Battery and stacked battery

Abstract

A battery includes a first electrode (10), a second electrode (20), and a solid electrolyte layer (30) between the first electrode and the second electrode. The first electrode includes a first current collector (11) and a first active material layer (12) between the first current collector and the solid electrolyte layer. The first current collector has at least one first slit (40, 440) that extends through the first current collector in a thickness direction and is connected to an outer edge portion of the first current collector.

Description

Technical Field

[0001] This disclosure relates to batteries and stacked batteries. Background Technology

[0002] Patent Document 1 discloses a lithium-ion battery with holes in the inner region of the current collector. Patent Document 2 discloses a battery that uses a porous metal body as the current collector.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 11-288723

[0006] Patent Document 2: Japanese Patent Application Publication No. 7-335209 Summary of the Invention

[0007] This disclosure provides highly reliable batteries and stacked batteries.

[0008] The battery disclosed herein includes: a first electrode, a second electrode, and a solid electrolyte layer located between the first electrode and the second electrode. The first electrode includes: a first current collector and a first active material layer located between the first current collector and the solid electrolyte layer. The first current collector has at least one first slit that penetrates the first current collector along the thickness direction and is connected to the outer edge of the first current collector.

[0009] According to this disclosure, highly reliable batteries and stacked batteries can be realized. Attached Figure Description

[0010] Figure 1 These are cross-sectional and top views showing the schematic structure of the battery according to Embodiment 1.

[0011] Figure 2 This is a cross-sectional view showing an example of the schematic structure of the slit provided on the current collector of the battery in Embodiment 1.

[0012] Figure 3 This is a cross-sectional view of a modified example 1 showing the schematic structure of the slit provided on the current collector of the battery in embodiment 1.

[0013] Figure 4 This is a cross-sectional view of a modified example 2, showing a schematic structure of the slit provided on the current collector of the battery in embodiment 1.

[0014] Figure 5 This is a cross-sectional view of a modified example 3 showing the schematic structure of the slit provided on the current collector of the battery in embodiment 1.

[0015] Figure 6 These are cross-sectional and top views showing the schematic structure of the battery according to Embodiment 2.

[0016] Figure 7 These are cross-sectional and top views showing the schematic structure of the battery according to Embodiment 3.

[0017] Figure 8 These are cross-sectional and top views showing the schematic structure of the battery in Embodiment 4.

[0018] Figure 9 These are cross-sectional and top views showing the schematic structure of the battery in Embodiment 5.

[0019] Figure 10 These are cross-sectional and top views showing the schematic structure of the stacked battery in Embodiment 6.

[0020] Figure 11 These are cross-sectional and top views showing the schematic structure of the stacked battery in Embodiment 7. Detailed Implementation

[0021] (Summary of this disclosure)

[0022] A battery according to this disclosure includes: a first electrode, a second electrode, and a solid electrolyte layer located between the first electrode and the second electrode. The first electrode includes: a first current collector, and a first active material layer located between the first current collector and the solid electrolyte layer. The first current collector has at least one first slit that penetrates the first current collector along its thickness direction and is connected to an outer edge of the first current collector.

[0023] According to this structure, delamination caused by residual air within the stack constituting the battery can be suppressed, resulting in a dense battery with few structural defects. This is particularly beneficial in large-area or thin-layer batteries where air tends to remain within the stack. In the battery according to this design, when the stack is pressurized, air is facilitated to escape from the central region of the stack along the slits to the outer edge. This suppresses structural defects and enables high-density stacks, thus achieving a highly reliable battery.

[0024] Alternatively, for example, the at least one first slit may also be a plurality of first slits.

[0025] This further facilitates the expulsion of air from inside the stack. In other words, air is more easily expelled, thus enabling the creation of dense batteries with fewer structural defects.

[0026] Alternatively, for example, the top view shape of the first current collector can also be rectangular or square. The plurality of first slits can also be four first slits, which are connected to the center of each side of the first current collector when viewed from above.

[0027] As a result, the deviation in the air discharge distribution is reduced and made more uniform within the plane. Furthermore, a short slit can be used to connect the area from the outer edge of the current collector to near the center. Therefore, the area of ​​the slit occupied by the current collector can be reduced, thereby increasing the battery capacity.

[0028] Alternatively, for example, the plurality of first slits may also be arranged in a point-symmetric manner with respect to the center of the first current collector when viewed from above.

[0029] As a result, the deviation in the distribution of exhaust air is reduced and homogenized within the plane. Therefore, warping can be suppressed, enabling the production of thin and large-sized batteries.

[0030] Alternatively, for example, the sidewall of the at least one first slit may also be inclined relative to the thickness direction of the first current collector.

[0031] In this way, due to the inclined sidewalls of the slit, the contact area between the sidewalls and the active material layer or electrolyte components filling the slit is increased. This effectively prevents current collector stripping. Therefore, it is possible to suppress structural defects in the battery while further strengthening the adhesion between the current collector and the active material layer.

[0032] Alternatively, for example, the cross-sectional shape of the at least one first slit may also be a trapezoidal shape in which the first side of the second electrode side is shorter than the second side opposite to the first side.

[0033] Therefore, the width of the slit narrows on the active material layer side of the current collector, thus creating a structure where even if the peeling stress of the current collector is applied, the filling components such as the active material layer or electrolyte within the slit will hold it in place, making it difficult for it to detach. This structure allows for the suppression of structural defects while further enhancing the adhesion of the current collector.

[0034] Alternatively, for example, the width of the at least one first slit may also be wider in a top view than the portion of the portion of the first current collector that is closer to the outer edge of the first current collector.

[0035] This further facilitates the expulsion of air from the interior of the stack. In other words, air is more easily expelled, thus enabling the creation of a dense battery with fewer structural defects.

[0036] Alternatively, for example, the at least one first slit may also have a bend when viewed from above.

[0037] This further enhances the anchoring effect between the current collector and the active material layer, thus enabling the development of batteries with higher reliability.

[0038] Alternatively, for example, the width of the first slit can be greater than 0.1 mm and less than 5 mm.

[0039] When the slit width is too large, the battery capacity decreases. By making the slit width between 0.1 mm and 5 mm, it is possible to simultaneously improve battery reliability through air expulsion and increase battery capacity.

[0040] Alternatively, for example, the first slit may extend from the outer edge in one direction toward the inside of the first current collector. The length of the first slit in that direction may also be more than 6% of the length of the first current collector in that direction.

[0041] This allows for the removal of any residual air that may be present in the portion closer to the outer edge, resulting in a highly reliable battery.

[0042] Alternatively, for example, the length of the first slit in one direction may also be less than 50% of the length of the first current collector in one direction.

[0043] This allows air to be efficiently expelled from the center of the stack, enabling highly reliable batteries.

[0044] Alternatively, for example, the area of ​​the first active material layer may be smaller than that of the first current collector when viewed from above. The first current collector may also have a first region in contact with the first active material layer and a second region in contact with the solid electrolyte layer.

[0045] Therefore, when the laminate is pressurized, after air is expelled from the slit located in the second region, the solid electrolyte, due to its flexibility, easily deforms into and fills the interior of the slit. Thus, a strong anchoring effect can be reliably obtained.

[0046] Alternatively, for example, the at least one first slit may be located in the second region instead of the first region.

[0047] For example, by placing a flexible solid electrolyte in the second region, the solid electrolyte deforms and easily fills the slits when the laminate is pressurized. Thus, the anchoring effect is strong even with only the second region. Therefore, it does not affect the power generation element, suppresses defects in large and thin batteries, and enables high-density operation.

[0048] Alternatively, for example, the first slit may be filled with a material contained in a layer that contacts the surface of the first current collector on the side facing the second electrode. Alternatively, for example, the layer may be the first active material layer or the solid electrolyte layer.

[0049] Therefore, when the laminate is pressurized, the slit becomes embedded in the active material layer or solid electrolyte layer that is in contact with the slit. This results in an anchoring effect, thus improving the interface strength between the current collector and the layer, enabling batteries with high cycle performance and reliability.

[0050] Alternatively, for example, the second electrode may also include a second current collector and a second active material layer located between the second current collector and the solid electrolyte layer. The second current collector may also have at least one second slit extending through the second current collector in the thickness direction and connected to the outer edge of the second current collector.

[0051] This allows air to be easily expelled from both sides of the stacking direction of the laminate. Because air is more easily expelled, a dense battery with few structural defects can be achieved.

[0052] Alternatively, for example, one embodiment of the stacked battery disclosed herein includes a first battery and a second battery, wherein the first battery and the second battery are batteries as described in any one of embodiments 1 to 16. The first battery may also be stacked on the surface of the first current collector of the second battery opposite to the first active material layer.

[0053] This enables the development of batteries with large capacity or high energy density and high reliability.

[0054] Alternatively, for example, the first current collector of the first battery and the first current collector of the second battery may be current collectors with different polarities. The first battery and the second battery may also be stacked such that their respective first current collectors are in contact with each other. The at least one first slit of the first battery may also not overlap with the at least one first slit of the second battery when viewed from above.

[0055] Therefore, by arranging the current collectors in a manner where the slits of the connected current collectors do not overlap, it is possible to form bipolar electrodes by connecting and overlapping current collectors. In other words, it is possible to connect batteries in series. For example, by multiplying large-size and thin batteries, it is possible to cope with high voltage and realize high-energy and high-capacity batteries.

[0056] Alternatively, for example, the first current collector of the first battery and the first current collector of the second battery may be current collectors with the same polarity. The first battery and the second battery may also be stacked such that their respective first current collectors are in contact with each other. At least a portion of the at least one first slit of the first battery may also overlap with the at least one first slit of the second battery when viewed from above.

[0057] Therefore, the active material layers or solid electrolytes of the upper and lower batteries can easily bond to each other through the slits. This allows for the formation of a single, highly reliable battery structure. For example, by constructing batteries connected in parallel, a high-capacity battery with high reliability can be achieved.

[0058] As described above, in each scheme, structural defects caused by the peeling of the layers constituting the laminate and the presence of residual air can be suppressed, thus enabling the realization of a highly reliable battery.

[0059] The embodiments will now be described in detail with reference to the accompanying drawings.

[0060] Furthermore, the embodiments described below are all general or specific examples. The numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, and connection methods shown in the following embodiments are merely examples and are not intended to limit this disclosure. In addition, the constituent elements of the following embodiments that are not described in the independent claims are described as optional constituent elements.

[0061] Furthermore, these figures are schematic diagrams and not necessarily precise representations. Therefore, for example, the scale may not be consistent across different figures. Also, substantially identical structures are labeled in the same way across different figures, and repetitive descriptions are omitted or simplified.

[0062] Furthermore, in this specification and accompanying drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional orthogonal coordinate system. In each embodiment, the z-axis direction is used as the thickness direction of the battery. Additionally, in this specification, "thickness direction" refers to the direction perpendicular to the surfaces of each stacked layer.

[0063] In addition, in this manual, "top view" refers to viewing the battery along the stacking direction of the battery, and "thickness" refers to the length of the battery and each layer along the stacking direction.

[0064] In addition, in this instruction manual, "inner" and "outer" in terms of "inner side" and "outer side" refer to the inner and outer sides when observing the battery along the stacking direction of the battery.

[0065] Furthermore, in this specification, the terms "upper" and "lower" in the context of battery structure do not refer to absolute spatial identification of "above" (vertically above) and "below" (vertically below), but rather are used as terms defined by relative positional relationships based on the stacking order in a stacked structure. Additionally, the terms "upper" and "lower" apply not only to situations where two components are spaced apart and other components exist between them, but also to situations where two components are in close contact.

[0066] (Implementation Method 1)

[0067] [Battery Overview]

[0068] First, use Figure 1 The battery of Embodiment 1 will be described.

[0069] Figure 1 These are cross-sectional and top views showing the schematic structure of battery 1 according to this embodiment. Specifically, Figure 1 (a) is a cross-sectional view of battery 1. Figure 1 (b) is a top view of battery 1 viewed from the front side of the z-axis. Figure 1 (a) shows the use of Figure 1 (b) The cross-section at the location indicated by line Ia-Ia. Furthermore, Figure 1 In (b), the slit 40 is shaded with diagonal lines to make its shape easier to distinguish. The same applies to the other top views described later.

[0070] like Figure 1 As shown, battery 1 includes a first electrode 10, a second electrode 20, and a solid electrolyte layer 30 located between the first electrode 10 and the second electrode 20. Battery 1 is an all-solid-state battery.

[0071] The first electrode 10 includes a first current collector 11 and a first active material layer 12. The first active material layer 12 is an example of a first electrode layer located between the first current collector 11 and the solid electrolyte layer 30. The first active material layer 12 is in contact with the surface of the first current collector 11 on the side closest to the solid electrolyte layer 30.

[0072] The second electrode 20 is the counter electrode opposite to the first electrode 10. The second electrode 20 includes a second current collector 21 and a second active material layer 22. The second active material layer 22 is an example of a second electrode layer located between the second current collector 21 and the solid electrolyte layer 30. The second active material layer 22 is in contact with the surface of the second current collector 21 on the side closest to the solid electrolyte layer 30.

[0073] The solid electrolyte layer 30 is an example of an electrolyte layer located between the first electrode 10 and the second electrode 20.

[0074] The following is a detailed description of each layer that constitutes battery 1.

[0075] In the battery 1 of this embodiment, the first electrode 10 is the positive electrode, and the second electrode 20 is the negative electrode. That is, the first current collector 11 is the positive current collector, and the first active material layer 12 contains the positive active material. The second current collector 21 is the negative current collector, and the second active material layer 22 contains the negative active material.

[0076] Alternatively, the first electrode 10 can be the negative electrode and the second electrode 20 can be the positive electrode. That is, the first current collector 11 can be the negative current collector, and the first active material layer 12 can contain negative active material. Alternatively, the second current collector 21 can be the positive current collector, and the second active material layer 22 can contain positive active material.

[0077] The top-view shapes of the first current collector 11, the first active material layer 12, the solid electrolyte layer 30, the second active material layer 22, and the second current collector 21 are all rectangular. There are no particular restrictions on the top-view shapes of the first current collector 11, the first active material layer 12, the solid electrolyte layer 30, the second active material layer 22, and the second current collector 21; they can be squares, circles, ellipses, polygons, or other shapes other than rectangles.

[0078] In addition, in this embodiment, the first current collector 11, the first active material layer 12, the solid electrolyte layer 30, the second active material layer 22, and the second current collector 21 are all the same size and have the same outline when viewed from above, but this is not a limitation. For example, the first active material layer 12 may be smaller than the second active material layer 22. The first active material layer 12 and the second active material layer 22 may be smaller than the solid electrolyte layer 30.

[0079] In this specification, without specifically distinguishing between the first current collector 11 and the second current collector 21, they are sometimes simply referred to as "current collectors". A current collector is not particularly limited as long as it is formed of a conductive material.

[0080] Current collectors can be made of materials such as foil, plates, or meshes, composed of stainless steel, nickel (Ni), aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), palladium (Pd), gold (Au), or platinum (Pt), or alloys of two or more of these. The material of the current collector should be appropriately selected considering its non-melting and non-decomposition under manufacturing processes, operating temperatures, and operating pressures, as well as the operating potential and conductivity of the battery applied to the current collector. Furthermore, the material of the current collector can be selected based on the required tensile strength and heat resistance. For example, the current collector can be a high-strength electrolytic copper foil or a cladding material laminated with different metal foils.

[0081] The thickness of the current collector is, for example, in the range of 10 μm or more and 100 μm or less. Furthermore, from the viewpoint of improving adhesion to the first active material layer 12 or the second active material layer 22, the surface of the current collector can also be processed into a rough surface with unevenness. Alternatively, an adhesive component such as an organic adhesive can be coated onto the surface of the current collector. This strengthens the bonding between the current collector and other layers, thereby improving the mechanical and thermal stability of the battery 1, as well as its cycle characteristics.

[0082] like Figure 1 (a) and Figure 1 As shown in (b), at least one slit 40 is provided in the first current collector 11. No slit is provided in the second current collector 21. The specific structure of the slit 40 and the effects of providing the slit 40 will be explained later.

[0083] The first active material layer 12 is located between the first current collector 11 and the solid electrolyte layer 30. Specifically, the first active material layer 12 is disposed in contact with the main surface of the first current collector 11 on the side adjacent to the solid electrolyte layer 30. In this embodiment, the first active material layer 12 covers the entire main surface of the first current collector 11. The first active material layer 12 contains at least a positive electrode active material. That is, the first active material layer 12 is a layer that mainly contains a positive electrode material such as a positive electrode active material.

[0084] The positive electrode active material is a substance that undergoes oxidation or reduction by inserting or removing metal ions such as lithium (Li) or magnesium (Mg) ions into its crystal structure at a higher potential than that of the negative electrode. The type of positive electrode active material can be appropriately selected according to the type of battery 1, and well-known positive electrode active materials can be used.

[0085] The positive electrode active material uses compounds containing lithium and transition metal elements, such as oxides containing lithium and transition metal elements, and phosphate compounds containing lithium and transition metal elements. For example, LiNi oxide can be used as an oxide containing lithium and transition metal elements. x M 1-xLithium-nickel composite oxides such as O2 (where M is at least one element selected from Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and x is 0 < x ≤ 1), layered oxides such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), and lithium manganese oxide (LiMn2O4), or lithium manganese oxides with a spinel structure such as LiMn2O4, Li2MnO3, and LiMnO2. Phosphoric acid compounds containing lithium and transition metal elements can be used, for example, lithium iron phosphate (LiFePO4) with an olivine structure. Additionally, sulfides such as sulfur (S) and lithium sulfide (Li2S) can be used as positive electrode active materials. In this case, substances obtained by coating or adding lithium niobate (LiNbO3) to positive electrode active material particles can be used as positive electrode active materials. Furthermore, only one of these materials can be used as the positive electrode active material, or two or more of these materials can be used in combination.

[0086] As described above, the first active material layer 12, which serves as the positive electrode active material layer, only needs to contain at least the positive electrode active material. The first active material layer 12 can also be a mixture layer composed of the positive electrode active material and other additives. Other additives may include, for example, solid electrolytes such as inorganic solid electrolytes or sulfide-based solid electrolytes, conductive additives such as acetylene black, and adhesives such as polyethylene oxide or polyvinylidene fluoride. By mixing the positive electrode active material and other additives such as solid electrolytes in a predetermined ratio, the lithium-ion conductivity and electronic conductivity within the first active material layer 12 can be improved.

[0087] The thickness of the first active material layer 12 is, for example, in the range of 5 μm or more and 300 μm or less, but is not limited thereto.

[0088] The second active material layer 22 is located between the second current collector 21 and the solid electrolyte layer 30. Specifically, the second active material layer 22 is disposed in contact with the main surface of the second current collector 21 on the side adjacent to the solid electrolyte layer 30. In this embodiment, the second active material layer 22 covers the entire main surface of the second current collector 21. The second active material layer 22 contains at least a negative electrode active material. That is, the second active material layer 22 is a layer that mainly contains a negative electrode material such as a negative electrode active material.

[0089] The negative electrode active material is a substance that inserts or releases metal ions such as lithium (Li) or magnesium (Mg) ions into its crystal structure at a lower potential than that of the positive electrode, followed by oxidation or reduction. The type of negative electrode active material can be appropriately selected according to the type of battery 1, and well-known negative electrode active materials can be used.

[0090] As negative electrode active materials, carbon materials such as natural graphite, artificial graphite, graphite carbon fibers, or resin-sintered carbon, as well as alloying materials combined with solid electrolytes, can be used. As alloying materials, examples include LiAl, LiZn, Li3Bi, Li3Cd, Li3Sb, Li4Si, and Li... 4.4 Pb, Li 4.4 Sn, Li 0.17 Lithium alloys such as C or LiC6, lithium titanate (Li4Ti5O) 12 Lithium oxides with transition metals, zinc oxide (ZnO), or silicon oxide (SiO) x Metal oxides, etc. Furthermore, the negative electrode active material can use only one of these materials, or it can use a combination of two or more of these materials.

[0091] As described above, the second active material layer 22, which serves as the negative electrode active material layer, only needs to contain at least the negative electrode active material. The second active material layer 22 can also be a mixture layer composed of the negative electrode active material and other additives. Other additives may include, for example, solid electrolytes such as inorganic solid electrolytes or sulfide-based solid electrolytes, conductive additives such as acetylene black, and adhesives such as polyethylene oxide or polyvinylidene fluoride. By mixing the negative electrode active material and other additives such as solid electrolytes in a predetermined ratio, the lithium-ion conductivity and electronic conductivity within the second active material layer 22 can be improved.

[0092] The thickness of the second active material layer 22 is, for example, in the range of 5 μm or more and 300 μm or less, but is not limited thereto.

[0093] A solid electrolyte layer 30 is disposed between the first active material layer 12 and the second active material layer 22, and they are in contact with each other. The solid electrolyte layer 30 contains at least a solid electrolyte. For example, the solid electrolyte layer 30 contains a solid electrolyte as a main component.

[0094] Any known battery-grade solid electrolyte with ionic conductivity can be used. For example, solid electrolytes that conduct metal ions such as lithium and magnesium ions can be used. The type of solid electrolyte should be selected appropriately based on the type of ions it conducts.

[0095] As solid electrolytes, inorganic solid electrolytes such as sulfide-based solid electrolytes or oxide-based solid electrolytes can be used. As sulfide-based solid electrolytes, lithium-containing sulfides such as Li₂S-P₂S₅, Li₂S-SiS₂, Li₂S-B₂S₃, Li₂S-GeS₂, Li₂S-SiS₂-LiI, Li₂S-SiS₂-Li₃PO₄, Li₂S-Ge₂S₂, Li₂S-GeS₂-P₂S₅, or Li₂S-GeS₂-ZnS can be used. As oxide-based solid electrolytes, lithium-containing metal oxides such as Li₂O-SiO₂ or Li₂O-SiO₂-P₂O₅ can be used. x P y O 1-z N z Lithium-containing metal nitrides, lithium phosphate (Li3PO4), and lithium titanium oxides, etc., are examples of lithium-containing transition metal oxides. Only one of these materials can be used as the solid electrolyte, or two or more of these materials can be used in combination. In this embodiment, as an example, the solid electrolyte layer 30 contains a solid electrolyte with lithium-ion conductivity.

[0096] In addition to the aforementioned solid electrolyte material, the solid electrolyte layer 30 may also include adhesives such as polyethylene oxide or polyvinylidene fluoride.

[0097] The thickness of the solid electrolyte layer 30 is, for example, in the range of 5 μm or more and 150 μm or less, but is not limited thereto.

[0098] Furthermore, the solid electrolyte layer 30 can be configured as an aggregate of solid electrolyte particles. Alternatively, the solid electrolyte layer 30 can also be composed of a sintered structure of solid electrolyte.

[0099] [Slit]

[0100] Next, details of the slit 40 provided in the first collector 11 will be explained.

[0101] like Figure 1 (a) and Figure 1 As shown in (b), at least one slit 40 is provided in the first current collector 11. The at least one slit 40 is an example of a first slit that penetrates the first current collector 11 along its thickness direction and is connected to the outer edge of the first current collector 11. The slit 40 extends from the outer edge of the first current collector 11 in a direction toward the inner side of the first current collector 11. Specifically, the slit 40 is formed by carving out the first current collector 11 from its outer edge toward the inner side. The outer edge is part of the outline of the first current collector 11 when viewed from above.

[0102] The slit 40 is filled with the material contained in the layer that contacts the surface of the first current collector 11 on the side facing the second electrode 20. In other words, the slit 40 is embedded in the layer that contacts the surface facing the second electrode 20. In this embodiment, since the layer that contacts the surface facing the second electrode 20 is the first active material layer 12, therefore... Figure 1 As shown in (a), a portion of the first active material layer 12 is filled. For example, a portion of the first active material layer 12 may completely fill the slit 40. Alternatively, a portion of the first active material layer 12 may be provided only in a portion of the slit 40. That is, gaps may remain in the slit 40 where a portion of the first active material layer 12 is not present.

[0103] In this embodiment, the first current collector 11 has a plurality of slits 40. Specifically, as Figure 1 As shown in (b), the first current collector 11 has four slits 40a, 40b, 40c, and 40d. The four slits 40a, 40b, 40c, and 40d are connected to the center of each side of the first current collector 11 when viewed from above. Specifically, the four slits 40a, 40b, 40c, and 40d are formed in a straight line from the midpoint of each of the four sides of the first current collector 11 toward the center of the first current collector 11.

[0104] Slits 40a and 40b are connected to the short side of the first current collector 11. Slits 40a and 40b are elongated strips extending from the center of the short side of the first current collector 11 in a direction orthogonal to the short side, i.e., parallel to the long side (x-axis direction). Slits 40a and 40b are located on the same straight line extending along the x-axis. Slits 40a and 40b, for example, have the same width w1 and the same length d1. Furthermore, the width of a slit refers to its length along its short side. The length of a slit refers to its length along its long side.

[0105] Slits 40c and 40d are connected to the long side of the first current collector 11. Slits 40c and 40d are elongated strips extending from the center of the long side of the first current collector 11 in a direction orthogonal to the long side, i.e., parallel to the short side (y-axis direction). Slits 40c and 40d are located on the same straight line extending along the y-axis direction. Slits 40c and 40d, for example, have the same width w2 and the same length d2. Width w2 is, for example, equal to width w1. Alternatively, width w2 may be shorter or longer than width w1. Similarly, length d2 is, for example, shorter than length d1. Alternatively, length d2 may be equal to or longer than length d1.

[0106] In addition, in this specification, the four slits 40a, 40b, 40c and 40d will be referred to as "slit 40" unless otherwise specified.

[0107] The width, length, and height of the slit 40 are set such that no delamination occurs in the stack when the battery 1 is integrally stacked. For example, consider a battery 1 that is a rectangle of 150mm × 100mm with a thickness of approximately 200μm. In this case, a Cu current collector of 150mm × 100mm with a thickness of approximately 15μm can be used as the first current collector 11. In this case, the widths w1 and w2 of the slit 40 are approximately 100μm. Slits 40a and 40b extend from the midpoint of the short side of the first current collector 11 toward the center of the first current collector 11. The length d1 of each of the slits 40a and 40b is, for example, approximately 33% of the length L1 of the long side of the first current collector 11, specifically 50mm. Slits 40c and 40d extend from the midpoint of the long side of the first current collector 11 toward the center of the first current collector 11. The length d2 of each of the slits 40c and 40d is, for example, about 30% of the short side length L2 of the first collector 11, specifically 30 mm. The slits 40a, 40b, 40c and 40d are arranged in a point-symmetrical manner with respect to the center of the first collector 11.

[0108] Furthermore, in the case of a thin laminate with a thickness of 100 μm, air may sometimes remain in the region approximately 6% of the inner side (relative to the distance from the opposite side) that enters from the outer edge and cannot be expelled. Therefore, for example, the length d1 of slits 40a and 40b is set to 6% or more of the length L1 of the long side of the first current collector 11. In addition, the length d2 of slits 40c and 40d is set to 6% or more of the length L2 of the short side of the first current collector 11. As a result, delamination of the laminate can be suppressed, and the generation of structural defects can be suppressed. Although it also depends on the location of air retention, by setting the slits 40 with a length of 6% or more relative to each side, a highly reliable battery 1 can be achieved.

[0109] The length d1 of slits 40a and 40b is, for example, less than 50% of the length L1 of the long side of the first current collector 11. That is, slits 40a and 40b are not connected to each other. The length d2 of slits 40c and 40d is, for example, less than 50% of the length L2 of the short side of the first current collector 11. That is, slits 40c and 40d are not connected to each other. Since no slit 40 is provided near the center of the battery 1, the power generation area can be reliably ensured. Furthermore, slit 40 can also reach the center of the first current collector 11, dividing the first current collector 11. Even with such a slit 40, it can be provided within a range that does not pose problems in manufacturing and with the characteristics of the battery 1.

[0110] Furthermore, the widths w1 and w2 of the slit 40 are, for example, 0.1 mm or more and 5 mm or less. The larger the widths w1 and w2 of the slit 40, the easier it is for air to escape, so it is effective in suppressing delamination. In addition, even when the slit 40 is small enough to cut the first current collector 11 with a cutting tool or the like, it can still achieve an air venting effect compared to the case without cutting.

[0111] The slit 40 is formed, for example, by cutting off a portion of the first current collector 11 after sequentially stacking the first current collector 11, the first active material layer 12, the solid electrolyte layer 30, the second active material layer 22, and the second current collector 21. Alternatively, the first current collector 11 with the slit 40 pre-formed may be used in the stack. Air within the stack is expelled by applying pressure in the thickness direction to the stack containing the first current collector 11 with the slit 40.

[0112] Figure 2 This is a cross-sectional view of a first example showing a schematic structure of the slit 40 of the first current collector 11 of the battery 1 in this embodiment. Specifically, Figure 2 This represents a section orthogonal to the long side of slit 40. (The following is related to...) Figures 3-5 The same applies.

[0113] like Figure 2 As shown, a portion of the first active material layer 12, which is in contact with the first current collector 11, is filled into the slit 40. That is, the sidewalls 41 and 42 of the slit 40 are in contact with the first active material layer 12. Therefore, the step difference in the first current collector 11 caused by the slit 40 is reduced due to the filling of a portion of the first active material layer 12. In this embodiment, the state in which the interior of the slit 40 is completely filled is schematically shown, but even with partial filling, a portion of the first active material layer 12 can achieve an anchoring effect through its interaction with the sidewalls 41 and 42 of the slit 40. Therefore, compared to the state where the slit 40 is not filled, the effect of suppressing the peeling of the first current collector 11 is further improved.

[0114] Furthermore, in addition to the slit 40 provided from the outer edge of the first current collector 11, in order to further improve the anchoring effect for preventing the first current collector 11 from peeling off, an appropriate number of holes of arbitrary shape may be provided in the first current collector 11 without adversely affecting the battery characteristics.

[0115] The function of the slit 40 formed in the first collector 11 will be explained in more detail below.

[0116] By providing a slit 40 connected to the outer edge of the first current collector 11, compared to the case where the slit 40 is not provided or where holes or grooves are provided that are not connected to the outer edge, air can be discharged to the outside of the laminate more effectively during compression. In addition, the anchoring effect of the first current collector 11 at the joint with the first active material layer 12 filled into the slit 40 can improve the fixation of the first current collector 11.

[0117] For example, in the absence of holes or slots communicating with the outer edge, the main surface of the first current collector 11 is blocked by the stamping die during compression. Therefore, these holes or slots do not function as air venting paths. Consequently, the larger, thinner, or denser the laminate becomes, the more air remains that cannot escape from the laminate, forming voids or delamination, making it difficult to obtain a defect-free, high-density laminate. In contrast, in the battery 1 according to this embodiment, since the slit 40 is connected to the outer edge of the first current collector 11, air can easily escape. Therefore, a dense, highly reliable battery 1 with few structural defects can be achieved.

[0118] Furthermore, the battery 1 according to this embodiment exhibits excellent air expulsion properties, thus enabling pressurization in the lamination pressing process and achieving a shorter pressurization time. Therefore, not only are the reliability and performance of battery 1 improved, but productivity is also increased. Consequently, it has significant industrial application value.

[0119] Furthermore, during the heating and stacking process, residual solvent and binder components vaporize from the solid electrolyte layer 30, the first active material layer 12, and the second active material layer 22, thereby creating structural defects. The slit 40 is also effective for the discharge of this vaporized gas.

[0120] Furthermore, by filling a portion of the first active material layer 12 in contact with the first current collector 11 into the slit 40, a stronger anchoring effect can be generated by the bonding of the sidewalls 41 and 42 of the slit 40 with the filling component. Such improved adhesion of the first current collector 11 is effective for improving the reliability of repeated charge-discharge characteristics and thermal cycling.

[0121] Based on the above structure, the slit 40, which is provided by cutting from the outer edge of the first current collector 11, can efficiently promote air expulsion even if the current collector surface is blocked by the stamping head during compression. This not only suppresses structural defects such as delamination caused by air, but also reduces voids, resulting in a dense laminate. Through this effect, a large-size and thin battery 1 can be achieved.

[0122] If the structure of the battery 1 in this embodiment is compared with the battery structures described in Patent Document 1 and Patent Document 2, the following differences exist.

[0123] Patent Document 1 describes a lithium-ion battery with multiple holes in the inner region of the current collector. However, no holes are provided in the outer peripheral region, and there are no holes communicating with the outer peripheral portion. Therefore, when the battery is stacked and pressurized, there is a problem that the holes provided on the pressing surface may become blocked, and air may easily remain in the stack.

[0124] On the other hand, Patent Document 2 discloses a battery that uses a porous metal membrane as the current collector. Like Patent Document 1, the battery disclosed in Patent Document 2 also lacks holes connected to the outer edge of the current collector. Furthermore, the battery in Patent Document 2 uses a liquid electrolyte, unlike the structure used to suppress solid-state structural defects in all-solid-state batteries.

[0125] In contrast, the battery 1 according to this embodiment can suppress the problems described above. Furthermore, neither Patent Document 1 nor Patent Document 2 discloses or teaches the battery 1 described in this embodiment, which has a slit 40 connected to the outer edge of the first current collector 11.

[0126] [Variation Example]

[0127] Next, use Figures 3-5 A variation example of the cross-sectional shape of slit 40 will be explained. First, using... Figure 3 The modified example 1 will be explained.

[0128] Figure 3 This is a cross-sectional view of a modified example 1 showing a schematic cross-section of the slit provided on the first current collector 11 of the battery 1 in this embodiment. A slit may also be provided on the first current collector 11. Figure 3 The slit 140 is shown.

[0129] The sidewalls 141 and 142 of the slit 140 are inclined relative to the thickness direction of the first current collector 11. For example... Figure 3 As shown, sidewalls 141 and 142 are parallel. That is, the distance between sidewalls 141 and 142, i.e., the width of slit 140, is constant.

[0130] Therefore, by tilting the sidewalls 141 and 142, the contact area with the components of the active material layer filling the slit 140 can be increased. This further enhances the bonding between the first current collector 11 and the first active material layer 12.

[0131] Furthermore, when the first current collector 11 is provided with a plurality of slits 140, the sidewalls of each of the plurality of slits 140 may be inclined at different angles. Furthermore, the cross-sectional shape of the slits 140 and the state in which a portion of the first active material layer 12 is filled can be confirmed, for example, by simply observing the cross-section obtained by cutting the first current collector 11 with a cutter using a microscope or the like, or by a cross-section made by a method such as ion milling.

[0132] Next, use Figure 4 The modified example 2 will be explained. Figure 4 This is a cross-sectional view of a modified example 2, showing a schematic cross-section of the slit provided on the first current collector 11 of the battery 1 in this embodiment. A slit may also be provided on the first current collector 11... Figure 4 The slit 240 is shown.

[0133] The sidewalls 241 and 242 of the slit 240 are inclined relative to the thickness direction of the first current collector 11. The sidewalls 241 and 242 are far apart from each other on the side of the first current collector 11 closest to the second electrode 20, and close together on their opposite sides. That is, the cross-sectional shape of the slit 240 is a trapezoidal shape in which the first side on the side closest to the second electrode 20 is longer than the second side opposite to that first side. In other words, the width of the slit 240 gradually narrows in the thickness direction of the first current collector 11, moving away from the second electrode 20.

[0134] Therefore, by tilting the sidewalls 241 and 242, the contact area with the components of the active material layer filling the slit 240 can be increased. This further enhances the bonding between the first current collector 11 and the first active material layer 12.

[0135] Next, use Figure 5 The modified example 3 will be explained. Figure 5 This is a cross-sectional view of a modified example 3 showing a schematic cross-section of the slit provided on the first current collector 11 of the battery 1 in this embodiment. A slit may also be provided on the first current collector 11. Figure 5 The slit 340 is shown.

[0136] The sidewalls 341 and 342 of the slit 340 are inclined relative to the thickness direction of the first current collector 11. The sidewalls 341 and 342 are close to each other on the side of the first current collector 11 closest to the second electrode 20, and far apart on their opposite sides. That is, the cross-sectional shape of the slit 340 is a trapezoidal shape in which the first side on the side closest to the second electrode 20 is shorter than the second side opposite to that first side. In other words, the width of the slit 340 gradually increases in the thickness direction of the first current collector 11 away from the second electrode 20.

[0137] Therefore, by filling the slit 340 with the components of the first active material layer 12, the filling components within the slit 340 will hold even when peel stress is applied to the first current collector 11. Thus, peeling of the first current collector 11 is less likely to occur, further suppressing structural defects and strengthening the bonding of the first current collector 11.

[0138] Furthermore, multiple slits 40, 140, 240, or 340 are arranged symmetrically with respect to the center of the first current collector 11. This results in a more uniform laminate and reduces warping.

[0139] (Implementation Method 2)

[0140] The following describes Embodiment 2. The main difference between Embodiment 2 and Embodiment 1 is that a slit is also provided in the second current collector. In the following description of Embodiment 2, the focus is on the differences from Embodiment 1, and the descriptions of commonalities are omitted or simplified.

[0141] Figure 6 These are cross-sectional and top views showing the schematic structure of the battery 401 in Embodiment 2. Specifically, Figure 6 (a) is a cross-sectional view of battery 401. Figure 6 (b) is a top view of the battery 401 viewed from the front side of the z-axis, through the first electrode 10, the solid electrolyte layer 30, and the second active material layer 22. That is, Figure 6 (b) is a top view showing the second collector 421 as seen from the positive side along the z-axis. Figure 6 (a) shows Figure 6 (b) The cross section at the location shown by line VIa-VIa.

[0142] like Figure 6 As shown, the battery 401 of this embodiment, compared to the battery 1 of Embodiment 1, includes a second electrode 420 instead of the second electrode 20. The second electrode 420 includes a second current collector 421 and a second active material layer 22. The second active material layer 22 includes different points such as dots with different shapes, but is substantially the same as that of Embodiment 1, so its description is omitted.

[0143] At least one slit 440 is provided in the second current collector 421. The at least one slit 440 is an example of a second slit that penetrates the second current collector 421 along the thickness direction and is connected to the outer edge of the second current collector 421.

[0144] The slit 440 in the second current collector 421 is the same as the slit 40 in the first current collector 11. Specifically, the structure used for slits 40, 140, 240, or 340 can also be used for slit 440. For example, the second current collector 421 has four slits 440 arranged in a point-symmetric manner. The positions and shapes of the four slits 40 and 440 in top view can also be the same. Furthermore, at least one of the number, position, and shape of the slits 40 in the first current collector 11 and the slits 440 in the second current collector 421 can be different. As a result, the compression state of the first active material layer 12, the second active material layer 22, and the solid electrolyte layer 30 contained in the laminate can be changed. Therefore, not only structural defects can be eliminated, but also the shape and arrangement of the slits 40 and 440 can be appropriately set for the purpose of suppressing the warping of the battery 401.

[0145] Additionally, the cross-sectional shape of slit 440 can also be similar to... Figures 2-5 The slits 40, 140, 240, or 340 shown have the same cross-sectional shape. In this case, the inclination of the sidewalls of the slits 40, 140, 240, or 340 in the first current collector 11 and the slit 440 in the second current collector 421 can also be different. By providing multiple slits with different sidewall inclinations, the durability against peel stress in different directions can be improved.

[0146] As described above, in the battery 401 of this embodiment, the slits 40 and 440 located on both sides of the two current collectors allow for easier air expulsion. Furthermore, through the anchoring effect generated by the components respectively filling the slits 40 and 440, even with further thinning of the battery, structural defects and warping can be suppressed.

[0147] (Implementation Method 3)

[0148] The following describes Embodiment 3. The main difference between Embodiment 3 and Embodiment 1 lies in the top view shape of the slit in the first current collector. In the following description of Embodiment 3, the focus is on the differences from Embodiment 1, omitting or simplifying descriptions of commonalities.

[0149] Figure 7 These are cross-sectional and top views showing the schematic structure of the battery 501 in Embodiment 3. Specifically, Figure 7 (a) is a cross-sectional view of battery 501. Figure 7 (b) is a top view of battery 501 viewed from the positive side along the z-axis. Figure 7 (a) shows Figure 7 (b) The cross section at the location shown by line VIIa-VIIa.

[0150] like Figure 7As shown, the battery 501 of this embodiment differs from the battery 1 of Embodiment 1 in that the first current collector 11 has a slit 540 instead of a slit 40. The width of the slit 540, when viewed from above, is wider near the outer edge of the first current collector 11 than further away from it. In other words, the width of the slit 540 widens towards the outer edge. The minimum and maximum widths of the slit 540 are both in the range of 0.1 mm or more and 5 mm or less. The top-view shape of the slit 540 is a trapezoid that is longer in the height direction. That is, the expansion of the width of the slit 540 is constant regardless of its distance from the outer edge. Alternatively, the slit 540 may expand more significantly closer to the outer edge.

[0151] As described above, in the battery 501 of this embodiment, the width of the slit can be increased as it gets closer to the outer edge, thereby further promoting the discharge of air.

[0152] Alternatively, only one of the multiple slits in the first current collector 11 may be a slit 540, with the remaining slits being slits 40. Slits with the same shape as the slit 540 in this embodiment may also be provided in the second current collector 21 in the same manner as in embodiment 2. In this case, the degree of expansion of the width of the slit 540 in the first current collector 11 and the slit in the second current collector 21 may also be different.

[0153] (Implementation Method 4)

[0154] The following describes Embodiment 4. The main difference between Embodiment 4 and Embodiment 1 lies in the top view shape of the slit in the first current collector. In the following description of Embodiment 4, the focus will be on the differences from Embodiment 1, omitting or simplifying descriptions of commonalities.

[0155] Figure 8 These are cross-sectional and top views showing the schematic structure of the battery 601 in Embodiment 4. Specifically, Figure 8 (a) is a cross-sectional view of battery 601. Figure 8 (b) is a top view of battery 501 viewed from the positive side along the z-axis. Figure 8 (a) shows Figure 8 The cross section at the location shown by line VIIIa-VIIIa in (b).

[0156] like Figure 8As shown, the battery 601 of this embodiment differs from the battery 1 of Embodiment 1 in that the first current collector 11 has a slit 640 instead of a slit 40. The slit 640 has a bent portion 641 when viewed from above. The slit 640 extends from the outer edge of the first current collector 11 in a first direction and extends in a second direction different from the first direction, with the bent portion 641 as the boundary. That is, the slit 640 has a zigzag shape that bends midway. The angle between the first direction and the second direction is, for example, an obtuse angle greater than 90°, but is not limited thereto. The first direction and the second direction may also be orthogonal. The bent portion 641 is located in the extension direction of the slit 640 at a position closer to the center of the first current collector 11 than the end on the outer edge side. Alternatively, the bent portion 641 may be located at the center of the slit 640 or at a position closer to the outer edge side of the first current collector 11 than the center.

[0157] As described above, according to the battery 601 of this embodiment, for example, in the event of peeling from the outer edge of the first current collector 11 relative to the first active material layer 12, the bending portion 641 can stop the peeling from advancing towards the center. By having such a bent linear slit 640 in the first current collector 11, the generation and expansion of structural defects caused by repeated charging and discharging and stress from thermal cycling can be suppressed. Therefore, a battery 601 that is not easily degraded and has high reliability can be realized.

[0158] Furthermore, a slit 640 may have multiple bends 641. For example, by increasing the number of bends 641, the effect of suppressing peeling is further improved. From the viewpoint of ease of manufacturing and production, an appropriate number of bends 641 can be provided.

[0159] Alternatively, the slit 640 can extend in a curved shape, such as an arc or an elliptical arc. That is, the slit 640 can also have a smoothly curved continuous bend 641. In this case, the effect of suppressing the peeling of the first current collector 11 can also be obtained.

[0160] Alternatively, only one of the multiple slits in the first current collector 11 may be a slit 640, with the remaining slits being slits 40 or 540. Slits with the same shape as the slit 640 in this embodiment may also be provided in the second current collector 21 in the same manner as in embodiment 2. In this case, the number, position, and degree of bending of the bent portions 641 of the slit 640 in the first current collector 11 and the slits in the second current collector 21 may also differ.

[0161] (Implementation Method 5)

[0162] The following describes Embodiment 5. The main difference between Embodiment 5 and Embodiment 1 is that the first active material layer and the second active material layer are each only provided on a portion of the main surface of the current collector. In the following description of Embodiment 5, the focus is on the differences from Embodiment 1, omitting or simplifying descriptions of commonalities.

[0163] Figure 9 These are cross-sectional and top views showing the schematic structure of the battery 701 in Embodiment 5. Specifically, Figure 9 (a) is a cross-sectional view of battery 701. Figure 9 (b) is a top view of battery 701 viewed from the front side along the z-axis. Figure 9 (a) shows Figure 9 (b) The cross section at the location shown by the IXa-IXa line.

[0164] like Figure 9 As shown, the battery 701 of this embodiment includes a first electrode 710, a second electrode 720, and a solid electrolyte layer 730. The first electrode 710 includes a first current collector 11 and a first active material layer 712. The second electrode 720 includes a second current collector 21 and a second active material layer 722. The first current collector 11 and the second current collector 21 are the same as in Embodiment 1.

[0165] The first active material layer 712 and the second active material layer 722 have different areas when viewed from above compared to the first active material layer 12 and the second active material layer 22 in Embodiment 1, respectively. Specifically, the area of ​​the first active material layer 712 when viewed from above is smaller than that of the first current collector 11. The area of ​​the second active material layer 722 when viewed from above is smaller than that of the second current collector 21.

[0166] Therefore, as Figure 9 As shown in (b), the first current collector 11 has a first region 711a that contacts the first active material layer 712 and a second region 711b that does not contact the first active material layer 712. In this embodiment, the slit 40 is provided in the second region 711b of the first current collector 11 but not in the first region 711a. That is, when viewed from above, the slit 40 does not overlap with the first active material layer 712, so the slit 40 is not filled with the material contained in the first active material layer 712. In other words, the slit 40 does not contain the first active material layer 712.

[0167] The solid electrolyte layer 730 includes a first solid electrolyte layer 731 and a second solid electrolyte layer 732. The first solid electrolyte layer 731, like the solid electrolyte layer 30 of Embodiment 1, is disposed in contact with the first active material layer 712 and the second active material layer 722. In plan view, the first solid electrolyte layer 731 has the same size and shape as the first active material layer 712 and the second active material layer 722.

[0168] The second solid electrolyte layer 732 is disposed around the first active material layer 712, the first solid electrolyte layer 731, and the second active material layer 722. Specifically, in top view, the second solid electrolyte layer 732 is disposed in the second region 711b of the first current collector 11. The second solid electrolyte layer 732 overlaps with the slit 40 in top view. Specifically, a portion of the second solid electrolyte layer 732 is filled in the slit 40.

[0169] The second solid electrolyte layer 732 contains the same solid electrolyte as the first solid electrolyte layer 731. Alternatively, the second solid electrolyte layer 732 may also contain a different solid electrolyte than the solid electrolyte contained in the first solid electrolyte layer 731. For example, the solid electrolyte contained in the second solid electrolyte layer 732 may be a material with a smaller Young's modulus and better deformability compared to the solid electrolyte contained in the first solid electrolyte layer 731. This makes it easier to fill a portion of the second solid electrolyte layer 732 into the slit 40.

[0170] For example, the solid electrolyte contained in the second solid electrolyte layer 732 can be a sulfide-based or amorphous material, or a material with a low Young's modulus and excellent deformability. For example, by using a material with a lower Young's modulus than the first current collector 11, a portion of the second solid electrolyte layer 732 is filled while deforming into the slit 40 provided in the first current collector 11 under pressure. As a result, a strong anchoring effect that firmly bonds to the sidewalls 41 and 42 of the slit 40 can be obtained.

[0171] As described above, in the battery 701 according to this embodiment, by filling a portion of the second solid electrolyte layer 732, which contains a highly deformable solid electrolyte, into the slit 40, its anchoring effect can be strengthened, thereby achieving a strong bonding effect between the first current collector 11 and the second solid electrolyte layer 732. Therefore, a battery 701 with higher reliability can be realized.

[0172] Furthermore, the slit 340 can be provided in the second current collector 21 in the same manner as in Embodiment 2. Alternatively, a portion of the second solid electrolyte layer 732 can be filled into the slit 340 provided in the second current collector 21.

[0173] Alternatively, the second solid electrolyte layer 732 may not completely surround the first solid electrolyte layer 731. For example, the second solid electrolyte layer 732 may be provided along one or more sides of the first solid electrolyte layer 731 when viewed from above. Alternatively, the second solid electrolyte layer 732 may be provided only in the portion that overlaps with the slit 40 of the first current collector 11 when viewed from above.

[0174] (Implementation Method 6)

[0175] The following describes Embodiment 6. The main difference between Embodiment 6 and Embodiment 1 is that multiple batteries are stacked. In the following description of Embodiment 6, the focus is on the differences from Embodiment 1, omitting or simplifying descriptions of commonalities.

[0176] Figure 10 These are cross-sectional and top views showing the schematic structure of the stacked battery 800 according to Embodiment 6. Specifically, Figure 10 (a) is a cross-sectional view of the 800 stacked battery. Figure 10 (b) is a top view of the stacked battery 800 viewed from the positive side of the z-axis. That is, Figure 10 (b) is a top view of battery 802 viewed from the positive side of the z-axis, on the negative side of the z-axis. Figure 10 (a) shows Figure 10 (b) The cross section at the location shown by the Xa-Xa line.

[0177] like Figure 10 As shown, the stacked battery 800 includes two batteries 801 and 802. Specifically, the two batteries 801 and 802 are stacked in the thickness direction. The two batteries 801 and 802 are bonded together by applying a conductive adhesive or the like.

[0178] In this embodiment, two batteries 801 and 802 are connected in series. Specifically, the positive terminal of one battery 801 and the negative terminal of the other are directly connected. For example, a so-called bipolar electrode is formed where one of the second current collector 421 of battery 801 and the first current collector 11 of battery 802 is the positive terminal and the other is the negative terminal. For example, in each of batteries 801 and 802, the first current collector 11 is the positive current collector and the second current collector 421 is the negative current collector.

[0179] Batteries 801 and 802 have the same structure as battery 401 in embodiment 2. Specifically, in batteries 801 and 802, a slit 40 is formed in the first current collector 11 and a slit 440 is formed in the second current collector 421, respectively. Figure 10 In (b), the slit 440 of the second current collector 421 provided in the battery 801 is indicated by a dashed line.

[0180] like Figure 10 As shown in (b), slits 40 and 440 do not overlap when viewed from above. Specifically, slit 40, located in the first current collector 11 of battery 802, is blocked by the second current collector 421 of battery 801. Therefore, a portion of the first active material layer 12 of battery 802 filling slit 40 does not contact the second active material layer 22 of battery 801. Similarly, slit 440, located in the second current collector 421 of battery 801, is blocked by the first current collector 11 of battery 802. Therefore, a portion of the second active material layer 22 of battery 801 filling slit 440 does not contact the first active material layer 12 of battery 802. Thus, by ensuring that slits 40 and 440 do not overlap when viewed from above, it is possible to prevent the active materials of the two stacked batteries 801 and 802, each with different polarities, from contacting each other.

[0181] As described above, since slits are provided in the current collectors of each of the multiple batteries 801 and 802, air and structural defects can be reduced in batteries 801 and 802 respectively, thus homogenizing the laminate and reducing warpage. Therefore, multiple batteries 801 and 802 can be overlapped and connected to form a multilayer structure.

[0182] Furthermore, in the stacked battery 800 of this embodiment, slits 40 and 440 do not overlap when viewed from above, so multiple batteries 801 and 802 can be connected in series. This enables the realization of high-energy batteries capable of handling high voltages and achieving highly reliable stacked batteries.

[0183] Furthermore, the slit 40 may not be provided in the first current collector 11 of battery 801. Alternatively, the slit 440 may not be provided in the second current collector 421 of battery 802.

[0184] Alternatively, the slit 440 may not be provided in the second current collector 421 of the battery 801. This allows the slit 40 in the first current collector 11 of the battery 802 to be reliably blocked by the second current collector 421. Similarly, the slit 40 may not be provided in the first current collector 11 of the battery 802. This allows the slit 440 in the second current collector 421 of the battery 801 to be reliably blocked by the first current collector 11.

[0185] Alternatively, the stacked battery 800 may also include battery 1, 401, 501, 601, or 701 to replace at least one of batteries 801 and 802. Furthermore, the number of stacked batteries in the stacked battery 800 is not limited to two; it can also include three or more.

[0186] (Implementation Method 7)

[0187] The following describes Embodiment 7. The main difference between Embodiment 7 and Embodiment 1 is that multiple batteries are stacked. In the following description of Embodiment 7, the focus is on the differences from Embodiment 1, omitting or simplifying descriptions of commonalities.

[0188] Figure 11 These are cross-sectional and top views showing the schematic structure of the stacked battery 900 according to Embodiment 7. Specifically, Figure 11 (a) is a cross-sectional view of the 900-cell stack. Figure 11 (b) is a top view of the stacked battery 900 viewed from the positive z-axis side, that is, from the positive z-axis side. Figure 11 (b) is a top view of battery 1 viewed from the positive side of the z-axis, on the negative side of the z-axis. Figure 11 (a) shows Figure 11 (b) The cross section at the location shown by the XIA-XIa line.

[0189] like Figure 11 As shown, the stacked battery 900 includes two batteries 1. Specifically, the two batteries 1 are stacked in the thickness direction. The two batteries 1 are bonded together by applying a conductive adhesive or the like.

[0190] In this embodiment, the two batteries 1 are connected in parallel. Specifically, the positive terminals of the two batteries 1 are directly connected to each other or their negative terminals are directly connected to each other. For example, the first current collectors 11 of the two batteries 1 are connected to each other.

[0191] In the first current collector 11, a slit 40 is provided, similar to that in Embodiment 1. In this embodiment, at least a portion of the slits 40 of each of the two batteries 1 overlap when viewed from above. For example... Figure 11 As shown in (b), the four slits 40 of the first current collector 11 located on one side of the two batteries 1 and the four slits 40 of the first current collector 11 located on the other side of the two batteries 1 are completely identical when viewed from above.

[0192] Thus, the first active material layer 12 is shared and integrated through the slit 40, thereby achieving strong bonding between the two cells 1. Therefore, a highly reliable stacked battery 900 can be realized.

[0193] Furthermore, the stacked battery 900 may also include batteries 401, 501, 601, 701, 801, or 802 instead of at least one of the two batteries 1. For example, when the stacked battery 900 includes two batteries 701, the second solid electrolyte layer 732 may also contain powder such as a sulfide-based solid electrolyte that is sintered during the powder pressing process. This allows the batteries 701 to be easily integrated with each other via the slit 40. Through this effect, high bonding reliability can be achieved.

[0194] In addition, the number of cells stacked in the stacked battery 900 is not limited to 2, but can also be 3 or more.

[0195] (Battery manufacturing method)

[0196] Next, an example of the manufacturing method of the battery and the stacked battery according to the above embodiments will be described. Hereinafter, the above... Figure 10 The manufacturing method of the stacked battery 800 of Embodiment 6 will be described.

[0197] First, pastes are prepared for use in the printing formation of the first active material layer 12 (specifically, the positive electrode active material layer) and the second active material layer 22 (specifically, the negative electrode active material layer). The solid electrolyte raw material used in the mixtures of the positive and negative electrode active material layers is, for example, a Li₂S-P₂S₅ sulfide glass powder with an average particle size of approximately 10 μm and a triclinic crystal structure as the main component. As this glass powder, for example, a 2 × 10⁻⁶ particle size distribution can be used. -3 S / cm or higher and 3×10 -3 Highly ionicly conductive glass powder with a particle size of less than S / cm. For example, Li·Ni·Co·Al composite oxide (LiNi) with an average particle size of approximately 5 μm and a layered structure is used as the positive electrode active material. 0.8 Co 0.15 Al 0.05 O2) powder. A paste for a positive electrode active material layer is prepared by dispersing the mixture containing the above-mentioned positive electrode active material and the above-mentioned glass powder in an organic solvent or the like. Alternatively, as the negative electrode active material, for example, natural graphite powder with an average particle size of approximately 10 μm is used. Similarly, a paste for a negative electrode active material layer is prepared by dispersing the mixture containing the above-mentioned negative electrode active material and the above-mentioned glass powder in an organic solvent or the like.

[0198] Next, a copper foil with a thickness of approximately 15 μm is prepared as the material for the first current collector 11 (specifically, the positive current collector) and the second current collector 21 (specifically, the negative current collector). Using screen printing, a paste for the positive active material layer and a paste for the negative active material layer are printed on one side of each copper foil in a predetermined shape and with a thickness of approximately 50 μm or more and approximately 100 μm or less. The pastes for the positive and negative active material layers are dried at a temperature between 80°C and 130°C, resulting in a thickness of 30 μm or more and 60 μm or less. Thus, current collectors (copper foils) with positive and negative active material layers respectively formed are obtained, namely the first electrode 10 (specifically, the positive electrode) and the second electrode 20 (specifically, the negative electrode).

[0199] Next, a paste for a solid electrolyte layer is prepared by dispersing the mixture containing the aforementioned glass powder in an organic solvent or the like. Using a metal mask, the paste for the solid electrolyte layer is printed onto the surfaces of the active material layers of both the positive and negative electrodes to a thickness of, for example, approximately 100 μm. Then, the positive and negative electrodes with the printed paste for the solid electrolyte layer are dried at a temperature between 80°C and 130°C.

[0200] Next, at least one of the positive and negative electrodes is cut from the surface side of the current collector using a cutting tool to form the shape of slit 40. Then, retaining the active material layer, the cut portion of the current collector is peeled off, thereby forming slits 40 and 440. Alternatively, slits may be formed only on one of the positive and negative electrodes.

[0201] Next, the solid electrolyte printed on the positive electrode active material layer and the solid electrolyte printed on the negative electrode active material layer are stacked opposite each other in a manner that they are in contact with each other.

[0202] Next, between the pressure mold plate and the upper surface of the current collector, an elastic modulus of 5×10⁻⁶ is inserted. 6 An elastomer sheet with a thickness of approximately 70 μm is used. The mold plate is then heated to 50°C under a pressure of 300 MPa for 90 seconds. During this pressurization, a portion of the active material layer enters the interior of the slit 40, contacting the sidewalls 41 and 42 of the slit 40. For example, when the current collector thickness is approximately 15 μm, a portion of the active material layer fills the slit 40 with a range of 10 μm to 15 μm.

[0203] Next, a thermosetting conductive paste containing silver particles is screen-printed onto the current collector surface of the battery 801 fabricated as described above, with a thickness of approximately 30 μm. Other batteries 802 are then positioned in predetermined locations and pressed. At this point, the slit 40 is blocked by the additional current collector when two batteries 801 and 802 are joined together. The predetermined number of batteries is repeated depending on the desired degree of multilayering. Then, for example, an application of approximately 1 kg / cm² is performed. 2 While under pressure, allow to stand still and perform a heat curing treatment at a temperature of approximately 100°C to 300°C for 60 minutes, then cool to room temperature.

[0204] After the above processes, the stacked battery 800 is manufactured. Furthermore, the methods and order of manufacturing battery 1 and the stacked battery 800 are not limited to the examples above.

[0205] Furthermore, the above manufacturing method shows an example of using printing to coat the paste for the positive electrode active material layer, the paste for the negative electrode active material layer, the paste for the solid electrolyte layer, and the conductor paste, but is not limited to this. As printing methods, for example, blade coating, calendering, spin coating, dip coating, inkjet printing, offset printing, die coating, spray coating, etc., can be used. Furthermore, the method of forming the slit 40 in the current collector can also be by using laser cutting or punching with a mold, etc.

[0206] In the above manufacturing method, a thermosetting conductive paste containing silver metal particles is shown as an example of a conductive paste, but it is not limited to this. Furthermore, the resin used in the thermosetting conductive paste only needs to function as an adhesive, and an appropriate resin can be selected based on the manufacturing process employed, such as printability and coating properties. The resin used in the thermosetting conductive paste includes, for example, thermosetting resins. Examples of thermosetting resins include (i) urea resin, melamine resin, guanidine resin, and other ammonia resins; (ii) bisphenol A type, bisphenol F type, phenolic varnish type, alicyclic epoxy resins, etc.; (iii) oxetane resin; (iv) methyl-type, phenolic varnish type, etc., phenolic resins; and (v) silicone-modified organic resins such as silicone epoxy and silicone polyester. Only one of these materials can be used as the resin, or two or more of these materials can be used in combination.

[0207] (Other implementation methods)

[0208] The battery and stacked battery of the present invention have been described above based on embodiments, but this disclosure is not limited to these embodiments. Various modifications that can be conceived by those skilled in the art to the embodiments, as well as other solutions constructed by combining some constituent elements of different embodiments, are also included within the scope of this disclosure, provided they do not depart from the spirit of the subject.

[0209] For example, there may be only one first slit provided in the first current collector. Alternatively, the first slit provided in the first current collector may extend from one end of the first current collector to the other. That is, at least one first slit may also be provided in a manner that divides the first current collector into multiple segments. Multiple first slits may also extend radially from or near the center of the first current collector and connect to the outer edge of the first current collector. The same applies to the second slit.

[0210] Furthermore, the above embodiments can be modified, replaced, added to, and omitted in various ways within the scope of patent protection or its equivalent.

[0211] Industrial availability

[0212] The batteries and stacked batteries disclosed herein can be used, for example, as secondary batteries such as all-solid-state batteries used in various electronic devices or automobiles.

[0213] Explanation of reference numerals in the attached figures

[0214] 1. Batteries: 401, 501, 601, 701, 801, 802

[0215] 10, 710 First Electrode

[0216] 11 First collector

[0217] 12, 712 First Active Material Layer

[0218] 20, 420, 720 Second Electrode

[0219] 21, 421 Second collector

[0220] 22, 722 Second active substance layer

[0221] 30, 730 solid electrolyte layer

[0222] 40, 40a, 40b, 40c, 40d, 140, 240, 340, 440, 540, 640 slits

[0223] 41, 42, 141, 142, 241, 242, 341, 342 Sidewalls

[0224] 641 Folded section

[0225] 711a First Area

[0226] 711b Second Area

[0227] 731 First Solid Electrolyte Layer

[0228] 732 Second Solid Electrolyte Layer

[0229] 800 and 900 stacked batteries

Claims

1. A battery, comprising: First electrode, Second electrode, and The solid electrolyte layer located between the first electrode and the second electrode, The first electrode has: The first collector, and The first active material layer is located between the first current collector and the solid electrolyte layer. The first current collector has at least one first slit, which penetrates the first current collector along its thickness direction and is connected to the outer edge of the first current collector. The first slit is filled with the material contained in the layer that contacts the surface of the first current collector on the side of the second electrode.

2. The battery according to claim 1, The at least one first slit is a plurality of first slits.

3. The battery according to claim 2, The top view of the first current collector is rectangular or square. The plurality of first slits are four first slits, and when viewed from above, they are connected to the center of each side of the first current collector.

4. The battery according to claim 2 or 3, The plurality of first slits are arranged in a point-symmetric manner with respect to the center of the first current collector when viewed from above.

5. The battery according to any one of claims 1 to 3, The sidewall of the at least one first slit is inclined relative to the thickness direction of the first current collector.

6. The battery according to claim 5, The cross-sectional shape of the at least one first slit is a trapezoidal shape in which the first side on the second electrode side is shorter than the second side opposite to the first side.

7. The battery according to any one of claims 1 to 3, The width of the at least one first slit, when viewed from above, is wider near the outer edge of the first current collector than far from the outer edge.

8. The battery according to any one of claims 1 to 3, The at least one first slit has a bend when viewed from above.

9. The battery according to any one of claims 1 to 3, The width of the first slit is greater than 0.1 mm and less than 5 mm.

10. The battery according to any one of claims 1 to 3, The first slit extends from the outer edge in one direction toward the inner side of the first current collector. The length of the first slit in one direction is more than 6% of the length of the first current collector in one direction.

11. The battery according to claim 10, The length of the first slit in one direction is less than 50% of the length of the first current collector in one direction.

12. The battery according to any one of claims 1 to 3, The area of ​​the first active material layer is smaller than that of the first current collector when viewed from above. The first current collector has: The first region in contact with the first active material layer, and The second region in contact with the solid electrolyte layer.

13. The battery according to claim 12, The at least one first slit is located in the second region, but not in the first region.

14. The battery according to any one of claims 1 to 3, The layer is either the first active material layer or the solid electrolyte layer.

15. The battery according to any one of claims 1 to 3, The second electrode has: Second collector, and The second active material layer is located between the second current collector and the solid electrolyte layer. The second current collector has at least one second slit that penetrates the second current collector along its thickness direction and is connected to the outer edge of the second current collector.

16. A stacked battery comprising a first battery and a second battery, wherein the first battery and the second battery are batteries according to any one of claims 1 to 15. The first battery is stacked on the surface of the first current collector of the second battery opposite to the first active material layer.

17. The stacked battery according to claim 16, The first current collector of the first battery and the first current collector of the second battery are current collectors with different polarities. The first battery and the second battery are stacked in such a way that their respective first current collectors are in contact with each other. The at least one first slit of the first battery does not overlap with the at least one first slit of the second battery when viewed from above.

18. The stacked battery according to claim 16, The first current collector of the first battery and the first current collector of the second battery are current collectors with the same polarity. The first battery and the second battery are stacked in such a way that their respective first current collectors are in contact with each other. At least a portion of the first slit of the first battery overlaps with the first slit of the second battery when viewed from above.

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