JP2023032295A - Soli-state battery unit - Google Patents

Abstract

A solid state battery unit that can easily suppress the occurrence of a short circuit is provided. A solid battery unit includes a laminate structure in which a positive electrode current collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector layer are laminated in this order. The positive electrode current collector layer has a positive electrode terminal that protrudes outward from the positive electrode layer when viewed in the stacking direction of the laminated structure. The negative electrode current collector layer has a negative electrode terminal projecting outward from the negative electrode layer at a position different from the positive electrode terminal when viewed in the stacking direction. When viewed in the stacking direction, the negative electrode current collector layer and the negative electrode layer corresponding to a portion where the positive electrode terminal protrudes are in the direction in which the positive electrode terminal protrudes from the boundary between the positive electrode terminal and the positive electrode current collector layer. is recessed in the opposite direction, and / or the positive electrode current collector layer and the positive electrode layer corresponding to the location where the negative electrode terminal protrudes are located from the boundary between the negative electrode terminal and the negative electrode current collector layer. It is recessed in the direction opposite to the direction of protrusion of . [Selection drawing] Fig. 3

Description

The present invention relates to solid state battery units.

A stacked solid-state battery is generally configured by stacking a plurality of solid-state battery units in which a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector are stacked. The plurality of solid-state battery units are connected in parallel by connecting positive terminals extending from respective positive current collectors and negative terminals extending from respective negative current collectors.

In such a stacked solid-state battery, it is desired to prevent a short circuit between the positive electrode terminal and the negative electrode side and a short circuit between the negative electrode terminal and the positive electrode side. Patent Literature 1 discloses providing an insulating layer on the side surface of a laminated structure of a solid battery unit for short circuit prevention.

JP 2018-49696 A

When providing an insulating layer to prevent a short circuit as in Patent Document 1, it is not always easy to form a desired insulating layer. For example, when an insulating layer is provided in a laminated structure in which a positive electrode current collector, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector are laminated, each layer may be very thin (for example, about 50 μm to 200 μm). However, it is difficult to reliably apply the insulating material to the place where the insulating layer is to be provided. On the other hand, when the insulating material is applied to the side surface of each layer before lamination, the insulating material sag (sagging or flowing into surfaces other than the side surfaces) occurs, and the sagging and hardened insulating material becomes an obstacle during lamination.

An object of the present invention is to provide a solid battery unit that can easily suppress the occurrence of a short circuit.

According to a first aspect of the invention,
A solid state battery unit,
A laminated structure in which a positive electrode current collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector layer are laminated in this order,
The positive electrode current collector layer has a positive electrode terminal projecting outward from the positive electrode layer when viewed in the stacking direction of the laminated structure,
The negative electrode current collector layer has a negative electrode terminal projecting outward from the negative electrode layer at a position different from the positive electrode terminal when viewed in the stacking direction,
When viewed in the stacking direction, the negative electrode current collector layer and the negative electrode layer corresponding to a portion where the positive electrode terminal protrudes are in the direction in which the positive electrode terminal protrudes from the boundary between the positive electrode terminal and the positive electrode current collector layer. is recessed in the opposite direction, and / or the positive electrode current collector layer and the positive electrode layer corresponding to the location where the negative electrode terminal protrudes are located from the boundary between the negative electrode terminal and the negative electrode current collector layer. A solid state battery unit is provided that is recessed in a direction opposite to the projecting direction of the .

In the solid-state battery unit of the first aspect, a recessed region may be defined in which an outer edge of the stacked structure viewed in the stacking direction is recessed inward, and the positive electrode terminal may be recessed when viewed in the stacking direction. A region may protrude from the positive current collector layer and/or the negative terminal may protrude from the negative electrode current collector layer at the recessed region.

In the solid battery unit of the first aspect, the positive electrode current collector layer, the positive electrode layer, the negative electrode layer, and the negative electrode current collector layer may have the same size when viewed in the stacking direction, The negative electrode current collector layer and the negative electrode layer may be recessed in a direction opposite to a direction in which the positive electrode terminal projects from a boundary between the positive electrode terminal and the positive electrode current collector layer at a portion where the positive electrode terminal protrudes, Further, at a portion where the negative electrode terminal protrudes, the positive electrode current collector layer and the positive electrode layer may be recessed in a direction opposite to a direction in which the negative electrode terminal projects from a boundary between the negative electrode terminal and the negative electrode current collector layer. .

In the solid battery unit of the first aspect, the negative electrode layer and the negative electrode current collector layer may be larger than the positive electrode layer and the positive electrode current collector layer when viewed in the stacking direction, and the positive electrode terminal protrudes. The negative electrode current collector layer and the negative electrode layer may be depressed in a direction opposite to the projecting direction of the positive electrode terminal from the boundary between the positive electrode terminal and the positive electrode current collector layer at the location where the positive electrode current collector layer and the positive electrode current collector layer are formed.

The solid state battery unit of the present invention can easily suppress the occurrence of short circuits.

FIG. 1 is a perspective view of stacked solid-state batteries according to the first and second embodiments of the present invention. FIG. 2(a) is a cross-sectional view of the stacked solid-state battery according to the first embodiment taken along line aa in FIG. FIG. 2(b) is a cross-sectional view of the stacked solid-state battery of the first embodiment taken along line bb in FIG. FIG. 3 is a perspective view of the battery unit according to the first embodiment. FIG. 4 is a vertically arranged plan view of the battery unit according to the first embodiment and each layer thereof. The top is a plan view of the battery unit, the second is a plan view of the negative electrode current collector and the negative electrode terminal, the third is a plan view of the negative electrode layer, the fourth is a plan view of the electrolyte layer, and the fifth is a plan view of the positive electrode layer. , and the bottom is a plan view of a positive electrode current collector and a positive electrode terminal. 5(a) to 5(e) are diagrams for explaining the manufacturing method of the battery unit. FIG. 5(a) is a perspective view of a member in which a positive electrode current collector and a positive electrode terminal are integrated; FIG. 5(b) is a perspective view of a member in which a negative electrode current collector and a negative electrode terminal are integrated; 5(c) is a perspective view of a structure in which a positive electrode layer is laminated on the positive electrode current collector of the member shown in FIG. 5(a), and FIG. 5(d) is a negative electrode of the member shown in FIG. 5(b). A perspective view of a structure in which a negative electrode layer is laminated on a current collector, and FIG. 5(e) is a perspective view of a structure in which an electrolyte layer is laminated on a positive electrode layer of the structure shown in FIG. 5(c). It is a diagram. FIG. 6(a) is a cross-sectional view of the stacked solid-state battery of the second embodiment taken along line aa in FIG. FIG. 6(b) is a cross-sectional view of the stacked solid-state battery of the second embodiment taken along line bb in FIG. FIG. 7 is a perspective view of a battery unit according to the second embodiment. FIG. 8 is a vertically arranged plan view of the battery unit and each layer thereof according to the second embodiment. The top is a plan view of the battery unit, the second is a plan view of the negative electrode current collector and the negative electrode terminal, the third is a plan view of the negative electrode layer, the fourth is a plan view of the electrolyte layer, and the fifth is a plan view of the positive electrode layer. , and the bottom is a plan view of a positive electrode current collector and a positive electrode terminal. FIG. 9 is a cross-sectional view of a stacked solid-state battery of a modified example. The position of the cross section corresponds to the position of the cross section in FIGS. 2(a) and 6(a).

<First Embodiment>
A stacked solid-state battery (solid-state battery module) 100 and solid-state battery units 11 to 14 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. Stacked solid-state battery 100 is a lithium-ion battery.

As shown in FIGS. 1, 2(a), and 2(b), the stacked solid-state battery 100 includes solid-state battery units 11 to 14, a positive electrode current collecting tab 50C, and a negative electrode current collecting tab 50A, which are stacked together. , and a housing 70 .

Solid battery unit 11 and solid battery unit 13 have the same structure, and solid battery unit 12 and solid battery unit 14 have the same structure. First, the structure of the solid-state battery units 11 and 13 will be described.

As shown in FIG. 3, the solid battery units 11 and 13 include a positive electrode current collector (positive electrode current collector layer) 1C, a positive electrode layer 2C, an electrolyte layer (solid electrolyte layer) 3, a negative electrode layer 2A, and a negative electrode current collector ( A laminated structure SS in which the negative electrode current collector layer) 1A is laminated in this order, a positive electrode terminal TC protruding from the positive electrode current collector 1C in a direction orthogonal to the lamination direction of the laminated structure SS, and a negative electrode current collector 1A. It mainly has a negative terminal TA protruding in a direction perpendicular to the stacking direction of the stacked structural body SS.

In the description of the solid-state battery units 11 and 13, the direction in which the positive terminal TC and the negative terminal TA extend is referred to as the front-rear direction, and the side on which the positive terminal TC and the negative terminal TA are provided is referred to as the front side. A direction orthogonal to the stacking direction and the front-rear direction is called a width direction, and the right and left sides when viewed from the front side are the right side and the left side, respectively. In the following, "planar view" means viewing in the stacking direction.

The positive electrode current collector 1C constitutes the outermost layer on one side in the stacking direction of the laminated structure SS. The positive electrode current collector 1C can be made of any conductive material. The positive electrode current collector 1C can be made of, for example, stainless steel (such as SUS), Ni, Ti, Fe, Cu, Al, or alloys thereof, carbon materials, or the like.

The positive electrode current collector 1C has a flat plate shape, and in a plan view (at the bottom in FIG. 4), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. A notch NN 1C recessed rearward is provided in a region near the right end of the front edge of the positive electrode current collector _1C . A positive electrode terminal TC (described later) is connected to a region near the left end of the front edge of the positive electrode current collector 1C.

The thickness of the positive electrode current collector 1C can be, for example, 10 μm to 100 μm. The positive electrode current collector 1C may have a foil shape, a mesh shape, or a punched shape instead of a flat plate shape.

The positive electrode layer 2C is provided over the entire surface of the positive electrode current collector 1C. The positive electrode layer 2C can be formed of a material containing a positive electrode active material (details will be described later).

The positive electrode layer 2C has a flat plate shape, and in a plan view (FIG. 4, second from the bottom), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The dimensions of the long side and the short side of the positive electrode layer 2C are equal to the dimensions of the long side and the short side of the positive electrode current collector 1C, respectively. A notch _N2C recessed rearward is provided in a region near the left end of the front edge of the positive electrode layer 2C. A notch NN 2C recessed backward is provided in a region near the right end of the front edge of the positive electrode layer _2C . The thickness of the positive electrode layer 2C can be, for example, 20 μm to 60 μm.

The electrolyte layer (solid electrolyte layer) 3 is provided over the entire surface of the positive electrode layer 2C. The electrolyte layer 3 can be formed of a material containing a solid electrolyte (details will be described later).

The electrolyte layer 3 has a flat plate shape, and in a plan view (FIG. 4, third from the bottom), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The dimensions of the long side and the short side of the electrolyte layer 3 are equal to the dimensions of the long side and the short side of the positive electrode layer 2C, respectively. A notch N3 recessed rearward is provided in a region near the left end of the front edge of the electrolyte layer ₃ . A notch NN 3 recessed rearward is provided in a region near the right end of the front edge of the electrolyte layer ₃ . The thickness of the electrolyte layer 3 may be, for example, 10 μm to 100 μm, or may be 10 μm to 30 μm.

The negative electrode layer 2A is provided on the entire one surface of the electrolyte layer 3 . The negative electrode layer 2A can be formed of a material containing a negative electrode active material (details will be described later).

The negative electrode layer 2A has a flat plate shape, and in a plan view (FIG. 4, third from the top), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The long side and short side dimensions of the negative electrode layer 2A are equal to the long side and short side dimensions of the electrolyte layer 3, respectively. A notch _N2A recessed backward is provided in a region near the left end of the leading edge of the negative electrode layer 2A. A notch NN 2A recessed backward is provided in a region near the right end of the leading edge of the negative electrode layer _2A . The thickness of the negative electrode layer 2A can be, for example, 20 μm to 70 μm.

The negative electrode current collector 1A is provided over the entire surface of the negative electrode layer 2A, and constitutes the outermost layer on the other side in the stacking direction of the stacked structure SS. The negative electrode current collector 1A can be made of any conductive material. The negative electrode current collector 1A may be made of the same material as that of the positive electrode current collector 1C, or may be made of a material different from that of the positive electrode current collector 1C.

The negative electrode current collector 1A has a flat plate shape, and in a plan view (FIG. 4, second from the top), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The long side and short side dimensions of the negative electrode current collector 1A are equal to the long side and short side dimensions of the negative electrode layer 2A, respectively. A notch _N1A recessed rearward is provided in a region near the left end of the front edge of the negative electrode current collector 1A. A negative electrode terminal TA (described later) is connected to a region near the right end of the front edge of the negative electrode current collector 1A.

The thickness of the negative electrode current collector 1A can be, for example, 10 μm to 100 μm. The negative electrode current collector 1A may have a foil shape, a net shape, or a punched shape instead of a flat plate shape.

As shown in FIG. 3 , in the laminated structure SS, cutouts N _{2C ,} N 3 , N 2A , N 2A , N 2C , N ₃ , N 2A , N 2A , N 2C , N 2A , N 2A , N 2C , N 2A , N 2A , N 2C , N 2A , N 2A , N 2C , N 2A , N 2A , N 2A , N 2C , N _2A , N 2A and the notch N _1A constitute the notch N. In addition, the notch NN is composed of the notch NN _1C , the notch NN _2C , the notch NN ₃ , and the notch NN _2A which are provided at the same position in the width direction at the front edge of each layer and have the same plan view shape. It is

The notch N is defined by a side surface Nx and a side surface Ny facing each other in the width direction, and a rear end surface Nz connecting the side surfaces Nx and Ny. The side surfaces Nx and Ny extend in a plane perpendicular to the width direction, and the rear end surface Nz extends in a plane perpendicular to the front-rear direction. The notch NN is defined by side surfaces NNx and NNy facing each other in the width direction, and a rear end surface NNz connecting the side surfaces NNx and NNy. The side surfaces NNx and NNy extend in a plane orthogonal to the width direction, and the rear end surface NNz extends in a plane orthogonal to the front-rear direction.

The depths of the cutouts N and NN (the dimensions of the side surfaces Nx, Ny, NNx, and NNy in the front-rear direction) can be, for example, 1 mm to 20 mm. The widths of the notches N and NN (the dimensions of the rear end surfaces Nz and NNz in the width direction) can be, for example, 5 mm to 20 mm. The deeper the notches N and NN, the better the suppression of short circuits (details will be described later), but the smaller the battery reaction portion (the overlapping portion of the positive electrode layer 2C, the electrolyte layer 3, and the negative electrode layer 2A).

The positive electrode terminal TC protrudes forward from a region near the left end of the front edge of the positive electrode current collector 1C to the outside of the laminated structure SS and the positive electrode layer 2C in plan view. The negative electrode terminal TA protrudes forward from a region near the right end of the front edge of the negative electrode current collector 1A to the outside of the laminated structure SS and the negative electrode layer 2A in plan view. The outside of the stacked structural body SS in plan view means the outside of the outer edge SSp of the stacked structural body SS shown in the top view of FIG. 4 . The outer edge SSp of the laminated structure SS is the outer edge of the region where at least one of the positive electrode current collector 1C, the positive electrode layer 2C, the electrolyte layer 3, the negative electrode layer 2A, and the negative electrode current collector 1A exists, and is rectangular in plan view. The outer edges of the laminated structure SS, the positive electrode current collector 1C, the positive electrode layer 2C, the electrolyte layer 3, the negative electrode layer 2A, and the negative electrode current collector 1A mean the outer edges of the regions excluding the notches. That is, the notch of a layer is inside the outer edge of that layer.

The positive terminal TC and the negative terminal TA are rectangular in plan view with the longitudinal direction being the longitudinal direction. The positive electrode terminal TC is formed integrally with the positive electrode current collector 1C from the same material as the positive electrode current collector 1C, and has a flat plate shape (or foil shape, net shape, or punching shape). That is, the positive electrode terminal TC is configured by a part of the front end of the substantially rectangular positive electrode current collector 1C extending forward therefrom. The negative electrode terminal TA is formed integrally with the negative electrode current collector 1A from the same material as the negative electrode current collector 1A, and has a flat plate shape (or foil shape, net shape, or punching shape). That is, the negative electrode terminal TA is formed by partially extending forward from the front end of the substantially rectangular negative electrode current collector 1A.

The notch N and the positive terminal TC are provided at the same position in the width direction. Specifically, the side surface Nx is positioned on the left side of the positive terminal TC (left end), and the side surface Ny is positioned on the right side of the positive terminal TC (right end). The rear end surface Nz is located behind the rear end portion TCz of the positive terminal TC (that is, the boundary between the positive terminal TC and the positive current collector 1C). A notch N is present behind the positive electrode terminal TC over the entire widthwise region.

The notch NN and the negative terminal TA are provided at the same position in the width direction. Specifically, the side surface NNx is positioned on the left side of the left side (left end) of the negative terminal TA, and the side surface NNy is positioned on the right side of the right side (right end) of the negative terminal TA. The rear end surface NNz is located behind the rear end portion TAz of the negative terminal TA (that is, the boundary between the negative terminal TA and the negative current collector 1A). A notch NN exists behind the negative electrode terminal TA over the entire widthwise region.

Solid-state battery units 12 and 14 have the same configuration as solid-state battery units 11 and 13 except for the arrangement of positive terminal TC, negative terminal TA, and cutouts N and NN. Specifically, the positive terminal TC of the solid-state battery units 12 and 14 protrudes forward from a region near the right end of the front edge of the positive electrode current collector 1C, and the negative electrode terminal TA protrudes forward from the left end of the front edge of the negative electrode current collector 1A. Projects anteriorly from neighboring regions. The notches N and NN are provided at the same positions as the positive terminal TC and the negative terminal TA in the width direction, respectively. The positional relationship between the notch N and the positive terminal TC and the positional relationship between the notch NN and the negative terminal TA are the same as those in the solid battery units 11 and 13 .

As shown in FIGS. 2A and 2B, in the stacked solid-state battery 100, the solid-state battery unit 12 is placed on the solid-state battery unit 11 arranged with the negative electrode current collector 1A facing upward. They are stacked with the negative electrode current collector 1A facing downward. The negative electrode current collector 1A of the solid battery unit 11 and the negative electrode current collector 1A of the solid battery unit 12 are in contact with each other and are electrically connected.

The solid battery unit 13 is overlaid on the solid battery unit 12 with the positive electrode current collector 1C facing downward. The positive electrode current collector 1C of the solid battery unit 12 and the positive electrode current collector 1C of the solid battery unit 13 are in contact with each other and are electrically connected. A solid battery unit 14 is overlaid on the solid battery unit 13 with the negative electrode current collector 1A facing downward. The negative electrode current collector 1A of the solid battery unit 13 and the positive electrode current collector 1A of the solid battery unit 14 are in contact with each other and are electrically connected.

As shown in FIG. 2A, the positive terminals TC of the solid battery units 12 to 14 are bent toward the positive terminal TC of the solid battery unit 11, and their front ends are stacked on the positive terminal TC of the solid battery unit 11. ing. The front ends of the four stacked positive terminals TC are joined to the rear ends of the positive current collecting tabs 50C.

As shown in FIG. 2B, the negative terminals TA of the solid battery units 13 and 14 are bent toward the negative terminals TA of the solid battery units 11 and 12, and their front ends are above the negative terminal TA of the solid battery unit 12. piled up on The front ends of the stacked four negative terminals TA are joined to the rear ends of the negative electrode current collecting tabs 50A.

The housing 70 is made of, for example, a bag-shaped laminated film made of thermoplastic resin. The solid battery units 11 to 14 and the regions near the rear end portions of the positive electrode current collecting tab 50C and the negative electrode current collecting tab 50A are accommodated in a sealed state and thermocompression bonded to form the stacked solid battery 100 as a pouch-type solid battery. obtain. Regions near the front end portions of the positive electrode current collecting tab 50C and the negative electrode current collecting tab 50A are arranged outside the housing 70 and constitute an external positive electrode terminal C and an external negative electrode terminal A, respectively.

In the stacked solid-state battery 100 having the above configuration, the positive terminals TC of the solid-state battery units 11 to 14 are electrically connected to each other and connected to the external positive terminal C. As shown in FIG. Further, the negative terminals TA of the solid battery units 11 to 14 are electrically connected to each other and connected to the external negative terminal A. That is, in the stacked solid-state battery 100, the solid-state battery units 11 to 14 are connected in parallel using the external positive terminal C and the external negative terminal A as terminals for external connection.

Advantageous effects of the solid-state battery units 11 to 14 and the stacked solid-state battery 100 of the first embodiment are summarized below.

In the solid-state battery units 11 to 14 of the present embodiment, a notch N is provided at a position where the positive terminal TC protrudes when viewed in the stacking direction, and a notch NN is provided at a position where the negative terminal TA protrudes. can be suppressed to

Specifically, due to the presence of the notch N at the position where the positive electrode terminal TC protrudes, the negative electrode current collector 1A and the negative electrode layer 2A are located at the position where the positive electrode terminal TC exists when viewed in the stacking direction. It is recessed to the inner side of the rear end portion TCz. In addition, due to the presence of the notch NN at the position where the negative electrode terminal TA protrudes, the positive electrode current collector 1C and the positive electrode layer 2C are located at the position where the negative electrode terminal TA is present when viewed in the stacking direction, and the positive electrode current collector 1C and the positive electrode layer 2C are located at the rear end portion of the negative electrode terminal TA. It is recessed to the inner side of TAz.

Therefore, even when the positive terminals TC of the plurality of stacked solid-state battery units 11 to 14 are bent in the stacking direction in order to collect the positive terminals TC, there is no gap between the positive terminal TC and the negative electrode current collector 1A and the negative electrode layer 2A. are sufficiently spaced to prevent them from touching and shorting. Similarly, even when the negative terminals TA of the plurality of stacked solid-state battery units 11 to 14 are bent in the stacking direction in order to collect the negative terminals TA, the negative electrode terminals TA, the positive current collector 1C, and the positive electrode layer 2C Sufficient spacing is ensured between them to prevent them from contacting and short-circuiting.

More specifically, the region 1C _fx behind the rear end TCz of the positive electrode terminal TC (the region of the positive electrode current collector 1C near the positive electrode terminal TC; the top diagram in FIG. 4) is a notch N are supported (constrained) by the laminated structure SS around the side surfaces Nx, Ny and the rear end surface Nz. Therefore, the region 1C _fx does not move even when the positive terminal TC is bent or curved. That is, the portion on the positive electrode side that moves in the stacking direction when the positive electrode terminals TC of the plurality of solid battery units 11 to 14 are brought together and joined is only the portion on the front side of the rear end portion TCz of the positive electrode terminal TC. On the other hand, the front edge of the negative electrode current collector 1A and the negative electrode layer 2A is the rear end surface Nz of the notch N, and is located behind the rear end portion TCz of the positive terminal TC.

Similarly, a region 1A _fx behind the rear end portion TAz of the negative electrode terminal TA (a region near the negative electrode terminal TA of the negative electrode current collector 1A; the top diagram in FIG. 4) is a region around the notch NN. It is supported (constrained) by the laminated structure SS at the positions of the side surfaces NNx, NNy and the rear end surface NNz. Therefore, the region 1A _fx does not move even when the negative terminal TA is bent or curved. That is, the portion on the negative electrode side that moves in the stacking direction when the negative terminals TA of the plurality of solid battery units 11 to 14 are joined is only the portion on the front side of the rear end portion TAz of the negative electrode terminal TA. On the other hand, the front edge of the positive electrode current collector 1C and the positive electrode layer 2C is the rear end surface NNz of the notch NN, and is located behind the rear end portion TAz of the negative electrode terminal TA.

2 and 4, the positions of the rear end portion TCz of the positive terminal TC and the rear end portion TAz of the negative terminal TA in the front-rear direction are indicated by a dashed line P1, and the rear end faces Nz and NNz of the notches N and NN in the front-rear direction. is indicated by a dashed line P2.

As described above, in this embodiment, at a position overlapping the terminal of one pole in the stacking direction, the front edge of the current collector or the like of the other pole is attached to the movable region (unconstrained region) of the one pole. In this case, the entire terminal) is arranged behind the rear end of the terminal. Therefore, even if the terminal of one pole moves (for example, bends or bends) in the stacking direction, a sufficient gap is maintained between the terminal of one pole and the current collector of the other pole. A short circuit is unlikely to occur between

A method for manufacturing the stacked solid-state battery 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG.

(1) Manufacture of Solid Battery Units 11 to 14 A member in which the positive electrode current collector 1C and the positive electrode terminal TC are integrated by punching out a thin plate of a conductive material, and a notch NN _1C is formed (FIG. 5(a)). Then, a member (FIG. 5(b)) in which the negative electrode current collector 1A and the negative electrode terminal TA are integrated and a notch _N1A is formed is prepared. 5(a) and 5(b), the positive terminal TC and the negative terminal TA are formed at the positions of the terminals of the solid battery units 11 and 13, respectively. In manufacturing the solid-state battery units 12 and 14, the positive terminal TC and the negative terminal TA are formed at the terminal positions of the solid-state battery units 12 and 14, respectively.

Next, a mixture is prepared by dispersing a positive electrode mixture containing a positive electrode active material and a solid electrolyte in a solvent. Then, this mixture is applied to the entire one surface of the positive electrode current collector 1C by wet coating or the like, and dried. As a result, a positive electrode layer 2C having cutouts _N2C and cutouts _NN2C is formed on one side of the positive electrode current collector 1C (FIG. 5(c)). Similarly, a mixture is prepared by dispersing a negative electrode mixture containing a negative electrode active material, a solid electrolyte, etc. in a solvent, and this mixture is applied to the entire surface of the negative electrode current collector 1A by wet coating or the like, and dried. As a result, a negative electrode layer 2A having cutouts _N2A and cutouts _NN2A is formed on the upper surface of the negative electrode current collector 1A (FIG. 5(d)).

Next, an electrolyte layer mixture containing a solid electrolyte is applied to the entire surface of the positive electrode layer 2C to form an electrolyte layer 3 having cutouts _N3 and _NN3 (FIG. 5(e)). Finally, the electrolyte layer 3 and the negative electrode layer 2A are pressed against each other. As described above, a solid battery unit (FIG. 3) including the laminated structure SS, the positive terminal TC, and the negative terminal TA is obtained.

(2) Assembly of Stacked Solid Battery 100 The solid battery units 11 to 14 are stacked in this order so that the positive electrode current collectors 1C and the negative electrode current collectors 1A are in contact with each other. Next, the front ends of the positive terminals TC of the solid battery units 11 to 14 and the rear ends of the positive current collecting tabs 50C are joined together, and the front ends of the negative terminals TA of the solid battery units 11 to 14 and the rear ends of the negative current collecting tabs 50A are joined together. are joined together (FIGS. 2(a) and 2(b)). Next, the solid battery units 11 to 14, the cathode collector tab 50C, and the vicinity of the rear ends of the anode collector tab 50A are placed in a housing 70 (laminated film as an example) and sealed by thermocompression bonding or the like. As described above, the stacked solid-state battery 100 is obtained.

According to the manufacturing method of the present embodiment, it is possible to easily manufacture the solid state battery units 11 to 14 in which the occurrence of short circuits is suppressed, and the stacked solid state battery 100 including the same.

In the above-described first embodiment, the notch N _2C in the positive electrode layer 2C, the notch N ₃ in the electrolyte layer 3, the notch N _2A in the negative electrode layer 2A, and the notch N _1A in the negative electrode current collector 1A. Although the notch N is configured, it is not limited to this. The notch N2C of the positive electrode layer _2C and the notch _N3 of the electrolyte layer 3 may be omitted, and the notch N may be formed by the notch N2A of the negative electrode layer _2A and the notch _N1A of the negative electrode current collector 1A. good. Also in this case, the short circuit between the positive terminal TC and the counter electrode is suppressed. In _this case, for example, when obtaining the laminated structure of the negative electrode current collector 1A and the negative electrode layer _2A shown in FIG. The negative electrode layer 2A may be formed.

Similarly, in the above first embodiment, the notch NN _1C of the positive electrode current collector 1C, the notch NN _2C of the positive electrode layer 2C, the notch NN ₃ of the electrolyte layer 3, and the notch NN 2A of the negative electrode layer _2A Although the notch NN is configured, it is not limited to this. The notch NN 2A of the negative electrode layer _2A and the notch NN ₃ of the electrolyte layer 3 may be omitted, and the notch NN may be configured by the notch NN _1C of the positive electrode current collector 1C and the notch NN _2C of the positive electrode layer 2C. good. Also in this case, the short circuit between the negative terminal TA and the counter electrode is suppressed. In this case, for example, when obtaining the laminated structure of the positive electrode current collector _1C and the positive electrode layer _2C shown in FIG. The positive electrode layer 2C may be formed.

In the first embodiment described above, the shape of the cutouts N and NN in plan view can be changed arbitrarily. Specifically, for example, the planar shape of the notches N and NN may be a backward recessed arc shape or a backward recessed V shape.

In the first embodiment described above, either one of the notch N and the notch NN may be omitted.

<Second embodiment>
A stacked solid-state battery 200 and solid-state battery units 15 to 18 according to a second embodiment of the present invention will be described with reference to FIGS. 1 and 6 to 8. FIG.

The stacked solid-state battery 200 of the second embodiment has solid-state battery units 15-18 instead of the solid-state battery units 11-14. The solid-state battery units 15 to 18 are provided with recesses R and RR (described later) instead of the notches N and NN, and the positive terminal and the negative electrode terminal are provided inside the recesses R and RR in plan view. It is the same as the solid battery units 11 to 14 except that the solid battery units 11 to 14 are provided. Differences from the stacked solid-state battery 100 and the solid-state battery units 11 to 14 of the first embodiment will be described below. Items not described are the same as those of the stacked solid-state battery 100 and the solid-state battery units 11 to 14 of the first embodiment.

As shown in FIG. 7, the solid battery units 15 and 17 of the second embodiment include a positive electrode current collector (positive electrode current collector layer) 5C, a positive electrode layer 6C, an electrolyte layer (solid electrolyte layer) 7, a negative electrode layer 6A, and A laminated structure SS2 in which the negative electrode collector (negative collector layer) 5A is laminated in this order, a positive electrode terminal TC2 projecting from the positive electrode collector 5C in a direction orthogonal to the lamination direction of the laminated structure SS2, It mainly has a negative electrode terminal TA2 protruding from the negative electrode current collector 5A in a direction perpendicular to the stacking direction of the laminated structure SS2.

The positive electrode current collector 5C has a flat plate shape, and in plan view (at the bottom in FIG. 8), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. A concave portion _R5C recessed backward is provided in a region near the left end of the front edge of the positive electrode current collector 5C, and the positive electrode terminal TC2 protrudes forward from the rear end surface of the concave portion _R5C . A recess RR5C recessed backward is provided in a region near the right end of the front edge of the positive electrode current collector _5C .

The positive electrode layer 6C has a flat plate shape, and in a plan view (FIG. 8, second from the bottom), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The dimensions of the long side and the short side of the positive electrode layer 6C are equal to the dimensions of the long side and the short side of the positive electrode current collector 5C, respectively. A recess R6C recessed backward is provided in a region near the left end of the front edge of the positive electrode layer _6C . A recess RR6C recessed backward is provided in a region near the right end of the front edge of the positive electrode layer _6C .

The electrolyte layer 7 has a flat plate shape, and in a plan view (FIG. 8, third from the bottom), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The dimensions of the long side and the short side of the electrolyte layer 7 are equal to the dimensions of the long side and the short side of the positive electrode layer 6C, respectively. A recess R ₇ recessed backward is provided in a region near the left end of the front edge of the electrolyte layer 7 . A recess RR ₇ recessed backward is provided in a region near the right end of the front edge of the electrolyte layer 7 .

The negative electrode layer 6A has a flat plate shape, and in a plan view (FIG. 8, third from the top), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. The long side and short side dimensions of the negative electrode layer 6A are equal to the long side and short side dimensions of the electrolyte layer 7, respectively. A recess R _{6A recessed backward is provided in a region near the left end of the front edge of the negative electrode layer 6A} . A recess RR 6A recessed backward is provided in a region near the right end of the front edge of the negative electrode layer _6A .

The negative electrode current collector 5A has a flat plate shape, and in a plan view (FIG. 8, second from the top), has a substantially rectangular shape with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. A concave portion R 5A recessed backward is provided in a region near the left end of the front edge of the negative electrode current collector _5A . A concave portion RR _5A recessed backward is provided in a region near the right end of the front edge of the negative electrode current collector 5A, and the negative electrode terminal TA2 protrudes forward from the surface defining the rear end portion of the concave portion RR _5A . .

As shown in FIG. 7, in the laminated structure SS2, recesses R _6C , R ₇ , R _6A , and R , which are provided at the same position in the width direction at the front edge of each layer and have the same plan view shape, are A concave portion R is configured by _5A . Further, recesses RR are formed by recesses RR _5C , RR _6C , RR ₇ , and RR _6A which are provided at the same position in the width direction at the front edge of each layer and have the same plan view shape.

The recess R is defined by a side surface Rx and a side surface Ry facing each other in the width direction, and a rear end surface Rz connecting the side surfaces Rx and Ry. The side surfaces Rx and Ry extend in a plane perpendicular to the width direction, and the rear end surface Rz extends in a plane perpendicular to the front-rear direction. The recess RR is defined by a side surface RRx and a side surface RRy facing each other in the width direction, and a rear end surface RRz (top view in FIG. 8) connecting the side surfaces RRx and RRy. The side surfaces RRx and RRy extend in a plane perpendicular to the width direction, and the rear end surface RRz extends in a plane perpendicular to the front-rear direction.

The depths of the recesses R and RR (the dimensions of the side surfaces Rx, Ry, RRx and RRy in the front-rear direction) can be, for example, 3 mm to 25 mm. The widths of the recesses R and RR (the dimensions of the rear end surfaces Rz and RRz in the width direction) can be, for example, 5 mm to 20 mm.

The positive electrode terminal TC2 protrudes forward from the rear end surface of the recess R5C of the positive electrode current collector _5C to the outside of the laminated structure SS2 and the positive electrode layer 6C in plan view. The negative electrode terminal TA2 protrudes forward from the rear end surface of the recessed portion RR5A of the negative electrode current collector _5A to the outside of the laminated structure SS2 and the negative electrode layer 6A in plan view. The outside of the stacked structural body SS2 in plan view means the outside of the outer edge SS2p of the stacked structural body SS2 shown in the top view of FIG. The outer edge SS2p of the laminated structure SS2 is the outer edge of the region in which at least one of the positive electrode current collector 5C, the positive electrode layer 6C, the electrolyte layer 7, the negative electrode layer 6A, and the negative electrode current collector 5A exists, and is located at two locations in plan view. is a substantially rectangular shape recessed inward.

The positive terminal TC2 and the negative terminal TA2 are rectangular in plan view with the front-rear direction as the longitudinal direction. The positive electrode terminal TC2 is formed integrally with the positive electrode current collector 5C from the same material as the positive electrode current collector 5C, and has a flat plate shape (or foil shape, net shape, or punching shape). The negative electrode terminal TA2 is formed integrally with the negative electrode current collector 5A from the same material as the negative electrode current collector 5A, and has a flat plate shape (or foil shape, mesh shape, or punching shape).

As shown in FIGS. 7 and 8, the recess R and the positive terminal TC2 are provided at the same position in the width direction. Specifically, the side surface Rx is positioned on the left side of the left side (left end) of the positive terminal TC2, and the side surface Ry is positioned on the right side of the right side (right end) of the positive terminal TC2. The recess _R5C is shallower than the recess R, and the rear end face Rz of the recess R is positioned behind the rear end TC2z of the positive terminal TC2 (that is, the boundary between the positive terminal TC2 and the positive current collector 5C). A region of the recess R on the far side (rear) of the rear end portion TC2z substantially corresponds to the notch N in the first embodiment, and is located inside the laminated structure SS2 and the outer edges of each layer. In plan view, the positive terminal TC2 protrudes forward from the positive electrode current collector 5C inside the recess R and extends to the outside of the recess R. As shown in FIG.

As shown in FIGS. 7 and 8, the recess RR and the negative terminal TA2 are provided at the same position in the width direction. Specifically, the side surface RRx is positioned on the left side of the left side (left end) of the negative terminal TA2, and the side surface RRy is positioned on the right side of the right side (right end) of the negative terminal TA2. The recess RR _5A is shallower than the recess RR, and the rear end surface RRz (FIG. 8, top view) of the recess RR is the rear end TA2z of the negative terminal TA2 (that is, the gap between the negative terminal TA2 and the negative current collector 5A). border). A region of the recess RR on the far side (rear) of the rear end portion TA2z substantially corresponds to the notch NN in the first embodiment, and is located inside the laminated structure SS2 and the outer edges of each layer. In plan view, the negative terminal TA2 protrudes forward from the negative electrode current collector 5A inside the recess RR and extends to the outside of the recess RR.

Solid-state battery units 16 and 18 have the same configuration as solid-state battery units 15 and 17 except for the arrangement of positive terminal TC2, negative terminal TA2, and recesses R and RR. Specifically, the positive terminal TC2 of the solid-state battery units 16 and 18 is provided near the right end of the front edge of the positive electrode current collector 5C, and the negative terminal TA2 is provided near the left end of the front edge of the negative electrode current collector 5A. It is The recesses R and RR are provided at locations where the positive terminal TC2 and the negative terminal TA2 protrude, respectively. The positional relationship between the recess R and the positive terminal TC2 and the positional relationship between the recess RR and the negative terminal TA2 are the same as those in the solid battery units 15 and 17 .

With the solid battery units 15 to 18 and the stacked solid battery 200 of the second embodiment, short circuits can be easily suppressed as in the first embodiment.

Specifically, the region 5C _fx behind the rear end portion TC2z of the positive electrode terminal TC2 (the region near the positive electrode terminal TC2 of the positive electrode current collector 5C; the top diagram in FIG. 8) is the periphery of the recess R are supported (restrained) at the positions of the side surfaces Rx, Ry and the rear end surface Rz by the laminated structure SS2. Therefore, the region 5C _fx does not move even when the positive terminal TC2 is bent or curved. That is, the part on the positive electrode side that moves in the stacking direction when the positive terminals TC2 of the plurality of solid battery units 15 to 18 are brought together and joined is only the part on the front side of the rear end TC2z of the positive terminal TC2. On the other hand, the front edge of the negative electrode current collector 5A and the negative electrode layer 6A is the rear end surface Rz of the recess R, and is located behind the rear end portion TC2z of the positive electrode terminal TC.

Similarly, the region 5A _fx behind the rear end portion TA2z of the negative electrode terminal TA2 (the region of the negative electrode current collector 5A near the negative electrode terminal TA2; the top diagram in FIG. It is supported (constrained) by the structure SS2 at the positions of the side surfaces RRx, RRy and the rear end surface RRz. Therefore, the region 5A _fx does not move even when the negative terminal TA2 is bent or curved. That is, the portion on the negative electrode side that moves in the stacking direction when connecting the negative electrode terminals TA2 of the plurality of solid battery units 15 to 18 is only the portion on the front side of the rear end portion TA2z of the negative electrode terminal TA2. On the other hand, the front edge of the positive electrode current collector 5C and the positive electrode layer 6C is the rear end surface RRz of the recess RR, which is located behind the rear end TA2z of the negative terminal TA2.

6 and 8, the positions of the rear end portion TC2z of the positive electrode terminal TC2 and the rear end portion TA2z of the negative electrode terminal TA2 in the front-rear direction are indicated by a dashed line P3. The position is indicated by a one-dot chain line P4.

As described above, in the present embodiment as well, the front edge of the current collector or the like of the other pole is placed in a movable region (unconstrained region. Here, the entire terminal is ) is located behind the rear end of the Therefore, even if the terminal of one pole moves (for example, bends or bends) in the stacking direction, a sufficient gap is maintained between the terminal of one pole and the current collector of the other pole, preventing a short circuit. is difficult to occur.

Further, in this embodiment, the positive terminals TC2 of the solid battery units 15 to 18 can be gathered inside the recess R, and the negative terminals TA2 can be gathered inside the recess RR. Therefore, the dimension in the front-rear direction of the stacked solid-state battery 200 can be reduced, and the volumetric energy density can be improved.

The solid battery units 15-18 of the second embodiment can also be manufactured by the same procedure as the solid battery units 11-14 of the first embodiment.

<Modification>
In each of the above embodiments, the following modifications can also be used.

In the first and second embodiments, four battery units constitute the stacked solid-state batteries 100 and 200, but the present invention is not limited to this. The number of battery units included in the stacked solid-state batteries 100 and 200 is arbitrary.

In the stacked solid-state battery 100 of the first embodiment, the solid-state battery units 12, 13, and 14 are sequentially stacked on the solid-state battery unit 11 arranged with the negative electrode current collector layer 1A facing upward. is not limited. Solid battery units 12, 13, and 14 may be sequentially stacked on solid battery unit 11 arranged with positive electrode current collector 1C facing upward. The same applies to the stacked solid-state battery 200 of the second embodiment.

In the laminated structures SS and SS2 of the first and second embodiments, the layers forming the laminated structures SS and SS2 have the same planar shape and dimensions, but the present invention is not limited to this. For example, the sizes of the negative electrode layers 2A and 6A and the negative electrode current collectors 1A and 5A in plan view may be larger than the sizes of the positive electrode layers 2C and 6C and the positive electrode current collectors 1C and 5C in plan view.

Specifically, for example, as shown in FIG. 9, the front edges of the negative electrode current collector 1A, the negative electrode layer 2A, and the electrolyte layer 3 are located forward of the front edges of the positive electrode current collector 1C and the positive electrode layer 2C. can be used. In such a mode, as shown in FIG. 9, the notch _N1A of the negative electrode current collector 1A and the notch _N2A of the negative electrode layer 2A are arranged such that the rear end surfaces thereof are located behind the rear end portion TCz of the positive electrode terminal TC. , the short circuit between the positive electrode terminal TC and the negative electrode current collector 1A and the negative electrode layer 2A can be suppressed.

In the first and second embodiments, the battery units are stacked with the positive electrode current collectors and the negative electrode current collectors in contact with each other, but the present invention is not limited to this. In a plurality of battery units, one of the positive electrode current collector and the negative electrode current collector of one battery unit and the other of the positive electrode current collector and the negative electrode current collector of the battery unit stacked thereon are separated by insulating separators ( They may be overlapped so as to face each other with an insulating film, an insulating plate) interposed therebetween.

In the first and second embodiments, a pair of positive electrode current collectors or a pair of negative electrode current collectors in contact with each other are electrically connected. Therefore, in each embodiment, a pair of positive electrode current collectors or a pair of negative electrode current collectors in contact with each other may be formed as a single-layer positive electrode current collector or a single-layer negative electrode current collector. In the present invention, "a laminated structure in which a positive electrode current collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector layer are laminated in this order" means a positive electrode current collector separable from other battery units. When having a body layer and/or a negative electrode current collector layer, the positive electrode current collector layer and/or the negative electrode current collector layer shared with the adjacent battery unit (i.e., the positive electrode current collector layer of the adjacent battery unit, the negative electrode current collector layer It includes both cases of having a positive electrode current collector layer and a negative electrode current collector layer integrated with or formed into a single layer with the current collector layer.

<Material>
Materials constituting the electrolyte layers 3 and 7, the positive electrode layers 2C and 6C, and the negative electrode layers 2A and 6A of the first and second embodiments are described below.

[Electrolyte layers 3 and 7]
Electrolyte layers 3 and 7 contain a solid electrolyte. Solid electrolytes can be, for example, sulfide solid electrolytes, oxide solid electrolytes or polymer electrolytes. The sulfide solid electrolyte contains at least lithium and sulfur, for example, Li ₂ SP ₂ S ₅ system (Li ₇ P ₃ S ₁₁ , Li ₃ PS ₄ , Li ₈ P ₂ S ₉ , etc.), Li ₂ S -SiS ₂ , LiI-Li ₂ S-SiS ₂ , LiI-Li ₂ SP ₂ S ₅ , LiI-LiBr-Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -GeS ₂ (Li ₁₃ GeP ₃ S ₁₆ , Li ₁₀ GeP ₂ S ₁₂ etc.), LiI-Li ₂ SP ₂ O ₅ , LiI-Li ₃ PO ₄ -P ₂ S ₅ , Li _7-x PS _6-x Cl _x etc. can be used.

Oxide solid electrolytes contain at least lithium _and oxygen, and can be classified into nasicon _type , _{perovskite type} , garnet type, _etc. by crystal structure _{. AlxGe2 -x} ( _{PO4 ) 3} , _{Li3xLa2 / 3- xTiO3 , Li7La3Zr2O12 ,} Li7 _{- xLa3Zr1 - xNbxO12, Li7- 3x} La ₃ Zr ₂ Al _x O ₁₂ , Li ₃ PO ₄ , or Li _3+x PO _4-x N _x (LiPON) or the like can be used. Among them, an oxide solid electrolyte having a garnet-type structure or a garnet-like structure containing at least Li, La, Zr and O is preferable. In particular, Li ₇ La ₃ Zr ₂ O ₁₂ (hereinafter referred to as “LLZ”) and LLZ elementally substituted with at least one of Mg and A (“A” is Ca, Sr, Ba or a combination thereof) (hereinafter referred to as "substituted LLZ") is preferred. Powders composed of LLZ or substituted LLZ electrolytes are called "LLZ powders".

When LLZ powder is used as the solid electrolyte for the electrolyte layers 3 and 7, it is preferable to further contain a lithium ion conduction aid. The lithium ion conduction aid contains an ionic liquid having lithium ion conductivity. An ionic liquid having lithium ion conductivity is, for example, an ionic liquid in which a lithium salt is dissolved. Note that the ionic liquid is a substance that consists of only cations and anions and is liquid at room temperature. Examples of the lithium salt include lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium perchlorate (LiClO ₄ ), lithium trifluoromethanesulfonate (Li(SO ₃ CF ₃ )), lithium bis(trifluoromethanesulfonyl)imide (LiN(SO ₂ CF ₃ ) ₂ ), lithium bis(fluorosulfonyl)imide (LiN(SO ₂ F) ₂ ) (hereinafter referred to as “LiFSI”), lithium bis (Pentafluoroethanesulfonyl) imide (LiN(SO ₂ C ₂ F ₅ ) ₂ ) and the like are used.

Examples of the ionic liquid include cations such as ammonium-based butyltrimethylammonium and trimethylpropylammonium, imidazolium-based 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium, and 1-butyl- Piperidinium compounds such as 1-methylpiperidinium and 1-methyl-1-propylpiperidinium, pyridinium compounds such as 1-butyl-4-methylpyridinium and 1-ethylpyridinium, and 1-butyl-1-methylpyrrolidinium , 1-methyl-1-propylpyrrolidinium and the like, sulfonium-based compounds such as trimethylsulfonium and triethylsulfonium, phosphonium-based compounds, morpholinium-based compounds, and the like are used.

In addition, as the above-mentioned ionic liquid, as anions, halides such as Cl ⁻ and Br ^{− ,} borides such as BF ₄ ⁻ , (NC) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (FSO ₂ ) Amines such as _2N- ^, sulfates and sulfonates such _{as CH3SO4- and CF3SO3-, phosphoric acids such as PF6- ,} ^{and the} _{like are} ^used _.

More specifically, as the ionic liquid, butyltrimethylammonium bis(trifluoromethanesulfonyl)imide, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, 1 -Ethyl-3-methylimidazolium tetrafluoroborate, 1-methyl-1-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, etc. are used. . When the LLZ-based powder is press-molded by containing the lithium-ion conductive aid, it intervenes in the grain boundaries of the LLZ-based powder to improve the lithium-ion conductivity at the grain boundaries.

The electrolyte layers 3 and 7 may contain a binder. Examples of binders include polyvinylidene fluoride, a copolymer of polyvinylidene fluoride and hexafluoropropylene (PVDF-HFP), polytetrafluoroethylene, polyimide, polyamide, silicone, styrene-butadiene rubber, acrylic resin, and polyethylene oxide. Used. Examples of additives such as LLZ powders (ion conductive powders), ionic liquids, and binders as described above are disclosed in, for example, Japanese Patent No. 6682708, and their use in the solid battery unit of the present invention can be done.

[Positive electrode layers 2C and 6C]
The positive electrode layers 2C and 6C contain a positive electrode active material, and may further contain additives such as solid electrolytes, lithium ion conduction aids, electron conduction aids, and binders that constitute the electrolyte layers 3 and 7 described above. Examples of positive electrode active materials include S, TiS ₂ , LiCoO ₂ , LiNiO ₂ , LiNi _1-x-y Co _{x Aly} O ₂ , LiNi _1-x-y Co _x Mny _{O 2} , LiMn ₂ O ₄ , _LiFePO4 etc. are mentioned. The ionic liquid having lithium ion conductivity described above may be included as a lithium ion conduction aid. The solid electrolyte also functions as a lithium ion conduction aid. As an electron conduction aid, an electron conduction aid such as conductive carbon, Ni, Pt, Ag can be used. As the binder, the same binder that can be included in the solid electrolyte layer can be used.

[Negative electrode layers 2A and 6A]
The negative electrode layers 2A, 6A contain a negative electrode active material, and may further contain additives such as solid electrolytes, lithium ion conduction aids, electron conduction aids, and binders that constitute the electrolyte layers 3, 7 described above. Examples of negative electrode active materials include Li metal, Li—Al alloy, Li ₄ Ti ₅ O ₁₂ , carbon, Si, and SiO. Lithium ion conduction aids may include the aforementioned ionic liquids having lithium ion conductivity. The solid electrolyte also functions as a lithium ion conduction aid. As an electron conduction aid, an electron conduction aid such as conductive carbon, Ni, Pt, Ag can be used. As the binder, the same binder that can be included in the solid electrolyte layer can be used.

Although the stacked solid-state battery and the manufacturing method thereof according to the present invention have been described above using the embodiments and examples, the technical scope of the present invention is not limited to the above range. It is obvious to those skilled in the art that various changes or improvements are added to the above-described embodiments and examples, and the forms with such changes or improvements can also be included in the technical scope of the present invention. It is also clear from the description of

The execution order of each process in the manufacturing method shown in the specification and drawings is not specified in particular, and unless the output of the previous process is used in the subsequent process, it can be executed in any order. I can. For the sake of convenience, "first", "next", etc. are used for explanation, but it does not mean that it is essential to carry out in this order.

1A, 5A negative electrode current collectors 1C, 5C positive electrode current collectors 2A, 6A negative electrode layers 2C, 6C positive electrode layers 3, 7 electrolyte layers 50A negative electrode current collecting tab 50C positive electrode current collecting tab 70 housings 100, 200 stacked solid battery N , NN notch R, RR recess SS, SS2 laminated structure TA, TA2 negative terminal TC, TC2 positive terminal

Claims (4)

A solid state battery unit,
A laminated structure in which a positive electrode current collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode current collector layer are laminated in this order,
The positive electrode current collector layer has a positive electrode terminal projecting outward from the positive electrode layer when viewed in the stacking direction of the laminated structure,
The negative electrode current collector layer has a negative electrode terminal projecting outward from the negative electrode layer at a position different from the positive electrode terminal when viewed in the stacking direction,
When viewed in the stacking direction, the negative electrode current collector layer and the negative electrode layer corresponding to a portion where the positive electrode terminal protrudes are in the direction in which the positive electrode terminal protrudes from the boundary between the positive electrode terminal and the positive electrode current collector layer. is recessed in the opposite direction, and / or the positive electrode current collector layer and the positive electrode layer corresponding to the location where the negative electrode terminal protrudes are located from the boundary between the negative electrode terminal and the negative electrode current collector layer. A solid-state battery unit that is recessed in the direction opposite to the projecting direction of the . A recessed region is defined in which an outer edge of the stacked structure viewed in the stacking direction is recessed inward,
2. The method according to claim 1, wherein the positive electrode terminal protrudes from the positive electrode current collector layer in the recessed region and/or the negative electrode terminal protrudes from the negative electrode current collector layer in the recessed region when viewed in the stacking direction. Solid state battery unit. the positive electrode current collector layer, the positive electrode layer, the negative electrode layer, and the negative electrode current collector layer have the same size when viewed in the stacking direction;
The negative electrode current collector layer and the negative electrode layer are recessed from the boundary between the positive electrode terminal and the positive electrode current collector layer in a direction opposite to the direction in which the positive electrode terminal projects, at a portion where the positive electrode terminal projects, and 2. The positive electrode current collector layer and the positive electrode layer are recessed from the boundary between the negative electrode terminal and the negative electrode current collector layer in a direction opposite to the projection direction of the negative electrode terminal at a portion where the negative electrode terminal protrudes. 3. The solid battery unit according to 2. When viewed in the stacking direction, the negative electrode layer and the negative electrode current collector layer are larger than the positive electrode layer and the positive electrode current collector layer,
2. The negative electrode current collector layer and the negative electrode layer are recessed from a boundary between the positive electrode terminal and the positive electrode current collector layer at a location where the positive electrode terminal protrudes in a direction opposite to the projecting direction of the positive electrode terminal. 3. or the solid battery unit according to 2.

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