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 and a current collecting tab connected to the electrode body. 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 includes a support. The solid electrolyte layer has a protruding portion protruding from end faces of the positive electrode active material layer and the negative electrode active material layer. The protruding portion is disposed so as to cover an end face of at least one of the positive electrode active material layer and the negative electrode active material layer.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: An electrode body and a current collecting tab connected to the electrode body, 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 includes a support; the solid electrolyte layer has protruding portions that protrude from end surfaces of the positive electrode active material layer and the negative electrode active material layer, In the solid-state battery, the protruding portion 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.

[0009] The term "solid electrolyte layer" refers to a layer that includes a support and a solid electrolyte, but does not include 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 that includes a positive electrode active material. The term "negative electrode active material layer" refers to a layer that includes a negative electrode active material. The term "support" refers to an insulator that has multiple pores, 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 that hold the solid electrolyte. The term "protruding portion" refers to a part of the solid electrolyte layer, and includes the support and the solid electrolyte. The number of pores in the support in the protruding portion is smaller than the number of pores in the support in the portion of the solid electrolyte layer that is not the protruding portion. The layer structure of the "electrode body" includes a monopolar structure or a bipolar structure.

[0010] In the first embodiment, the protruding portion 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. This prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. As a result, the occurrence of a short circuit is suppressed in the solid state battery of the first embodiment.

[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, Between two adjacent unit electrode bodies, the protruding portions of the adjacent solid electrolyte layers are arranged in a connected relationship. <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 protruding portions of the adjacent solid electrolyte layers are connected between two adjacent unit electrode bodies. That is, at least one of the positive electrode active material layer and 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 protruding portions. This 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 protruding portions are arranged in the unit electrode body so as to connect the adjacent solid electrolyte layers to each other; <2> The solid-state battery is described in

[0015] In a third aspect, the stacked structure of the electrode assembly is a structure in which a plurality of unit electrode assemblies having a monopolar structure are connected in parallel. In the third aspect, the protruding portions of adjacent solid electrolyte layers in the unit electrode assembly are connected to each other. That is, in the unit electrode assembly, the positive electrode active material layer or the negative electrode active material layer disposed between adjacent solid electrolyte layers is likely to be reliably covered by the protruding portions. This more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. In addition, the protruding portions more reliably prevent 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 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 protruding portions of the adjacent solid electrolyte layers are arranged to be connected to each other at the first side surface portion and the second side surface portion, <2> or <3> The solid-state battery is described in

[0017] 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. The "side surface of the electrode body" includes the end face of the positive electrode active material layer, the end face of the non-protruding portion of the solid electrolyte layer, and the end face of the negative electrode active material layer, but does not include the protruding portion of the solid electrolyte layer. The "non-protruding portion of the solid electrolyte layer" refers to a portion of the solid electrolyte layer that is not a protruding portion. The side surface of the electrode body may include at least one of the end face of the positive electrode current collector and the end face of the negative electrode current collector.

[0018] In a fourth aspect, the protruding portions of adjacent solid electrolyte layers are connected to each other at the first side surface portion and the second side surface portion. This ensures that the protruding portions prevent electrical contact between the positive electrode active material layer and the negative electrode active material layer at the first side surface portion and the second side surface portion. The protruding portions more reliably prevent 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 further reduced in the solid battery of the fourth aspect.

[0019] <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 protruding portions of the adjacent solid electrolyte layers are connected to each other at the third side surface portion and the fourth side surface portion, <2> ~ <4> The solid-state battery according to any one of the above items.

[0020] In the fifth aspect, the protruding portions of adjacent solid electrolyte layers are connected to each other at the third side surface portion and the fourth side surface portion. That is, at the third side surface portion and the fourth side surface portion, the positive electrode active material layer or the negative electrode active material layer disposed between the solid electrolyte layer and the current collecting tab is likely to be reliably covered by the protruding portions. As a result, the protruding portions more reliably prevent electrical contact between the positive electrode active material layer and the negative electrode active material layer. The protruding portions more reliably prevent 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 fifth aspect is more reliably prevented from short-circuiting.

[0021] <6> The solid-state battery of the sixth aspect is the protruding portion is connected to the current collecting tab; <1> The solid-state battery is described in

[0022] That is, the protruding portion is disposed so as to cover the end surface of at least one of the positive electrode active material layer and the negative electrode active material layer. This more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. The protruding portion 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 more suppressed in the solid-state battery of the sixth aspect.

[0023] <7> The seventh aspect of the solid-state battery 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 protruding portions are arranged on the third side surface portion and the fourth side surface portion so as to be connected to the current collecting tabs; <6> The solid-state battery is described in

[0024] In the seventh aspect, the protruding portions are connected to the current collecting tabs at the third and fourth side surface portions. That is, the positive electrode active material layer or the negative electrode active material layer disposed between the solid electrolyte layer and the current collecting tab at the third and fourth side surface portions is likely to be reliably covered by the protruding portions. This more reliably prevents electrical contact between the positive electrode active material layer and the negative electrode active material layer. The protruding portions more reliably prevent 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 seventh aspect is more reliably prevented from short-circuiting.

[0025] <8> The solid-state battery of the eighth embodiment is The support is a nonwoven fabric. <1> ~ <7> The solid-state battery according to any one of the above items.

[0026] "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.

[0027] In an eighth embodiment, the support is a nonwoven fabric, and as a result, the solid-state battery of the eighth embodiment has more satisfactory battery performance than a battery in which the support is not a nonwoven fabric.

[0028] <9> A method for producing a solid-state battery according to a ninth aspect includes the steps of: forming an electrode assembly precursor having a plurality of protruding portions; densifying the electrode body precursor to connect adjacent projecting portions; and the electrode assembly precursor includes a plurality of unit electrode assemblies stacked along a 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, which are stacked along the stacking direction, In the method for manufacturing a solid-state battery, the protruding portions indicate portions of the solid electrolyte layer that protrude relative to end faces of the negative electrode active material layer and the positive electrode active material layer.

[0029] The term "densification" refers to the application of pressure. Densification makes the solid electrolyte in the solid electrolyte layer denser, and increases the area of ​​the bonding interfaces between the solid electrolyte layer and the positive electrode active material layer and the negative electrode active material layer.

[0030] The method for manufacturing a solid state battery according to the ninth embodiment can manufacture a solid state battery in which the occurrence of short circuits is suppressed. [Effects of the Invention]

[0031] 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]

[0032] [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 diagram for explaining the method for manufacturing the solid state battery of the first embodiment. [Figure 6] FIG. 6 is a diagram for explaining the method for manufacturing the solid state battery of the first embodiment. [Figure 7] FIG. 7 is a front view of the electrode body according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a diagram for explaining the method for manufacturing the solid state battery according to the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining a method for manufacturing a solid state battery according to the second embodiment. [Figure 11] FIG. 11 is a front view of an electrode body according to the third embodiment. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. [Figure 14] FIG. 14 is a diagram for explaining a method for manufacturing a solid state battery according to the third embodiment. [Figure 15] FIG. 15 is a diagram for explaining a method for manufacturing a solid state battery according to the third embodiment. [Figure 16] FIG. 16 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

[0033] 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.

[0034] 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.

[0035] (1) First embodiment (1.1) Solid state battery 1, the solid state battery 1A according to the first embodiment includes an electrode assembly 10A, a plurality of positive electrode current collector tabs 21 (an example of a current collector tab), a plurality of negative electrode current collector tabs 22 (an example of a current collector tab), a positive electrode terminal 31, a negative electrode terminal 32, and an exterior body 40. The electrode assembly 10A is a rectangular parallelepiped object.

[0036] In the first embodiment, the longitudinal direction of the main surface S10 of the electrode body 10A is defined as the X-axis direction. The lateral direction of the main surface S10 of the electrode body 10A is defined as the Y-axis direction. The thickness direction of the electrode body 10A is defined as the Z-axis direction. The X-axis, Y-axis, and Z-axis are perpendicular to each other. 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.

[0037] The positive electrode terminal 31, the multiple positive electrode current collector tabs 21, the electrode assembly 10A, the multiple negative electrode current collector tabs 22, and the negative electrode terminal 32 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 31 to the electrode assembly 10A. The multiple negative electrode current collector tabs 22 electrically connect the negative electrode terminal 32 to the electrode assembly 10A. The exterior housing 40 covers the electrode assembly 10A, the multiple positive electrode current collector tabs 21, and the multiple negative electrode current collector tabs 22. The electrode assembly 10A, the positive electrode current collector tabs 21, and the negative electrode current collector tabs 22 are sealed by the positive electrode terminal 31, the negative electrode terminal 32, and the exterior housing 40.

[0038] (1.1.1) Electrode body The electrode body 10A functions as a power generating element of the solid state battery 1A.

[0039] The electrode body 10A is a rectangular parallelepiped. As shown in FIG. 2, the electrode body 10A 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.

[0040] 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).

[0041] The length L1 (thickness) in the Z-axis direction of the electrode body 10A (see FIGS. 3 and 4) is not particularly limited, and is, for example, 18.5 mm.

[0042] 3 and 4, the electrode assembly 10A includes a plurality of unit electrode bodies 10AU. The plurality of unit electrode bodies 10AU are stacked along the Z-axis direction. The plurality of unit electrode bodies 10AU are connected in parallel.

[0043] The unit electrode body 10AU has a monopolar layer structure. Specifically, the unit electrode body 10AU has two solid electrolyte layers 11A, 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 11A, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layer 11A, the positive electrode active material layer 12, and the positive electrode current collector 14 are layered in this order along the Z-axis direction.

[0044] (1.1.1.1) Solid electrolyte layer The solid electrolyte layer 11A 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.

[0045] (1.1.1.1.1)Protruding parts The solid electrolyte layer 11A has a protruding portion P11A and a non-protruding portion N11. As shown in FIGS. 3 and 4 , the protruding portion P11A protrudes relative to each of 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. The non-protruding portion N11 is a portion of the solid electrolyte layer 11A that is not the protruding portion P11A. The non-protruding portion N11 does not protrude relative to each of 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. Each of the protruding portion P11A and the non-protruding portion N11 includes a support 110 and a solid electrolyte 111. The number of pores in the support 110 in the protruding portion P11A is smaller than the number of pores in the support 110 in the non-protruding portion N11. The support 110 in the protruding portion P11A may have a melting history.

[0046] In the first embodiment, the protruding portions P11A of adjacent solid electrolyte layers 11A within a unit electrode body 10AU are connected to each other in the first side surface portion S10A (see FIG. 4) and the third side surface portion S10C (see FIG. 3). The protruding portions P11A of adjacent solid electrolyte layers 11A between two adjacent unit electrode bodies 10AU are connected to each other in the second side surface portion S10B (see FIG. 4) and the fourth side surface portion S10D (see FIG. 3). A solid electrolyte 111 is disposed on the surface of the protruding portion P11A. The protruding portions P11A may be connected to each other by applying heat and pressure.

[0047] The protruding portion P11A may or may not be in contact with at least a portion of each of the second side surface portion S10B, the third side surface portion S10C, and the fourth side surface portion S10D of the electrode body 10A.

[0048] In the third side surface portion S10C and the fourth side surface portion S10D, the length L2 (see FIG. 3) of the protruding portion P11A in the X-axis direction is not particularly limited and may be 0.1 mm to 1.0 mm. In the first side surface portion S10A and the second side surface portion S10B, the length L3 (see FIG. 4) of the protruding portion P11A in the Y-axis direction is not particularly limited and may be 0.1 mm to 1.0 mm.

[0049] (1.1.1.1.2) 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.

[0050] The support 110 is made of a porous resin material and has a plurality of pores.

[0051] 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Examples of the support 110 include a nonwoven fabric, a porous film, 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.

[0056] The term "porous film" refers to a resin film that does not contain resin fibers and has a plurality of pores. The term "mesh sheet" refers to a woven fabric that contains a plurality of resin fibers and has pores between the resin fibers.

[0057] 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.

[0058] 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.

[0059] 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), polypropylene (PP)), and polyamide-based resins (e.g., nylon, aramid, etc.).

[0060] Examples of materials for the porous film include polyolefin resins (such as polyethylene (PE) or polypropylene (PP)).

[0061] 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.

[0062] (1.1.1.1.3) 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 the 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 11A with a scanning electron microscope (SEM), randomly selecting particles, and measuring the average particle size.

[0063] 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.

[0064] (1.1.1.1.4) 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.).

[0065] (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.

[0066] 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.

[0067] Examples of the positive electrode solid electrolyte that can be used in the positive electrode active material layer include the same solid electrolytes as those exemplified as the solid electrolyte contained in the solid electrolyte layer.

[0068] 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).

[0069] Examples of the binder include the same binders as those exemplified as the binder contained in the solid electrolyte layer.

[0070] (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.

[0071] 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).

[0072] 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.

[0073] 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.

[0074] 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.

[0075] (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.

[0076] (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.

[0077] (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 31. 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 31. It is preferable that the positive electrode current collector tab 21 is formed continuously from the positive electrode current collector 14.

[0078] The negative electrode current collector tab 22 electrically connects the negative electrode current collector 15 and the negative electrode terminal 32. 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 32. It is preferable that the negative electrode current collector tab 22 is formed continuously from the positive electrode current collector 14.

[0079] The material of the positive electrode current collector tab and the negative electrode current collector tab is not particularly limited, and may be a metal (for example, aluminum, stainless steel (SUS), nickel, or the like).

[0080] (1.1.3) Negative and positive terminals The positive electrode terminal 31 and the negative electrode terminal 32 are used to conduct electricity generated in the electrode body 10A to the outside of the solid state battery 1A. The positive electrode terminal 31 and the negative electrode terminal 32 are rectangular parallelepiped objects. Examples of materials for the positive electrode terminal 31 and the negative electrode terminal 32 include metals (e.g., aluminum, stainless steel (SUS), nickel, etc.).

[0081] (1.1.4) Exterior body The exterior body 40 covers the electrode body 10A and seals the electrode body 10A together with the positive terminal 31 and the negative terminal 32. In the first embodiment, the exterior body 40 is a metal container. The exterior body 40 is a rectangular parallelepiped (i.e., square). The exterior body 40 has a first wall facing the third side surface portion S10C of the electrode body 10A and a second wall facing the fourth side surface portion S10D of the electrode body 10A. The first wall has one through-hole. The positive terminal 31 is exposed from the through-hole of the first wall, as shown in FIG. 1. 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 40 is metal (e.g., aluminum, copper, stainless steel (SUS), nickel, etc.). The exterior body 40 may have an electrical insulator on the surface (inner peripheral wall) facing the electrode body 10A to prevent electrical connection with the electrode body 10A. The electrical insulator may be a layered material or a bag.

[0082] (1.1.5) 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.

[0083] (1.2) Manufacturing method of solid-state battery The manufacturing method for a solid-state battery of the first embodiment is a method for manufacturing a solid-state battery 1A. In this manufacturing method, the densification of the electrode body precursor is performed by a batch process. This manufacturing method includes an electrode body precursor forming step, a densification pressing step, a unit electrode forming step, a stacking step, a thermocompression bonding step, a connection step, and a sealing step. The electrode body precursor forming step, densification pressing step, unit electrode forming step, stacking step, thermocompression bonding step, connection step, and sealing step are performed in this order.

[0084] (1.2.1) Electrode body precursor formation process In the electrode body precursor-forming step, a sheet 10d (see FIG. 5) (an example of an electrode body precursor) having a plurality of protruding portions P11a is formed. The protruding portions P11a are portions that become the protruding portions P11A through densification. The electrode body precursor-forming step includes a preparing step, a negative electrode active material layer-forming step, a cutting step, a solid electrolyte layer-forming step, and a positive electrode active material layer-forming step. The preparing step, negative electrode active material layer-forming step, cutting step, solid electrolyte layer-forming step, and positive electrode active material layer-forming step are performed in this order. In FIG. 5, the protruding portions P11a are represented as protruding portions P11ac and P11ad.

[0085] (1.2.1.1) Preparation process In the preparation step, the negative electrode current collector sheet 150 is prepared.

[0086] The negative electrode current collector sheet 150 is a raw material for the negative electrode current collector 15 and the negative electrode current collector tab 22. In the first embodiment, the negative electrode current collector 15 and the negative electrode current collector tab 22 are one and the same. The method for preparing the negative electrode current collector sheet 150 is not particularly limited, and may be any known method.

[0087] (1.2.1.2) Negative electrode active material layer formation process In the negative electrode active material layer forming step, a paste for the negative electrode active material layer is applied to a portion of both surfaces MS150 of the negative electrode current collector sheet 150 and dried to form the negative electrode active material layer 13. This results in a sheet 10a (see FIG. 5). The sheet 10a includes the negative electrode current collector sheet 150 and the negative electrode active material layer 13 formed on a portion of both surfaces MS150 of the negative electrode current collector sheet 150.

[0088] The paste for the negative electrode active material layer contains a negative electrode active material and a known dispersion medium, and may contain at least one of a negative electrode solid electrolyte, a conductive additive, and a binder, as necessary. The methods for preparing, applying, and drying the paste for the negative electrode active material layer may be known methods.

[0089] (1.2.1.3) Cutting process In the cutting step, the sheet 10a is cut. This results in a plurality of sheets 10b (see FIG. 5). The sheet 10b includes a negative electrode current collector 15 (hereinafter also referred to as a "negative electrode current collector 151") with a negative electrode current collector tab 22 attached thereto, and a negative electrode active material layer 13 formed on a portion of both surfaces MS15 of the negative electrode current collector 151.

[0090] The cutting method is not particularly limited, and any known method may be used.

[0091] (1.2.1.4) Solid electrolyte layer formation process In the solid electrolyte layer forming step, solid electrolyte layers 11a1 are formed on surfaces MS13 of both negative electrode active material layers 13 of sheet 10b, thereby obtaining sheet 10c.

[0092] The method for forming the solid electrolyte layer 11a1 is not particularly limited, and examples thereof include a method in which a solid electrolyte sheet is prepared and then disposed on the surface MS13 of the negative electrode active material layer 13. The solid electrolyte sheet is the raw material for the solid electrolyte layer 11A. The solid electrolyte sheet can be obtained, for example, by applying a solid electrolyte paste to the entire support 110 and drying it. The solid electrolyte paste contains the solid electrolyte 111 and a known dispersion medium, and may also contain a binder as necessary. The application method, drying method, and disposition method may be any known method.

[0093] (1.2.1.5) Positive electrode active material layer formation process In the positive electrode active material layer forming step, a paste for the positive electrode active material layer is applied to the surfaces MS11 of both solid electrolyte layers 11a1 of sheet 10c and dried to form positive electrode active material layers 12. This results in sheet 10d (see FIG. 5) (an example of an electrode body precursor).

[0094] The solid electrolyte layer 11a1 has a protruding portion P11a. The protruding portion P11a protrudes from each 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 13. The protruding portion P11a is similar to the protruding portion P11A except that it has not been subjected to any processing (for example, connection processing).

[0095] Hereinafter, the protruding portion P11a that protrudes relative to the side surface of the sheet 10d corresponding to the third side surface portion S10C of the electrode body 10A will also be referred to as the "protruding portion P11ac." The protruding portion P11a that protrudes relative to the side surface of the sheet 10d corresponding to the fourth side surface portion S10D of the electrode body 10A will also be referred to as the "protruding portion P11ad." The protruding portion P11a that protrudes relative to the side surface of the sheet 10d corresponding to the first side surface portion S10A of the electrode body 10A will also be referred to as the "protruding portion P11aa." The protruding portion P11a that protrudes relative to the side surface of the sheet 10d corresponding to the second side surface portion S10B of the electrode body 10A will also be referred to as the "protruding portion P11ab."

[0096] The length L4 (see FIG. 5) of the protruding portion P11ac in the X-axis direction is not particularly limited and may be 0.175 mm to 1.075 mm. The length L5 (see FIG. 5) of the protruding portion P11ad in the X-axis direction is not particularly limited and may be 0.19 mm to 1.09 mm. The lengths (not shown) of the protruding portions P11aa and P11ab in the Y-axis direction are not particularly limited and may be the same as length L4.

[0097] The paste for the positive electrode active material layer contains a positive electrode active material and a known dispersion medium, and may contain at least one of a positive electrode solid electrolyte, a conductive additive, and a binder, as necessary. The methods for preparing, applying, and drying the paste for the positive electrode active material layer may be known methods.

[0098] (1.2.2) Densification pressing process In the densification press process, the sheet 10d is densified to connect the protruding portions P11ac of adjacent solid electrolyte layers 11a1. This forms a solid electrolyte layer 11a2 having a protruding portion P11A from the solid electrolyte layer 11a1. A sheet 10e (see FIG. 5) is obtained.

[0099] The distance L6 (see FIG. 5) in the Z-axis direction between adjacent solid electrolyte layers 11a2 of sheet 10e is not particularly limited, and may be 0.15 mm.

[0100] The densification method is not particularly limited, and examples include a method using a pair of metal rolls. In the method using a pair of metal rolls, the sheet 10d is sandwiched between the pair of metal rolls from the protruding portion P11ac of the sheet 10d toward the positive direction of the X-axis, and heat and pressure are applied to a portion of the sheet 10d. The "portion of the sheet 10d" refers to a portion of the sheet 10d corresponding to the non-protruding portion N11. The portion of the sheet 10d corresponding to the protruding portion P11ad is not densified. In this case, both main surfaces of the protruding portion P11ac may be sandwiched between protective films to protect the protruding portion P11ac.

[0101] (1.2.3) Unit electrode formation process In the unit electrode formation step, a positive electrode current collector 14 with a positive electrode current collecting tab 21 (hereinafter also referred to as a "positive electrode current collector 141") is formed on the surface MS12 of both positive electrode active material layers 12 of the sheet 10e, thereby obtaining a unit electrode body 10f (see FIG. 5).

[0102] The positive electrode current collector 141 may be prepared and formed by any known method.

[0103] (1.2.4) Lamination process In the stacking step, a plurality of unit electrode bodies 10f are stacked along the Z-axis direction to form an electrode body 10g (see FIG. 6).

[0104] The distance L7 (see FIG. 6) in the Z-axis direction between the adjacent solid electrolyte layers 11a2 of two adjacent unit electrode bodies 10f is not particularly limited, and may be 0.18 mm.

[0105] The lamination method is not particularly limited, and any known method may be used.

[0106] (1.2.5) Thermocompression bonding process In the thermocompression bonding step, the protruding portions P11ad (see FIG. 6) of the adjacent solid electrolyte layers 11a2 of the electrode assembly 10g are thermocompression bonded to each other, the protruding portions P11aa (not shown) are thermocompression bonded to each other, and the protruding portions P11ab (not shown) are thermocompression bonded to each other. As a result, the protruding portions P11ad, P11aa, and P11ab form the protruding portion P11A. An electrode assembly 10A is obtained in which the positive electrode current collector tab 21 and the negative electrode current collector tab 22 are connected.

[0107] The thermocompression bonding method is not particularly limited, and examples thereof include a method using a pair of heat bars, etc. The thermocompression bonding method may be a known method.

[0108] (1.2.6) Connection process In the connection step, the multiple positive electrode current collector tabs 21 connected to the electrode body 10A are connected to the positive electrode terminal 31, and the multiple negative electrode current collector tabs 22 connected to the electrode body 10A are connected to the negative electrode terminal 32. More specifically, in the first embodiment, a first bundle including the multiple positive electrode current collector tabs 21 is formed, and the first bundle is electrically connected to the positive electrode terminal 31. Similarly, a second bundle including the multiple negative electrode current collector tabs 22 is formed, and the second bundle is electrically connected to the negative electrode terminal 32.

[0109] The connection method is not particularly limited and may be any known method.

[0110] (1.2.7) Sealing process In the sealing step, the electrode body 10A to which the positive electrode terminal 31 and the negative electrode terminal 32 are connected is sealed with an exterior body 40. In this way, a solid state battery 1A is obtained.

[0111] The sealing method is not particularly limited, and any known method may be used.

[0112] (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 6, the solid state battery 1A includes an electrode assembly 10A, a positive electrode current collector tab 21, and a negative electrode current collector tab 22. The electrode assembly 10A includes a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11A, 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 11A includes a support 110. The solid electrolyte layer 11A has a protruding portion P11A. The protruding portion P11A is disposed to cover an end face S12 of the positive electrode active material layer 12 and an end face S13 of the negative electrode active material layer 13. The protruding portion P11A prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. As a result, the occurrence of short circuits is suppressed in the solid state battery 1A.

[0113] 1 to 6, the electrode body 10A includes a plurality of unit electrode bodies 10AU stacked along the X-axis direction. Each unit electrode body 10AU includes a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11A, a negative electrode active material layer 13, and a negative electrode current collector 15. Between two adjacent unit electrode bodies AU, the protruding portions P11A of the adjacent solid electrolyte layers 11A are arranged so as to be connected to each other. Between two adjacent unit electrode bodies 10AU, the positive electrode active material layer 12 or the negative electrode active material layer 13 disposed between adjacent solid electrolyte layers 11A is likely to be reliably covered by the protruding portion P11A. As a result, the protruding portion P11A more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. In addition, the protruding portion P11A 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 40. As a result, the occurrence of short circuits in the solid state battery 1A is further suppressed.

[0114] 1 to 6, the unit electrode body 10AU is formed by laminating a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11A, a negative electrode active material layer 13, a negative electrode current collector 15, a negative electrode active material layer 13, a solid electrolyte layer 11A, a positive electrode active material layer 12, and a positive electrode current collector 14 in this order along the X-axis direction. Within the unit electrode body 10AU, the protruding portions P11A of adjacent solid electrolyte layers 11A are arranged so as to be connected to each other. In the unit electrode body 10AU, the positive electrode active material layer 12 or the negative electrode active material layer 13 disposed between adjacent solid electrolyte layers 11A is likely to be reliably covered by the protruding portion P11A. As a result, the protruding portion P11A more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. In addition, the protruding portion P11A 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 40. As a result, the occurrence of short circuits in the solid state battery 1A is further suppressed.

[0115] As described with reference to Figures 1 to 6, the electrode body 10A 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 positive electrode current collector tab 21 protrudes from the third side surface portion S10C. The negative electrode current collector tab 22 protrudes from the fourth side surface portion S10D. The protruding portions P11A of adjacent solid electrolyte layers 11A are connected to each other at the first side surface portion S10A and the second side surface portion S10B. As a result, in the first side surface portion S10A and the second side surface portion S10B, the protruding portion P11A reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. The protruding portion P11A more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13 and the exterior body 40. As a result, the occurrence of a short circuit is further suppressed in the solid state battery 1A.

[0116] As described with reference to FIGS. 1 to 6, the protruding portions P11A of adjacent solid electrolyte layers 11A are arranged to be connected to each other at the third side surface portion S10C and the fourth side surface portion S10D. As a result, in the third side surface portion S10C and the fourth side surface portion S10D, the protruding portion P11A reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. The protruding portion P11A more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13 and the exterior body 40. As a result, the occurrence of a short circuit is further suppressed in the solid state battery 1A.

[0117] As described with reference to FIGS. 1 to 6, 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.

[0118] As described with reference to FIGS. 1 to 6, the manufacturing method of the first embodiment includes an electrode body precursor forming step and a densification pressing 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.

[0119] (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 configuration of the electrode body.

[0120] The solid state battery 1B includes an electrode body 10B, a plurality of positive electrode current collector tabs 21, a plurality of negative electrode current collector tabs 22, a positive electrode terminal 31, a negative electrode terminal 32, and an exterior body 40.

[0121] The electrode body 10B is a rectangular parallelepiped object and 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, as shown in FIG.

[0122] The electrode body 10B is similar to the electrode body 10A except that solidified resin 16 is formed on the first side surface portion S10A and the second side surface portion S10B of the electrode body 10B instead of the protruding portion P11A.

[0123] The electrode assembly 10B includes a plurality of unit electrode bodies 10BU, as shown in Fig. 8. The plurality of unit electrode bodies 10BU are stacked along the Z-axis direction.

[0124] Each electrode unit 10BU has two solid electrolyte layers 11B, two positive electrode active material layers 12, two negative electrode active material layers 13, two positive electrode current collectors 14, one negative electrode current collector 15, and a resin solidified material 16. The positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layer 11B, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layer 11B, the positive electrode active material layer 12, and the positive electrode current collector 14 are stacked in this order along the Z-axis direction. The resin solidified material 16 is formed on the entire surface of each end surface of the electrode unit 10BU corresponding to the first side surface portion S10A and the second side surface portion S10B.

[0125] The solid electrolyte layer 11B includes a support 110 and a solid electrolyte 111. The solid electrolyte layer 11B is similar to the solid electrolyte layer 11A except that the solid electrolyte layer 11B does not have a protruding portion P11A that protrudes from each of the first side surface portion S10A and the second side surface portion S10B.

[0126] The resin solidified material 16 prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. The resin solidified material 16 is a solidified resin composition. 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 battery 1B (e.g., 120°C or lower). The resin composition contains a known resin (e.g., a thermoplastic resin, a thermosetting resin, a photocurable resin, etc.). The resin composition may further contain a polymerization initiator, a curing agent, etc., as necessary.

[0127] (2.2) Manufacturing method of solid-state battery The manufacturing method for a solid-state battery according to the second embodiment is a method for manufacturing a solid-state battery 1B. In this manufacturing method, the densification of the electrode body precursor is carried out in a continuous process. This manufacturing method includes a preparation step, a densification pressing step, a first cutting step, a unit electrode forming step, a second cutting step, a lamination step, a thermocompression bonding step, a resin solidified material forming step, a connection step, and a sealing step. The preparation step, densification pressing step, first cutting step, unit electrode forming step, second cutting step, lamination step, thermocompression bonding step, resin solidified material forming step, connection step, and sealing step are carried out in this order.

[0128] In the method for manufacturing a solid state battery according to the second embodiment, the electrode body precursor is densified in a continuous process, and therefore the method for manufacturing a solid state battery according to the second embodiment is superior to the method for manufacturing a solid state battery according to the first embodiment in terms of productivity of the solid state battery 1B.

[0129] (2.2.1) Preparation process In the preparation step, a sheet 10h (an example of an electrode body electrical frame) (see FIG. 9) is prepared.

[0130] The sheet 10h is an elongated object with its longitudinal direction in the Y-axis direction. The sheet 10h includes two solid electrolyte layers 11b1L, two positive electrode active material layers 12L, two negative electrode active material layers 13L, and a negative electrode current collector 15L (hereinafter also referred to as the "negative electrode current collector 151L") with a negative electrode current collector tab 22L. The positive electrode active material layer 12L, the solid electrolyte layer 11b1L, the negative electrode active material layer 13L, the negative electrode current collector 151L, the negative electrode active material layer 13L, the solid electrolyte layer 11b1L, and the positive electrode active material layer 12L are stacked in this order along the Z-axis direction.

[0131] The solid electrolyte layer 11b1L has a protruding portion P11a (i.e., the protruding portion P11ac and the protruding portion P11ad) and a non-protruding portion N11. The protruding portion P11a (i.e., the protruding portion P11ac and the protruding portion P11ad) is a portion that becomes the protruding portion P11A through densification. The "protruding portion P11ac" is a protruding portion that protrudes from the side surface of the sheet 10h corresponding to the third side surface portion S10C (see FIG. 7) of the electrode body 10B. The "protruding portion P11ad" is a protruding portion that protrudes from the side surface of the sheet 10h corresponding to the fourth side surface portion S10D (see FIG. 7) of the electrode body 10B.

[0132] The length L8 (see FIG. 9) of the protruding portion P11ac in the X-axis direction is not particularly limited, and may be 1.675 mm to 2.675 mm.

[0133] The solid electrolyte layer 11b1L is a raw material for the solid electrolyte layer 11B. The solid electrolyte layer 11b1L is similar to the solid electrolyte layer 11B except that it extends in the Y-axis direction and that the protruding portions are not processed. The positive electrode active material layer 12L is a raw material for the positive electrode active material layer 12. The positive electrode active material layer 12L is similar to the positive electrode active material layer 12 except that it extends in the Y-axis direction. The negative electrode active material layer 13L is a raw material for the negative electrode active material layer 13. The negative electrode active material layer 13L is similar to the negative electrode active material layer 13 except that it extends in the Y-axis direction. The negative electrode current collector 15L is similar to the negative electrode current collector 15 except that it extends in the Y-axis direction. The negative electrode current collector tab 22L is similar to the negative electrode current collector tab 22 except that it extends in the Y-axis direction.

[0134] The method for preparing the sheet 10h is not particularly limited, and any known method may be used.

[0135] (2.2.2) Densification press process In the densification press process, the sheet 10h is densified to connect the protruding portions P11ac of adjacent solid electrolyte layers 11b1L. As a result, a solid electrolyte layer 11b2L having a protruding portion P11Ac is formed from the solid electrolyte layer 11b1L. The sheet 10j (see FIG. 9) is obtained. The length of the protruding portion P11Ac in the X-axis direction is longer than the length L2 of the protruding portion P11A in the X-axis direction. As a result, the protruding portion P11Ac is easily formed.

[0136] The densification pressing step includes a first pressing step and a second pressing step, which are carried out continuously in this order.

[0137] (2.2.2.1) First pressing process In the first pressing step, the portion of the sheet 10h corresponding to the non-protruding portion N11 is densified. Specifically, as shown in FIG. 10, the sheet 10h is continuously unwound in the conveying direction D (Y-axis direction) from an electrode roll 910 around which the sheet 10h is wound. Next, the portion of the conveyed sheet 10h corresponding to the non-protruding portion N11 is sandwiched between a pair of metal rolls 920 and densified. This results in a sheet 10i in which the portion corresponding to the non-protruding portion N11 is densified.

[0138] The surface temperature and pressure of the pair of metal rolls 920 are adjusted appropriately depending on the constituent material of the sheet 10h, etc.

[0139] (2.2.2.2) Second pressing process In the second pressing step, the protruding portions P11ac of adjacent solid electrolyte layers 11b1L of the sheet i are densified to connect the protruding portions P11ac. Specifically, the protruding portions P11ac of adjacent solid electrolyte layers 11b1L of the conveyed sheet 10h are sandwiched between a pair of metal rolls 930 to densify them. As a result, a solid electrolyte layer 11b2L having protruding portions P11Ac is formed from the solid electrolyte layer 11b1L. A sheet 10j (see FIG. 9) is obtained.

[0140] The surface temperature and pressure of the pair of metal rolls 930 are adjusted appropriately depending on the material of the solid electrolyte 111 and the like.

[0141] The sheet 10j is wound into a roll to form an electrode roll 940.

[0142] (2.2.3) First cutting process In the first cutting step, the protruding portion P11Ac of the sheet 10j is cut to form the protruding portion P11A. Specifically, the tip of the protruding portion P11Ac of the sheet 10j unwound from the electrode roll 940 is cut along the Y-axis direction. This improves the structural efficiency of the resulting solid-state battery 1B. "Structural efficiency" refers to the ratio of the total volume of the power generating elements included in the battery to the total volume of the battery. This results in the sheet 10k.

[0143] The cutting method is not particularly limited, and any known method may be used.

[0144] (2.2.4) Unit electrode formation process In the unit electrode formation step, a positive electrode current collector 14L with a positive electrode current collecting tab 21L (hereinafter also referred to as a "positive electrode current collector 141L") is formed on the surface of both positive electrode active material layers 12L of the sheet 10k. This results in a unit electrode body 10m. The unit electrode body 10m is an elongated object with its longitudinal direction in the Y-axis direction.

[0145] The positive electrode current collector 14L extends in the Y-axis direction and is otherwise similar to the positive electrode current collector 14. The positive electrode current collector tab 21L extends in the Y-axis direction and is otherwise similar to the positive electrode current collector tab 21. The positive electrode current collector 141L may be prepared and formed by any known method.

[0146] (2.2.5) Second cutting process In the second cutting step, the unit electrode body 10m is cut to form a plurality of unit electrode bodies 10n. Specifically, the unit electrode body 10m is cut along the short side direction (X-axis direction) of the unit electrode body 10m at specific intervals in the longitudinal direction (Y-axis direction) of the unit electrode body 10m.

[0147] The unit electrode body 10m has two solid electrolyte layers 11b2, two positive electrode active material layers 12, two negative electrode active material layers 13, a positive electrode current collector 14 (i.e., a positive electrode current collector 141) with a positive electrode current collector tab 21, and a negative electrode current collector 15 (i.e., a negative electrode current collector 151) with a negative electrode current collector tab 22. The positive electrode current collector 141, the positive electrode active material layer 12L, the solid electrolyte layer 11b2, the negative electrode active material layer 13, the negative electrode current collector 151, the negative electrode active material layer 13, the solid electrolyte layer 11b2, the positive electrode active material layer 12, and the positive electrode current collector 141 are stacked in this order along the Z-axis direction.

[0148] The cutting method is not particularly limited and may be any known method.

[0149] (2.2.6) Lamination process In the stacking step, a plurality of unit electrode bodies 10n are stacked in this order along the Z-axis direction to form the electrode body 10p.

[0150] The lamination method is not particularly limited, and any known method may be used.

[0151] (2.2.7) Thermocompression bonding process In the thermocompression bonding step, the protruding portions P11ad (see FIG. 9) of the adjacent solid electrolyte layers 11b2 of the unit electrode body 10n are thermocompression bonded to each other. As a result, the protruding portion P11A is formed from the protruding portion P11ad. In this way, the electrode body 10q is obtained.

[0152] The thermocompression bonding method is not particularly limited, and examples thereof include a method using a pair of heat bars, etc. The thermocompression bonding method may be a known method.

[0153] (2.2.8) Resin solidification process In the resin solidified material forming step, a resin solidified material is formed on the entire end faces of the electrode body 10q corresponding to the first side surface portion S10A and the second side surface portion S10B, thereby obtaining the electrode body 10B.

[0154] The method for forming the solidified resin product is not particularly limited. For example, an unsolidified resin composition may be applied, and the applied product may be solidified to form a solidified resin product. The application method may be a 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 product may be solidified by cooling. The cooling method is not particularly limited, and examples include a method of leaving it at room temperature (25°C) or a method of blowing cooling air onto it. When the resin composition is a photocurable resin composition, the applied product may be solidified by irradiating it with active energy rays (for example, visible light, ultraviolet light, X-rays, or electron beams).

[0155] (2.2.9) Connection process In the connection process, similar to the first embodiment, the multiple positive electrode current collecting tabs 21 connected to the electrode body 10B are connected to the positive electrode terminal 31, and the multiple negative electrode current collecting tabs 22 connected to the electrode body 10B are connected to the negative electrode terminal 32.

[0156] The connection method is not particularly limited and may be any known method.

[0157] (2.2.10) Sealing process In the sealing step, the electrode body 10B to which the positive electrode terminal 31 and the negative electrode terminal 32 are connected is sealed with an exterior body 40. In this way, a solid state battery 1B is obtained.

[0158] The sealing method is not particularly limited, and any known method may be used.

[0159] (2.3) Action and Effect The solid state battery 1B is similar to the solid state battery 1A except that the first side surface portion S10A and the second side surface portion S10B of the electrode body 10B have solidified resin 16 formed thereon instead of the protruding portion P11A, and therefore the solid state battery 1B exhibits the same effects as the solid state battery 1A.

[0160] (3) Third embodiment (3.1) Solid state battery The solid state battery 1C according to the third embodiment is similar to the solid state battery 1A according to the first embodiment except for the configuration of the electrode body.

[0161] The solid state battery 1C includes an electrode body 10C, a plurality of positive electrode current collector tabs 21, a plurality of negative electrode current collector tabs 22, a positive electrode terminal 31, a negative electrode terminal 32, and an exterior body 40.

[0162] The electrode body 10C is a rectangular parallelepiped object and 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, as shown in FIG.

[0163] The electrode body 10C is similar to the electrode body 10A except that a protruding portion P11B is formed in place of the protruding portion P11A on the third side surface portion S10C and the fourth side surface portion S10D of the electrode body 10C, and a resin solidified material 16 is formed in place of the protruding portion P11A on the first side surface portion S10A and the second side surface portion S10B of the electrode body 10C.

[0164] 12 and 13, the electrode assembly 10C includes a plurality of unit electrode bodies 10CU. The plurality of unit electrode bodies 10CU are stacked along the Z-axis direction.

[0165] The electrode unit 10CU has two solid electrolyte layers 11C, two positive electrode active material layers 12, two negative electrode active material layers 13, two positive electrode current collectors 14, one negative electrode current collector 15, and a resin solidified material 16. The positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layer 11C, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layer 11C, the positive electrode active material layer 12, and the positive electrode current collector 14 are stacked in this order along the Z-axis direction. The resin solidified material 16 is formed on the entire surface of each end surface of the electrode unit 10CU corresponding to the first side surface portion S10A and the second side surface portion S10B.

[0166] The solid electrolyte layer 11C includes a support 110 and a solid electrolyte 111.

[0167] The solid electrolyte layer 11C has a protruding portion P11B and a non-protruding portion N11. The protruding portion P11B is similar to the protruding portion P11A, except that the protruding portion P11B is connected to the positive electrode current collector tab 21 or the negative electrode current collector tab 22 and does not protrude beyond either the first side surface portion S10A or the second side surface portion S10B.

[0168] In the third embodiment, when the electrode body 10C to which the positive electrode current collector tab 21 and the negative electrode current collector tab 22 are connected is viewed from the Z-axis direction (see FIG. 11), the protruding portion P11B is formed in a portion that overlaps with the positive electrode current collector tab 21 and the negative electrode current collector tab 22. The protruding portion P11B is not formed on the first side surface portion S10A (see FIGS. 11 and 13), the second side surface portion S10B (see FIGS. 11 and 13), part of the third side surface portion S10C (see FIGS. 11 and 12), and part of the fourth side surface portion S10D (see FIGS. 11 and 12).

[0169] 12, in the third embodiment, the protruding portions P11B of adjacent solid electrolyte layers 11C are arranged so as to be connected to the positive electrode current collector tab 21 at the third side surface portion S10C. The protruding portions P11B of adjacent solid electrolyte layers 11C are arranged so as to be connected to the negative electrode current collector tab 22 at the fourth side surface portion S10D. The protruding portions P11B and the positive electrode current collector tab 21 or the negative electrode current collector tab 22 may be connected by applying heat and pressure.

[0170] The solidified resin 16 is formed on the side surface portions S10A to S10D of the electrode body 10C in the areas where the protruding portion P11B is not formed.

[0171] (3.2) Manufacturing method of solid-state battery The manufacturing method for a solid-state battery of the third embodiment is a method for manufacturing a solid-state battery 1C. In this manufacturing method, the densification of the electrode body precursor is performed by a batch process. This manufacturing method includes an electrode body precursor forming step, a densification pressing step, a unit electrode forming step, a lamination step, a thermocompression bonding step, a resin-solidified material forming step, a connection step, and a sealing step. The electrode body precursor forming step, densification pressing step, unit electrode forming step, lamination step, thermocompression bonding step, resin-solidified material forming step, connection step, and sealing step are performed in this order.

[0172] (3.2.1) Electrode body precursor formation process In the electrode body precursor-forming step, a sheet 10t (see FIG. 14) (an example of an electrode body precursor) having a protruding portion P11b is formed. The protruding portion P11b is a portion that will become the protruding portion P11B through densification. The electrode body precursor-forming step includes a preparing step, a negative electrode active material layer-forming step, a cutting step, a solid electrolyte layer-forming step, and a positive electrode active material layer-forming step. The preparing step, negative electrode active material layer-forming step, cutting step, solid electrolyte layer-forming step, and positive electrode active material layer-forming step are performed in this order. In FIG. 14, the protruding portion P11b is represented as the protruding portion P11bc and the protruding portion P11bd.

[0173] (3.2.1.1) Preparation Step, Negative Electrode Active Material Layer Formation Step, and Cutting Step The preparation step, the negative electrode active material layer forming step, and the cutting step of the third embodiment are the same as those exemplified as the preparation step, the negative electrode active material layer forming step, and the cutting step of the first embodiment.

[0174] (3.2.1.2) Solid electrolyte layer formation process In the solid electrolyte layer forming step, solid electrolyte layers 11b1 are formed on surfaces MS13 of both negative electrode active material layers 13 of sheet 10b, thereby obtaining sheet 10r (see FIG. 14).

[0175] The solid electrolyte layer 11b1 is similar to the solid electrolyte layer 11a1 except that the protruding portion P11b is formed to correspond to the protruding portion P11B.

[0176] The method for forming the solid electrolyte layer 11b1 is not particularly limited, and may be the same as the method exemplified as the method for forming the solid electrolyte layer 11a1.

[0177] (3.2.1.3) Positive electrode active material layer formation process In the positive electrode active material layer forming step, a paste for the positive electrode active material layer is applied to the surfaces MS11 of both solid electrolyte layers 11a1 of the sheet 10t and dried to form the positive electrode active material layers 12. This results in a sheet 10s (see FIG. 14) (an example of an electrode body precursor).

[0178] The solid electrolyte layer 11b1 has a protruding portion P11b. The protruding portion P11b protrudes from each 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 13. The protruding portion P11b is similar to the protruding portion P11B except that it has not been subjected to any processing (for example, connection processing).

[0179] Hereinafter, the protruding portion P11b protruding from the side surface of the sheet 10s corresponding to the third side surface S10C of the electrode body 10C will also be referred to as the "protruding portion P11bc." The protruding portion P11b protruding from the side surface of the sheet 10s corresponding to the fourth side surface S10D of the electrode body 10C will also be referred to as the "protruding portion P11bd."

[0180] The length L9 (see FIG. 14) of the protruding portion P11bd in the X-axis direction is not particularly limited, and may be 0.165 mm to 1.065 mm.

[0181] The paste for the positive electrode active material layer contains a positive electrode active material and a known dispersion medium, and may contain at least one of a positive electrode solid electrolyte, a conductive additive, and a binder, as necessary. The methods for preparing, applying, and drying the paste for the positive electrode active material layer may be known methods.

[0182] (3.2.2) Densification Pressing Process In the densification press step, the sheet 10s is densified to connect the protruding portion P11bd to the negative electrode current collecting tab 22. As a result, a solid electrolyte layer 11b2 having the protruding portion P11B is formed from the solid electrolyte layer 11b1, and a sheet 10t (see FIG. 14) is obtained.

[0183] The densification method is not particularly limited, and examples include a method using a pair of metal rolls. In the method using a pair of metal rolls, the sheet 10s is sandwiched between the pair of metal rolls from the protruding portion P11bd of the sheet 10s toward the negative direction of the X axis, and heat and pressure are applied to a portion of the sheet 10s. The "portion of the sheet 10s" refers to a portion of the sheet 10s corresponding to the non-protruding portion N11. The portion of the sheet 10s corresponding to the protruding portion P11bc is not densified. In this case, both main surfaces of the protruding portion P11bd may be sandwiched between protective films to protect the protruding portion P11bd.

[0184] (3.2.3) Unit electrode formation process In the unit electrode formation step, a positive electrode current collector 14 (i.e., a positive electrode current collector 141) with a positive electrode current collecting tab 21 is formed on the surface MS12 of both positive electrode active material layers 12 of the sheet 10t, thereby obtaining a unit electrode body 10u (see FIG. 14).

[0185] The positive electrode current collector 141 may be prepared and formed by any known method.

[0186] (3.2.4) Lamination process In the stacking step, a plurality of unit electrode bodies 10u are stacked along the Z-axis direction to form an electrode body 10v (see FIG. 15).

[0187] The lamination method is not particularly limited, and any known method may be used.

[0188] (3.2.5) Thermocompression bonding process In the thermocompression bonding step, the protruding portion P11bc is thermocompression bonded to the positive electrode current collector tab 21. As a result, the protruding portion P11B is formed from the protruding portion P11bc, and the electrode body 10w is obtained.

[0189] The thermocompression bonding method is not particularly limited, and examples thereof include a method using a pair of heat bars, etc. The thermocompression bonding method may be a known method.

[0190] (3.2.6) Resin solidification process In the resin solidified material forming step, a resin solidified material is formed on the side surface of the electrode body 10w in a region where the protruding portion P11B is not formed, thereby obtaining the electrode body 10C.

[0191] The method for forming the resin solidified material is not particularly limited, and may be the same as the method exemplified as the method for forming the resin solidified material in the second embodiment.

[0192] (3.2.7) Connection process In the connection process, similar to the first embodiment, multiple positive electrode current collecting tabs 21 connected to the electrode body 10C are connected to the positive electrode terminal 31, and multiple negative electrode current collecting tabs 22 connected to the electrode body 10C are connected to the negative electrode terminal 32.

[0193] The connection method is not particularly limited and may be any known method.

[0194] (3.2.8) Sealing process In the sealing step, the electrode body 10C to which the positive electrode terminal 31 and the negative electrode terminal 32 are connected is sealed with an exterior body 40. In this way, a solid state battery 1C is obtained.

[0195] The sealing method is not particularly limited, and any known method may be used.

[0196] (3.3) Action and effect The effects of the solid state battery 1C will be specifically described below with reference to the drawings. As described with reference to FIGS. 11 to 15, the solid battery 1C includes an electrode assembly 10C, a positive electrode current collector tab 21, and a negative electrode current collector tab 22. The electrode assembly 10C includes a positive electrode current collector 14, a positive electrode active material layer 12, a solid electrolyte layer 11C, 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 11C includes a support 110. The solid electrolyte layer 11C has a protruding portion P11B. The protruding portion P11B is disposed to cover an end face S12 of the positive electrode active material layer 12 and an end face S13 of the negative electrode active material layer 13. The protruding portion P11B prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. As a result, the occurrence of short circuits is suppressed in the solid state battery 1C.

[0197] As described with reference to FIGS. 11 to 15, the protruding portion P11B is connected to the positive electrode current collector tab 21 or the negative electrode current collector tab 22. As shown in FIG. The protruding portion P11B is disposed so as to cover the end face of the positive electrode active material layer 12 or the negative electrode active material layer 13. This more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. The protruding portion P11B 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 40. As a result, the occurrence of a short circuit is more suppressed in the solid battery 1C.

[0198] As described with reference to FIGS. 11 to 15, the electrode body 10C 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 positive electrode current collector tab 21 protrudes from the third side surface portion S10C. The negative electrode current collector tab 22 protrudes from the fourth side surface portion S10D. The protruding portion P11B is arranged on the third side surface portion S10C and connected to the positive electrode current collector tab 21. The protruding portion P11B is arranged on the fourth side surface portion S10D and connected to the negative electrode current collector tab 22. In the third side surface portion S10C, the positive electrode active material layer 12 disposed between the protruding portion P11B and the positive electrode current collector tab 21 is likely to be reliably covered by the protruding portion P11B. In the fourth side surface portion S10D, the negative electrode active material layer 13 disposed between the protruding portion P11B and the negative electrode current collector tab 22 is likely to be reliably covered by the protruding portion P11B. This more reliably prevents electrical contact between the positive electrode active material layer 12 and the negative electrode active material layer 13. The protruding portion P11B 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 40. As a result, the occurrence of a short circuit in the solid state battery 1C is more reliably suppressed.

[0199] As described with reference to FIGS. 11 to 15, the support 110 is preferably a nonwoven fabric. As a result, the solid-state battery 1C has more satisfactory battery performance than when the support 110 is not made of nonwoven fabric.

[0200] As described with reference to FIGS. 11 to 15, the manufacturing method of the third embodiment includes an electrode body precursor forming step and a densification pressing step. The method for manufacturing a solid state battery according to the third embodiment can manufacture a solid state battery 1C in which the occurrence of short circuits is suppressed.

[0201] (4) Variations In the first embodiment, the protruding portions P11A of adjacent solid electrolyte layers 11A are connected to each other at the first side surface portion S10A and the second side surface portion S10B, but the present disclosure is not limited to this. The protruding portions P11A of adjacent solid electrolyte layers 11A do not have to be connected to each other at at least one of the first side surface portion S10A and the second side surface portion S10B. In this case, a resin solidified material 16 may be formed on the first side surface portion S10A and the second side surface portion S10B.

[0202] In the first to third embodiments, the electrode assemblies 10A, 10B, and 10C include a plurality of unit electrode bodies 10AU, 10BU, and 10CU, but the present disclosure is not limited to this. The electrode assemblies 10A, 10B, and 10C may each include one unit electrode body 10AU, 10BU, and 10CU.

[0203] In the first to third embodiments, the unit electrode bodies 10AU, 10BU, and 10CU are formed by stacking the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layers 11A, 11B, and 11C, the negative electrode active material layer 13, the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layers 11A, 11B, and 11C, 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 bodies 10AU, 10BU, and 10CU may also be formed by stacking the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layers 11A, 11B, and 11C, 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 bodies 10AU, 10BU, and 10CU may be formed by stacking the negative electrode current collector 15, the negative electrode active material layer 13, the solid electrolyte layers 11A, 11B, and 11C, the positive electrode active material layer 12, the positive electrode current collector 14, the positive electrode active material layer 12, the solid electrolyte layers 11A, 11B, and 11C, 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 bodies 10AU, 10BU, and 10CU 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.

[0204] In the first embodiment, adjacent solid electrolyte layers 11A are arranged so as to be connected to each other within a unit electrode body 10AU and between two adjacent unit electrode bodies AU, but the present disclosure is not limited to this. In the present disclosure, adjacent solid electrolyte layers 11A may be arranged so as to be connected to each other either within a unit electrode body 10AU or between two adjacent unit electrode bodies AU. Adjacent solid electrolyte layers 11A do not have to be arranged so as to be connected to each other within a unit electrode body 10AU or between two adjacent unit electrode bodies AU.

[0205] In the first to third embodiments, the exterior body 40 is a rectangular metal container, but the present disclosure is not limited to this. The exterior body 40 may be a container made of at least one laminate film, or may be a cylindrical metal container.

[0206] In the first to third 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.

[0207] In the first to third embodiments, the stacked configuration of the electrode assemblies 10A, 10B, and 10C is a configuration in which multiple unit electrode assemblies 10AU, 10BU, and 10C having a monopolar structure are connected in parallel, but the present disclosure is not limited to this. The stacked configuration of the electrode assemblies may be a configuration in which multiple unit electrode assemblies having a monopolar structure are connected in series (hereinafter also referred to as a "monopolar series configuration"). In a monopolar series configuration, the electrode assemblies have a conductor electrically connecting the positive electrode current collector 14 and the negative electrode current collector 15, and do not have a bundle including multiple positive electrode current collector tabs 21 or multiple negative electrode current collector tabs 22. The stacked configuration of the electrode assemblies may be a configuration in which multiple unit electrode assemblies having a bipolar structure are connected in series. An example of an electrode assemblies having a configuration in which multiple unit electrode assemblies having a bipolar structure are connected in series is shown in FIG. 16. [Explanation of symbols]

[0208] 1A, 1B, 1C: solid-state battery, 10A, 10B, 10C: electrode body, 10AU, 10BU, 10CU: unit electrode body, 11A, 11B, 11C: 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, 40: exterior body, P11A, P11B: protruding portion

Claims

1. An electrode body and a current collecting tab connected to the electrode body, 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 includes a support; the solid electrolyte layer has protruding portions that protrude from end surfaces of the positive electrode active material layer and the negative electrode active material layer, the protruding portion 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.

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 protruding portions of the solid electrolyte layers adjacent to each other are connected to each other 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 protruding portions are arranged in the unit electrode body so as to connect adjacent ones of the solid electrolyte layers to each other.

4. The electrode body A first side surface 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 2 , wherein the protruding portions of the adjacent solid electrolyte layers are arranged so as to be connected to each other at the first side surface portion and the second side surface portion.

5. The electrode body A first side surface 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 2 , wherein the protruding portions of the adjacent solid electrolyte layers are arranged so as to be connected to each other at the third side surface portion and the fourth side surface portion.

6. The solid-state battery according to claim 1 , wherein the protruding portion is connected to the current collecting tab.

7. The electrode body A first side surface 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 6 , wherein the protruding portions are arranged on the third side surface portion and the fourth side surface portion so as to be connected to the current collecting tabs.

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

9. forming an electrode assembly precursor having a plurality of protruding portions; densifying the electrode body precursor to connect adjacent projecting portions; and the electrode assembly precursor includes a plurality of unit electrode assemblies stacked along a stacking direction, the unit electrode body 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 along the stacking direction, the protruding portions refer to portions of the solid electrolyte layer that protrude beyond end faces of the negative electrode active material layer and the positive electrode active material layer.

Images