

[0100] (1.2.3) Lamination process In the stacking process, multiple unit electrode bodies with current collecting tabs are stacked in this order along the Z-axis direction to obtain an electrode body 10 (hereinafter also referred to as an "electrode body with current collecting tabs") in which a positive electrode current collecting tab 21 and a negative electrode current collecting tab 22 are connected.

[0101] The lamination method is not particularly limited, and any known method may be used.

[0102] (1.2.4) Protective material forming process In the protective material forming process, a protective material 30A is formed, which is placed on the side of the electrode body with current collecting tabs (an example of an electrode body) and connected to the fluff P110. This results in an electrode body with current collecting tabs (hereinafter also referred to as an "electrode body with protective material") to which the protective material 30A is attached.

[0103] The method for forming the protective material 30A is not particularly limited. For example, an unsolidified resin composition may be applied, and the applied material may be solidified to form a solidified resin material. The application method may be any known method. The solidification method is appropriately selected depending on the type of resin composition, etc. When the resin composition is a thermoplastic resin composition or a thermosetting resin composition, the applied material of the molten resin composition may be solidified by cooling. The cooling method is not particularly limited, and examples include leaving it at room temperature (25°C) or blowing cooling air onto it. When the resin composition is a photocurable resin composition, the applied material of the resin composition may be solidified by irradiating it with active energy rays (e.g., visible light, ultraviolet light, X-rays, or electron beams).

[0104] (1.2.5) Connection process In the connection step, the positive electrode current collecting tabs 21 of the electrode body with the protective material are connected to the positive electrode terminal 41, and the negative electrode current collecting tabs 22 of the electrode body with the protective material are connected to the negative electrode terminal .

[0105] The connection method is not particularly limited and may be any known method.

[0106] (1.2.6) Sealing process In the sealing step, the electrode body with the protector, to which the positive electrode terminal 41 and the negative electrode terminal 42 are connected, is sealed with the exterior body 50. In this way, the solid state battery 1A is obtained.

[0107] The sealing method is not particularly limited, and any known method may be used.

[0108] (1.3) Action and effect The effects of the solid state battery 1A will be specifically described below with reference to the drawings. As described with reference to FIGS. 1 to 4, the solid battery 1A includes an electrode assembly 10, a positive electrode current collector tab 21, a negative electrode current collector tab 22, and a protective material 30A. The electrode assembly 10 includes a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11, a negative electrode active material layer 13, and a negative electrode current collector 15, which are stacked along the Z-axis direction. The solid electrolyte layer 11 includes a support 110 including a plurality of fibers made of a material different from that of the protective material 30A. The support 110 protrudes from an end surface S11 of the solid electrolyte layer 11. The protective material 30A is connected to the support 110 (i.e., fluff P110) and is disposed on the end surface S11 of the solid electrolyte layer 11. This makes the contact area of ​​the protective material 30A with the electrode assembly 10 larger than when the protective material 30A is connected to the support 110 (i.e., the fluff P110) and not disposed on the end surface S11 of the solid electrolyte layer 11. Therefore, even when the solid battery 1A is repeatedly charged and discharged, the adhesive strength of the protective material 30A to the electrode assembly 10 is less likely to decrease. In other words, the protective material 30A is less likely to peel off from the electrode assembly 10. As a result, the occurrence of short circuits in the solid battery 1A is suppressed.

[0109] 1 to 4, the electrode body 10 includes a plurality of unit electrode bodies 10U stacked along the X-axis direction. Each unit electrode body 10U includes a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11, a negative electrode active material layer 13, and a negative electrode current collector 15. The protective material 30A is connected to the support 110 (i.e., the fluff P110) between two adjacent unit electrode bodies 10U and is disposed on the end surface S11 of the adjacent solid electrolyte layer 11. That is, the positive electrode active material layer 12 or the negative electrode active material layer 13 disposed between the adjacent solid electrolyte layers 11 between two adjacent unit electrode bodies 10U is likely to be reliably covered by the protective material 30A. As a result, the protective material 30A more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. In addition, the protective material 30A more reliably prevents electrical contact between at least one of the positive electrode active material layer 12 and the negative electrode active material layer 13 and the exterior body 50. As a result, the occurrence of short circuits in the solid state battery 1A is more suppressed.

[0110] 1 to 4, the unit electrode body 10U is formed by laminating a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11, a negative electrode active material layer 13, a negative electrode current collector 15, a negative electrode active material layer 13, a solid electrolyte layer 11, a positive electrode active material layer 12, and a positive electrode current collector 14 in this order along the X-axis direction. The protective member 30A is connected to the support 110 within the unit electrode body 10U and is disposed on an end face S11 of the adjacent solid electrolyte layer 11. That is, the positive electrode active material layer 12 or the negative electrode active material layer 13 disposed between adjacent solid electrolyte layers 11 in the unit electrode body 10U is likely to be reliably covered by the protective material 30A. As a result, the protective material 30A more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. In addition, the protective material 30A more reliably prevents electrical contact between at least one of the positive electrode active material layer 12 and the negative electrode active material layer 13 and the exterior body 50. As a result, the occurrence of short circuits in the solid state battery 1A is more suppressed.

[0111] As described with reference to FIGS. 1 to 4, the protective material 30A is disposed so as to cover at least one of the end surface S12 of the positive electrode active material layer 12 and the end surface S13 of the negative electrode active material layer . This allows the protective material 30A to more reliably prevent electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. In addition, the protective material 30A more reliably prevents electrical contact between at least one of the positive electrode active material layer 12 and the negative electrode active material layer 13 and the exterior body 50. As a result, the occurrence of short circuits in the solid state battery 1A is further suppressed.

[0112] As described with reference to FIGS. 1 to 4, the support 110 is preferably a nonwoven fabric. As a result, the solid-state battery 1A has more satisfactory battery performance than when the support 110 is not made of nonwoven fabric.

[0113] As described with reference to FIGS. 1 to 4, the manufacturing method of the first embodiment includes a preparation step and a protection material forming step. The method for manufacturing a solid state battery according to the first embodiment can manufacture a solid state battery 1A in which the occurrence of short circuits is suppressed.

[0114] (2) Second embodiment (2.1) Solid state battery The solid state battery 1B according to the second embodiment is similar to the solid state battery 1A according to the first embodiment except for the arrangement of the protective material.

[0115] The solid state battery 1B includes an electrode assembly 10, a plurality of positive electrode current collector tabs 21, a plurality of negative electrode current collector tabs 22, a protective member 30B, a positive electrode terminal 41, a negative electrode terminal 42, and an exterior body 50.

[0116] The protective material 30B is similar to the protective material 30A except for the different arrangement. The protective material 30B is connected to the support 110 (fluff P110) and disposed on the end surface S11 of the solid electrolyte layer 11. As shown in FIG. 6, the protective material 30B is connected to the support 110 (fluff P110) within the unit electrode body 10U and between two adjacent unit electrode bodies 10U and disposed on the end surface S11 of the adjacent solid electrolyte layer 11. As shown in FIG. 7, the protective material 30B is disposed so as to cover the first side surface portion S10A and the second side surface portion S10B. As shown in FIG. 6, the protective material 30B is disposed so as to be connected to each of the positive electrode current collecting tab 21 and the negative electrode current collecting tab 22 on the third side surface portion S10C and the fourth side surface portion S10D. As shown in Figures 6 and 7, the protective material 30B is arranged to cover the end face S12 of the positive electrode active material layer 12 and the end face S13 of the negative electrode active material layer 13 on the first side face portion S10A, the second side face portion S10B, the third side face portion S10C, and the fourth side face portion S10D.

[0117] (2.2) Manufacturing method of solid-state battery The manufacturing method of the solid-state battery of the second embodiment is a method for manufacturing the solid-state battery 1B. The manufacturing method includes a preparation step, a current collecting tab connecting step, a lamination step, a protective material forming step, a connecting step, and a sealing step. The preparation step, current collecting tab connecting step, lamination step, protective material forming step, connecting step, and sealing step are performed in this order.

[0118] The method for manufacturing a solid state battery according to the second embodiment is the same as the method for manufacturing a solid state battery according to the first embodiment, except that the position of the protective material 30B is different in the protective material forming step.

[0119] (2.3) Action and Effect The effects of the solid state battery 1B will be specifically described below with reference to the drawings. The solid state battery 1B is similar to the solid state battery 1A except that the protective material 30A is replaced with a protective material 30B. Therefore, the solid state battery 1B exhibits the same effects as the solid state battery 1A.

[0120] As described with reference to FIGS. 5 to 7, the protective material 30B is disposed to cover the first side surface portion S10A and the second side surface portion S10B. This ensures that the protective material 30B prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13 more reliably than when the protective material 30B is not disposed to cover the first side surface portion S10A and the second side surface portion S10B. The protective material 30B more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13 on the first side surface portion S10A and the second side surface portion S10B and the exterior body 50. As a result, the occurrence of short circuits is further reduced in the solid state battery 1B.

[0121] 5 to 7, the protective material 30B is arranged on the third side surface portion S10C and connected to the positive electrode current collector tab 21. The protective material 30B is arranged on the fourth side surface portion S10D and connected to the negative electrode current collector tab 22. That is, the positive electrode active material layer 12 disposed between the solid electrolyte layer 11 and the positive electrode current collector tab 21 is likely to be reliably covered by the protective material 30B. The negative electrode active material layer 13 disposed between the solid electrolyte layer 11 and the negative electrode current collector tab 22 is likely to be reliably covered by the protective material 30B. As a result, the protective material 30B more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. The protective material 30B more reliably prevents electrical contact between at least one of the positive electrode active material layer 12 and the negative electrode active material layer 13 and the exterior body 50. As a result, the occurrence of short circuits is more suppressed in the solid battery 1B.

[0122] As described with reference to FIGS. 5 to 7, the manufacturing method of the second embodiment includes a preparation step and a protection material forming step. The method for manufacturing a solid state battery according to the second embodiment can manufacture a solid state battery 1B in which the occurrence of short circuits is suppressed.

[0123] (4) Variations In the first and second embodiments, a plurality of fluffs P110 protrude from the end surface S11 of the solid electrolyte layer 11, but the present disclosure is not limited to this. A fiber aggregate (for example, a part of a nonwoven fabric or a part of a mesh sheet) may protrude from the end surface S11 of the solid electrolyte layer 11.

[0124] In the first and second embodiments, the electrode assembly 10 includes a plurality of unit electrode bodies 10U, but the present disclosure is not limited to this. The electrode assembly 10 may include one unit electrode body 10U.

[0125] In the first and second embodiments, the unit electrode body 10U is formed by stacking the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layer 11, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layer 11, the positive electrode active material layer 12, and the positive electrode current collector 14 in this order along the Z-axis direction, but the present disclosure is not limited to this. The unit electrode body 10U may also be formed by stacking the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layer 11, the negative electrode active material layer 13, and the negative electrode current collector 15 in this order along the Z-axis direction. The unit electrode body 10U may be formed by stacking the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layer 11, the positive electrode active material layer 12, the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layer 11, the negative electrode active material layer 13, and the negative electrode current collector 15 in this order along the Z-axis direction. The unit electrode body 10U may further include an insulating layer on the surface of at least one of the positive electrode current collectors 14 opposite to the positive electrode active material layer 12.

[0126] In the first embodiment, the protective materials 30A, 30B are arranged in the unit electrode body 10U and between two adjacent unit electrode bodies 10U, connected to the fluff P110 of the adjacent solid electrolyte layer 11, but the present disclosure is not limited to this. In the present disclosure, the protective materials 30A, 30B may be arranged in either the unit electrode body 10U or between two adjacent unit electrode bodies AU, connected to the fluff P110 of the adjacent solid electrolyte layer 11. The protective materials 30A, 30B do not have to be arranged in the unit electrode body 10U or between two adjacent unit electrode bodies AU, connected to the fluff P110 of the adjacent solid electrolyte layer 11.

[0127] In the first and second embodiments, the stacked structure of the electrode assembly 10 is a configuration in which multiple unit electrode bodies 10U having a monopolar structure are connected in parallel, but the present disclosure is not limited to this. The stacked structure of the electrode assembly may be a configuration in which multiple unit electrode bodies having a monopolar structure are connected in series (hereinafter also referred to as a "monopolar series configuration"). In a monopolar series configuration, the electrode assembly has a conductor electrically connecting the positive electrode current collector 14 and the negative electrode current collector 15, and does not have a bundle including multiple positive electrode current collector tabs 21 or multiple negative electrode current collector tabs 22. The stacked structure of the electrode assembly 10 may be a configuration in which multiple unit electrode bodies having a bipolar structure are connected in series. An example of a configuration in which multiple unit electrode bodies having a bipolar structure are connected in series is shown in FIG. 8.

[0128] In the first and second embodiments, the exterior body 50 is a rectangular metal container, but the present disclosure is not limited to this. The exterior body 50 may be a container made of at least one laminate film, or may be a cylindrical metal container.

[0129] In the first and second embodiments, the positive electrode current collector 14 and the positive electrode current collector tab 21 are separate bodies, and the negative electrode current collector 15 and the negative electrode current collector tab 22 are separate bodies, but the present disclosure is not limited to this. The positive electrode current collector 14 and the positive electrode current collector tab 21 may be the same body. The negative electrode current collector 15 and the negative electrode current collector tab 22 may be the same body. [Explanation of symbols]

[0130] 1A, 1B: solid-state battery, 10: electrode body, 10U: unit electrode body, 11: solid electrolyte layer, 110: support, 111: solid electrolyte, 12: positive electrode active material layer, 13: negative electrode active material layer, 14: positive electrode current collector, 15: negative electrode current collector, 21: positive electrode current collector tab, 22: negative electrode current collector tab, 30A, 30B: protective material, 41: negative electrode terminal, 42: positive electrode terminal, 50: exterior body, P110: fluff

Claims

1. The battery includes an electrode body, a current collecting tab connected to the electrode body, and a protective material, the electrode body has a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector, which are stacked along a stacking direction; the solid electrolyte layer has a support including a plurality of fibers made of a material different from that of the protective material, the support protrudes from an end surface of the solid electrolyte layer, The protective material is connected to the support and disposed on the end surface.

2. the electrode body includes a plurality of unit electrode bodies stacked along the stacking direction, the unit electrode body includes the positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, and the negative electrode current collector, The solid-state battery according to claim 1 , wherein the protective material is connected to the support and disposed on the end surface of the adjacent solid electrolyte layer between two adjacent unit electrode bodies.

3. the unit electrode body is formed by stacking the positive electrode current collector, the positive electrode active material layer, the solid electrolyte layer, the negative electrode active material layer, the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer, and the positive electrode current collector in this order along the stacking direction, The solid-state battery according to claim 2 , wherein the protective material is connected to the support and disposed on the end surface of the adjacent solid electrolyte layer within the unit electrode body.

4. The solid-state battery according to claim 1 , wherein the protective material is disposed so as to cover at least one end surface of the positive electrode active material layer and the negative electrode active material layer.

5. The electrode body A first side portion; a second side surface portion facing the first side surface portion; a third side surface portion connecting the first side surface portion and the second side surface portion; a fourth side surface portion connecting the first side surface portion and the second side surface portion and facing the third side surface portion; and the current collecting tab protrudes from at least one of the third side surface portion and the fourth side surface portion, The solid-state battery according to claim 1 , wherein the protective material is disposed to cover the first side surface portion and the second side surface portion.

6. The electrode body A first side portion; a second side surface portion facing the first side surface portion; a third side surface portion connecting the first side surface portion and the second side surface portion; a fourth side surface portion connecting the first side surface portion and the second side surface portion and facing the third side surface portion; and the current collecting tab protrudes from at least one of the third side surface portion and the fourth side surface portion, The solid-state battery according to claim 1 , wherein the protective material is arranged in the third side surface portion and the fourth side surface portion so as to be connected to the current collecting tab.

7. The solid-state battery according to claim 1 , wherein the support is a nonwoven fabric.

8. preparing an electrode assembly having a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector stacked along a stacking direction, wherein the solid electrolyte layer has a support including a plurality of fibers, and the support protrudes from an end face of the solid electrolyte layer; forming a protective material connected to the support on the end surface; and A method for manufacturing a solid-state battery, wherein the material of the fiber and the material of the protective material are different.

Images