Solid battery unit and solid battery stack

Abstract

To provide a solid battery unit and a solid battery stack, capable of reducing a power collection resistance while improving an electric capacitance and comparatively easily performing an electric connection with an external part.SOLUTION: A solid battery unit 1 comprises: an electrode sheet 10; a positive electrode power collection plate 11; and a negative electrode power collection plate 12. Also, the positive electrode power collection plate comprises: a positive electrode first plate 110; a positive electrode second plate 111, and a positive electrode coupling part 112 that couples one end of the positive electrode first plate and one end of the positive electrode second plate. The negative electrode power collection plate comprises: a negative electrode first plate 120; a negative electrode second plate 121; and a negative electrode coupling part 122 that couples one end of the negative electrode first plate and the one end of the negative electrode second plate. The negative electrode first plate is inserted from between the other end of the positive electrode first plate and the other end of the positive electrode second plate, and the positive electrode second plate is inserted from between the other end of the negative electrode first plate and the other end of the negative electrode second plate. An electrode sheet is arranged to between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a solid-state battery unit and a solid-state battery stack. [Background technology]

[0002] In recent years, a solid-state battery using a lithium ion conductive solid electrolyte has become known. This solid-state battery includes a unit cell part in which a solid electrolyte layer is disposed between a positive electrode layer and a negative electrode layer, a positive electrode current collector disposed on the opposite side of the solid electrolyte layer with respect to the positive electrode layer, and a negative electrode current collector disposed on the opposite side of the solid electrolyte layer with respect to the negative electrode layer.

[0003] In order to improve the battery capacity of such solid-state batteries, it has been proposed to repeatedly stack positive electrode current collectors and negative electrode current collectors with the above-mentioned unit battery parts sandwiched therebetween (see, for example, Patent Document 1).

[0004] In a solid-state battery such as that described in Patent Document 1, each of the positive and negative electrode current collectors usually has a current collecting tab for electrical connection with the outside, and these current collecting tabs are welded to a terminal member (lead wire). However, when the number of stacked solid-state batteries is increased to improve the battery capacity, the number of current collecting tabs also increases, which is problematic in that the energy required to weld the current collecting tabs to the terminal members increases.

[0005] In view of this, it has been proposed to fold the positive and negative current collectors in a zigzag manner and place an electrode layer between the positive and negative current collectors (see, for example, Patent Document 2). The solid-state battery of Patent Document 2 has only one current collecting tab even if the number of stacked solid-state batteries (unit battery parts) is increased, which allows for improved battery capacity and easy electrical connection to the outside. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-251417 A [Patent Document 2] JP 2020-113434 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the solid-state battery of Patent Document 2, the positive electrode current collector and the negative electrode current collector are folded in a zigzag shape, so that the length of the positive electrode current collector and the negative electrode current collector is long, and therefore, as the number of layers increases, the current collection resistance increases.

[0008] The present invention provides a solid-state battery unit and a solid-state battery stack that can improve electric capacity, can be electrically connected to the outside relatively easily, and can reduce current collection resistance. [Means for solving the problem]

[0009] The present invention [1] provides an electrode sheet including an electrolyte layer, a positive electrode layer disposed on one side of the electrolyte layer, and a negative electrode layer disposed on the other side of the electrolyte layer, a positive electrode current collector in contact with the positive electrode layer of the electrode sheet, and a negative electrode current collector in contact with the negative electrode layer of the electrode sheet, the positive electrode current collector including a positive electrode first plate and a positive electrode second plate disposed opposite to each other with a gap therebetween, and a positive electrode connection portion connecting one end of the positive electrode first plate and one end of the positive electrode second plate, the other end of the positive electrode first plate and the other end of the positive electrode second plate being open, and the negative electrode current collector including a negative electrode first plate and a negative electrode second plate disposed opposite to each other with a gap therebetween, a negative electrode connecting portion connecting one end of a first plate and one end of the negative electrode second plate, the gap between the other end of the negative electrode first plate and the other end of the negative electrode second plate is open, the positive electrode current collector plate and the negative electrode current collector plate are arranged such that the negative electrode first plate is inserted between the other end of the positive electrode first plate and the other end of the positive electrode second plate, and the positive electrode second plate is inserted between the other end of the negative electrode first plate and the other end of the negative electrode second plate, and the electrode sheets are respectively arranged between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate.

[0010] According to this solid-state battery unit, the positive electrode current collector and the negative electrode current collector are arranged such that the negative electrode first plate is inserted between the other end of the positive electrode first plate and the other end of the positive electrode second plate, and the positive electrode second plate is inserted between the other end of the negative electrode first plate and the other end of the negative electrode second plate. The electrode sheets are arranged between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate, respectively. Therefore, the number of each current collector plate relative to the number of electrode sheets can be reduced, and the electrical capacity can be improved while making it relatively easy to electrically connect to the outside. In addition, the length of the positive electrode current collector and the negative electrode current collector is short, and the current collection resistance can be reduced.

[0011] The present invention [2] includes the solid-state battery unit according to [1], wherein the electrode sheets are disposed respectively between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate.

[0012] In this solid-state battery unit, one electrode sheet is disposed between the first positive electrode plate and the first negative electrode plate, one between the first negative electrode plate and the second positive electrode plate, and one between the second positive electrode plate and the second negative electrode plate, so that the length of each current collector plate can be made shorter, and current collection resistance can be reduced.

[0013] The present invention [3] includes the solid-state battery unit according to [1], wherein the electrode sheets are arranged between the first positive electrode plate and the first negative electrode plate, between the first negative electrode plate and the second positive electrode plate, and between the second positive electrode plate and the second negative electrode plate, with two or more electrode sheets being the same number, and adjacent electrode sheets are stacked electrically in series.

[0014] In this solid-state battery unit, two or more electrode sheets are disposed between the first positive electrode plate and the first negative electrode plate, between the first negative electrode plate and the second positive electrode plate, and between the second positive electrode plate and the second negative electrode plate, respectively, and the same number of electrode sheets are disposed between the first negative electrode plate and the second positive electrode plate. This makes it possible to further reduce the number of current collector plates relative to the number of electrode sheets, thereby making it relatively easy to electrically connect to the outside while increasing the voltage.

[0015] The present invention [4] includes a solid-state battery stack in which a plurality of the solid-state battery units according to [2] are stacked, in which the plurality of solid-state battery units are stacked such that in adjacent solid-state battery units, a positive electrode first plate of one solid-state battery unit and a negative electrode second plate of the other solid-state battery unit face each other with an electrode sheet interposed therebetween, and one intervening electrode sheet is disposed for each of the solid-state battery stacks, in which the positive electrode layer of the intervening electrode sheet is in contact with the positive electrode first plate and the negative electrode layer of the intervening electrode sheet is in contact with the negative electrode second plate.

[0016] The present invention [5] is a solid-state battery stack in which a plurality of solid-state battery units according to [3] are stacked, and the plurality of solid-state battery units are stacked such that, in adjacent solid-state battery units, a positive electrode first plate of one solid-state battery unit and a negative electrode second plate of the other solid-state battery unit face each other with an electrode sheet interposed therebetween, and the number of electrode sheets arranged between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate of the plurality of solid-state battery units is the same, and The solid-state battery stack includes two or more electrode sheets, the number of interposed electrode sheets being the same as the number of electrode sheets disposed between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate of the solid-state battery unit, the interposed electrode sheets being adjacent to each other and stacked electrically in series, and the positive electrode layer on one side of the interposed electrode sheet stack being in contact with the positive electrode first plate, and the negative electrode layer on the other side of the interposed electrode sheet stack being in contact with the negative electrode second plate.

[0017] According to this solid-state battery stack, a plurality of the solid-state battery units are stacked. Therefore, the number of current collectors relative to the number of electrode sheets can be reduced, and electrical connection to the outside can be relatively easily performed while improving the electric capacity. In addition, the length of the positive and negative current collectors is short, and current collection resistance can be reduced.

[0018] The present invention [6] includes the solid-state battery stack according to [4] or [5], wherein the positive current collector further comprises a positive current collector tab protruding from an edge, and the negative current collector further comprises a negative current collector tab protruding from an edge.

[0019] According to this solid-state battery stack, the positive current collector plate further includes a positive current collector tab protruding from an edge, and the negative current collector plate further includes a negative current collector tab protruding from an edge, which makes it relatively easy to establish electrical connection with the outside.

[0020] The present invention [7] includes the solid-state battery stack according to [4] or [5], wherein in a direction perpendicular to the stacking direction, the positive electrode connectors of each of the plurality of solid-state battery units are arranged on one side and the negative electrode connectors of each of the plurality of solid-state battery units are arranged on the other side, and the stacking direction is further provided with a positive electrode lead that is directly connected to each of the positive electrode connectors of each of the plurality of solid-state battery units and extends in the stacking direction, and a negative electrode lead that is directly connected to each of the negative electrode connectors of each of the plurality of solid-state battery units and extends in the stacking direction.

[0021] This solid-state battery stack further includes a positive electrode lead that is directly connected to each of the positive electrode connectors in the plurality of solid-state battery units and extends in the stacking direction, and a negative electrode lead that is directly connected to each of the negative electrode connectors in the plurality of solid-state battery units and extends in the stacking direction, so that electrical connection with the outside does not require a tab, thereby further reducing energy for welding, etc. Effect of the Invention

[0022] The solid-state battery unit of the present invention has an improved electric capacity, is relatively easy to electrically connect to the outside, and can reduce current collection resistance.

[0023] The solid-state battery stack of the present invention has an improved electric capacity, is relatively easy to electrically connect to the outside, and can reduce current collection resistance. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a perspective view of a first embodiment of a solid-state battery unit according to the present invention. [Diagram 2]2A to 2G are an example of a manufacturing method of the first embodiment of the solid-state battery unit. Fig. 2A shows a first step of preparing a negative current collector, Fig. 2B shows a second step of arranging an electrode sheet on one side of the negative second plate in the negative current collector, Fig. 2C shows a third step of arranging a positive current collector so that the positive second plate is arranged on one side of the electrode sheet arranged on the negative second plate, Fig. 2D shows a fourth step of arranging an electrode sheet on one side of the positive second plate, Fig. 2E shows a fifth step of bending the negative current collector so that the negative first plate is arranged on one side of the electrode sheet arranged on the positive second plate, Fig. 2F shows a sixth step of arranging an electrode sheet on one side of the negative first plate, and Fig. 2G shows a seventh step of bending the positive current collector so that the positive first plate is arranged on one side of the electrode sheet arranged on the negative first plate. [Diagram 3] FIG. 3 is a perspective view of a second embodiment of a solid-state battery unit of the present invention. [Figure 4] FIG. 4 is a perspective view of a first embodiment of a solid-state battery stack of the present invention. [Diagram 5] FIG. 5 is a perspective view of a second embodiment of a solid-state battery stack of the present invention. [Figure 6] FIG. 6 is a perspective view of a third embodiment of a solid-state battery stack of the present invention. [Figure 7] FIG. 7 is a cross-sectional view of a fourth embodiment of a solid-state battery stack of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 1.Solid-state battery unit The solid-state battery unit of the present invention will be described with reference to FIGS.

[0026] First Embodiment A first embodiment of a solid-state battery unit of the present invention will be described with reference to FIG.

[0027] The solid-state battery unit 1 includes an electrode sheet 10 , a positive electrode current collector plate 11 , and a negative electrode current collector plate 12 .

[0028] [Electrode sheet] The electrode sheet 10 has, for example, a sheet shape (including a film shape).

[0029] The electrode sheet 10 has, for example, a generally rectangular shape in plan view.

[0030] The length of one side of the electrode sheet 10 in the surface direction X direction (the X direction is a direction along two parallel sides of the electrode sheet 10) is not particularly limited, but is, for example, equal to or less than the length of one side of the positive electrode first plate 110, the positive electrode second plate 111, the negative electrode first plate 120, and the negative electrode second plate 121 in the surface direction X direction, which will be described later.

[0031] The length of one side of the electrode sheet 10 in the planar direction Y (the Y direction is a direction perpendicular to the X direction) is not particularly limited, but is, for example, less than the length of one side of the positive electrode first plate 110, the positive electrode second plate 111, the negative electrode first plate 120, and the negative electrode second plate 121 described below in the planar direction Y.

[0032] The planar area of ​​electrode sheet 10 is not particularly limited, but is, for example, less than or equal to the planar areas of positive electrode first plate 110, positive electrode second plate 111, negative electrode first plate 120, and negative electrode second plate 121 described below.

[0033] The thickness of the electrode sheet 10 is, for example, 100 μm or more, preferably 200 μm or more, and for example, 1000 μm or less, preferably 800 μm or less.

[0034] The electrode sheet 10 includes an electrolyte layer 101 , a positive electrode layer 102 disposed on one side of the electrolyte layer 101 , and a negative electrode layer 103 disposed on the other side of the electrolyte layer 101 .

[0035] Specifically, the electrode sheet 10 can be obtained, for example, by forming a positive electrode layer 102, an electrolyte layer 101, and a negative electrode layer 103, and then pressure-molding the formed positive electrode layer 102, electrolyte layer 101, and negative electrode layer 103. In this manner, the electrode sheet 10 can be manufactured individually. Therefore, the electrode sheet 10 has excellent handling properties.

[0036] {electrolyte layer} The electrolyte layer 101 is formed of, for example, a material containing a solid electrolyte. Furthermore, the electrolyte layer 101 may contain materials such as a binder that are commonly used in the field of batteries, as necessary.

[0037] The solid electrolyte is not particularly limited as long as it exhibits lithium ion conductivity, and examples thereof include organic solid electrolytes and inorganic solid electrolytes, and preferably, inorganic solid electrolytes are used.

[0038] The solid electrolytes can be used alone or in combination of two or more kinds.

[0039] Examples of inorganic solid electrolytes include sulfides, oxides, nitrides, and hydrides, and preferably, sulfides.

[0040] The sulfide may, for example, contain Li2S and another sulfide containing at least one element selected from the group consisting of Group 13 elements, Group 14 elements, and Group 15 elements of the periodic table.

[0041] The elements of Groups 13, 14 and 15 of the periodic table are not particularly limited, but include, for example, P, Si, Ge, As, Sb and Al, preferably P, Si and Ge, and more preferably P.

[0042] Specifically, examples of sulfides include Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-B2S3, Li2S-Ga2S3, Li2S-Al2S3, Li2S-GeS2-P2S5, Li2S-Al2S3-P2S5, Li2S-P2S3, Li2S-P2S3-P2S5, LiX-Li2S-P2S5, LiX-Li2S-SiS2, and LiX-Li2S-B2S3 (X: I, Br, or Cl).

[0043] The thickness of the electrolyte layer 101 is, for example, 10 μm or more, preferably 30 μm or more, and for example, 300 μm or less, preferably 100 μm or less.

[0044] {Positive electrode layer} The positive electrode layer 102 may be formed, for example, from a material consisting of only a positive electrode active material, or may be formed from a material containing a positive electrode active material and a solid electrolyte. The positive electrode layer 102 is preferably formed from a material containing a positive electrode active material and a solid electrolyte. In addition, the positive electrode layer 102 may contain materials such as a binder that are commonly used in the field of batteries, as necessary.

[0045] The positive electrode active material is not particularly limited as long as it is a material capable of inserting and extracting lithium ions. For example, lithium-nickel composite oxide (LiNi X M 1-X O2), lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), lithium nickel cobalt aluminum oxide (LiNi 0.8 Co 0.15 Al 0.05 Examples of the oxide include lithium oxides such as lithium ion-excess oxide (Li2MnO3-LiMO2), lithium manganate (lithium spinel manganate (LiMn2O4)), and Li-excess composite oxide (Li2MnO3-LiMO2). Examples of the oxides include olivine compounds (LiMPO4) and sulfur-containing compounds (Li2S). In the above formula, M represents a transition metal. As the positive electrode active material, from the viewpoint of easily obtaining a high capacity, a lithium-containing oxide containing at least one selected from the group consisting of Co, Ni, and Mn is preferably used.

[0046] The positive electrode active materials can be used alone or in combination of two or more kinds.

[0047] In addition, from the viewpoint of improving rate characteristics, the surface of the positive electrode active material may be covered with a coating material.

[0048] The coating material is, for example, Li4Ti5O 12, LiTaO3, Li4NbO3, LiAlO2, Li2ZrO3, Li2WO4, Li2TiO3, Li2B4O7, Li3PO4, Li2MoO4, LiBO2, alumina (Al2O3), and carbon (C).

[0049] The solid electrolyte contained in the positive electrode layer 102 may be, for example, the same as the solid electrolyte contained in the electrolyte layer 101. Specifically, the solid electrolyte may be, for example, an organic solid electrolyte or an inorganic solid electrolyte.

[0050] The ratio of the positive electrode active material to the solid electrolyte in the positive electrode layer 102 is not particularly limited.

[0051] The thickness of the positive electrode layer 102 is, for example, 50 μm or more, preferably 100 μm or more, and for example, 500 μm or less, preferably 300 μm or less.

[0052] {Negative electrode layer} The negative electrode layer 103 is disposed on the other surface of the electrolyte layer 101 .

[0053] The negative electrode layer 103 may be formed, for example, from a material consisting of only a negative electrode active material, or may be formed from a material containing a negative electrode active material and a solid electrolyte. The negative electrode layer 103 is preferably formed from a material containing a negative electrode active material and a solid electrolyte. Furthermore, the negative electrode layer 103 may contain materials such as a binder that are commonly used in the field of batteries, as necessary.

[0054] The negative electrode active material is not particularly limited as long as it is a material capable of inserting and extracting lithium ions, and examples thereof include carbon materials, simple metals and semimetals, metal alloys, and metal or semimetal compounds.

[0055] Examples of carbon materials include graphite (natural graphite, artificial graphite), hard carbon, and amorphous carbon. Examples of metal and semimetal elements and metal alloys include lithium metal and its alloys, and simple silicon. Examples of metal or semimetal compounds include oxides, sulfides, nitrides, hydrates, and silicides (lithium silicides) of metals or semimetals, and examples of metal or semimetal oxides include titanium oxide and silicon oxide.

[0056] The negative electrode active material may be used alone or in combination of two or more thereof. For example, silicon oxide and a carbon material may be used in combination as the negative electrode active material.

[0057] The solid electrolyte contained in the negative electrode layer 103 may be, for example, the same as the solid electrolyte contained in the electrolyte layer 101. Specifically, the solid electrolyte is not particularly limited as long as it exhibits lithium ion conductivity, and examples of the solid electrolyte include organic solid electrolytes and inorganic solid electrolytes.

[0058] In the negative electrode layer 103, the ratio of the negative electrode active material to the solid electrolyte is not particularly limited.

[0059] The thickness of the negative electrode layer 103 is, for example, 50 μm or more, preferably 100 μm or more, and for example, 500 μm or less, preferably 300 μm or less.

[0060] [Positioning of electrode sheets] The electrode sheets 10 are respectively disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121. The details of the positive electrode first plate 110, the positive electrode second plate 111, the negative electrode first plate 120, and the negative electrode second plate 121 will be described later. Specifically, one electrode sheet 10 is respectively disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121.

[0061] As described above, the electrode sheets 10 are disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121, respectively, so that the number of current collector plates relative to the number of electrode sheets can be reduced, and electrical connection to the outside can be made relatively easy while improving the electrical capacity. If one electrode sheet 10 is disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121, respectively, the number of current collector plates relative to the number of electrode sheets can be reduced, and electrical connection to the outside can be made relatively easy while improving the electrical capacity, and further, the length of each current collector plate can be shortened, thereby reducing the current collection resistance.

[0062] [Positive current collector plate] The positive electrode current collector 11 is in contact with the positive electrode layer 102 of the electrode sheet 10 .

[0063] Positive current collector 11 includes a positive electrode first plate 110, a positive electrode second plate 111, and a positive electrode connecting portion 112. Specifically, positive current collector 11 includes positive electrode first plate 110 and positive electrode second plate 111 arranged opposite to each other with a gap therebetween, and positive electrode connecting portion 112 connecting one end of positive electrode first plate 110 and one end of positive electrode second plate 111.

[0064] The positive electrode current collector plate 11 has, for example, a generally rectangular shape in plan view.

[0065] The cross-sectional shape of the positive current collector plate 11 differs depending on the cross-sectional shape of a positive electrode connecting portion 112 described later, and is, for example, a substantially U-shaped cross-section.

[0066] {Positive electrode 1st plate} The positive electrode first plate 110 is disposed opposite to and spaced apart from a positive electrode second plate 111, which will be described later.

[0067] The positive electrode first plate 110 has, for example, a sheet shape (including a film shape, a thin plate shape, and a foil shape).

[0068] The positive electrode first plate 110 has, for example, a generally rectangular shape in plan view.

[0069] The positive electrode first plate 110 overlaps, for example, the positive electrode layer 102 of the electrode sheet 10 .

[0070] The length of one side of the positive electrode first plate 110 in the planar direction X is not particularly limited, but is, for example, equal to or greater than the total length of the electrode sheet 10 in the planar direction X.

[0071] The length of one side of the positive electrode first plate 110 in the plane direction Y is not particularly limited, but is, for example, equal to or greater than the total length of the electrode sheet 10 in the plane direction Y.

[0072] The area of ​​the positive electrode first plate 110 in the plane is not particularly limited, but is, for example, equal to or larger than the area of ​​the electrode sheet 10 in the plane.

[0073] The thickness of the positive electrode first plate 110 is, for example, 1 μm or more, preferably 5 μm or more, and for example, 100 μm or less, preferably 50 μm or less.

[0074] Examples of materials for the positive electrode first plate 110 include copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), indium (In), lithium (Li), tin (Sn), and alloys thereof.

[0075] The positive electrode first plate 110 is preferably one that has been subjected to a roughening treatment on its surface from the viewpoint of improving adhesion to the electrode sheet 10. The roughening treatment is a treatment for increasing the surface roughness by etching or the like.

[0076] {Positive electrode 2nd plate} The positive electrode second plate 111 is disposed opposite to the positive electrode first plate 110 with a gap therebetween.

[0077] The shape, plan view shape, length of one side in the planar direction X, length of one side in the planar direction Y, area in the plane, thickness, and material of the positive electrode second plate 111 are, for example, the same as those of the positive electrode first plate 110 described above.

[0078] The positive electrode second plate 111 overlaps with the positive electrode layer 102 of the electrode sheet 10, for example.

[0079] {Positive electrode connection part} The positive electrode connector 112 has, for example, a sheet shape (including a film shape, a thin plate shape, and a foil shape). The positive electrode connector 112 connects one end of the positive electrode first plate 110 and one end of the positive electrode second plate 111. That is, the positive electrode connector 112 has, for example, a curved or bent shape.

[0080] In other words, the cross-sectional shape of the positive electrode connector 112 is not particularly limited as long as it can connect one end of the positive electrode first plate 110 and one end of the positive electrode second plate 111, and specifically, examples of the cross-sectional shape of the positive electrode connector 112 include a generally U-shaped cross-sectional shape, a generally V-shaped cross-sectional shape, and a generally C-shaped cross-sectional shape. Note that the generally U-shaped cross-sectional shape and the generally V-shaped cross-sectional shape are inclined by 90° to the surface direction X.

[0081] The length of one side of the positive electrode connector 112 in the planar direction Y is not particularly limited, but is the same as the length of one side of the positive electrode first plate 110 and the positive electrode second plate 111 in the planar direction Y, for example.

[0082] The thickness direction length of the positive electrode connecting portion 112 is not particularly limited, and can be adjusted, for example, by the number of electrode sheets arranged between the positive electrode first plate 110 and the negative electrode first plate 120, and between the negative electrode first plate 120 and the positive electrode second plate 111, respectively.

[0083] The thickness and material of the positive electrode connecting portion 112 are, for example, the same as those of the positive electrode first plate 110 and the positive electrode second plate 111 described above.

[0084] {Positive electrode collector plate configuration} In the positive current collector plate 11, a positive first plate 110 and a positive second plate 111 are disposed opposite each other with a gap therebetween.

[0085] In addition, in the positive current collector plate 11, the positive electrode connecting portion 112 connects one end of the positive electrode first plate 110 and one end of the positive electrode second plate 111. Specifically, the positive electrode connecting portion 112 connects one end of the positive electrode first plate 110 on one side in the planar direction X direction and one end of the positive electrode second plate 111 on one side in the planar direction X direction.

[0086] On the other hand, in the positive current collector plate 11, the other end of the positive electrode first plate 110 and the other end of the positive electrode second plate 111 are open. Specifically, one end of the positive electrode first plate 110 on the other side in the planar direction X direction and one end of the positive electrode second plate 111 on the other side in the planar direction X direction are open.

[0087] The positive electrode first plate 110, the positive electrode second plate 111, and the positive electrode connecting portion 112 may be formed by bending one positive electrode current collector plate 11. The positive electrode first plate 110, the positive electrode second plate 111, and the positive electrode connecting portion 112 thus formed are continuous. The positive electrode first plate 110, the positive electrode second plate 111, and the positive electrode connecting portion 112 may be formed separately and joined together. Preferably, the positive electrode first plate 110, the positive electrode second plate 111, and the positive electrode connecting portion 112 are formed by bending one positive electrode current collector plate 11.

[0088] The maximum length of one side in the plane of the positive electrode collector plate 11 (the sum of the lengths of one side in the planar direction X of the positive electrode first plate 110 and the positive electrode second plate 111 and the length in the thickness direction of the positive electrode connecting portion 112) can be adjusted by the number of electrode sheets arranged between the positive electrode first plate 110 and the negative electrode first plate 120 and between the negative electrode first plate 120 and the positive electrode second plate 111, respectively, and can be prevented from becoming excessively long, thereby reducing the current collection resistance.

[0089] [Negative current collector plate] The negative electrode current collector 12 is in contact with the negative electrode layer 103 of the electrode sheet 10 .

[0090] The negative electrode current collector 12 includes a negative electrode first plate 120, a negative electrode second plate 121, and a negative electrode connecting portion 122. Specifically, the negative electrode current collector 12 includes the negative electrode first plate 120 and the negative electrode second plate 121 arranged opposite to each other with a gap therebetween, and the negative electrode connecting portion 122 connecting one end of the negative electrode first plate 120 and one end of the negative electrode second plate 121.

[0091] The negative electrode current collector 12 has, for example, a generally rectangular shape in plan view.

[0092] The cross-sectional shape of the negative electrode current collector plate 12 differs depending on the cross-sectional shape of a negative electrode connector 122 described later, and is, for example, a generally U-shaped cross-section.

[0093] {Negative electrode 1st plate} Negative electrode first plate 120 is disposed opposite to and spaced apart from negative electrode second plate 121, which will be described later.

[0094] The shape, plan view shape, length of one side in the planar direction X, length of one side in the planar direction Y, area in plan, thickness, and material of negative electrode first plate 120 are, for example, the same as those of positive electrode first plate 110 described above.

[0095] It should be noted that the negative electrode first plate 120 overlaps, for example, the negative electrode layer 103 of the electrode sheet 10.

[0096] {Negative electrode second plate} Negative electrode second plate 121 is disposed opposite negative electrode first plate 120 with a gap therebetween.

[0097] The shape, plan view shape, length of one side in the planar direction X, length of one side in the planar direction Y, area in the plane, thickness, and material of the negative electrode second plate 121 are, for example, the same as those of the positive electrode second plate 111 described above.

[0098] The negative electrode second plate 121 overlaps, for example, the negative electrode layer 103 of the electrode sheet 10.

[0099] {Negative electrode connection part} The shape, cross-sectional shape, length of one side in the planar direction Y, length in the thickness direction, thickness, and material of the negative electrode connector 122 are, for example, the same as those of the positive electrode connector 112 described above.

[0100] The thickness direction length of the negative electrode connecting portion 122 can be adjusted, for example, by the number of electrode sheets arranged between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121, respectively.

[0101] {Configuration of negative electrode collector plate} In the negative current collector plate 12, the negative first plate 120 and the negative second plate 121 are disposed opposite to each other with a gap therebetween.

[0102] In addition, in the negative current collector plate 12, the negative electrode connecting portion 122 connects one end of the negative electrode first plate 120 to one end of the negative electrode second plate 121. Specifically, the negative electrode connecting portion 122 connects one end of the negative electrode first plate 120 on the other side in the planar direction X direction to one end of the negative electrode second plate 121 on the other side in the planar direction X direction.

[0103] On the other hand, in the negative current collector plate 12, the other end of the negative electrode first plate 120 and the other end of the negative electrode second plate 121 are open. Specifically, one end of the negative electrode first plate 120 on one side in the planar direction X direction and one end of the negative electrode second plate 121 on one side in the planar direction X direction are open.

[0104] The negative electrode first plate 120, the negative electrode second plate 121, and the negative electrode connecting portion 122 may be formed by bending one negative electrode current collector plate 12. The negative electrode first plate 120, the negative electrode second plate 121, and the negative electrode connecting portion 122 thus formed are continuous. The negative electrode first plate 120, the negative electrode second plate 121, and the negative electrode connecting portion 122 may be formed separately and joined together. Preferably, the negative electrode first plate 120, the negative electrode second plate 121, and the negative electrode connecting portion 122 are formed by bending one negative electrode current collector plate 12.

[0105] The maximum length of one side in the plane of the negative electrode current collecting plate 12 (the sum of the lengths of one side in the planar direction X of the negative electrode first plate 120 and the negative electrode second plate 121 and the length in the thickness direction of the negative electrode connecting portion 122) can be adjusted by the number of electrode sheets arranged between the negative electrode first plate 120 and the positive electrode second plate 111 and between the positive electrode second plate 111 and the negative electrode second plate 121, respectively, and can be prevented from becoming excessively long, thereby reducing the current collection resistance.

[0106] [Positive and negative current collector arrangement] As described above, in the positive current collector plate 11, one end of the positive first plate 110 on one side in the surface direction X and one end of the positive second plate 111 on one side in the surface direction X are connected by the positive connection part 112, while one end (the other end) of the positive first plate 110 on the other side in the surface direction X and one end (the other end) of the positive second plate 111 on the other side in the surface direction X are open. In contrast, in the negative current collector plate 12, one end of the negative first plate 120 on the other side in the surface direction X and one end of the negative second plate 121 on the other side in the surface direction X are connected by the negative connection part 122, while one end (the other end) of the negative first plate 120 on one side in the surface direction X and one end (the other end) of the negative second plate 121 on one side in the surface direction X are open.

[0107] That is, in the planar direction X, one connected end of the positive electrode first plate 110 and the positive electrode second plate 111 is opposite to one connected end of the negative electrode first plate 120 and the negative electrode second plate. Also, in the planar direction X, one open end (other end) of the positive electrode first plate 110 and the positive electrode second plate 111 is opposite to one open end (other end) of the negative electrode first plate 120 and the negative electrode second plate. Furthermore, the positive electrode connector 112 is disposed opposite to the negative electrode connector 122 in the X direction.

[0108] The positive electrode current collector plate 11 and the negative electrode current collector plate 12 are arranged such that the negative electrode first plate 120 is inserted between the other end of the positive electrode first plate 110 and the other end of the positive electrode second plate 111, and the positive electrode second plate 111 is inserted between the other end of the negative electrode first plate 120 and the other end of the negative electrode second plate 121. Specifically, the negative electrode first plate 120 is inserted from the other side in the X direction toward one side between one end (the other end) of the positive electrode first plate 110 on the other side of the surface direction X direction and one end (the other end) of the positive electrode second plate 111 on the other side of the surface direction X direction. In addition, the positive electrode second plate 111 is inserted from one side in the X direction toward the other side between one end (the other end) of the negative electrode first plate 120 on one side of the surface direction X direction and one end (the other end) of the negative electrode second plate 121 on one side of the surface direction X direction.

[0109] The inserted negative electrode first plate 120 does not contact the positive electrode connecting portion 112. In other words, (the other end of) the inserted negative electrode first plate 120 is disposed at a distance from the positive electrode connecting portion 112. In addition, the inserted positive electrode second plate 111 does not contact the negative electrode connecting portion 122. In other words, (the other end of) the inserted positive electrode second plate 111 is disposed at a distance from the negative electrode connecting portion 122.

[0110] [Insulating material] Although not shown, the solid-state battery unit 1 may include an insulating member as necessary.

[0111] The insulating member can insulate the electrode sheet 10 and suppress short circuits.

[0112] The insulating members are disposed, for example, along the edges of each electrode sheet 10 .

[0113] The insulating member has a shape in plan view that is, for example, approximately rectangular in plan view with respect to one electrode sheet 10.

[0114] The thickness of the insulating member is not particularly limited as long as it can insulate the electrode sheet 10, and is preferably the same as the thickness of the electrode sheet 10. The thickness of the insulating member is, for example, 100 μm or more, preferably 200 μm or more, and for example, 1000 μm or less, preferably 800 μm or less.

[0115] The material of the insulating member may be, for example, a polymer material.

[0116] Examples of polymeric materials include polyethylene terephthalate (PET) films, polyimide films, and fluororesin films.

[0117] [Manufacturing method of solid-state battery unit] A method for manufacturing the solid-state battery unit of the first embodiment will be described with reference to FIGS. 2A to 2G.

[0118] The solid-state battery unit includes, for example, a first step of preparing a negative electrode current collector 12, a second step of arranging an electrode sheet 10 on one side of the negative electrode second plate 121 of the negative electrode current collector 12, a third step of arranging a positive electrode current collector 11 so that the positive electrode second plate 111 is arranged on one side of the electrode sheet 10 arranged on the negative electrode second plate 121, a fourth step of further arranging the electrode sheet 10 on one side of the positive electrode second plate 111, a fifth step of bending the negative electrode current collector 12 so that the negative electrode first plate 120 is arranged on one side of the electrode sheet 10 arranged on the positive electrode second plate 111, a sixth step of further arranging the electrode sheet 10 on one side of the negative electrode first plate 120, and a seventh step of bending the positive electrode current collector 11 so that the positive electrode first plate 110 is arranged on one side of the electrode sheet 10 arranged on the negative electrode first plate 120.

[0119] (1st step) As shown in FIG. 2A, in the first step, a negative electrode current collector plate 12 is prepared.

[0120] (2nd process) 2B, in the second step, an electrode sheet 10 is placed on one surface of the negative electrode second plate 121 of the negative electrode current collector 12. Specifically, one electrode sheet 10 is placed on one surface of the negative electrode second plate 121 of the negative electrode current collector 12 such that the negative electrode second plate 121 and the negative electrode layer 103 of the electrode sheet 10 overlap. The negative electrode first plate 120 of the negative electrode current collector 12 is located on one side of the negative electrode second plate 121 in the surface direction X direction.

[0121] (3rd step) 2C, in the third step, the positive electrode current collector 11 is disposed so that the positive electrode second plate 111 is disposed on one side of the electrode sheet 10 disposed on the negative electrode second plate 121. Specifically, the positive electrode current collector 11 is disposed so that the positive electrode layer 102 of the electrode sheet 10 and the positive electrode second plate 111 of the positive electrode current collector 11 overlap on one side of the electrode sheet 10 disposed on the negative electrode second plate 121. The positive electrode first plate 110 of the positive electrode current collector 11 is located on the other side of the positive electrode second plate 111 in the surface direction X direction.

[0122] (4th step) 2D, in the fourth step, an electrode sheet 10 is further disposed on one surface of the positive electrode second plate 111. Specifically, one electrode sheet 10 is further disposed on one surface of the positive electrode second plate 111 such that the positive electrode second plate 111 and the positive electrode layer 102 of the electrode sheet 10 overlap each other.

[0123] (5th step) 2E, in the fifth step, the negative electrode current collector 12 is bent so that the negative electrode first plate 120 is disposed on one side of the electrode sheet 10 disposed on the positive electrode second plate 111. Specifically, the negative electrode current collector 12 is bent so that the negative electrode layer 103 of the electrode sheet 10 and the negative electrode first plate 120 of the negative electrode current collector 12 prepared in the first step are overlapped and disposed on one side of the electrode sheet 10 disposed on the positive electrode second plate 111.

[0124] (6th step) 2F, in the sixth step, an electrode sheet 10 is further disposed on one surface of the negative electrode first plate 120. Specifically, one electrode sheet 10 is further disposed on one surface of the negative electrode first plate 120 such that the negative electrode first plate 120 and the negative electrode layer 103 of the electrode sheet 10 overlap with each other.

[0125] (7th step) 2G, in the seventh step, the positive electrode current collector 11 is bent so that the positive electrode first plate 110 is disposed on one side of the electrode sheet 10 disposed on the negative electrode first plate 120. Specifically, the positive electrode current collector 11 is bent so that the positive electrode layer 102 of the electrode sheet 10 and the positive electrode first plate 110 of the positive electrode current collector 11 disposed in the third step are overlapped on one side of the electrode sheet 10 disposed on the negative electrode first plate 120.

[0126] In this manner, the solid-state battery unit 1 is manufactured.

[0127] According to the manufacturing method of the solid-state battery unit 1 described above, the solid-state battery unit 1 can be manufactured relatively easily, and the negative electrode connecting portion 122 of the negative electrode current collector 12 is arranged on one side in the planar direction X direction, and the positive electrode connecting portion 112 of the positive electrode current collector 11 is arranged on the other side in the planar direction X direction, so that short circuits between the connecting portions can be suppressed.

[0128] In the above-described method for manufacturing the solid-state battery unit 1, the order in which the positive electrode current collector plate 11 and the negative electrode current collector plate 12 are stacked may be reversed. Specifically, the manufacturing method of the solid-state battery unit 1 may include, for example, a first step of preparing a positive current collector 11, a second step of arranging an electrode sheet 10 on one side of the positive second plate 111 of the positive current collector 11, a third step of arranging a negative current collector 12 so that the negative second plate 121 is arranged on one side of the electrode sheet 10 arranged on the positive second plate 111, a fourth step of further arranging an electrode sheet 10 on one side of the negative second plate 121, a fifth step of bending the positive current collector 11 so that the positive first plate 110 is arranged on one side of the electrode sheet 10 arranged on the negative second plate 121, a sixth step of further arranging an electrode sheet 10 on one side of the positive first plate 110, and a seventh step of bending the negative current collector 12 so that the negative first plate 120 is arranged on one side of the electrode sheet 10 arranged on the positive first plate 110.

[0129] The manufacturing method of the solid-state battery unit 1 may also include a step of arranging an insulating member. Specifically, the manufacturing method of the solid-state battery unit 1 may include, for example, a step of arranging an insulating member having a generally square shape in plan view along an edge of the electrode sheet 10 on one side of each current collector plate to be laminated on the electrode sheet 10, prior to each step (second step, fourth step, sixth step) of arranging the electrode sheet 10.

[0130] Furthermore, in the above-described manufacturing method of the solid-state battery unit 1, each current collector plate may have an insulating member arranged thereon in advance. Specifically, at least one selected from the positive electrode first plate 110, the positive electrode second plate 111, the negative electrode first plate 120, and the negative electrode second plate 121 may include an insulating member.

[0131] <Second embodiment> A second embodiment of the solid state battery unit of the present invention will be described with reference to FIG.

[0132] In addition, regarding the configuration of a second embodiment of the solid-state battery unit 1 described later, detailed description of the configuration similar to that of the first embodiment of the solid-state battery unit 1 described above will be omitted.

[0133] [Positioning of electrode sheets] Two or more electrode sheets 10 are disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121, and the same number of electrode sheets 10 are disposed between each of the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121.

[0134] As described above, two or more electrode sheets 10 are arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121, and the same number of electrode sheets are arranged between each of these plates. This makes it possible to further reduce the number of current collector plates relative to the number of electrode sheets, thereby making it relatively easy to make electrical connection to the outside while further increasing the voltage.

[0135] Adjacent electrode sheets are laminated electrically in series. Specifically, the positive electrode layer 102 and the negative electrode layer 103 of the electrode sheets 10 adjacent to each other are in contact with each other.

[0136] Moreover, the positive electrode layer 102 on one side of each of the electrode sheet laminates described above contacts the positive electrode current collector plate 11, and the negative electrode layer 103 on the other side of each of the electrode sheet laminates described above contacts the negative electrode current collector plate 12. Note that the electrode sheet laminate is a plurality of electrode sheets stacked in series.

[0137] 2.Solid-state battery stack The solid-state battery stack of the present invention will be described with reference to FIGS.

[0138] First Embodiment With reference to FIG. 4, a first embodiment of a solid-state battery stack of the present invention will be described.

[0139] The solid-state battery stack 2 is formed by stacking a plurality of the solid-state battery units 1 of the first embodiment described above. Specifically, the solid-state battery stack 2 includes the solid-state battery unit 1a of the first embodiment described above, an electrode sheet 10, and the solid-state battery unit 1b of the first embodiment described above in this order in the stacking direction.

[0140] More specifically, in all of the stacked solid-state battery units 1, the number of electrode sheets 10 disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 is one each. That is, in the solid-state battery unit 1a and the solid-state battery unit 1b, the number of electrode sheets 10 disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 is one each.

[0141] In such a solid-state battery stack 2, a plurality of the above-mentioned solid-state battery units 1 are stacked. Therefore, the number of current collector plates relative to the number of electrode sheets 10 can be reduced, and electrical connection to the outside can be made relatively easy while improving the electric capacity. In addition, the length of the positive electrode current collector plate 11 and the negative electrode current collector plate 12 is short, and the current collection resistance can be reduced.

[0142] The multiple solid-state battery units 1 are stacked such that the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b of adjacent solid-state battery units 1 in the stacking direction face each other with the electrode sheet 10 interposed therebetween.

[0143] In the solid-state battery stack 2, the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b are arranged to face each other via the electrode sheet 10 in the solid-state battery units 1 adjacent to each other in the stacking direction, so that the lengths of the positive electrode current collector 11 and the negative electrode current collector 12 are short, and the current collection resistance can be reduced.

[0144] In the solid-state battery stack 2, the multiple solid-state battery units 1 are preferably stacked in the same arrangement. Specifically, in the direction perpendicular to the stacking direction, the multiple solid-state battery units 1 are stacked with their positive electrode connectors 112 on one side and their negative electrode connectors 122 on the other side.

[0145] The electrode sheet 10 is disposed between the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b in the solid-state battery units 1 adjacent to each other in the stacking direction described above.

[0146] The number of interposed electrode sheets 10 is preferably the same as the number of electrode sheets 10 disposed between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 in the plurality of solid-state battery units 1. Specifically, as shown in Fig. 4, if a plurality of solid-state battery units 1 of the above-mentioned first embodiment are stacked, the number of interposed electrode sheets 10 is one for each.

[0147] In the solid-state battery units 1 adjacent to each other in the stacking direction, the positive electrode layer 102 of the electrode sheet 10 arranged so as to be interposed between the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b contacts the positive electrode first plate 110 of the solid-state battery unit 1a. In addition, in the solid-state battery units 1 adjacent to each other in the stacking direction, the negative electrode layer 103 of the electrode sheet 10 arranged so as to be interposed between the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b contacts the negative electrode second plate 121 of the solid-state battery unit 1b.

[0148] In addition, an insulating member may be disposed between the positive electrode first plate 110 and the negative electrode second plate 121 of the solid-state battery units 1 adjacent to each other in the stacking direction described above, together with the electrode sheet 10. The insulating member is disposed, for example, along the edge of the electrode sheet 10, and has a generally square shape in plan view.

[0149] The number of stacked solid-state battery units 1 in the solid-state battery stack 2 can be appropriately selected according to the desired battery capacity.

[0150] <Second embodiment> With reference to FIG. 5, a second embodiment of a solid-state battery stack of the present invention will be described.

[0151] In addition, regarding the configuration of a second embodiment of the solid-state battery stack 2 described later, detailed description of the configuration similar to that of the first embodiment of the solid-state battery stack 2 described above will be omitted.

[0152] The solid-state battery stack 2 is formed by stacking a plurality of the solid-state battery units 1 of the second embodiment described above. Specifically, the solid-state battery stack 2 includes the solid-state battery unit 1a of the second embodiment described above, an electrode sheet 10, and the solid-state battery unit 1b of the second embodiment described above in this order in the stacking direction.

[0153] It is preferable that the multiple solid-state battery units 1 have the same configuration. Specifically, it is preferable that the solid-state battery unit 1a and the solid-state battery unit 1b have the same configuration.

[0154] In other words, it is preferable that the number of electrode sheets 10 arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 in all of the stacked solid-state battery units 1 is the same. More specifically, it is preferable that the number of electrode sheets 10 arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 in the solid-state battery unit 1a and the solid-state battery unit 1b is the same.

[0155] More specifically, the number of electrode sheets 10 arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 in all of the stacked solid-state battery units 1 is two or more and is the same number. As shown in Fig. 5, the number of electrode sheets 10 arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 in the solid-state battery unit 1a and the solid-state battery unit 1b is two, respectively.

[0156] In such a solid-state battery stack 2, a plurality of the above-mentioned solid-state battery units 1 are stacked. Therefore, the number of current collector plates relative to the number of electrode sheets 10 can be reduced, and electrical connection to the outside can be made relatively easy while improving the electric capacity. In addition, the length of the positive electrode current collector plate 11 and the negative electrode current collector plate 12 is short, and the current collection resistance can be reduced.

[0157] The number of interposed electrode sheets 10 is, for example, two or more, and is the same as the number of electrode sheets arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 of the solid-state battery unit 1. As shown in FIG. 5, if the number of electrode sheets 10 arranged between the positive electrode first plate 110 and the negative electrode first plate 120, between the negative electrode first plate 120 and the positive electrode second plate 111, and between the positive electrode second plate 111 and the negative electrode second plate 121 in the solid-state battery unit 1a and the solid-state battery unit 1b is two, the number of interposed electrode sheets 10 is two.

[0158] In addition, in the interposed electrode sheets 10, adjacent electrode sheets are stacked electrically in series. Specifically, in the interposed electrode sheets 10, the positive electrode layer 102 and the negative electrode layer 103 are in contact with each other in the adjacent electrode sheets 10.

[0159] In addition, in the solid-state battery units 1 adjacent to each other in the stacking direction, the positive electrode layer 102 on one side of the laminate of the electrode sheets 10 arranged so as to be interposed between the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b contacts the positive electrode first plate 110 of the solid-state battery unit 1a. In addition, in the solid-state battery units 1 adjacent to each other in the stacking direction, the negative electrode layer 103 on the other side of the laminate of the electrode sheets 10 arranged so as to be interposed between the positive electrode first plate 110 of one solid-state battery unit 1a and the negative electrode second plate 121 of the other solid-state battery unit 1b contacts the negative electrode second plate 121 of the solid-state battery unit 1b. In addition, the electrode sheet laminate is a laminate of a plurality of electrode sheets stacked in series.

[0160] <Third embodiment> A third embodiment of a solid-state battery stack of the present invention will now be described with reference to FIG.

[0161] In addition, regarding the configuration of a third embodiment of the solid-state battery stack 2 described later, detailed description of the configuration similar to that of the first embodiment of the solid-state battery stack 2 described above will be omitted.

[0162] In the solid-state battery stack 2, the positive electrode current collector plate 11 further includes a positive electrode current collector tab 113 protruding from an edge, and the negative electrode current collector plate 12 further includes a negative electrode current collector tab 123 protruding from an edge. Specifically, in the solid-state battery stack 2 in which a plurality of solid-state battery units 1 are stacked, each of the plurality of solid-state battery units 1 includes one positive electrode current collector tab 113 and one negative electrode current collector tab 123.

[0163] In such a solid-state battery stack 2, the positive current collector plate 11 further includes a positive current collector tab 113 protruding from the edge, and the negative current collector plate 12 further includes a negative current collector tab 123 protruding from the edge. This makes it relatively easy to establish an electrical connection with the outside.

[0164] Specifically, the solid-state battery stack 2 is relatively easy to connect electrically to the outside because it is connected via the positive electrode current collector tab 113 and the negative electrode current collector tab 123. More specifically, in the solid-state battery stack 2, all the positive electrode current collector tabs 113 and all the negative electrode current collector tabs 123 are welded together to prepare bundles of the respective current collector tabs (a bundle of the positive electrode current collector tabs 113 and a bundle of the negative electrode current collector tabs 123), and a lead wire (not shown) is joined to each bundle of the current collector tabs, making it relatively easy to connect electrically to the outside.

[0165] {Positive electrode current collecting tab} The positive electrode current collecting tab 113 protrudes, for example, from an edge of the positive electrode current collecting plate 11. That is, the positive electrode current collecting tab 113 protrudes, for example, from an edge of any of the positive electrode first plate 110, the positive electrode second plate 111, or the positive electrode connecting portion 112. Specifically, the positive electrode current collecting tab 113 protrudes from one side of the positive electrode first plate 110 between the center and an end of the side in a direction perpendicular to the side.

[0166] In this manner, one positive electrode current collecting tab 113 protrudes from the edge of one positive electrode current collecting plate 11. This makes it possible to reduce the number of current collecting tabs for the electrode sheet 10, and thus reduces the energy required to weld the current collecting tabs.

[0167] The positive current collector tab 113 may be formed in a tab shape by a part of the edge of the positive current collector plate 11 protruding, or the positive current collector tab 113 may be separately joined to the edge of the positive current collector plate 11. The positive current collector tab 113 is preferably formed in a tab shape by a part of the edge of the positive current collector plate 11 protruding. In other words, it is preferable that the positive current collector tab 113 and the positive current collector plate 11 are continuous.

[0168] The positive electrode current collecting tab 113 has, for example, a generally rectangular shape in a plan view.

[0169] The thickness of the positive electrode current collecting tab 113 is the same as the thickness of the positive electrode first plate 110, the positive electrode second plate 111, or the positive electrode connecting portion 112 from which the positive electrode current collecting tab 113 protrudes, and the material of the positive electrode current collecting tab 113 is the same as the material of the positive electrode first plate 110, the positive electrode second plate 111, or the positive electrode connecting portion 112 from which the positive electrode current collecting tab 113 protrudes.

[0170] {Negative electrode current collecting tab} The negative electrode current collector tab 123 protrudes, for example, from an edge of the negative electrode current collector plate 12. That is, the negative electrode current collector tab 123 protrudes, for example, from any edge of the negative electrode first plate 120, the negative electrode second plate 121, or the negative electrode connecting part 122. Specifically, the negative electrode current collector tab 123 protrudes from one side of the negative electrode first plate 120 between the center and an end of the side in a direction perpendicular to the side.

[0171] In this manner, one negative electrode current collecting tab 123 protrudes from the edge of one negative electrode current collecting plate 12. This makes it possible to reduce the number of current collecting tabs for the electrode sheet 10, and thus reduces the energy required to weld the current collecting tabs.

[0172] The negative electrode current collector tab 123 may be formed in a tab shape by a part of the edge of the negative electrode current collector plate 12 protruding, or the negative electrode current collector tab 123 may be separately joined to the edge of the negative electrode current collector plate 12. The negative electrode current collector tab 123 is preferably formed in a tab shape by a part of the edge of the negative electrode current collector plate 12 protruding. In other words, it is preferable that the negative electrode current collector tab 123 and the negative electrode current collector plate 12 are continuous.

[0173] The negative electrode current collecting tab 123 has, for example, a generally rectangular shape in a plan view.

[0174] The thickness of the negative electrode current collecting tab 123 is the same as the thickness of the negative electrode first plate 120, the negative electrode second plate 121, or the negative electrode connecting portion 122 from which the negative electrode current collecting tab 123 protrudes, and the material of the positive electrode current collecting tab 113 is the same as the material of the negative electrode first plate 120, the negative electrode second plate 121, or the negative electrode connecting portion 122 from which the negative electrode current collecting tab 123 protrudes.

[0175] {Protruding direction of positive and negative electrode current collecting tabs} In each solid-state battery unit 1, the protruding direction of the positive electrode current collector tab 113 is, for example, opposite to the protruding direction of the negative electrode current collector tab 123. Specifically, in each solid-state battery unit 1, the protruding side of the positive electrode current collector tab 113 on the positive electrode first plate 110 extends in the X direction, and the protruding side of the negative electrode current collector tab 123 on the negative electrode first plate 120 also extends in the X direction. In each solid-state battery unit 1, the protruding side of the positive electrode current collector tab 113 is disposed, for example, opposite to the protruding side of the negative electrode current collector tab 123 in the Y direction. In other words, the positive electrode current collector tab 113 protrudes from the side in one direction in the Y direction, while the negative electrode current collector tab 123 protrudes from the side in the other direction in the Y direction.

[0176] In each solid-state battery unit 1, if the protruding direction of the positive electrode current collector tab 113 is opposite to the protruding direction of the negative electrode current collector tab 123, contact between the positive electrode current collector tab 113 and the negative electrode current collector tab 123 can be suppressed, thereby suppressing a short circuit. Furthermore, in each solid-state battery unit 1, if the positive electrode current collector tab 113 protrudes from one side in the X direction from the center of the side, while the negative electrode current collector tab 123 protrudes from the other side in the X direction from the center of the side, contact between the positive electrode current collector tab 113 and the negative electrode current collector tab 123 can be further suppressed.

[0177] Moreover, in the solid-state battery stack 2, the multiple solid-state battery units 1 are preferably stacked in the same arrangement. Specifically, in the direction perpendicular to the stacking direction, the multiple solid-state battery units 1 are stacked with their positive electrode connectors 112 on one side and their negative electrode connectors 122 on the other side.

[0178] That is, in the solid-state battery stack 2 in which a plurality of solid-state battery units 1 are stacked, preferably, the protruding directions of the positive electrode current collector tabs 113 of the plurality of solid-state battery units 1 are the same direction, and the protruding directions of the negative electrode current collector tabs 123 of the plurality of solid-state battery units 1 are the same direction.

[0179] As described above, if the protruding directions of the positive electrode current collector tabs 113 and the negative electrode current collector tabs 123 of the multiple solid-state battery units 1 are the same, it is easy to weld the current collector tabs together, and further, short circuits can be suppressed.

[0180] 6, in the first embodiment of the solid-state battery stack 2 described above, the plurality of solid-state battery units 1 each include one positive electrode current collector tab 113 and one negative electrode current collector tab 123, but are not limited thereto. Specifically, although not shown, in the second embodiment of the solid-state battery stack 2 described above, the plurality of solid-state battery units 1 each may include one positive electrode current collector tab 113 and one negative electrode current collector tab 123.

[0181] <Fourth embodiment> A fourth embodiment of a solid-state battery stack of the present invention will now be described with reference to FIG.

[0182] In addition, regarding the configuration of a fourth embodiment of the solid-state battery stack 2 described later, detailed description of the configuration similar to that of the first embodiment of the solid-state battery stack 2 described above will be omitted.

[0183] The solid-state battery stack 2 further includes a positive electrode lead 114 that is directly connected to each of the positive electrode connectors 112 in the plurality of solid-state battery units 1 and extends in the stacking direction, and a negative electrode lead 124 that is directly connected to each of the negative electrode connectors 122 in the plurality of solid-state battery units 1 and extends in the stacking direction.

[0184] Such a solid-state battery stack 2 further includes a positive electrode lead 114 that is directly connected to each of the positive electrode connectors 112 in the plurality of solid-state battery units 1 and extends in the stacking direction, and a negative electrode lead 124 that is directly connected to each of the negative electrode connectors 122 in the plurality of solid-state battery units 1 and extends in the stacking direction. Therefore, unlike the second embodiment described above, the electrical connection with the outside does not go through a tab, and energy for welding, etc. can be further reduced.

[0185] [Positive lead] The positive electrode lead 114 is joined to the positive electrode connecting portion 112, and electrically connects the solid-state battery stack 2 to the outside.

[0186] There are no particular limitations on the positive electrode lead 114, so long as it can be used as a lead wire for a battery.

[0187] Examples of materials for the positive electrode lead 114 include metals such as aluminum, copper, silver, gold, platinum, and nickel.

[0188] The length of the positive electrode lead 114 varies depending on the configuration of the solid-state battery stack 2 and is not particularly limited. Specifically, in the solid-state battery stack 2, as the number of stacked solid-state battery units 1 increases, the length of the positive electrode lead 114 increases, and as the number of stacked solid-state battery units 1 decreases, the length of the positive electrode lead 114 decreases.

[0189] The cross-sectional area of ​​the positive electrode lead 114 is not particularly limited, and can be appropriately selected depending on the length of the positive electrode lead 114 .

[0190] [Negative lead] The negative electrode lead 124 is joined to the negative electrode connecting portion 122, and electrically connects the solid-state battery stack 2 to the outside.

[0191] There are no particular limitations on the negative electrode lead 124 as long as it is usable as a lead wire for a battery. The material, length, and cross-sectional area of ​​the negative electrode lead 124 are the same as those of the positive electrode lead 114.

[0192] In the solid-state battery stack 2, the multiple solid-state battery units 1 are preferably stacked in the same arrangement. Specifically, in a direction perpendicular to the stacking direction, the multiple solid-state battery units 1 are stacked with their positive electrode connectors 112 on one side and their negative electrode connectors 122 on the other side. The positive electrode lead 114 is joined to the positive electrode connectors 112 of the multiple solid-state battery units 1, and the negative electrode lead 124 is joined to the negative electrode connectors 122 of the multiple solid-state battery units 1.

[0193] 7, the solid-state battery stack 2 of the first embodiment described above further includes a positive electrode lead 114 that is directly connected to each positive electrode connector 112 in the plurality of solid-state battery units 1 and extends in the stacking direction, and a negative electrode lead 124 that is directly connected to each negative electrode connector 122 in the plurality of solid-state battery units 1 and extends in the stacking direction, but is not limited thereto. Specifically, although not shown, the solid-state battery stack 2 of the second embodiment described above may further include a positive electrode lead 114 that is directly connected to each positive electrode connector 112 in the plurality of solid-state battery units 1 and extends in the stacking direction, and a negative electrode lead 124 that is directly connected to each negative electrode connector 122 in the plurality of solid-state battery units 1 and extends in the stacking direction.

[0194] Moreover, the solid-state battery stack 2 such as that in the above-described first, second, third and fourth embodiments may be enclosed in an exterior body.

[0195] Examples of the exterior body include a laminate type exterior body and a case type exterior body.

[0196] The material of the exterior body is not particularly limited as long as it is stable to the electrolyte, and examples thereof include metals and resins. Examples of metals include aluminum. Examples of resins include polypropylene, polyethylene, and acrylic.

[0197] The shape of the exterior body is not particularly limited as long as it can enclose the solid-state battery stack 2.

[0198] Moreover, it is preferable that the exterior body that encloses the solid-state battery stack 2 of the above-mentioned third embodiment can expose each bundle of tabs to the outside.

[0199] Furthermore, it is preferable that the exterior body that encloses the solid-state battery stack 2 of the above-mentioned fourth embodiment can expose each lead wire to the outside.

[0200] (Variation 1) As shown in FIG. 6, in the solid-state battery stack 2 of the third embodiment described above, the protruding direction of the positive electrode current collector tab 113 of each solid-state battery unit 1 is opposite to the protruding direction of the negative electrode current collector tab 123, but is not limited to this.

[0201] Although not shown, in the solid-state battery stack 2, the protruding direction of the positive electrode current collector tab 113 and the protruding direction of the negative electrode current collector tab 123 included in each solid-state battery unit 1 may be the same. In other words, the protruding side of the positive electrode current collector tab 11 in the positive electrode current collector plate 11 and the protruding side of the negative electrode current collector tab 123 in the negative electrode current collector plate 12 may be on the same side in a plan view. Specifically, the positive electrode current collector tab 113 protrudes from one side in the X direction or one side in the Y direction from the center of the side, while the negative electrode current collector tab 123 protrudes from the other side in the X direction or the other side in the Y direction from the center of the side, thereby preventing the positive electrode current collector tab 113 and the negative electrode current collector tab 123 from contacting each other.

[0202] Although not shown, in the solid-state battery stack 2, the protruding direction of the positive electrode current collector tab 113 included in each solid-state battery unit 1 may be a direction perpendicular to the protruding direction of the negative electrode current collector tab 123. In other words, the protruding side of the positive electrode current collector tab 113 on the positive electrode current collector plate 11 may be, for example, a side perpendicular to the protruding side of the negative electrode current collector tab 123 on the negative electrode current collector plate 12 in a plan view.

[0203] As described above, in the solid-state battery stack 2, the protruding directions of the positive electrode current collector tab 113 and the negative electrode current collector tab 123 of each solid-state battery unit 1 can be appropriately selected depending on the intended use.

[0204] (Variation 2) As shown in FIGS. 4 to 6, in the solid-state battery stacks 2 of the first, second, and third embodiments, the solid-state battery units 1 are stacked in a direction perpendicular to the stacking direction, with the positive electrode connectors 112 on one side and the negative electrode connectors 122 on the other side, but this is not limiting.

[0205] Although not shown, in the solid-state battery stacks 2 of the first embodiment, the second embodiment, and the third embodiment, the arrangement of the positive electrode connector 112 and the negative electrode connector 122 of each solid-state battery unit 1 may be different from each other. Specifically, the positive electrode connector 112 of the solid-state battery unit 1a may be disposed on one side in the X direction and the negative electrode connector 122 may be disposed on the other side in the X direction, while the positive electrode connector 112 of the solid-state battery unit 1b may be disposed on the other side in the X direction and the negative electrode connector 122 may be disposed on one side in the X direction. Also, the positive electrode connector 112 of the solid-state battery unit 1a may be disposed on one side in the X direction and the negative electrode connector 122 may be disposed on the other side in the X direction, while the positive electrode connector 112 of the solid-state battery unit 1b may be disposed on one side in the Y direction and the negative electrode connector 122 may be disposed on the other side in the Y direction.

[0206] (Application) The above-described solid-state battery unit 1 and solid-state battery stack 2 can be thinned and have an improved battery capacity. Therefore, they can be suitably used not only as a power source for small portable devices such as mobile phones, smartphones, and notebook computers, but also as a power source for large devices such as electric vehicles. [Explanation of symbols]

[0207] 1 Solid-state battery unit 10 Electrode sheet 11 Positive current collector 12 Negative current collector 101 Electrolyte layer 102 Positive electrode layer 103 Negative electrode layer 110 Positive electrode No. 1 plate 111 Positive electrode second plate 112 Positive electrode connection part 120 Negative electrode first plate 121 Negative electrode second plate 122 negative electrode connector

Claims

1. an electrode sheet including an electrolyte layer, a positive electrode layer disposed on one surface of the electrolyte layer, and a negative electrode layer disposed on the other surface of the electrolyte layer; a positive electrode current collector in contact with the positive electrode layer of the electrode sheet; a negative electrode current collector in contact with the negative electrode layer of the electrode sheet; Equipped with the positive current collector plate includes a positive first plate and a positive second plate arranged opposite to each other with a gap therebetween, and a positive connection portion connecting one end of the positive first plate and one end of the positive second plate, and the other end of the positive first plate and the other end of the positive second plate are open between each other end of the positive first plate and the positive second plate; the negative current collector plate includes a negative first plate and a negative second plate arranged opposite to each other with a gap therebetween, and a negative connection portion connecting one end of the negative first plate and one end of the negative second plate, the other end of the negative first plate and the other end of the negative second plate being open; the positive electrode current collector plate and the negative electrode current collector plate are arranged such that the negative electrode first plate is inserted between the other end of the positive electrode first plate and the other end of the positive electrode second plate, and the positive electrode second plate is inserted between the other end of the negative electrode first plate and the other end of the negative electrode second plate, the electrode sheets are respectively disposed between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate.

2. 2. The solid-state battery unit according to claim 1, wherein one electrode sheet is disposed between the positive electrode first plate and the negative electrode first plate, one electrode sheet is disposed between the negative electrode first plate and the positive electrode second plate, and one electrode sheet is disposed between the positive electrode second plate and the negative electrode second plate.

3. The electrode sheets are arranged between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate, with two or more sheets being the same number, The solid-state battery unit according to claim 1 , wherein each of the electrode sheets adjacent to each other are electrically stacked in series.

4. A solid-state battery stack in which a plurality of solid-state battery units according to claim 2 are stacked, the plurality of solid-state battery units are stacked such that, in adjacent solid-state battery units, a positive electrode first plate of one solid-state battery unit and a negative electrode second plate of the other solid-state battery unit face each other with the electrode sheet interposed therebetween; The interposed electrode sheets are arranged one by one, The positive electrode layer of the interposed electrode sheet is in contact with the positive electrode first plate, a negative electrode layer of the interposed electrode sheet in contact with the negative electrode second plate.

5. A solid-state battery stack in which a plurality of solid-state battery units according to claim 3 are stacked, the plurality of solid-state battery units are stacked such that, in adjacent solid-state battery units, a positive electrode first plate of one solid-state battery unit and a negative electrode second plate of the other solid-state battery unit face each other with the electrode sheet interposed therebetween; the number of the electrode sheets disposed between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate in the plurality of solid-state battery units is the same; The interposed electrode sheets are arranged in two or more sheets, the interposed electrode sheets are arranged in the same number as the electrode sheets arranged between the positive electrode first plate and the negative electrode first plate, between the negative electrode first plate and the positive electrode second plate, and between the positive electrode second plate and the negative electrode second plate of the solid-state battery unit; The adjacent electrode sheets are stacked electrically in series, The positive electrode layer on one side of the interposed electrode sheet stack is in contact with the positive electrode first plate, a negative electrode layer on the other side of the interposed stack of electrode sheets in contact with the negative electrode second plate.

6. The positive electrode current collector further includes a positive electrode current collector tab protruding from an edge thereof, 6. The solid-state battery stack of claim 4 or 5, wherein the negative current collector plate further comprises a negative current collector tab protruding from an edge thereof.

7. In a direction perpendicular to a stacking direction, the positive electrode connecting portion of each of the plurality of solid-state battery units is disposed on one side, and the negative electrode connecting portion of each of the plurality of solid-state battery units is disposed on the other side, a positive electrode lead directly connected to each of the positive electrode connection portions in the plurality of solid-state battery units and extending in a stacking direction; a negative electrode lead that is directly connected to each of the negative electrode connection portions in the plurality of solid-state battery units and extends in a stacking direction; The solid-state battery stack of claim 4 or 5, further comprising:

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