JP7694491B2 - All-solid-state battery and method for producing same - Google Patents

Description

This disclosure relates to an all-solid-state battery and a method for manufacturing the same.

An all-solid-state battery is a battery that has a solid electrolyte layer between a positive electrode active material layer and a negative electrode active material layer, and has the advantage that it is easier to simplify safety devices compared to liquid batteries that have an electrolyte solution containing a flammable organic solvent. Patent Document 1 discloses a method for manufacturing an all-solid-state battery in which a liquid resin is supplied to the side portion of the all-solid-state battery and then the liquid resin is hardened. Patent Document 2 discloses a stacked battery in which an insulating layer is provided on the end of the electrode layer.

Patent No. 6445601 JP 2021-057321 A

When manufacturing an all-solid-state battery, for example, a protective member to ensure insulation may be placed on the side of the short side of the all-solid-state battery, and then the long side of the all-solid-state battery may be cut. In this case, if the protective member peels off, the insulation may decrease.

This disclosure was made in consideration of the above-mentioned circumstances, and its main objective is to provide an all-solid-state battery that prevents deterioration of insulation properties due to peeling of the protective member.

[1]
An all-solid-state battery having an electrode body having a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector, and a current collecting tab connected to the electrode body, wherein the electrode body has a first side portion, a second side portion facing the first side portion, and a third side portion connecting the first side portion and the second side portion, in which the first active material layer, the solid electrolyte layer, and the second active material layer are flush with each other, and a protective member is provided on the first side portion to cover a side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer. an all-solid-state battery in which the first active material layer, the solid electrolyte layer, and the second active material layer are disposed on 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 fastening member X covering a side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer is disposed on the third side surface portion, and when the electrode body is viewed in a plan view in a thickness direction, (i) the electrode body has a first side defined by the first side surface portion, a second side defined by the second side surface portion, and a third side defined by the third side surface portion, (ii) a first end portion of the protective member is disposed on the inside of the axis _AX3 defined by the _third side, and (iii) the fastening member X extends so as to contact the first end portion of the protective member.

[2]
the electrode body has a fourth side portion connecting the first side portion and the second side portion and facing the third side portion, in which the first active material layer, the solid electrolyte layer, and the second active material layer are flush with each other in the fourth side portion, and a fastening member Y covering a side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer is disposed in the fourth side portion, and when the electrode body is viewed in a plan view in a thickness direction, (iv) the electrode body has a fourth side defined by the fourth side portion, (v) a second end of the protective member is disposed on the inside of the axis _AX4 based on the axis _AX4 defined by the fourth side, and (vi) the fastening member Y extends so as to contact the second end of the protective member.

[3]
The all-solid-state battery according to [1] or [2], wherein, in a cross-sectional view in a thickness direction of the electrode body, an end of the first active material layer in the second side portion protrudes beyond an end of the second active material layer in the second side portion.

[4]
the electrode body has a first active material layer A and a first active material layer B as the first active material layer, a solid electrolyte layer A and a solid electrolyte layer B as the solid electrolyte layer, a second active material layer A and a second active material layer B as the second active material layer, and a second current collector A and a second current collector B as the second current collector, and the electrode body has the second current collector A, the second active material layer A, the solid electrolyte layer A, the first active material layer A, the first current collector, the first active material layer B, the solid electrolyte layer B, the second active material layer B, and the second current collector B in this order in a thickness direction.

[5]
The all-solid-state battery according to [4], wherein the protective member is arranged in the first side portion so as to cover a side surface of the solid electrolyte layer A, a side surface of the first active material layer A, a side surface of the first current collector, a side surface of the first active material layer B, and a side surface of the solid electrolyte layer B.

[6]
The all-solid-state battery according to any one of [1] to [5], wherein the first current collector and the first active material layer are a negative electrode current collector and a negative electrode active material layer, respectively, and the second current collector and the second active material layer are a positive electrode current collector and a positive electrode active material layer, respectively.

[7]
The all-solid-state battery according to any one of [1] to [6], wherein the electrode body has a plurality of the protective members in a thickness direction.

[8]
A method for producing an all-solid-state battery according to any one of [1] to [7], comprising: a preparation step of preparing a precursor member of an electrode body having the first side surface portion and the second side surface portion and having the protective member disposed thereon; and a cutting step of cutting the precursor member to form the third side surface portion.
and a disposing step of disposing the fastening member X on the third side surface portion.

The present disclosure has the effect of providing an all-solid-state battery that prevents deterioration of insulation properties due to peeling of the protective member.

1A and 1B are a schematic plan view and a schematic cross-sectional view illustrating an all-solid-state battery according to the present disclosure. FIG. 2 is an enlarged view of a part of FIG. FIG. 2 is an enlarged view of a part of the BB cross-sectional view of FIG. FIG. 1 is a schematic plan view illustrating an all-solid-state battery according to the present disclosure. FIG. 1 is an explanatory diagram for explaining problems and effects of the present disclosure. FIG. 1 is a schematic cross-sectional view illustrating an all-solid-state battery according to the present disclosure. FIG. 1 is a schematic cross-sectional view illustrating an all-solid-state battery according to the present disclosure. 1A to 1C are schematic cross-sectional views illustrating a preparation step in the present disclosure. 1A to 1C are schematic cross-sectional views illustrating a cutting step and an arrangement step in the present disclosure.

The all-solid-state battery of this disclosure will be described in detail below with reference to the drawings. Each of the drawings shown below is a schematic illustration, and the size and shape of each part are appropriately exaggerated to make it easier to understand. Furthermore, hatching of each part may be omitted as appropriate.

A. All-Solid-State Battery Fig. 1(a) is a schematic plan view illustrating an all-solid-state battery in the present disclosure, and Fig. 1(b) is a cross-sectional view taken along line A-A in Fig. 1(a). Fig. 2 is an enlarged view of a portion of Fig. 1(b). Fig. 3 is an enlarged view of a portion of the cross-sectional view taken along line B-B in Fig. 1(a).

The all-solid-state battery 100 shown in Fig. 1(a) and (b) has an electrode body 10, a current collector tab T, a protective member 20, and a fastening member 30. The electrode body 10 shown in Fig. 1(a) has a first active material layer 2a, a solid electrolyte layer 3a, a second active material layer 4a, and a second current collector 5a, which are arranged in this _order from one surface of the first current collector 1 along the thickness direction _DT , and a first active material layer 2b, a solid electrolyte layer 3b, a second active material layer 4b, and a second current collector 5b, which are arranged in this order from the other surface of the first current collector 1 along the thickness direction DT. As shown in Fig. 1(a) and (b), the all-solid-state battery 100 has, as current collector tabs T, a first current collector tab T1 connected to the first current collector 1, a second current collector tab T5a connected to the second current collector 5a, and a second current collector tab T5b connected to the second current collector 5b.

The electrode body in the present disclosure has a main surface and a side surface. The main surface refers to a surface whose normal direction is parallel to the thickness direction of the electrode body. The side surface refers to a surface whose normal direction intersects with the normal direction of the main surface. The electrode body 10 shown in FIG. 1(a) has at least a first side surface portion SS ₁ , a second side surface portion SS ₂ , and a third side surface portion SS ₃ as side surface portions. In FIG. 1(b) and FIG. 2, in the first side surface portion SS ₁ , the first current collector 1, the first active material layer 2 (2a, 2b), the solid electrolyte layer 3 (3a, 3b), and the second active material layer 4 (4a, 4b) are flush with each other. In FIG. 2, a protective member 20 is disposed on the first side surface portion SS ₁ to cover the side surface of the first current collector 1, the side surface of the first active material layer 2 (2a, 2b), and the side surface of the solid electrolyte layer 3 (3a, 3b).

In Fig. 3, in the third side surface portion _SS3 , the first current collector 1, the first active material layer 2 (2a, 2b), the solid electrolyte layer 3 (3a, 3b), the second active material layer 4 (4a, 4b), and the second current collector 5 (5a, 5b) are flush with each other, and a fastening member X (fastening member 30X) is disposed to cover these side surfaces. As shown in Fig. 4, when the electrode body 10 is viewed in plan from the thickness direction, (i) the electrode body 10 _has a first side S1 defined by the first side surface portion, a second side _S2 (not shown) defined by the second side surface portion, and a third side _S3 defined by the third side surface _portion . Also, (ii) the first end 21 of the protective member 20 is disposed inside the axis _AX3 defined by the third side _S3 . In addition, (iii) the fastening member X (fastening member 30X) extends so as to contact the first end 21 of the protection member 20.

According to the present disclosure, by providing a specific protective member, an all-solid-state battery is obtained in which a decrease in insulation due to peeling of the protective member is prevented. Furthermore, by providing a specific fastening member, an all-solid-state battery is obtained in which the occurrence of a short circuit is suppressed. As described above, when manufacturing an all-solid-state battery, for example, a protective member for ensuring insulation may be placed on the side portion of the short side of the all-solid-state battery, and then the long side of the all-solid-state battery may be cut. In this case, the protective member may peel off, resulting in a decrease in insulation.

For example, as shown in FIG. 5(a), when the electrode body 10 has a first side surface portion SS ₁ and the first side surface portion SS ₁ is flush, the protective member 20 is disposed on the first side surface portion SS ₁ to prevent short circuit. When cutting along Cut Line 1 and Cut Line 2, if the protective member 20 is in a position where it is cut, stress is applied to the protective member 20 at the time of cutting, and peeling of the protective member 20 may occur. In particular, when the thickness of the protective member 20 is thin, peeling of the protective member 20 is likely to occur. In contrast, as shown in FIG. 5(b), when cutting along Cut Line 1 and Cut Line 2, the protective member 20 is in a position where it is not cut, so that it is possible to prevent stress from being applied to the protective member 20 at the time of cutting. On the other hand, when cutting along Cut Line 1 and Cut Line 2, if the protective member 20 is in a position where it is not cut, a part of the first side surface portion SS ₁ is not protected by the protective member 20, and therefore insulation may be reduced. In contrast, in the present disclosure, as shown in Fig. 4, the fastening member 30 extends so as to contact the ends (first end 21 and second end) of the protective member 20, i.e., the fastening member 30 protects the first side surface portion _SS1 that is not protected by the protective member 20. This results in an all-solid-state battery that suppresses the occurrence of short circuits. Furthermore, the fastening member 30X extends from the third side surface portion _SS3 to the first side surface portion _SS1 and has an L-shape, thereby improving the adhesion (adhesion) to the electrode body 10.

1. Configuration of All-Solid-State Battery The all-solid-state battery according to the present disclosure has an electrode body, a current collecting tab, a protective member, and a fastening member.

The electrode body in the present disclosure has a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector. The configuration of the electrode body is not particularly limited as long as it functions as a battery. For example, the electrode body may have a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector in this order in the thickness direction. In addition, the electrode body may have one, two, or three or more power generation units composed of a first active material layer, a solid electrolyte layer, and a second active material layer. When the electrode body has multiple power generation units, they may be connected in parallel or in series.

For example, the electrode body 10 shown in FIG. 1(b) has (i) a first active material layer 2 including a first active material layer A (first active material layer 2a) and a first active material layer B (first active material layer 2b), (ii) a solid electrolyte layer 3 including a solid electrolyte layer A (solid electrolyte layer 3a) and a solid electrolyte layer B (solid electrolyte layer 3b), (iii) a second active material layer 4 including a second active material layer A (second active material layer 4a) and a second active material layer B (second active material layer 4b), and (iv) a second current collector 5 including a second current collector A (second current collector 5a) and a second current collector B (second current collector 5b). These layers are arranged in the thickness direction in the following order: second current collector A (second current collector 5a), second active material layer A (second active material layer 4a), solid electrolyte layer A (solid electrolyte layer 3a), first active material layer A (first active material layer 2a), first current collector 1, first active material layer B (first active material layer 2b), solid electrolyte layer B (solid electrolyte layer 3b), second active material layer B (second active material layer 4b), and second current collector B (second current collector 5b).

The electrode body 10 shown in FIG. 1(a) has a first side surface portion SS ₁ , a second side surface portion SS ₂ , a third side surface portion SS _3, and a fourth side surface portion SS ₄ as side surface portions. The second side surface portion SS ₂ is disposed so as to face the first side surface portion SS _1. The third side surface portion SS ₃ is disposed so as to connect the first side surface portion SS ₁ and the second side surface portion SS _2. The fourth side surface portion SS ₄ is disposed so as to connect the first side surface portion SS ₁ and the second side surface portion SS ₂ and face the third side surface portion SS _3. As shown in FIG. 1(a), the first side surface portion SS ₁ and the second side surface portion SS ₂ may correspond to the side surface portions on the short side, and the third side surface portion SS ₃ and the fourth side surface portion SS ₄ may correspond to the side surface portions on the long side.

As shown in FIG. 2, in the first side surface portion SS ₁ , the first active material layer 2a, the solid electrolyte layer 3a, and the second active material layer 4a are flush with each other. In this way, if the solid electrolyte layer 3a and the first active material layer 2a and the second active material layer 4a arranged on both sides thereof are flush with each other, a short circuit is likely to occur. Therefore, it is preferable to insulate them with a protective member. In the present disclosure, "flush" means that, as shown in FIG. 2, when the side surface portion is viewed in cross section, in a direction D _X perpendicular to the thickness direction D _T , for example, in the first side surface portion SS ₁ shown in FIG. 2, the position of the end 2t of the first active material layer 2a, the position of the end 3t of the solid electrolyte layer 3a, and the position of the end 4t of the second active material layer 4a are completely aligned in the thickness direction D _T. Therefore, in the direction D _X , the distance (δ ₁ ) between the end of the most protruding layer and the end of the least protruding layer is 0.

As shown in Fig. 2, in the first side surface portion _SS1 , the three layers of the first active material layer 2a, the solid electrolyte layer 3a, and the second active material layer 4a may be flush with the first current collector 1. Also, as shown in Fig. 2, in the first side surface portion _SS1 , the first current collector 1, the first active material layer 2 (2a, 2b), the solid electrolyte layer 3 (3a, 3b), and the second active material layer 4 (4a, 4b) may all be flush with each other.

The protective member in the present disclosure covers the side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer. For example, when the protective member covers the side surface of the first active material layer, the protective member may cover the entire side surface of the first active material layer, or may cover a part of the side surface of the first active material layer. This is also true when the protective member covers the side surface of the solid electrolyte layer and when the protective member covers the side surface of the second active material layer. The protective member 20 shown in FIG. 2 covers at least the entire side surface of the first active material layer 2a and a part of the side surface of the solid electrolyte layer 3a. Also, as shown in FIG. 2, the protective member 20 may cover the side surface of the first current collector 1, the side surface of the first active material layer 2 (2a, 2b), and the side surface of the solid electrolyte layer 3 (3a, 3b).

As shown in FIG. 2, when the thickness (length in the direction _DX ) of the protective member 20 is _T20 , _T20 is, for example, 10 μm or more and 200 μm or less, and may be 50 μm or more and 100 μm or less.

As shown in FIG. 3, in the third side surface portion _SS3 , the first active material layer 2a, the solid electrolyte layer 3a, and the second active material layer 4a are flush with each other. If the solid electrolyte layer 3a and the first active material layer 2a and the second active material layer 4a arranged on both sides thereof are flush with each other, a short circuit is likely to occur. Therefore, it is preferable to insulate them by the fastening member X. Also, as shown in FIG. 3, in the third side surface portion _SS3 , the three layers of the first active material layer 2a, the solid electrolyte layer 3a, and the second active material layer 4a may be flush with the first current collector 1. Also, as shown in FIG. 3, in the third side surface portion _SS3 , the first current collector 1, the first active material layer 2 (2a, 2b), the solid electrolyte layer 3 (3a, 3b), the second active material layer 4 (4a, 4b), and the second current collector 5 (5a, 5b) may all be flush with each other.

The fastening member X in the present disclosure is disposed on the third side surface portion _SS3 . By providing the fastening member X, it is possible to prevent the positional deviation of each layer constituting the electrode body. The fastening member X usually covers the side surface of at least one layer of the first active material layer, the solid electrolyte layer, and the second active material layer. For example, when the fastening member X covers the side surface of the first active material layer, the fastening member X may cover the entire side surface of the first active material layer, or may cover a part of the side surface of the first active material layer. This point is the same when the fastening member X covers the side surface of the solid electrolyte layer, the side surface of the second active material layer, and the side surface of the second current collector. The fastening member X (fastening member 30X) shown in FIG. 3 at least covers the entire side surface of the first active material layer 2a, the entire side surface of the solid electrolyte layer 3a, and the entire side surface of the second active material layer 4a. Furthermore, as shown in FIG. 3 , the fastening member X (fastening member 30X) may cover a side surface of the first current collector 1, a side surface of the first active material layer 2 (2a, 2b), a side surface of the solid electrolyte layer 3 (3a, 3b), a side surface of the second active material layer 4a, and a side surface of the second current collector 5 (5a, 5b).

As shown in FIG. 3 , when the thickness (length in a direction D- _Y perpendicular to the directions D- _X and D- _T ) of the fastening member X (fastening member 30X) is T- ₃₀ , T- ₃₀ is, for example, not less than 50 μm and not more than 5 mm, and may be not less than 100 μm and not more than 3 mm.

FIG. 4 is a schematic plan view illustrating an all-solid-state battery in the present disclosure. In FIG. 4, the second current collector 5 and the second current collector tab T5 are shown by continuous dotted lines for convenience, but the second current collector 5 corresponds to a member constituting the electrode body 10. As shown in FIG. 4, when the electrode body 10 is viewed in a plan view from the thickness direction, (i) the electrode body 10 has a first side S ₁ defined by the first side portion, a second side S ₂ (not shown) defined by the second side portion, and a third side S ₃ defined by the third side portion. In addition, (ii) the first end 21 of the protective member 20 is disposed on the inner side of the axis AX ₃ (the fourth side S ₄ side) based on the axis AX ₃ defined by the third side S _3. In addition, (iii) the fastening member X (fastening member 30X) extends so as to contact the first end 21 of the protective member 20. That is, the fastening member X (fastening member 30X) extends inward from the axis _AX3 (toward the fourth side _S4 ) with respect to the axis _AX3 as the reference, and is in contact with the first end portion 21.

As shown in FIG. 4, when the distance _W30 is between the end of the fastening member X (fastening member 30X) and the axis _AX3 in the direction _DY , _W30 is, for example, 1 mm or more and 10 mm or less.

As shown in FIG. 4, when the electrode body 10 is viewed in plan from the thickness direction, it is preferable that the first end 21 of the protective member 20 is located at a position that does not overlap with the second current collecting tab T5. This is because the occurrence of a short circuit can be further suppressed. In FIG. 4, a region E is formed that includes the first end 21 and does not overlap with the second current collecting tab T5. Also, as shown in FIG. 6, the electrode body 10 may have a plurality of protective members 20 in the thickness direction D _T. In this case, it is preferable that the third side portion is flush. Such a third side portion can be obtained by performing a cutting process described later on a precursor member of the electrode body having a plurality of protective members 20.

The electrode body 10 shown in FIG. 1(a) has a fourth side surface portion _SS4 facing the third side surface portion _SS3 as a side surface portion. A fastening member Y (fastening member 30Y) may be disposed on the fourth side surface portion _SS4 . Details of the fastening member Y are the same as those described for the fastening member X described above, and therefore will not be described here. In addition, as shown in FIG. 4, when the electrode body 10 is viewed in a plan view from the thickness direction, (iv) the electrode body 10 may further have a fourth side _S4 defined by the fourth side surface portion. In addition, (v) the second end portion 22 of the protective member 20 may be disposed on the inner side of the axis _AX4 (the third side _S3 side) with respect to the axis _AX4 defined by the fourth side _S4 . In addition, (vi) the fastening member Y (fastening member 30Y) extends so as to contact the second end portion 22 of the protective member 20. That is, the fastening member Y (fastening member 30Y) may extend inward from the axis _AX4 (toward the third side _S3 ) with respect to the axis _AX4 as the reference, and may be in contact with the second end portion 22.

As shown in FIG. 7, in a cross-sectional view of the electrode body 10 in the thickness direction D _T , the end of the first active material layer 2a at the second side surface portion SS ₂ preferably protrudes from the end of the second active material layer 4a at the second side surface portion SS _2. By providing such a step, a short circuit is less likely to occur. "Protruding" means that, as shown in FIG. 6, the distance (δ ₂ ) between the end of the first active material layer 2a and the end of the second active material layer _4a in the direction D X is greater than 1 mm. Similarly, the end of the solid electrolyte layer 3a at the second side surface portion SS ₂ preferably protrudes from the end of the second active material layer 4a at the second side surface portion SS _2. By providing such a step, a short circuit is less likely to occur. In the direction D _X , the distance (δ ₃ ) between the end of the solid electrolyte layer 3a and the end of the second active material layer 4a is preferably the same as the above-mentioned δ ₂ .

2. Components of the All-Solid-State Battery The all-solid-state battery according to the present disclosure has an electrode body, a current collecting tab, a protective member, and a fastening member.

The electrode body in the present disclosure has a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector. The first current collector and the first active material layer may be a positive electrode current collector and a positive electrode active material layer, respectively. In this case, the second current collector and the second active material layer are a negative electrode current collector and a negative electrode active material layer, respectively. Conversely, the first current collector and the first active material layer may be a negative electrode current collector and a negative electrode active material layer, respectively. In this case, the second current collector and the second active material layer are the first current collector and the first active material layer, respectively.

The positive electrode active material layer contains at least a positive electrode active material. The positive electrode active material layer may further contain at least one of a conductive material, a solid electrolyte, and a binder. Examples of the positive electrode active material include oxide active materials such as LiNi _1/3 Co _1/3 Mn _1/3 O _2. Examples of the conductive material include carbon materials. The solid electrolyte may be an organic solid electrolyte such as a gel electrolyte, or an inorganic solid electrolyte such as an oxide solid electrolyte or a sulfide solid electrolyte. Examples of the binder include a rubber-based binder and a fluoride-based binder.

The negative electrode active material layer contains at least a negative electrode active material. The negative electrode active material layer may further contain at least one of a conductive material, a solid electrolyte, and a binder. Examples of the negative electrode active material include metal active materials such as Li and Si, carbon active materials such as graphite, and oxide active materials such as Li ₄ Ti ₅ O _12. The conductive material, solid electrolyte, and binder are the same as those described above. In addition, the solid electrolyte layer is disposed between the positive electrode active material layer and the negative electrode active material layer, and contains at least a solid electrolyte. The solid electrolyte is the same as those described above.

The positive electrode current collector collects the current from the positive electrode active material layer. Examples of the material for the positive electrode current collector include metals such as aluminum, SUS, and nickel. Examples of the shape of the positive electrode current collector include a foil shape. The positive electrode current collector may have a carbon coating layer on the surface on the positive electrode active material layer side. The negative electrode current collector collects the current from the negative electrode active material layer. Examples of the material for the negative electrode current collector include metals such as copper, SUS, and nickel. Examples of the shape of the negative electrode current collector include a foil shape. The negative electrode current collector may have a carbon coating layer on the surface on the negative electrode active material layer side.

The all-solid-state battery of the present disclosure has, as current collecting tabs, a first current collecting tab connected to a first current collector and a second current collecting tab connected to a second current collector. In the thickness direction of the electrode body, the first current collecting tab is disposed at a position not overlapping with the first active material layer. Similarly, the second current collecting tab is disposed at a position not overlapping with the second active material layer. One of the first current collecting tab and the second current collecting tab is a positive electrode tab, and the other is a negative electrode tab. In FIG. 1(b), the first current collecting tab T1 extends from the second side surface portion _SS2 of the electrode body 10 in a direction intersecting with the thickness direction _DT of the electrode body 10. In addition, in FIG. 1(b), the second current collecting tab T5 (T5a, T5b) extends from the first side surface portion _SS1 of the electrode body 10 in a direction intersecting with the thickness direction _DT of the electrode body 10. 1(b), the first current collector tab T1 is preferably formed continuously from the first current collector 1. Similarly, the second current collector tab T5 is preferably formed continuously from the second current collector 5. The material of the current collector tab is not particularly limited, but examples thereof include the same materials as those of the current collector described above.

The material of the protective member in this disclosure is not particularly limited, but examples thereof include resins. Examples of the resins include olefin resins such as polyethylene and polypropylene; and polyimide resins. The material of the fastening member in this disclosure is not particularly limited, but examples thereof include resins. The resin used for the fastening member is, for example, the same as the resin used for the protective member described above.

The all-solid-state battery of the present disclosure may have a current collecting terminal electrically connected to the current collecting tab. The current collecting terminal is a terminal for conducting electricity generated in the electrode body to the outside of the all-solid-state battery. The shape of the current collecting terminal may be, for example, a plate shape. The material of the current collecting terminal may be, for example, a metal such as Al or SUS. The all-solid-state battery of the present disclosure usually has an exterior body that covers the electrode body, the current collecting tab, the protective member, and the fastening member. The exterior body may be a laminate type exterior body or a case type exterior body.

The all-solid-state battery in this disclosure is typically a lithium-ion secondary battery. Applications of the all-solid-state battery include, for example, power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, it is preferable to use the all-solid-state battery as a driving power source for hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), or electric vehicles (BEVs). The all-solid-state battery in this disclosure may also be used as a power source for moving objects other than vehicles (e.g., railways, ships, and aircraft), and may also be used as a power source for electrical products such as information processing devices.

B. Manufacturing Method of All-Solid-State Battery The manufacturing method of an all-solid-state battery in the present disclosure is the manufacturing method of the all-solid-state battery described above, and includes a preparation step of preparing a precursor member of an electrode body having the first side portion and the second side portion and having the protective member disposed thereon, a cutting step of cutting the precursor member at a side portion connecting the first side portion and the second side portion to form the third side portion, and a disposing step of disposing the fastening member X on the third side portion.

According to the present disclosure, by providing a specified protective member, an all-solid-state battery can be obtained that prevents a decrease in insulation properties due to peeling of the protective member. Furthermore, by providing a specified fastening member, an all-solid-state battery can be obtained that suppresses the occurrence of short circuits.

1. Preparation step The preparation step in the present disclosure is a step of preparing a precursor member of an electrode body having the first side portion and the second side portion and having the protective member disposed thereon. This precursor member usually has a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector. The precursor member preferably has a first current collector tab formed continuously from the first current collector and a second current collector tab formed continuously from the second current collector. The precursor member also has a first side portion and a second side portion facing the first side portion, and the first active material layer, the solid electrolyte layer, and the second active material layer are flush with each other in the first side portion. In addition, a protective member that covers at least the side surface of the first active material layer is disposed on the first side portion. Details of these and preferred aspects are the same as those described in "A. All-solid-state battery" above. The precursor member may also have a plurality of protective members in the thickness direction.

FIG. 8 is a schematic cross-sectional view illustrating a preparation step in the present disclosure. First, as shown in FIG. 8(a), a first current collector 1 (including a first current collector tab T1) is prepared. Next, as shown in FIG. 8(b), a first active material layer 2a and a first active material layer 2b are formed on both sides of the first current collector 1, respectively. For example, a method of forming the first active material layer 2 includes a method of applying a slurry for forming the first active material layer 2 and drying it (coating method). Next, as shown in FIG. 8(c), a solid electrolyte layer 3a is formed on the first active material layer 2a, and a solid electrolyte layer 3b is formed on the first active material layer 2b. For example, a method of forming the solid electrolyte layer 3 includes a method of transferring the solid electrolyte layer 3 onto the first active material layer 2 using a sheet on which the solid electrolyte layer 3 is formed on a metal foil (transfer method). Next, as shown in FIG. 8(d), a second active material layer 4a is formed on the solid electrolyte layer 3a, and a second active material layer 4b is formed on the solid electrolyte layer 3b. The method of forming the second active material layer 4 may be, for example, the same method as the transfer method or coating method described above. Then, a part of the obtained laminate is cut along the thickness direction to form the first side surface portion _SS1 . Next, as shown in FIG. 8(e), a protective member 20 is placed on the first side surface portion _SS1 . As a method of placing the protective member 20, for example, welding may be used. Next, as shown in FIG. 8(f), a second current collector 5a (including a second current collector tab T5a) is placed on the second active material layer 4a, and a second current collector 5b (including a second current collector tab T5b) is placed on the second active material layer 4b. This results in a precursor member 101.

2. Cutting Step and Arranging Step The cutting step in the present disclosure is a step of cutting the precursor member to form the third side surface portion. Also, the arranging step in the present disclosure is a step of arranging the fastening member X on the third side surface portion.

9A and 9B are schematic cross-sectional views illustrating the cutting step and the arranging step in the present disclosure. As shown in FIGS. 9A and 9B, the precursor member 101 is cut along Cut Line ₁ to form a third side surface portion SS3. At this time, the first end portion 21 of the protective member 20 is disposed at a position not cut by Cut Line 1. Also, in FIGS. 9A and 9B, the precursor member 101 is cut along Cut Line 2 to form a fourth side surface portion _SS4 . At this time, the second end portion 22 of the protective member 20 is disposed at a position not cut by Cut Line 2.

Next, as shown in Fig. 9(c), the fastening member X (fastening member 30X) is placed on the third side surface portion _SS3 . Furthermore, the fastening member X (fastening member 30X) is placed so as to contact the first end portion 21 of the protective member 20. Moreover, in Fig. 9(c), the fastening member Y (fastening member 30Y) is placed on the fourth side surface portion _SS3 . Furthermore, the fastening member Y (fastening member 30Y) is placed so as to contact the second end portion 22 of the protective member 20. In this manner, the all-solid-state battery 100 is obtained.

3. All-Solid-State Battery The all-solid-state battery obtained by the above-described steps is similar to that described in "A. All-Solid-State Battery" above, and therefore will not be described here.

This disclosure is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical ideas described in the claims of this disclosure and exhibits similar effects is included within the technical scope of this disclosure.

Reference Signs List 1: First current collector 2: First active material layer 3: Solid electrolyte layer 4: Second active material layer 5: Second current collector 10: Electrode body 20: Protective member 30: Binding member 100: All-solid-state battery

Claims (8)

An all-solid-state battery comprising: an electrode assembly having a first current collector, a first active material layer, a solid electrolyte layer, a second active material layer, and a second current collector; and a current collecting tab connected to the electrode assembly,
the electrode body has a first side surface portion, a second side surface portion opposing the first side surface portion, a third side surface portion connecting the first side surface portion and the second side surface portion, and a fourth side surface portion connecting the first side surface portion and the second side surface portion and opposing the third side surface portion ;
the current collecting tabs include a first current collecting tab connected to the first current collector and a second current collecting tab connected to the second current collector;
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 to cover a 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 fastening member X is disposed on the third side surface portion to cover a side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer;
The protective member and the fastening member X are separate members,
When the electrode body is viewed in a plan view from the thickness direction,
(i) the electrode body has a first side defined by the first side portion, a second side defined by the second side portion, and a third side defined by the third side portion;
(ii) the first end of the protective member is disposed on the inside of the axis _AX3 defined by the third side, with the axis _AX3 being used as a reference; and
(iii) The all-solid-state battery, wherein the fastening member X extends so as to contact the first end of the protective member. In the fourth side surface portion, the first active material layer, the solid electrolyte layer, and the second active material layer are flush with each other,
a fastening member Y is disposed on the fourth side surface portion to cover a side surface of at least one of the first active material layer, the solid electrolyte layer, and the second active material layer;
When the electrode body is viewed in a plan view from the thickness direction,
(iv) the electrode body has a fourth side defined by the fourth side surface portion,
(v) the second end of the protection member is disposed on the inside of the axis _AX4 defined by the fourth side, with the axis _AX4 being used as a reference; and
(vi) The all-solid-state battery according to claim 1, wherein the fastening member Y extends so as to contact the second end of the protective member. The all-solid-state battery according to claim 1 or 2, wherein, in a cross-sectional view in the thickness direction of the electrode body, the end of the first active material layer in the second side portion protrudes beyond the end of the second active material layer in the second side portion. the electrode body has a first active material layer A and a first active material layer B as the first active material layer, a solid electrolyte layer A and a solid electrolyte layer B as the solid electrolyte layer, a second active material layer A and a second active material layer B as the second active material layer, and a second current collector A and a second current collector B as the second current collector,
3. The all-solid-state battery according to claim 1, wherein the electrode body has, in a thickness direction, the second current collector A, the second active material layer A, the solid electrolyte layer A, the first active material layer A, the first current collector, the first active material layer B, the solid electrolyte layer B, the second active material layer B, and the second current collector B, in this order. The all-solid-state battery according to claim 4, wherein the protective member is arranged in the first side portion so as to cover the side of the solid electrolyte layer A, the side of the first active material layer A, the side of the first current collector, the side of the first active material layer B, and the side of the solid electrolyte layer B. the first current collector and the first active material layer are a negative electrode current collector and a negative electrode active material layer, respectively;
3. The all-solid-state battery according to claim 1, wherein the second current collector and the second active material layer are a positive electrode current collector and a positive electrode active material layer, respectively. The all-solid-state battery according to claim 1 or 2, wherein the electrode body has a plurality of the protective members in the thickness direction. A method for producing the all-solid-state battery according to claim 1 or 2, comprising the steps of:
a preparation step of preparing a precursor member of an electrode body having the first side surface portion and the second side surface portion and having the protective member disposed thereon;
a cutting step of cutting the precursor member to form the third side surface portion;
a placement step of placing the fastening member X on the third side surface portion;
The present invention relates to a method for producing an all-solid-state battery.