Unit solid-state battery and method for manufacturing the unit solid-state battery

Abstract

The present invention provides: unit solid-state batteries which have a single structure and are capable of constituting a solid-state battery module having an arbitrary capacity and an arbitrary output by being combined with each other without generating an ineffective portion of an electrode material in both ends of the stack; and a method for producing this unit solid-state battery.　A unit solid-state battery which constitutes a solid-state battery, and which comprises: a solid electrolyte layer; and a negative electrode material layer and a positive electrode material layer, which are superposed on both surfaces of the solid electrolyte layer as electrode material layers. With respect to this unit solid-state battery, the negative electrode material layer and the positive electrode material layer do not contain a collector. If this unit solid-state battery is viewed in plan from the stacking direction, it is preferable that the area of the solid electrolyte layer is larger than the areas of the negative electrode material layer and the positive electrode material layer, and that the outer edge of the solid electrolyte layer is positioned outside the outer edges of the negative electrode material layer and the positive electrode material layer.

Description

[Technical Field]

[0001] The present invention relates to a unit solid-state battery and a method for manufacturing the unit solid-state battery. [Background technology]

[0002] Lithium-ion secondary batteries have been widely used as secondary batteries with high energy density. Lithium-ion secondary batteries have a structure in which a separator is placed between a positive electrode and a negative electrode and filled with a liquid electrolyte.

[0003] The electrolyte solution of lithium ion secondary batteries is usually a flammable organic solvent, which can pose a problem in terms of safety, particularly with respect to heat. Therefore, solid-state batteries using inorganic solid electrolytes instead of organic liquid electrolytes have been proposed. For example, a technology has been proposed for a solid-state battery including an element portion formed by stacking a first solid electrode layer, a solid electrolyte layer having lithium ion conductivity, and a second solid electrode layer in this order (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-76178 Summary of the Invention [Problem to be solved by the invention]

[0005] When a solid-state battery is constructed using cell units each having a solid electrode layer with a current collector, as proposed in Patent Document 1, there is a problem that ineffective portions of the electrode material are generated at both ends of the stack when stacking the cell units. In addition, since it is necessary to stack multiple types of electrodes, there is a problem from the viewpoint of improving productivity.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a unit solid-state battery and a manufacturing method thereof, which does not generate ineffective portions of electrode material at both ends of the stack and can configure a solid-state battery module having any capacity and output by combining unit solid-state batteries having a single structure. [Means for solving the problem]

[0007] (1) The present invention relates to a unit solid-state battery that constitutes a solid-state battery, the unit solid-state battery having a solid electrolyte layer and an anode material layer and a cathode material layer as electrode material layers laminated on both sides of the solid electrolyte layer, wherein the anode material layer and the cathode material layer do not include current collectors.

[0008] According to the invention (1), it is possible to provide a unit solid-state battery in which no ineffective portions of the current collecting electrodes are generated at both ends of the stack and a solid-state battery module having any capacity and output can be configured by combining unit solid-state batteries having a single structure.

[0009] (2) The unit solid-state battery according to (1), wherein, when the unit solid-state battery is viewed from above in a stacking direction, an area of ​​the solid electrolyte layer is larger than an area of ​​the negative electrode material layer and the positive electrode material layer, and an outer edge of the solid electrolyte layer is disposed outside an outer edge of the negative electrode material layer and the positive electrode material layer.

[0010] According to the invention (2), it is possible to provide a unit solid-state battery that can prevent short circuits when stacked.

[0011] (3) A solid-state battery module having a stacked cell structure formed by stacking a plurality of unit solid-state batteries according to (1) or (2), wherein the stacked cell structure is a first stacked cell structure in which collector electrodes are disposed between the unit solid-state batteries, adjacent unit solid-state batteries are disposed such that the positive electrode material layers and the negative electrode material layers are adjacent to each other, a negative electrode plate as the collector electrode is disposed between adjacent negative electrode material layers, and a positive electrode plate as the collector electrode is disposed between adjacent positive electrode material layers, and the collector electrodes or the electrode material layers disposed at both stacking ends of the stacked unit solid-state batteries are of the same type.

[0012] According to the invention of (3), there is no ineffective portion of the current collecting electrode on both ends of the stack, and a solid state battery module having any capacity can be provided by combining unit solid state batteries having a single structure.

[0013] (4) The solid-state battery module according to (3), wherein the first stacked cell structure is stacked in a plurality of layers, and the collector electrode plates or the electrode material layers arranged at both stacking ends of adjacent first stacked cell structures are of different types.

[0014] According to the invention (4), a solid-state battery module having any capacity and output can be provided.

[0015] (5) A solid-state battery module having a stacked cell structure formed by stacking a plurality of unit solid-state batteries according to (1) or (2), wherein the stacked cell structure is a second stacked cell structure in which collector electrodes are disposed between the unit solid-state batteries, adjacent unit solid-state batteries are disposed such that the negative electrode material layers and the positive electrode material layers are adjacent to each other, a negative electrode plate as the collector electrode is disposed between adjacent negative electrode material layers, and a positive electrode plate as the collector electrode is disposed between adjacent positive electrode material layers, and the collector electrodes or the electrode material layers disposed at both stacking ends of the stacked unit solid-state batteries are of different types.

[0016] According to the invention (5), it is possible to provide a solid-state battery module in which stacked structures having any capacity can be connected in series.

[0017] (6) A solid-state battery module having a stacked cell structure formed by stacking a plurality of unit solid-state batteries according to (1) or (2), wherein the stacked cell structure is such that collector electrodes are disposed between the unit solid-state batteries, adjacent unit solid-state batteries are disposed such that the negative electrode material layer and the positive electrode material layer are adjacent to each other, a bipolar electrode plate is disposed between the adjacent negative electrode material layer and the positive electrode material layer, the collector electrodes or the electrode material layers disposed at both stacking ends of the stacked unit solid-state batteries are of different materials, and the negative electrode plate is disposed in contact with the negative electrode material layer and the positive electrode plate is disposed in contact with the positive electrode material layer at both stacking ends, which is a third stacked cell structure of the solid-state battery module.

[0018] According to the invention of (6), it becomes possible to connect unit solid-state batteries having a single structure in series, and it is possible to provide a solid-state battery module having any capacity and output.

[0019] (7) The present invention also relates to a method for manufacturing a unit solid-state battery that constitutes a solid-state battery, the method including: a sheet forming step of forming an anode material sheet containing an anode material, a cathode material sheet containing a cathode material, and a solid electrolyte sheet containing a solid electrolyte; and a pressurizing step of pressing the anode material sheet and the cathode material sheet with the solid electrolyte sheet sandwiched therebetween.

[0020] According to the invention of (7), it is possible to manufacture a unit solid-state battery in which no ineffective portions of the current collecting electrodes are generated at both ends of the stack, and a solid-state battery module having any capacity and output can be constructed by combining unit solid-state batteries having a single structure.

[0021] (8) The present invention also relates to a method for manufacturing a unit solid-state battery that constitutes a solid-state battery, the method including: an anode material coating step of coating one surface of a solid electrolyte sheet containing a solid electrolyte with an anode material layer containing an anode material; and a cathode material coating step of coating the other surface of the solid electrolyte sheet with a cathode material layer containing a cathode material.

[0022] According to the invention of (8), it is possible to manufacture a unit solid-state battery in which no ineffective portions of the current collecting electrodes are generated at both ends of the stack, and a solid-state battery module having any capacity and output can be constructed by combining unit solid-state batteries having a single structure.

[0023] (9) A method for producing a unit solid state battery according to (7), comprising: a first cutting step of cutting the negative electrode material sheet and the positive electrode material sheet; a second cutting step of cutting the solid electrolyte sheet so that the solid electrolyte sheet has an area larger than that of the positive electrode material sheet and the negative electrode material sheet in a plan view; and a stacking step of stacking the negative electrode material sheet, the solid electrolyte sheet, and the positive electrode material sheet in this order.

[0024] According to the invention (9), a unit solid-state battery that can prevent short circuits during stacking can be manufactured.

[0025] (10) A method for manufacturing a solid-state battery module by stacking a plurality of unit solid-state batteries manufactured by the method for manufacturing a unit solid-state battery according to (9), the method comprising, between the stacking step and the pressing step, a disposing step of disposing a collector electrode plate between adjacent unit solid-state batteries.

[0026] According to the invention (10), the manufacturing process of the solid-state battery module can be simplified. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view showing a unit solid state battery according to one embodiment of the present invention. [Figure 2] FIG. 1 is a schematic plan view of a unit solid state battery according to one embodiment of the present invention, viewed from the negative electrode material layer side. [Figure 3] FIG. 1 is a schematic plan view of a unit solid state battery according to an embodiment of the present invention, viewed from the positive electrode material layer side. [Figure 4A] 1 is a cross-sectional view showing a first laminated structure according to one embodiment of the present invention. [Figure 4B] 1 is a cross-sectional view showing a solid-state battery module having a first stacked structure according to one embodiment of the present invention. [Figure 5A] FIG. 4 is a cross-sectional view showing a third stacked structure according to one embodiment of the present invention. [Figure 5B] FIG. 3 is a cross-sectional view showing a solid-state battery module having a third stacked structure according to one embodiment of the present invention. [Figure 6] FIG. 3 is a cross-sectional view showing a solid-state battery module having a third stacked structure according to one embodiment of the present invention. [Figure 7A] FIG. 1 is a schematic plan view of a solid-state battery module according to an embodiment of the present invention. [Figure 7B] 1 is a cross-sectional view showing a solid-state battery module having a first stacked structure according to one embodiment of the present invention. [Figure 8A] FIG. 1 is a schematic plan view of a solid-state battery module according to an embodiment of the present invention. [Figure 8B] 1 is a cross-sectional view showing a solid-state battery module having a first stacked structure according to one embodiment of the present invention. [Figure 9A] FIG. 1 is a schematic plan view of a solid-state battery module according to an embodiment of the present invention. [Figure 9B] FIG. 2 is a cross-sectional view showing a solid-state battery module having a second stacked structure according to one embodiment of the present invention. [Figure 9C] FIG. 1 is an exploded perspective view of a solid-state battery module according to an embodiment of the present invention. [Figure 9D] 1 is a transparent perspective view showing a solid-state battery module according to an embodiment of the present invention. [Figure 10A] FIG. 1 is a schematic plan view of a solid-state battery module according to an embodiment of the present invention. [Figure 10B] FIG. 3 is a cross-sectional view showing a solid-state battery module having a third stacked structure according to one embodiment of the present invention. [Figure 11A] FIG. 1 is a schematic plan view of a solid-state battery module according to an embodiment of the present invention. [Figure 11B] FIG. 2 is a cross-sectional view showing a solid-state battery module having a second stacked structure according to one embodiment of the present invention. [Figure 11C] FIG. 1 is an exploded perspective view of a solid-state battery module according to an embodiment of the present invention. [Figure 11D] 1 is a transparent perspective view showing a solid-state battery module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] <Unit solid-state battery> Fig. 1 is a cross-sectional schematic diagram showing a unit solid state battery 1 according to an embodiment of the present invention. The unit solid state battery 1 according to this embodiment is one unit of solid state batteries that constitute a solid state battery module. As shown in Fig. 1, the unit solid state battery 1 is formed by forming an anode material layer 2 and a cathode material layer 3 on both sides of a solid electrolyte layer 4.

[0029] The negative electrode material layer 2 and the positive electrode material layer 3 are layers that do not include current collectors such as current collector foils or electrode plates. The negative electrode material layer 2 and the positive electrode material layer 3 may be individually manufactured in sheet form and integrated with the solid electrolyte layer 4 by pressing or the like, or may be formed into layers by coating both sides of the solid electrolyte layer 4. With the above configuration, the unit solid state battery 1 is formed as an integrated unit without including current collectors. This allows a solid state battery module with any capacity and output to be constructed by combining unit solid state batteries 1, and no ineffective portions of the current collector electrodes are generated at both ends of the stack. Furthermore, since the negative electrode material layer 2 and the positive electrode material layer 3 do not include current collectors such as current collector foils, the adhesion of the negative electrode material layer 2 and the positive electrode material layer 3 to the solid electrolyte layer 4 can be improved, thereby improving the input / output characteristics of the unit solid state battery 1.

[0030] (Negative electrode material layer) The negative electrode material layer 2 is a layer that essentially contains a negative electrode active material, but does not contain a current collector such as a current collector foil or a current collector plate. In addition to the negative electrode active material, the negative electrode material layer 2 may optionally contain a conductive additive, a binder, etc.

[0031] The negative electrode active material contained in the negative electrode layer 2 is not particularly limited, and may be appropriately selected from known materials capable of absorbing and releasing charge transfer media such as lithium ions. Examples include lithium transition metal oxides such as lithium titanate, transition metal oxides such as TiO2, Nb2O3, and WO3, Si, SiO, metal sulfides, metal nitrides, carbon materials such as artificial graphite, natural graphite, graphite, soft carbon, and hard carbon, metallic lithium, metallic indium, and lithium alloys.

[0032] (Cathode material layer) The positive electrode layer 3 is a layer that essentially contains a positive electrode active material and does not contain a current collector such as a current collector foil or a current collector plate. In addition to the positive electrode active material, the positive electrode layer 3 may optionally contain a conductive additive, a binder, etc.

[0033] The positive electrode active material contained in the positive electrode layer 3 is not particularly limited, and any known material capable of absorbing and releasing a charge transfer medium such as lithium ions can be appropriately selected and used. Examples include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, heteroelement-substituted Li-Mn spinel, lithium metal phosphate, lithium sulfide, and sulfur. Specific examples include LiCoO2, Li(Ni 5 / 10 Co 2 / 10 Mn 3 / 10 )O 2、 Li(Ni) 6 / 10 Co 2 / 10 Mn 2 / 10 )O 2、 Li(Ni) 8 / 10 Co 1 / 10 Mn 1 / 10 )O 2、 Li(Ni) 0.8 Co 0.15 Al 0.05 )O 2、 Li(Ni) 1 / 6 Co 4 / 6 Mn 1 / 6 )O 2、 Li(Ni) 1 / 3 Co 1 / 3 Mn 1 / 3 )O 2、Examples include LiCoO4, LiMn2O4, LiNiO2, and LiFePO4.

[0034] The negative electrode material layer 2 and the positive electrode material layer 3 may contain other components in addition to the active material. The other components are not particularly limited and may be any components that can be used when fabricating a solid-state battery. Examples include a conductive additive and a binder. An example of a conductive additive for the positive electrode is acetylene black, and an example of a binder for the positive electrode is polyvinylidene fluoride. Examples of a binder for the negative electrode are sodium carboxymethyl cellulose, styrene butadiene rubber, and sodium polyacrylate.

[0035] (solid electrolyte layer) The solid electrolyte layer 4 is a layer containing at least a solid electrolyte material, which is a solid or gel electrolyte. Charge transfer can occur between the positive electrode active material and the negative electrode active material via the solid electrolyte material.

[0036] As shown in FIGS. 2 and 3 , the solid electrolyte layer 4 has a larger area than the anode material layer 2 and the cathode material layer 3 when viewed from above in the stacking direction. Here, FIG. 2 is a view viewed from the anode material layer 2 side, and FIG. 3 is a view viewed from the cathode material layer 3 side. In addition to the above, the layers are arranged so that the outer edge of the solid electrolyte layer 4 when viewed from above in the stacking direction includes the outer edges of the anode material layer 2 and the cathode material layer 3. Specifically, as shown in FIG. 2 , the outer edge of the solid electrolyte layer 4 is positioned outward from the outer edge of the anode material layer 2 by a length D1. Similarly, as shown in FIG. 3 , the outer edge of the solid electrolyte layer 4 is positioned outward from the outer edge of the cathode material layer 3 by a length D2. The length D1 may be equal to or greater than the thickness of the anode material layer 2, and the length D2 may be equal to or greater than the thickness of the cathode material layer 3. The lengths D1 and D2 may be, for example, 1 mm. This prevents short circuits when the unit solid state batteries 1 are stacked.

[0037] The solid electrolyte material contained in the solid electrolyte layer 4 is not particularly limited, but for example, a sulfide solid electrolyte material, an oxide solid electrolyte material, a nitride solid electrolyte material, a halide solid electrolyte material, etc. can be used.

[0038] <Manufacturing method for unit solid-state battery> [First manufacturing method] The method for manufacturing the unit solid state battery 1 preferably includes a sheet forming step of forming an anode material sheet containing an anode material, a cathode material sheet containing a cathode material, and a solid electrolyte sheet containing a solid electrolyte, and a pressurizing step of integrating the anode material sheet and the cathode material sheet by sandwiching the solid electrolyte sheet therebetween and pressing them with a press or the like.

[0039] Furthermore, after the sheet forming step, the method preferably includes a first cutting step of cutting the positive electrode material sheet and the negative electrode material sheet, a second cutting step of cutting the solid electrolyte sheet so that the area is larger in plan view than the positive electrode material sheet and the negative electrode material sheet, and a stacking step of stacking the negative electrode material sheet, the solid electrolyte sheet, and the positive electrode material sheet in this order. In the stacking step, the negative electrode material sheet and the positive electrode material sheet are preferably stacked so that the outer edges of the negative electrode material sheet and the positive electrode material sheet do not protrude beyond the outer edge of the solid electrolyte sheet. This makes it possible to manufacture a unit solid battery 1 that can prevent short circuits when stacked. Furthermore, it is possible to improve the adhesion between the solid electrolyte sheet and the negative electrode material sheet and the positive electrode material sheet.

[0040] [Second manufacturing method] Instead of the first manufacturing method, the manufacturing method of the unit solid state battery 1 may include an anode material coating step of coating one side of a solid electrolyte sheet containing a solid electrolyte with an anode material layer containing an anode material, and a cathode material coating step of coating the other side of the solid electrolyte sheet with a cathode material layer containing a cathode material. In the anode material coating step and the cathode material coating step, it is preferable to coat the anode material layer and the cathode material layer so that their outer edges do not extend beyond the outer edges of the solid electrolyte sheet. This makes it possible to manufacture a unit solid state battery 1 that can prevent short circuits when stacked. Furthermore, it is possible to improve the adhesion between the solid electrolyte sheet and the anode material layer and the cathode material layer.

[0041] The coating methods for the anode material and the cathode material in the anode material coating step and the cathode material coating step are not particularly limited, and the anode material containing the anode active material and the cathode material containing the cathode active material can be coated onto the solid electrolyte sheet by a method such as electrostatic coating, for example.

[0042] <Solid-state battery module> [First laminated structure] The configuration of a solid state battery module 10 having a first stacked structure L1 will be described below with reference to FIGS. 4A and 4B. FIG. 4A is an explanatory diagram showing the first stacked structure L1 of the solid state battery module 10. The first stacked structure L1 is formed by stacking a plurality of unit solid state batteries 1, as shown in FIG. 4A. The plurality of unit solid state batteries 1 are arranged so that the negative electrode material layers 2 and the positive electrode material layers 3 are adjacent to each other. A negative electrode plate 21 is arranged between adjacent negative electrode material layers 2. A positive electrode plate 31 is arranged between adjacent positive electrode material layers 3. The number of stacked unit solid state batteries 1 is an even number, and the collector electrode plates arranged at both stacking ends of the stacked unit solid state batteries 1 are negative electrode plates 21 of the same type.

[0043] 4B is a diagram showing the configuration of a solid state battery module 10 having a first stacked structure L1. The plurality of negative electrode plates 21 in the solid state battery module 10 are each connected to a negative electrode terminal 22. Similarly, the plurality of positive electrode plates 31 are each connected to a positive electrode terminal 32. This connects four unit solid state batteries 1 in parallel. The dashed line in FIG. 4B visualizes the potential difference P1 of the solid state battery module 10. Although not shown, the solid state battery module 10 may include an exterior body made of a laminate film or the like in addition to the first stacked structure L1.

[0044] (negative and positive plates) The negative electrode plate 21 as a collector electrode plate is not particularly limited, but may be made of, for example, nickel, copper or a copper alloy, stainless steel, etc. The positive electrode plate 31 as a collector electrode plate is not particularly limited, but may be made of, for example, aluminum, an aluminum alloy, stainless steel, nickel, iron, titanium, etc. The negative electrode plate 21 and the positive electrode plate 31 may have, for example, a foil shape, a plate shape, etc.

[0045] According to the solid-state battery module 10 having the first stack structure L1, a solid-state battery module with any desired capacity can be constructed by stacking unit solid-state batteries 1 having the same configuration so that the same type of electrode material layers are adjacent to each other. Furthermore, since the negative electrode plate 21 or the positive electrode plate 31 is disposed at both ends of the stack, no electrode material is disposed at both ends of the stack, and no ineffective portions of the electrode material are generated, as compared with a conventional solid-state battery in which an electrode layer including a current collector and a solid electrolyte layer are stacked. This improves the energy density of the module unit.

[0046] [Second laminated structure] The configuration of a solid-state battery module 10e having a second stacked structure L2 will be described below with reference to FIG. 9B . Similar to the first stacked structure L1, the second stacked structure L2 is arranged so that the negative electrode material layers 2 and the positive electrode material layers 3 are adjacent to each other. The second stacked structure L2 differs from the first stacked structure L1 in that the number of stacked unit solid-state batteries 1 in the second stacked structure L2 is odd, and the electrode material layers or collector electrode plates arranged at both stacked ends of the stacked unit solid-state batteries 1 are different types of electrode material layers or collector electrode plates. By combining multiple such second stacked structures L2, the second stacked structures L2 can be connected in series. Therefore, by adjusting the number of stacked unit solid-state batteries 1 constituting the second stacked structure L2 and the number of series connections between the second stacked structures L2, a solid-state battery module with any capacity and voltage can be configured. Other configurations of the solid-state battery module 10e will be described in detail later.

[0047] [Third layered structure] The configuration of a solid state battery module 10a having a third stack structure L3 will be described below with reference to FIGS. 5A and 5B. FIG. 5A is an explanatory diagram showing the third stack structure L3 of the solid state battery module 10a. The third stack structure L3 is formed by stacking a plurality of unit solid state batteries 1, as shown in FIG. 5A. The plurality of unit solid state batteries 1 are arranged such that the negative electrode material layer 2 and the positive electrode material layer 3 are adjacent to each other. A bipolar electrode plate 5 is arranged between adjacent negative electrode material layers 2 and positive electrode material layers 3. The collector electrode plates arranged at both stacking ends of the stacked unit solid state batteries 1 are different types of electrode plates: a negative electrode plate 21 and a positive electrode plate 31.

[0048] 5B is a diagram showing the configuration of a solid state battery module 10a having a third stack structure L3. The negative electrode plate 21 in the solid state battery module 10a is connected to a negative electrode terminal 22. Similarly, the positive electrode plate 31 is connected to a positive electrode terminal 32. Bipolar electrode plates 5 are disposed between the multiple unit solid state batteries 1. This connects four unit solid state batteries 1 in series. The dashed lines in FIG. 5B visualize the potential difference P2 of the solid state battery module 10a.

[0049] (bipolar electrode plate) The bipolar electrode plate 5 is an electrode formed by, for example, forming a negative electrode composite layer, which will become the negative electrode of the polarizable electrode, on one surface of a sheet-like current collector (current collector foil), and forming a positive electrode composite layer, which will become the positive electrode of the polarizable electrode, on the other surface. The sheet-like current collector is not particularly limited, but examples thereof include stainless steel foil.

[0050] According to the solid state battery module 10a having the third stack structure L3, a solid state battery module having any voltage can be constructed by stacking unit solid state batteries 1 having the same configuration so that different electrode material layers are adjacent to each other. Also, similar to the solid state battery module having the first stack structure L1, no ineffective portions of the electrode material are generated at both ends of the stack, and the energy density of the module unit can be improved.

[0051] Third stack structures L3 can also be connected in parallel. FIG. 6 is a diagram showing the configuration of a solid-state battery module 10b in which six third stack structures L3 having a potential difference P2 are connected in parallel. Adjacent electrode material layers arranged at the stacking ends of adjacent third stack structures L3 are of the same type. Furthermore, the negative electrode plate 21 or positive electrode plate 31 arranged between adjacent electrode material layers of the same type serves as a common collector electrode plate. Furthermore, multiple negative electrode plates 21 and multiple positive electrode plates 31 are connected to a common negative electrode terminal 22 and a common positive electrode terminal 32, respectively. This allows multiple third stack structures L3 to be connected in parallel. Therefore, by adjusting the number of third stack structures L3 connected in parallel, a solid-state battery module with any capacity can be configured.

[0052] First Embodiment Next, the configuration of a solid state battery module according to a preferred embodiment of the present invention will be described. As shown in FIG. 7B, a solid state battery module 10c according to this embodiment has a first stacked structure L1. The first stacked structure L1 is housed in an exterior body 6.

[0053] (exterior body) The exterior body 6 is the exterior body of the solid-state battery module 10c and accommodates the first laminate structure L1 inside. The exterior body 6 is not particularly limited, but may be, for example, a laminate cell. A laminate cell has a multilayer structure in which a heat-sealable resin layer such as polyolefin is laminated on the outside of a metal layer made of, for example, aluminum, stainless steel (SUS), or the like. In addition to the above, the laminate cell may also have a layer made of polyamide such as nylon, polyester such as polyethylene terephthalate, or an adhesive layer made of any laminate adhesive. The exterior body 6 is not limited to a laminate cell and may be, for example, a metal can.

[0054] As shown in Fig. 7A, the solid-state battery module 10c has the negative electrode terminal 22 and the positive electrode terminal 32 disposed on the same side of the solid-state battery module 10c. Therefore, as schematically shown by the arrow in Fig. 7A, a current flows from the negative electrode terminal 22 to the positive electrode terminal 32. This allows the negative electrode terminal 22 and the positive electrode terminal 32 to extend in the same direction. This improves the layout flexibility of the solid-state battery module 10c.

[0055] Other embodiments of the present invention will be described below, and the description of the same configuration as that described above may be omitted.

[0056] Second Embodiment As shown in FIG. 8B , the solid-state battery module 10d according to this embodiment is formed by stacking a first stacked structure L1a and a first stacked structure L1b. The first stacked structure L1a has a negative electrode plate 21 disposed at its outer end, and a negative electrode material layer 2 disposed at its inner end adjacent to the first stacked structure L1b. The first stacked structure L1b has a positive electrode plate 31 disposed at its outer end, and a positive electrode material layer 3 disposed at its inner end adjacent to the first stacked structure L1a. The adjacent negative electrode material layers 2 and positive electrode material layers 3 of the first stacked structures L1a and L1b are connected by a clad electrode 7. The clad electrode 7 has a clad structure in which dissimilar metals, such as copper or a copper alloy and aluminum or an aluminum alloy, are layered by ultrasonic welding, vibration welding, or other methods. The clad electrode 7 electrically connects the negative and positive electrodes made of dissimilar metals.

[0057] The negative electrode plates 21 of the first stack structure L1a are connected to the negative electrode terminal 22, and the positive electrode plates 31 are connected to the positive electrode terminal 33. The negative electrode plates 21 of the first stack structure L1b are connected to the negative electrode terminal 23, and the positive electrode plates 31 are connected to the positive electrode terminal 32. The negative electrode terminal 23 and the positive electrode terminal 33 are disposed inside the exterior body 6. As shown in FIG. 8A, the negative electrode terminal 22 and the positive electrode terminal 33, and the negative electrode terminal 23 and the positive electrode terminal 32, are disposed on opposite sides of the solid-state battery module 10d in a plan view. Therefore, as indicated by arrow y1 in FIG. 8A, a current flows from the negative electrode terminal 23 to the positive electrode terminal 32. Similarly, as indicated by arrow y2, a current flows from the negative electrode terminal 22 to the positive electrode terminal 33. The arrangement of the negative electrode terminal and the positive electrode terminal allows a charge transfer medium to be uniformly transferred on the electrode plates. This reduces internal resistance and improves the output of the solid-state battery module 10d.

[0058] 8B, the solid-state battery module 10d has the same potential at both stacked ends, so there is no need to place a member for preventing short circuits, such as an insulating member, between the first stacked structure L1a and the first stacked structure L1b and the exterior body 6.

[0059] Third Embodiment As shown in FIG. 9B , the solid-state battery module 10e according to this embodiment has a second stack structure L2. The second stack structure L2, located on the left side in FIG. 9B , has a negative electrode plate 21 disposed at its outer end and a positive electrode layer 3 and a positive electrode collector plate 34 disposed at its inner end. The second stack structure L2, located on the right side in FIG. 9B , has a positive electrode plate 31 disposed at its outer end and a negative electrode layer 2 and a negative electrode collector plate 24 disposed at its inner end. An insulating member 8 is disposed between the two second stack structures L2. The solid-state battery module 10e has a plurality of negative electrode terminals 22a, 22b, 22c, and 22d and a plurality of positive electrode terminals 32a, 32b, 32c, and 32d. The negative electrode plate 21 and positive electrode plate 31 of the second stack structure L2 are connected to the positive electrode terminal and negative electrode terminal, respectively. This allows current to flow through each electrode plate, as schematically shown by the dashed lines in FIG. 9A . The solid-state battery module 10e has a plurality of positive and negative electrode terminals, which allows the charge transfer medium to be uniformly transferred on the electrode plates, thereby reducing the internal resistance and improving the output of the solid-state battery module 10e.

[0060] FIG. 9C is an exploded perspective view of the solid-state battery module 10e. The negative electrode collector plate 24 is made of, for example, a metal plate made of the same material as the negative electrode plate 21, such as copper or a copper alloy. The negative electrode collector plate 24 is electrically connected to multiple negative electrode terminals. Alternatively, a portion of the negative electrode collector plate 24 may serve as the negative electrode terminal. The positive electrode collector plate 34 is made of, for example, a metal plate made of the same material as the positive electrode plate 31, such as aluminum or an aluminum alloy. The positive electrode collector plate 34 is electrically connected to multiple positive electrode terminals. Alternatively, a portion of the positive electrode collector plate 34 may serve as the positive electrode terminal. As shown in FIGS. 9B and 9D, the negative electrode terminal 23a and the positive electrode terminal 33a, to which the multiple negative electrode plates are connected, are electrically connected inside the exterior body 6. This allows multiple second stacked structures L2 to be connected in series inside the cell. For this connection, a clad material having a clad structure in which different metals are layered can be used. The clad material can have a structure similar to that of the clad electrode 7.

[0061] Fourth Embodiment As shown in FIG. 10B , the solid state battery module 10f according to this embodiment has a third stack structure L3. In this embodiment, four third stack structures L3 are connected in parallel. The number of parallel connections can be any number. A negative electrode plate 21 or a positive electrode plate 31, which is a common collector electrode plate, is disposed between each third stack structure L3. The number of unit solid state batteries 1 constituting each third stack structure L3 can be any number according to the desired potential difference P3. As a result, a solid state battery module 10f having any capacity and voltage can be constructed by stacking unit solid state batteries 1 having the same structure.

[0062] Fifth Embodiment As shown in FIG. 11B, the solid-state battery module 10g according to this embodiment has a third stack structure L3. Adjacent third stack structures L3 are stacked so that the same electrode material layers are adjacent to each other. The number of stacked layers in the third stack structure L3 can be any number. The negative electrode plate 21 and the positive electrode plate 31 of the third stack structure L3 are electrically connected to multiple negative electrode terminals 22a, 22b and multiple positive electrode terminals 32a, 33b inside the exterior body 6. This allows current to flow through each electrode plate, as schematically shown by the dashed lines in FIG. 11A. The solid-state battery module 10g has multiple positive and negative electrode terminals, allowing the charge transfer medium to be uniformly transferred across the electrode plates. This reduces internal resistance and improves the output of the solid-state battery module 10g.

[0063] FIG. 11C is an exploded perspective view of a solid-state battery module 10g. The solid-state battery module 10g includes a negative electrode collector plate 24 and a positive electrode collector plate 34 having the same configuration as those in the third embodiment. In this embodiment, the plurality of negative electrode plates 21 and the negative electrode collector plate 24 are electrically connected to the negative electrode terminal 22b inside the exterior body 6, as shown in FIG. 11D. Similarly, the plurality of positive electrode plates 31 and the positive electrode collector plate 34 are electrically connected to the positive electrode terminal 32a. The negative electrode terminal 22b and the positive electrode terminal 32a may be part of the negative electrode collector plate 24 and the positive electrode collector plate 34, respectively. With the above configuration, a series or parallel connection within the cell can be realized, and a solid-state battery module 10g having any capacity and voltage can be configured.

[0064] <Solid-state battery module manufacturing method> The manufacturing method of the solid state battery module according to this embodiment includes an arrangement step of arranging predetermined collector electrode plates between unit solid state batteries 1, and a pressurizing step of applying pressure to the stacked unit solid state batteries 1 and the collector electrode plates with a press or the like to integrate them.

[0065] When the method for manufacturing the unit solid state batteries 1 includes a pressurizing step of stacking and pressing an anode material sheet, a solid electrolyte sheet, and a cathode material sheet in this order, a placement step of placing predetermined collector electrode plates between the unit solid state batteries 1 before pressing may be provided. This allows a solid state battery module to be manufactured without the pressurizing step for integrating the unit solid state batteries 1.

[0066] The pressurizing step for manufacturing the unit solid state battery 1 and the pressurizing step for manufacturing the solid state battery module may be separate steps, thereby improving the adhesion between the solid electrolyte sheet in the unit solid state battery 1 and the negative electrode material sheet and the positive electrode material sheet.

[0067] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications are also included within the scope of the present invention. [Explanation of symbols]

[0068] 1 unit solid-state battery 2 Negative electrode material layer 3 Cathode material layer 4 Solid electrolyte layer 10, 10a, 10b, 10c, 10d, 10e, 10f, 10g Solid-state battery module 21 Negative electrode plate 31 Positive electrode plate 5 Bipolar electrode plate L1 First stacked cell structure L2 Second stacked cell structure L3 Third layer cell structure

Claims

1. a solid-state battery module having a stacked cell structure formed by stacking a plurality of unit solid-state batteries that constitute a solid-state battery; the unit solid state battery has a solid electrolyte layer, and a negative electrode material layer and a positive electrode material layer as electrode material layers laminated on both sides of the solid electrolyte layer, The negative electrode material layer and the positive electrode material layer do not include a current collector, the stacked cell structure has a collector electrode plate disposed between the unit solid-state batteries, The battery has a plurality of positive electrode terminals and a plurality of negative electrode terminals to which the collector electrode plates are connected, the positive electrode terminal and the negative electrode terminal are arranged so as to extend from at least three sides of an outer shape of the stacked cell structure when the solid-state battery module is viewed in a plan view from the stacking direction, the positive electrode terminals and the negative electrode terminals adjacent to each other in a stacking direction of the solid-state battery modules are arranged at positions that do not overlap each other when the solid-state battery modules are viewed in a plan view from the stacking direction, a solid-state battery module, wherein one of the positive electrode terminal and the negative electrode terminal is disposed so that a current flows between the one of the positive electrode terminal and the negative electrode terminal, which are provided on adjacent sides of the outer shape of the stacked cell structure, and the other of the negative electrode terminal and the positive electrode terminal, respectively.

2. When the unit solid state battery is viewed in a plan view from the stacking direction, 2. The solid state battery module according to claim 1, wherein an area of ​​the solid electrolyte layer is larger than areas of the negative electrode material layer and the positive electrode material layer, and an outer edge of the solid electrolyte layer is positioned outward from outer edges of the negative electrode material layer and the positive electrode material layer.

3. adjacent unit solid state batteries are arranged such that the positive electrode material layers are adjacent to each other and the negative electrode material layers are adjacent to each other, a negative electrode plate serving as the collector electrode plate is disposed between adjacent negative electrode material layers, a positive electrode plate serving as the collector electrode plate is disposed between adjacent positive electrode material layers; 3. The solid-state battery module according to claim 1, wherein the collector electrode plates or the electrode material layers arranged at both stacking ends of the stacked unit solid-state batteries are of the same type in a first stacked cell structure.

4. a plurality of the first stacked cell structures are stacked, The solid-state battery module according to claim 3 , wherein the collector electrode plates or the electrode material layers arranged at both stacking ends of adjacent first stacked cell structures are made of different materials.

5. adjacent unit solid state batteries are arranged such that the negative electrode material layers are adjacent to each other and the positive electrode material layers are adjacent to each other, a negative electrode plate serving as the collector electrode plate is disposed between adjacent negative electrode material layers, a positive electrode plate serving as the collector electrode plate is disposed between adjacent positive electrode material layers; 3. The solid state battery module according to claim 1, wherein the collector electrode plates or the electrode material layers arranged at both stacking ends of the stacked unit solid state batteries are of different types to form a second stacked cell structure.

6. Adjacent unit solid state batteries are arranged such that the negative electrode material layer and the positive electrode material layer are adjacent to each other, a bipolar electrode plate is disposed between the adjacent negative electrode material layer and the adjacent positive electrode material layer; the collector electrode plates or the electrode material layers disposed at both stacking ends of the stacked unit solid state batteries are of different materials; 3. The solid state battery module according to claim 1, wherein the third stacked cell structure has a negative electrode plate disposed in contact with the negative electrode material layer and a positive electrode plate disposed in contact with the positive electrode material layer at both stacking ends.

7. A method for manufacturing a solid-state battery module having a stacked cell structure formed by stacking a plurality of unit solid-state batteries that constitute a solid-state battery, comprising: a sheet forming step of forming a negative electrode material sheet including a negative electrode material, a positive electrode material sheet including a positive electrode material, and a solid electrolyte sheet including a solid electrolyte; a pressurizing step of pressing the negative electrode material sheet and the positive electrode material sheet with the solid electrolyte sheet sandwiched therebetween to produce the unit solid state battery; a step of disposing collector electrodes between the unit solid state batteries and disposing positive and negative terminals connected to the collector electrodes, the step of disposing the positive and negative terminals so as to extend from at least three sides of an outer shape of the stacked cell structure when the solid state battery module is viewed in a plane in the stacking direction, disposing the positive and negative terminals adjacent to each other in the stacking direction of the solid state battery module at positions where they do not overlap each other when the solid state battery module is viewed in a plane in the stacking direction, and disposing one of the positive and negative terminals so that a current flows between the one of the positive and negative terminals and the other of the negative and positive terminals provided on the adjacent sides of the outer shape of the stacked cell structure, respectively.

8. A method for manufacturing a solid-state battery module having a stacked cell structure formed by stacking a plurality of unit solid-state batteries that constitute a solid-state battery, comprising: a negative electrode material coating step of coating one surface of a solid electrolyte sheet containing a solid electrolyte with a negative electrode material layer containing a negative electrode material; a cathode material coating step of coating the other surface of the solid electrolyte sheet with a cathode material layer containing a cathode material, thereby producing the unit solid state battery; a step of disposing collector electrodes between the unit solid state batteries and disposing positive and negative terminals connected to the collector electrodes, the step of disposing the positive and negative terminals so as to extend from at least three sides of an outer shape of the stacked cell structure when the solid state battery module is viewed in a plane in the stacking direction, disposing the positive and negative terminals adjacent to each other in the stacking direction of the solid state battery module at positions where they do not overlap each other when the solid state battery module is viewed in a plane in the stacking direction, and disposing one of the positive and negative terminals so that a current flows between the one of the positive and negative terminals and the other of the negative and positive terminals provided on the adjacent sides of the outer shape of the stacked cell structure, respectively.

9. a first cutting step of cutting the negative electrode material sheet and the positive electrode material sheet; a second cutting step of cutting the solid electrolyte sheet so that the solid electrolyte sheet has an area larger than that of the positive electrode material sheet and the negative electrode material sheet in a plan view; The method for manufacturing a solid state battery module according to claim 7 , further comprising: a lamination step of laminating the negative electrode material sheet, the solid electrolyte sheet, and the positive electrode material sheet in this order.

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