JP2023032294A - Lamination type solid-state battery and manufacturing method of them - Google Patents

Abstract

An object of the present invention is to provide a stacked solid-state battery in which terminals are less likely to be damaged. A stacked solid-state battery includes a plurality of battery units stacked on top of each other. Each of the plurality of battery units includes a laminated structure in which a positive electrode collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode collector layer are laminated in this order; It has a positive electrode terminal extending in a direction crossing the stacking direction of the laminated structure, and a negative electrode terminal extending from the negative electrode current collector layer in a direction crossing the stacking direction. In at least one pair of adjacent battery units among the plurality of battery units, the stacked solid-state battery includes a conductive positive electrode spacer sandwiched in contact with the positive electrode terminal and a conductive positive electrode spacer in contact with the negative electrode terminal. Further comprising at least one of the sandwiched electrically conductive anode spacers. [Selection drawing] Fig. 2

Description

TECHNICAL FIELD The present invention relates to a stacked solid-state battery and a method for manufacturing a stacked solid-state battery.

2. Description of the Related Art Solid-state batteries used as power sources for electronic devices come in various shapes such as coin-type, cylindrical-type, square-type, and pouch-type. Among these, pouch-type solid-state batteries are widely used because they have a high degree of freedom in shape and are lightweight.

As pouch-type solid batteries, there are known a wound type in which an electrode element composed of a positive electrode, a separator, and a negative electrode is wound, and a laminated type in which a plurality of electrode elements are stacked, and the laminated type is the mainstream. It's becoming Stacked solid-state batteries are described, for example, in Patent Documents 1 to 3.

Patent No. 4095912 specification Patent No. 5191993 Patent No. 5430591 specification

Each of the stacked solid-state batteries described in Patent Documents 1 to 3 has a shape in which terminals protrude from each of the positive electrode and the negative electrode. Therefore, for example, when a large force is applied from the outside, there is a risk that the terminals will be damaged, causing problems such as a short circuit or a decrease in capacity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a stacked solid-state battery in which terminals are less likely to be damaged, and a method for manufacturing the same.

According to a first aspect of the invention,
A stacked solid-state battery,
comprising a plurality of battery units superimposed on each other,
each of the plurality of battery units,
a laminated structure in which a positive electrode collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode collector layer are laminated in this order;
a positive electrode terminal extending from the positive electrode current collector layer in a direction crossing the lamination direction of the laminated structure;
a negative electrode terminal extending in a direction intersecting with the stacking direction from the negative electrode current collector layer;
In at least one pair of adjacent battery units among the plurality of battery units, a conductive positive electrode spacer in contact with and sandwiched between the positive electrode terminals and a conductive spacer in contact with and sandwiched between the negative electrode terminals. A stacked solid state battery is provided that further comprises at least one of the negative electrode spacers.

In the stacked solid-state battery of the first aspect, the plurality of battery units are superimposed such that the positive electrode current collectors and/or the negative electrode current collectors of two adjacent battery units are in contact with each other. Alternatively, the conductive positive electrode spacer may be positioned between the positive terminals of the two adjacent battery units where the negative electrode current collectors abut, and/or the positive electrode current collectors may The conductive negative electrode spacer may be positioned between the negative terminals of the two adjacent battery units in contact.

In the stacked solid-state battery of the first aspect, when viewed in the stacking direction, the conductive positive electrode spacer is a connection region between a positive electrode current collecting tab for connecting the stacked solid-state battery to the outside and the positive electrode terminal. and/or the conductive negative electrode spacer may be located in a connection region between a negative electrode current collecting tab for connecting the stacked solid state battery to the outside and the negative electrode terminal.

In the stacked solid-state battery of the first aspect, the conductive positive electrode spacer and/or the conductive negative electrode spacer may be separate members from the positive electrode terminal and the negative electrode terminal.

In the stacked solid-state battery of the first aspect, the conductive positive electrode spacer is formed integrally with the positive electrode terminal of at least one of the plurality of battery units, and is folded back from the tip of the positive electrode terminal to form the positive electrode. may have a laminated structure including at least a first layer in contact with a terminal, and/or the conductive negative electrode spacer is integrally formed with the negative electrode terminal of at least one of the plurality of battery units; It may have a laminated structure including at least a first layer that is folded back from the tip of the negative electrode terminal and contacts the negative electrode terminal.

The stacked solid-state battery of the first aspect further includes a current-collecting tab for connecting the stacked solid-state battery to the outside, wherein the current-collecting tab connected to either one of the positive electrode terminal and the negative electrode terminal is further provided. The conductive positive electrode spacer and/or the conductive negative electrode spacer are integrally formed with the current collecting tab and folded back from one end of the current collecting tab to abut on the current collecting tab. It may have a laminated structure including at least the first layer.

In the stacked solid-state battery of the first aspect, in each of the plurality of battery units, 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 and/or the negative terminal may be positioned in the recessed region when viewed in the stacking direction.

According to a second aspect of the invention,
A method for manufacturing a stacked solid-state battery,
a plurality of battery units each having 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;
a positive electrode terminal extending from the positive electrode current collector layer in a direction crossing the lamination direction of the laminated structure;
stacking a plurality of battery units each having a negative electrode terminal extending from the negative electrode current collector layer in a direction crossing the stacking direction;
For connecting the stacked solid-state battery to the outside in a state in which a conductive positive electrode spacer is arranged between the positive electrode terminals of at least one pair of adjacent battery units among the plurality of battery units. contacting a positive electrode current collecting tab to the positive electrode terminal to fix the positive electrode current collecting tab, the positive electrode terminal and the positive electrode spacer together and/or adjacent to at least one set of the plurality of battery units; In a state in which a conductive negative electrode spacer is arranged between the negative electrode terminals of the two battery units that meet, a negative electrode collector tab for connecting the stacked solid state battery to the outside is brought into contact with the negative electrode terminal, A manufacturing method is provided that includes fixing the negative electrode current collecting tab, the negative electrode terminal, and the negative electrode spacer together.

ADVANTAGE OF THE INVENTION According to this invention, the laminated solid state battery and its manufacturing method which are hard to produce the breakage of a terminal are provided.

FIG. 1 is a perspective view of stacked solid-state batteries according to the first, second, third, and fourth embodiments of the present invention. FIG. 2(a) is a cross-sectional view of the stacked solid-state battery of 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. FIG. 4 is a front view of four battery units stacked on top of each other. 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 is a plan view of a connecting portion between a positive current collecting tab and a positive electrode terminal and a connecting portion between a negative current collecting tab and a negative electrode terminal. FIG. 7(a) is a cross-sectional view of the stacked solid-state battery of the second embodiment taken along line aa in FIG. FIG. 7(b) is a cross-sectional view of the stacked solid-state battery of the second embodiment taken along line bb in FIG. FIG. 8(a) is a cross-sectional view of the stacked solid-state battery of the third embodiment taken along line aa in FIG. FIG. 8(b) is a cross-sectional view of the stacked solid-state battery of the third embodiment taken along line bb in FIG. FIGS. 9(a) and 9(b) are perspective views of battery units included in the stacked solid-state battery of the fourth embodiment. FIG. 10 is a perspective view showing the arrangement of battery units, positive electrode spacers, and negative electrode spacers in the stacked solid-state battery of the fourth embodiment. FIG. 11 is a side view showing a state in which positive electrode spacers are arranged only in some of the plurality of gaps between positive electrode terminals in a stacked solid-state battery according to a modification.

<First embodiment>
A stacked solid-state battery (solid-state battery module) 100 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 battery units (solid-state battery units) 11 to 14 that are stacked on top of each other, and positive electrodes facing the battery units 11 to 14. It mainly includes a positive electrode spacer 50C provided between terminals TC and a negative electrode spacer 50A provided between opposing negative terminals TA of battery units 11-14.

The stacked solid-state battery 100 further includes an external positive terminal C and an external negative terminal A, a positive current collecting tab 70C connecting the battery units 11 to 14 to the external positive terminal C, and connecting the battery units 11 to 14 to the external negative terminal A. A negative electrode current collecting tab 70A to be connected and a housing 90 are provided.

Battery unit 11 and battery unit 13 have the same structure, and battery unit 12 and battery unit 14 have the same structure. First, the structure of the battery units 11 and 13 will be described.

As shown in FIG. 3, the 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 (negative electrode A laminated structure SS in which the current collector layer) 1A is laminated in this order, a positive terminal TC protruding from the positive electrode current collector 1C in a direction perpendicular to the lamination direction of the laminated structure SS, and from the negative electrode current collector 1A It mainly has a negative electrode terminal TA projecting in a direction orthogonal to the stacking direction of the stacked structure SS.

In the description of the 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 is rectangular in plan view, with the longitudinal direction being the longitudinal direction and the width direction being the lateral direction. 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 has the same shape and dimensions in plan view as those of the positive electrode current collector 1C in plan view. 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 is flat, and has the same shape and dimensions in plan view as those of the positive electrode layer 2C. 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 has the same shape and dimensions in plan view as the electrolyte layer 3 in plan view. 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 is flat, and has the same shape and dimensions in plan view as those of the negative electrode layer 2A. 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.

The positive electrode terminal TC protrudes forward (that is, outside the positive electrode layer 2C, the electrolyte layer 3, and the negative electrode layer 2A in plan view) from a region near the left end of the front edge of the positive electrode current collector 1C. 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. In this embodiment, the positive terminal TC and the negative terminal TA protrude in a direction orthogonal to the stacking direction, but the present invention is not limited to this, and they may protrude in a direction intersecting the stacking direction.

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 that of the positive electrode current collector 1C, and has a plate shape (or foil shape or mesh shape). The negative electrode terminal TA is formed integrally with the negative electrode current collector 1A from the same material as that of the negative electrode current collector 1A, and has a flat plate shape (or foil shape, net shape, or punching shape).

Battery units 12 and 14 have the same configuration as battery units 11 and 13 except for the positions of positive terminal TC and negative terminal TA. Specifically, the positive terminals TC of the battery units 12 and 14 protrude forward from a region near the right end of the front edge of the positive electrode current collector 1C, and the negative terminals TA protrude near the left end of the front edge of the negative electrode current collector 1A. protrudes anteriorly from the area of Other configurations of the battery units 12 and 14 are the same as those of the battery units 11 and 13 .

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

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

As shown in FIG. 4, in the vicinity of the left ends of the battery units 11 to 14, the upper surface of the positive terminal TC of the battery unit 11 and the lower surface of the positive terminal TC of the battery unit 12 are in the stacking direction (the stacking direction of the battery units 11 to 14). , and the upper surface of the positive terminal TC of the battery unit 13 and the lower surface of the positive terminal TC of the battery unit 14 face each other with a gap in the stacking direction. The upper surface of the positive terminal TC of the battery unit 12 and the lower surface of the positive terminal TC of the battery unit 13 face each other and are in contact with each other.

Near the right ends of the battery units 11 to 14, the upper surface of the negative terminal TA of the battery unit 12 and the lower surface of the negative terminal TA of the battery unit 13 face each other with a gap in the stacking direction. The upper surface of the negative terminal TA of the battery unit 11 and the lower surface of the negative terminal TA of the battery unit 12, and the upper surface of the negative terminal TA of the battery unit 13 and the lower surface of the negative terminal TA of the battery unit 14 face each other and are in contact with each other.

One positive electrode spacer 50C is provided between the positive terminal TC of the battery unit 11 and the positive terminal TC of the battery unit 12 and between the positive terminal TC of the battery unit 13 and the positive terminal TC of the battery unit 14. ing. The positive electrode spacer 50C electrically connects the pair of positive terminals TC and functions as a cushioning material that prevents the pair of positive terminals TC from approaching each other.

As an example, the positive electrode spacer 50C can be made of a metal mainly composed of aluminum. Alternatively, the positive electrode spacer 50C may be made of the same material as the positive electrode current collector 1C and/or the negative electrode current collector 1A. Electrochemical stability is improved by forming the positive electrode spacer 50C from the same material as the positive electrode current collector 1C and the positive electrode terminal TC.

The positive electrode spacer 50C can be a thin plate or foil that is rectangular in plan view. The thickness of the positive electrode spacer 50C can be, for example, 20 μm to 1 mm. (because it is drawn on an enlarged scale). The positive electrode spacer 50C of this embodiment is separated from the positive electrode terminal TC and the positive electrode current collecting tab 70C, and is a separate member (separate member) from these.

The upper surface of each of the positive electrode spacers 50C is fixed in contact with the lower surface of the positive electrode terminal TC on the upper side of the positive electrode spacer 50C, and the lower surface of each of the positive electrode spacers 50C is fixed to the upper surface of the positive terminal TC on the lower side of the positive electrode spacer 50C. is fixed in contact with the Accordingly, the positive electrode spacer 50C is sandwiched between the upper positive terminal TC and the lower positive terminal TC in contact with each other, and electrically connects the upper positive terminal TC and the lower positive terminal TC. there is

As shown in FIG. 2(a), the positive electrode spacer 50C and the laminated structure SS of the battery units 11 to 14 (in particular, the negative electrode current collector 1A and the negative electrode layer 2A) are spaced apart in the front-rear direction. This prevents a short circuit between the positive electrode spacer 50C, the negative electrode current collector 1A, and the negative electrode layer 2A. In this embodiment, the positive spacer 50C is fixed near the front end of the positive terminal TC, and the front-rear dimension of the positive spacer 50C is smaller than the front-rear dimension of the positive terminal TC.

Negative spacer 50A is provided between negative terminal TA of battery unit 12 and negative terminal TA of battery unit 13 . The negative spacer 50A electrically connects the pair of negative terminals TA and functions as a cushioning material that prevents the pair of negative terminals TA from approaching each other.

The negative electrode spacer 50A can be made of, for example, a metal mainly composed of copper or a metal mainly composed of nickel. Alternatively, the negative electrode spacer 50A may be made of the same material as the positive electrode current collector 1C and/or the negative electrode current collector 1A. Electrochemical stability is improved by forming the negative electrode spacer 50A from the same material as the negative electrode current collector 1A and the negative electrode terminal TA.

The negative electrode spacer 50A can be a thin plate or foil that is rectangular in plan view, like the positive electrode spacer 50C. The thickness of the negative electrode spacer 50A can be, for example, 20 μm to 1 mm. The negative electrode spacer 50A of the present embodiment is separated from the negative electrode terminal TA and the negative electrode current collecting tab 70A, and is a separate member (separate member) from these.

The upper surface of the negative electrode spacer 50A abuts and is fixed to the lower surface of the positive electrode terminal TA on the upper side of the negative spacer 50A, and the lower surface of the negative electrode spacer 50A abuts on the upper surface of the negative electrode terminal TA on the lower side of the negative spacer 50A. Fixed. As a result, the negative electrode spacer 50A is sandwiched between the upper negative terminal TA and the lower negative terminal TA, and electrically connects the upper negative terminal TA and the lower negative terminal TA. there is

As shown in FIG. 2B, the negative electrode spacer 50A and the laminated structure SS of the battery units 11 to 14 (in particular, the positive electrode current collector 1C and the positive electrode layer 2C) are spaced apart in the front-rear direction. This prevents a short circuit between the negative electrode spacer 50A and the positive current collector 1C and the positive electrode layer 2C. In this embodiment, the negative spacer 50A is fixed near the front end of the negative terminal TA, and the longitudinal dimension of the negative spacer 50A is smaller than the longitudinal dimension of the negative terminal TA.

The positive electrode current collecting tab 70C is a strip-shaped conducting wire (lead wire) that electrically connects the positive electrode terminals TC of the battery units 11 to 14 and the external positive terminals C. As shown in FIG. As shown in FIG. 2A, one end (rear end) of the positive electrode current collecting tab 70C is connected to the upper surface of the positive electrode terminal TC of the battery unit 14, and the other end (front end) of the housing 90 is connected to the upper surface of the positive electrode terminal TC. It is connected to an external positive electrode terminal C arranged outside. One ends of the positive electrode terminals TC, the two positive electrode spacers 50C, and the positive electrode current collecting tabs 70C of the battery units 11 to 14 are integrally joined (fixed) to each other by welding (for example, resistance welding or ultrasonic welding). Conducting.

The negative electrode current collecting tab 70A is a strip-shaped conductive wire that electrically connects the negative electrode terminal TA and the external negative electrode terminal A of the battery units 11-14. As shown in FIG. 2B, one end (rear end) of the negative electrode current collecting tab 70A is connected to the upper surface of the negative electrode terminal TA of the battery unit 14, and the other end (front end) of the housing 90 is connected to the upper surface of the negative electrode terminal TA. It is connected to an external negative electrode terminal A arranged outside. The negative terminals TA, the negative spacers 50A, and the negative current collecting tabs 70A of the battery units 11 to 14 are integrally joined (fixed) by welding or the like and electrically connected to each other.

The housing 90 is made of, for example, a bag-like laminated film made of thermoplastic resin. The battery units 11 to 14, the positive electrode spacer 50C, the negative electrode spacer 50A, the positive electrode current collecting tab 70C, and the negative electrode current collecting tab 70A are accommodated in a sealed state and thermocompressed to form the stacked solid battery 100 as a pouch-type solid battery. obtain.

In the stacked solid-state battery 100 having the above configuration, the positive terminals TC of the battery units 11 to 14 are electrically connected to each other and connected to the external positive terminal C by the positive spacer 50C. Further, the negative terminals TA of the battery units 11 to 14 are electrically connected to each other and connected to the external negative terminal A by the negative spacer 50A. That is, in the stacked solid-state battery 100, the 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 stacked solid-state battery 100 of the first embodiment are summarized below.

In the stacked solid-state battery 100 of the first embodiment, the positive electrode spacer 50C and the negative electrode spacer 50A are sandwiched between the positive electrode terminals TC and the negative electrode terminals TA of the battery units 11 to 14 that are stacked and adjacent to each other. ing. Therefore, even if a force in the stacking direction is applied to the positive terminal TC from the outside of the housing 90, movement of the positive terminal TC in the stacking direction is suppressed by the positive electrode spacer 50C. In this way, since the movement of the positive electrode terminal TC is suppressed by the positive electrode spacer 50C, even when an external force is applied, the positive electrode terminal TC is less likely to bend excessively, and the positive electrode terminal TC is damaged (for example, the positive electrode breakage of the connecting portion between the terminal TC and the positive electrode current collector 1C) is less likely to occur. For the same reason, the negative electrode terminal TA is also less likely to bend excessively, and the negative electrode terminal TA is less likely to be damaged. Therefore, there is little risk of problems such as a short circuit or a decrease in capacity due to breakage of the terminals.

In the first embodiment, only four battery units 11 to 14 are superimposed, but more battery units can be superimposed. As the number of stacked battery units increases, that is, as the thickness of the stacked solid-state battery 100 in the stacking direction increases, the range of motion (in other words, possible bending) of the positive terminal TC and the negative terminal TA in the stacking direction increases. angle width) increases. Therefore, the advantageous effects described above are exhibited more remarkably in a stacked solid-state battery including a larger number of battery units.

Further, in the stacked solid-state battery 100 of the first embodiment, the positive electrode spacer 50C and the negative electrode spacer 50A are each made of a conductive material, and the positive electrode terminal TC extending in the direction orthogonal to the stacking direction of the battery units 11 to 14 , the negative electrode terminal TA is electrically connected by the positive electrode spacer 50C and the negative electrode spacer 50A. Therefore, unlike the mode in which the terminals themselves are bent and brought together in order to conduct between the terminals, there is no bending or bending in the positive terminal TC and the negative terminal TA in normal times (when no external force is applied). but very little. Therefore, even if the positive terminal TC and the negative terminal TA are slightly bent or bent by receiving a large external force, the positive terminal TC and the negative terminal TA are less likely to be damaged.

In addition, although each positive electrode spacer 50C is separated from each other in the above-described first embodiment, the present invention is not limited to this. A plurality of positive electrode spacers 50C arranged in a plurality of gaps may be integrally connected. When using a plurality of negative electrode spacers 50A, the same applies to the negative electrode spacers 50A.

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 6. FIG.

(1) Manufacture of battery units 11 to 14 A thin plate of a conductive material is punched out, and a member (FIG. 5(a)) in which the positive electrode current collector 1C and the positive electrode terminal TC are integrated, and the negative electrode current collector 1A and the A member integrated with the negative terminal TA (FIG. 5(b)) is prepared. 5(a) and 5(b), the positive terminal TC and the negative terminal TA are formed at the terminal positions of the battery units 11 and 13, respectively. In manufacturing the battery units 12 and 14 , the positive terminal TC and the negative terminal TA are formed at the terminal positions of the battery units 12 and 14 .

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. Thereby, a positive electrode layer 2C 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. Thereby, the negative electrode layer 2A 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 the electrolyte layer 3 (FIG. 5(e)). Finally, the electrolyte layer 3 and the negative electrode layer 2A are pressed against each other to obtain a battery unit (FIG. 3) including the laminated structure SS, the positive terminal TC, and the negative terminal TA.

(2) Preparation of the positive electrode spacer 50C and the negative electrode spacer 50A The positive electrode spacer 50C and the negative electrode spacer 50A may be prepared, for example, by punching out a flat plate member, or by folding a foil-like member in a bellows shape (zigzag). You may When the foil member is folded and prepared, the thickness of the positive electrode spacer 50C and the negative electrode spacer 50A can be easily adjusted according to the gap between the terminals by adjusting the number of times of folding. When the foil-shaped member is folded, it may be folded so that the stacking direction of the foil coincides with the stacking direction of the battery units 11 to 14, and the stacking direction of the foil is the front-rear direction or width direction of the battery units 11-14. may be folded to match the

(3) Assembly of Stacked Solid Battery 100 The 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 (FIG. 4). A positive spacer 50C is arranged between the positive terminal TC of the battery unit 11 and the positive terminal TC of the battery unit 12, and between the positive terminal TC of the battery unit 13 and the positive terminal TC of the battery unit 14. One end of the positive current collecting tab 70C is brought into contact with the upper surface of the positive terminal TC. A negative electrode spacer 50A is arranged between the negative terminal TA of the battery unit 12 and the negative terminal TA of the battery unit 13, and one end of the negative current collecting tab 70A is brought into contact with the upper surface of the negative terminal TA of the battery unit 14.

Next, the upper surface of the positive electrode current collecting tab 70C and the lower surface of the positive electrode terminal TC of the battery unit 11 are sandwiched integrally and welded (for example, resistance welding or ultrasonic welding), and the positive electrode terminal TC of the battery units 11 to 14 are welded together. , two positive electrode spacers 50C, and one end of the positive electrode collector tab 70C are joined (fixed) together. Similarly, the upper surface of the negative electrode current collecting tab 70A and the lower surface of the negative electrode terminal TA of the battery unit 11 are sandwiched and welded together, and the negative electrode terminals TA, the negative electrode spacers 50A, and the negative electrode current collecting tabs of the battery units 11 to 14 are welded together. One end of 70A is joined (fixed) together.

Here, as shown in FIG. 6, a positive electrode spacer 50C is present in a region where the positive electrode current collecting tab 70C and the positive electrode terminal TC are in contact with each other in plan view, and the negative electrode current collecting tab 70A and the negative electrode terminal TA are in contact with each other. Anode spacers 50A are present in the region. Therefore, for example, when the positive electrode current collecting tab 70C is pressed against the positive electrode terminal TC in order to weld the positive electrode current collecting tab 70C and the positive electrode terminal TC (when applying a force in the stacking direction to the positive electrode current collecting tab 70C), the positive electrode current collecting tab 70C and the positive electrode terminal TC are welded together. Movement is suppressed by positive electrode spacer 50C. Therefore, the positive terminal TC and the negative terminal TA are less likely to be bent or damaged during welding.

In FIG. 6, the positive electrode spacer 50C and the negative electrode spacer 50A are present in the entire region where the positive electrode current collecting tab 70C, the negative electrode current collecting tab 70A, the positive electrode terminal TC, and the negative electrode terminal TA are in contact with each other. do not have. If the positive electrode spacer 50C and the negative electrode spacer 50A are present in at least a part of the region where the positive electrode current collecting tab 70C and the negative electrode current collecting tab 70A contact the positive electrode terminal TC and the negative electrode terminal TA, the positive electrode terminal due to the welding operation It is possible to suppress bending and breakage of the TC and the negative terminal TA.

Next, the other ends of the positive electrode current collecting tab 70C and the negative electrode current collecting tab 70A are connected to the external positive electrode terminal C and the negative electrode terminal A, respectively. Then, the battery units 11 to 14, the positive electrode spacer 50C, the negative electrode spacer 50A, the positive electrode collector tab 70C, and the negative electrode collector tab 70A are placed in a housing 90 (laminated film as an example) and sealed by thermocompression bonding or the like.

<Second embodiment>
A stacked solid-state battery 200 according to a second embodiment of the present invention will be described with reference to FIGS. 1, 7(a) and 7(b).

The stacked solid-state battery 200 of the second embodiment is the same as the stacked solid-state battery 100 of the first embodiment except that the positive electrode spacer 50C and the negative electrode spacer 50A are replaced with a positive electrode spacer 52C and a negative electrode spacer 52A. be. Differences from the stacked solid-state battery 100 of the first embodiment will be described below. Items not described are the same as those of the stacked solid-state battery 100 of the first embodiment.

As shown in FIG. 7A, in the stacked solid-state battery 200 of the second embodiment, between the positive terminal TC of the battery unit 11 and the positive terminal TC of the battery unit 12, and between the positive terminal TC of the battery unit 13 and the battery Positive electrode spacers 52C are provided between the positive terminals TC of the units 14, respectively.

The positive electrode spacer 52C is formed by folding a strip-shaped conductor integrated with the positive electrode terminal TC and extending forward from the front edge of the positive electrode terminal TC in a bellows shape (zigzag). _Therefore , the positive electrode spacer 52C has a laminated structure (one layer (including structures having only

Regarding the positive spacer 52C provided between the positive terminal TC of the battery unit 11 and the positive terminal TC of the battery unit 12, the front edge of the positive terminal TC of the battery unit 11 and the front edge of the conductive layer _L1 of the positive spacer 52C are connected by a portion curved in a U shape when viewed in the width direction. The lower surface of the conductor layer L ₁ is in contact with the upper surface of the positive terminal TC of the battery unit 11 , and the upper surface of the conductor layer L ₁₈ (outermost layer) is in contact with the lower surface of the positive terminal TC of the battery unit 12 .

Regarding the positive electrode spacer 52C provided between the positive electrode terminal TC of the battery unit 13 and the positive electrode terminal TC of the battery unit 14, the front edge of the positive electrode terminal TC of the battery unit 13 and the front edge of the conductive layer _L1 of the positive electrode spacer 52C are connected by a portion curved in a U shape when viewed in the width direction. The lower surface of the conductor layer L ₁ is in contact with the upper surface of the positive terminal TC of the battery unit 13 , and the upper surface of the conductor layer L ₁₈ (outermost layer) is in contact with the lower surface of the positive terminal TC of the battery unit 14 .

The conductor layer _Ln and the conductor layer Ln ₊₁ of the positive electrode spacer 52C are connected by a portion where one of the leading edge and the trailing edge curves into a U shape when viewed in the width direction. The upper surface of the conductor layer _Ln and the lower surface of the conductor layer Ln ₊₁ are in contact with each other.

The negative electrode spacer 52A shown in FIG. 7(b) is integral with the negative terminal TA and is formed by folding a strip-shaped conductor extending forward from the front edge of the negative terminal TA in a bellows shape (zigzag). there is The negative electrode spacer 52A has a laminated structure similar to that of the positive electrode spacer 52C.

In the production of the stacked solid-state battery 200 of the second embodiment, a member in which the positive electrode current collector 1C and the positive electrode terminal TC are integrated (FIG. 5A), and a negative electrode current collector 1A and the negative electrode terminal TA are integrated. When cutting out the resulting member (FIG. 5B), the strip-shaped conductors extending forward from the front edges of the positive terminal TC and the negative terminal TA are also integrally cut out. Then, in assembling the stacked solid-state battery 200, the strip-shaped conductor is folded into a bellows shape to form a positive electrode spacer 52C and a negative electrode spacer 52A, which are arranged between the opposing terminals.

In the above description, a belt-like conductor is provided only on one side of the opposing terminals and folded to form the positive electrode spacer 52C and the negative electrode spacer 52A, but the present invention is not limited to this. A spacer may be formed by combining strip-shaped conductors (half the length of one terminal) on opposite terminals and stacking them to form a laminate. Moreover, in the above description, the laminated body is formed by bending the belt-shaped conductor extending from the tip of the terminal in the same direction as the terminal (front-to-rear direction), but the present invention is not limited to this. The laminate may be formed by bending a strip-shaped conductor extending from the tip of the terminal in a direction crossing the terminal (for example, the width direction). Further, the strip-shaped conductor may be folded so that the stacking direction of the laminate is the front-rear direction or the width direction.

The stacked solid-state battery 200 of the second embodiment also has the same effect as the stacked solid-state battery 100 of the first embodiment. In addition, in the stacked solid-state battery 200 of the second embodiment, the positive electrode spacer 52C and the negative electrode spacer 52A are formed using a strip-shaped conductor integrally formed with the positive electrode terminal TC and the negative electrode terminal TA. The negative electrode spacer 52A can be provided more easily. Specifically, the thickness of the positive electrode spacer 52C and the negative electrode spacer 52A can be adjusted only by adjusting the length of the strip-shaped conductor integrally formed with the positive electrode terminal TC and the negative electrode terminal TC. Further, since the positive electrode spacer 52C and the negative electrode spacer 52A are integrated with the positive electrode terminal TC and the negative electrode terminal TA, respectively, there is no need to align the terminals and the spacers.

<Third Embodiment>
A stacked solid-state battery 300 according to a third embodiment of the present invention will be described with reference to FIGS. 1, 8(a) and 8(b).

The stacked solid-state battery 300 of the third embodiment is the same as the stacked solid-state battery 100 of the first embodiment except that the positive electrode spacer 50C and the negative electrode spacer 50A are replaced with a positive electrode spacer 53C and a negative electrode spacer 53A. be. Differences from the stacked solid-state battery 100 of the first embodiment will be described below. Items not described are the same as those of the stacked solid-state battery 100 of the first embodiment.

As shown in FIG. 8A, in the stacked solid-state battery 300 of the third embodiment, between the positive terminal TC of the battery unit 11 and the positive terminal TC of the battery unit 12, and between the positive terminal TC of the battery unit 13 and the battery A positive electrode spacer 53C is provided between the positive terminals TC of the unit 14 .

The positive electrode spacer 53C is formed by folding a belt-shaped conductor integrated with the positive electrode current collecting tab 70C and extending from the end of the positive electrode current collecting tab 70C in a bellows shape (zigzag). _Therefore , the positive electrode spacer 53C has a laminated structure (one layer (including structures having only

The upper surface of the region near the end (rear end) of the positive electrode current collecting tab 70</b>C is in contact with the lower surface of the positive electrode terminal TC of the battery unit 14 . The end portion of the positive electrode current collecting tab 70C and the rear edge of the conductive layer _LL1 of the positive electrode spacer 53C are connected by a portion curved in a U shape when viewed in the width direction. The upper surface of the conductor layer _LL1 is in contact with the lower surface of the region near the end of the positive electrode current collecting tab 70C. The lower surface of the conductor layer LL ₁₁ (outermost layer) is in contact with the upper surface of the positive electrode terminal TC of the battery unit 11 .

The conductor layer LL _n and the conductor layer LL _n+1 of the positive electrode spacer 53C are connected by a portion where one of the leading edge and the trailing edge curves into a U shape when viewed in the width direction. The bottom surface of the conductor layer _LLn and the top surface of the conductor layer LLn ₊₁ are in contact with each other. In this embodiment, the positive terminals TC of the battery units 12 and 13 are sandwiched between the conductor layers _LL5 and _LL6 . Therefore, the lower surface of the conductor layer LL ₅ is in contact with the upper surface of the positive terminal TC of the battery unit 13 , and the upper surface of the conductor layer LL ₆ is in contact with the lower surface of the positive terminal TC of the battery unit 12 .

The negative electrode spacer 53A shown in FIG. 8(b) is integrated with the negative electrode current collecting tab 70A and is formed by folding a strip-shaped conductor extending from the end of the negative electrode current collecting tab 70A in a bellows shape (zigzag). It is The negative electrode spacer 53A has a laminated structure similar to that of the positive electrode spacer 53C.

In assembling the stacked solid-state battery 300 of the third embodiment, when connecting the positive electrode current collecting tab 70C and the negative electrode current collecting tab 70A to the positive electrode terminal TC and the negative electrode current collecting tab TA, the positive electrode current collecting tab 70C and the negative electrode current collecting tab are connected. A strip-shaped conductor provided integrally with 70A is folded into a bellows shape to form a positive electrode spacer 53C and a negative electrode spacer 53A, which are arranged between the opposing terminals. As shown in FIG. 8A, by sandwiching a terminal between the conductor layer LL _n and the conductor layer LL _n+1 , a spacer formed of one belt-shaped conductor is formed into a plurality of gaps arranged in the stacking direction. can be placed in

The stacked solid-state battery 300 of the third embodiment also has the same effect as the stacked solid-state battery 100 of the first embodiment. In addition, in the stacked solid-state battery 300 of the third embodiment, the positive electrode spacer 53C and the negative electrode spacer 53A are formed using strip-shaped conductors integrally formed with the positive electrode current collecting tab 70C and the negative electrode current collecting tab 70A. The positive electrode spacer 53C and the negative electrode spacer 53A can be provided more easily. Specifically, the thickness of the positive electrode spacer 53C and the negative electrode spacer 53A can be adjusted only by adjusting the length of the strip-shaped conductor 53. FIG. Further, since the positive electrode spacer 53C and the negative electrode spacer 53A are integrated with the positive electrode current collecting tab 70C and the negative electrode current collecting tab 70A, respectively, there is no need to perform alignment between the current collecting tab and the spacer.

<Fourth Embodiment>
A stacked solid state battery 400 according to a fourth embodiment of the present invention will be described with reference to FIGS. 1, 9(a), 9(b) and 10. FIG.

The stacked solid-state battery 400 of the fourth embodiment differs from the stacked solid-state battery 100 of the first embodiment in that battery units 15-18 are used instead of the battery units 11-14. The battery units 15-18 are the same as the battery units 11-14 of the first embodiment except for the arrangement of the positive terminal and the negative terminal. Differences from the stacked solid-state battery 100 of the first embodiment will be described below. Items not described are the same as those of the stacked solid-state battery 100 of the first embodiment.

As shown in FIG. 9A, in the battery units 15 and 17 included in the stacked solid-state battery 400 of the fourth embodiment, the right front corner of the positive electrode current collector 5C, the positive electrode layer 6C, the electrolyte layer 7, and the negative electrode Both corners on the front side of the layer 6A and a corner on the left front side of the negative electrode current collector 5A are notched into a substantially square shape in plan view.

In a plan view of the laminated structure SS4, a region defined at the left front corner where the positive electrode layer 6C, the electrolyte layer 7, the negative electrode layer 6A, and the negative electrode current collector 5A do not exist is called a positive electrode recessed region RC. In a plan view of the laminated structure SS4, a region defined at the right front corner where the positive electrode current collector 5C, the positive electrode layer 6C, the electrolyte layer 7, and the negative electrode layer 6A do not exist is called a negative electrode recessed region RA.

As shown in FIG. 9(b), the battery units 16 and 18 included in the stacked solid-state battery 400 of the fourth embodiment have the negative electrode recessed area RA defined at the left front corner and the negative electrode recessed area RA at the right front corner. It has the same structure as the battery units 15 and 17 except that the positive electrode concave region RC is defined.

In this embodiment, the positive electrode current collector 5C present in the positive electrode recessed region RC is used as the positive electrode terminal TC4, and the negative electrode current collector 5A present in the negative electrode recessed region RA is used as the negative electrode terminal TA4. In the present embodiment, the recessed positive electrode region RC and the recessed negative electrode region RA are regions in which the outer edge of the laminated structural body SS4 is recessed inward in plan view. The positive electrode terminal TC4 and the negative electrode terminal TA4 are located in the positive electrode recessed region RC and the negative electrode recessed region RA, respectively, when viewed in the stacking direction. In this embodiment, the battery reaction portion (the portion where the positive electrode layer 6C, the electrolyte layer 7, and the negative electrode layer 6A overlap) has a convex shape (a shape in which the center in the width direction protrudes forward) in plan view.

As shown in FIG. 10, in the state where the battery units 15 to 18 are superimposed, there is a gap between the positive terminal TC4 of the battery unit 15 and the positive terminal TC4 of the battery unit 16, and between the positive terminal TC4 of the battery unit 17 and the battery unit 18. A positive electrode spacer 50C is provided between each of the positive terminals TC4. A negative electrode spacer 50A is provided between the negative terminal TA4 of the battery unit 16 and the negative terminal TA4 of the battery unit 17 .

The stacked solid-state battery 400 of the fourth embodiment also has the same effect as the stacked solid-state battery 100 of the first embodiment. Further, in the stacked solid-state battery 400 of the fourth embodiment, since the positive electrode spacer 50C and the negative electrode spacer 50A are arranged inside the positive electrode recessed region RC and the negative electrode recessed region RA, the battery units 15 to 18, the positive electrode spacer 50C and the negative electrode Spacer 50A can be arranged compactly. This improves the volumetric energy density of the stacked solid-state battery 400 .

In the manufacture of the battery units 15 to 18, for example, after forming the laminate structure SS4, each layer at the corner is removed to provide the recessed positive electrode region RC and the recessed negative electrode region RA. In the battery units 15 to 18, the recessed positive electrode region RC and the recessed negative electrode region RA are provided at the corners of the laminated structural body SS4 in plan view, but the present invention is not limited to this. For example, the positive electrode recessed region RC and/or the negative electrode recessed region RA recessed inward may be provided in a region (region between a pair of front corners) different from the corners of the front edge of the laminated structure SS4.

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

In the above embodiment, four battery units constitute the stacked solid-state batteries 100 to 400, but the present invention is not limited to this. The number of battery units included in the stacked solid-state batteries 100-400 is arbitrary.

In the above embodiments, spacers are arranged in all the gaps defined between adjacent terminals, but the invention is not limited to this. A spacer may only be placed in at least one of a plurality of gaps defined between adjacent terminals.

Specifically, for example, spacers may be arranged only between terminals arranged in the vicinity of the ends in the overlapping direction. Terminals in the vicinity of the ends in the overlapping direction can bend more when subjected to an external force than terminals in the vicinity of the center in the overlapping direction. In this modified example, by selecting a terminal that can cause a large bend and arranging the spacer, it is possible to reduce the amount of use of the spacer (that is, cost and labor) while suppressing breakage of the terminal. FIG. 11 shows a specific example of this modification, in which a positive electrode spacer 50C is arranged only between the positive terminals TC near the ends in the overlapping direction.

In each of the above embodiments, one of the positive electrode spacers 50C, 52C, 53C and the negative electrode spacers 50A, 52A, 53 may be omitted.

In the above-described embodiment, the battery units 11 to 14 are stacked with the positive electrode current collectors 1C and the negative electrode current collectors 1A 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 1C and the negative electrode current collector 1A of a certain battery unit is insulated from the other of the positive electrode current collector 1C and the negative electrode current collector 1A of the battery unit stacked thereon. They may be overlapped so as to face each other with an insulating separator (insulating film, insulating plate) interposed therebetween.

In the above embodiment, the pair of positive electrode current collectors 1C or the pair of negative electrode current collectors 1A in contact with each other are electrically connected. Therefore, in each embodiment, a pair of positive electrode current collectors 1C or a pair of negative electrode current collectors 1A in contact with each other may be formed as a single-layer positive electrode current collector 1C or a single-layer negative electrode current collector 1A. In the present invention, each of the "multiple battery units stacked together" is 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 stacked in this order". When each battery unit has a positive electrode current collector layer and/or a negative electrode current collector layer that can be separated from other battery units, and the positive electrode current collector layer and/or shared by adjacent battery units Or in the case of having a negative electrode current collector layer (that is, the positive electrode current collector layer of the adjacent battery unit, the positive electrode current collector layer integrated with the negative electrode current collector layer, or the negative electrode current collector layer integrated with the negative electrode current collector layer, the negative electrode current collector layer) Including both.

In the laminated structures SS and SS4 of the battery units 11 to 18 of each of the embodiments described above, the layers constituting the laminated structures SS and SS4 have the same planar shape and dimensions, but this is not the only option. . For example, the size of the negative electrode layer 2A and the negative electrode current collector 1A in plan view may be larger than the size of the positive electrode layer 2C and the positive electrode current collector 1C in plan view. In this case, for example, the positive terminal TC may be longer than the negative terminal TA in the front-rear direction.

You may use combining said each embodiment and each modification. Specifically, for example, in the stacked solid-state battery 400 of the fourth embodiment, the positive electrode spacer 52C and/or the negative electrode spacer 52A of the second embodiment or the positive electrode spacer 53C and/or the negative electrode spacer 53A of the third embodiment are used. may

<Material>
Materials forming the electrolyte layers 3 and 7, the positive electrode layers 2C and 6C, and the negative electrode layers 2A and 6A in each of the above embodiments will be 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, 52A, 53A negative electrode spacers 50C, 52C, 53C positive electrode spacer 70A negative electrode current collecting tab 70C positive electrode Current collecting tab 90 Housings 100, 200, 300, 400 Stacked solid state batteries SS, SS4 Stacked structures TA, TA4 Negative terminals TC, TC4 Positive terminals

Claims (8)

A stacked solid-state battery,
comprising a plurality of battery units superimposed on each other,
each of the plurality of battery units,
a laminated structure in which a positive electrode collector layer, a positive electrode layer, an electrolyte layer, a negative electrode layer, and a negative electrode collector layer are laminated in this order;
a positive electrode terminal extending from the positive electrode current collector layer in a direction crossing the lamination direction of the laminated structure;
a negative electrode terminal extending in a direction intersecting with the stacking direction from the negative electrode current collector layer;
In at least one pair of adjacent battery units among the plurality of battery units, a conductive positive electrode spacer in contact with and sandwiched between the positive electrode terminals and a conductive spacer in contact with and sandwiched between the negative electrode terminals. A stacked solid-state battery further comprising at least one of negative electrode spacers. The plurality of battery units are overlapped with the positive electrode current collectors and/or the negative electrode current collectors of two adjacent battery units in contact with each other,
The conductive positive electrode spacer is positioned between the positive terminals of the two adjacent battery units where the negative electrode current collectors abut and/or the adjacent two where the positive electrode current collectors abut. 2. The stacked solid state battery of claim 1, wherein said conductive negative electrode spacer is positioned between said negative terminals of two said battery units. When viewed in the stacking direction, the conductive positive electrode spacer is located in a connection region between the positive electrode current collecting tab for connecting the stacked solid-state battery to the outside and the positive electrode terminal, and/or 3. The stacked solid-state battery according to claim 1, wherein a negative electrode spacer is positioned in a connection region between a negative electrode collector tab for connecting the stacked solid-state battery to the outside and the negative electrode terminal. The stacked solid-state battery according to any one of claims 1 to 3, wherein the conductive positive electrode spacer and/or the conductive negative electrode spacer are members separate from the positive electrode terminal and the negative electrode terminal. The conductive positive electrode spacer is integrally formed with the positive electrode terminal of at least one of the plurality of battery units, and includes at least a first layer that is folded back from the tip of the positive electrode terminal and contacts the positive electrode terminal. and/or the conductive negative electrode spacer is formed integrally with the negative electrode terminal of at least one of the plurality of battery units, and is folded back from the tip of the negative electrode terminal to contact the negative electrode terminal. The stacked solid-state battery according to any one of claims 1 to 3, having a stacked structure including at least a first layer in contact with the first layer. A current collecting tab for connecting the stacked solid-state battery to the outside, further comprising a current collecting tab connected to one of the positive electrode terminal and the negative electrode terminal,
The conductive positive electrode spacer and/or the conductive negative electrode spacer are formed integrally with the current collecting tab, and at least a first layer is folded back from one end of the current collecting tab to abut on the current collecting tab. The stacked solid-state battery according to claim 1 or 2, having a stacked structure comprising: In each of the plurality of battery units, an outer edge of the laminated structure viewed in the stacking direction defines a recessed region in which the positive terminal and/or the negative electrode terminal is recessed inwardly. The stacked solid-state battery according to any one of claims 1 to 6, located in the recessed area. A method for manufacturing a stacked solid-state battery,
a plurality of battery units each having 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;
a positive electrode terminal extending from the positive electrode current collector layer in a direction crossing the lamination direction of the laminated structure;
stacking a plurality of battery units each having a negative electrode terminal extending from the negative electrode current collector layer in a direction crossing the stacking direction;
For connecting the stacked solid-state battery to the outside in a state in which a conductive positive electrode spacer is arranged between the positive electrode terminals of at least one pair of adjacent battery units among the plurality of battery units. contacting a positive electrode current collecting tab to the positive electrode terminal to fix the positive electrode current collecting tab, the positive electrode terminal and the positive electrode spacer together and/or adjacent to at least one set of the plurality of battery units; In a state in which a conductive negative electrode spacer is arranged between the negative electrode terminals of the two battery units that meet, a negative electrode collector tab for connecting the stacked solid state battery to the outside is brought into contact with the negative electrode terminal, A manufacturing method including integrally fixing the negative electrode current collecting tab, the negative electrode terminal, and the negative electrode spacer.

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