All-solid-state battery

Abstract

An all-solid-state battery includes a laminate comprising a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer. At least a portion of an edge of the positive electrode layer and the negative electrode layer has a zigzag pattern. The zigzag pattern includes a plurality of unit patterns, each having a peak and a valley. The positive electrode layer and the negative electrode layer are formed such that the zigzag patterns partially overlap in a thickness direction of the laminate.

Description

ALL-SOLID-STATE BATTERY

[0001] The present disclosure relates to an all-solid-state battery.

[0002] Recently, as portable electronic devices are required to be down-sized and used for a long term, high-capacity batteries are required, and safety of batteries is required due to the popularization of wearable electronic devices.

[0003] Since currently commercially available lithium ion batteries use an electrolyte containing a flammable organic solvent, there is a possibility of overheating and fire when a short circuit occurs. Accordingly, an all-solid-state battery using a solid electrolyte instead of an electrolyte solution has been proposed.

[0004] Because the all-solid-state battery does not use a flammable organic solvent, the possibility of fire or explosion in the event of a short circuit may be considerably reduced. Therefore, the all-solid-state battery may considerably increase safety compared to the lithium ion battery using the electrolyte solution.

[0005] A chip-type all-solid-state battery is formed in a laminated structure in which a solid electrolyte may be disposed between electrode layers of a positive electrode layer and negative electrode layer, a margin region may be disposed in a portion where the positive electrode layer and the negative electrode layer do not overlap with each other, and a protective layer is disposed on both ends in a lamination direction.

[0006] At this time, due to the solid electrolyte layer having relatively high deformation at the edge portion of the positive electrode layer and the negative electrode layer, a crack or delamination may occur at the interface between layers after plasticization. When the crack or delamination occurs at the interlayer interface, ion conduction between layers is deteriorated, which causes degradation of the characteristics of the all-solid-state battery. Accordingly, a method for alleviating delamination between layers in the chip and increasing the chip strength is required.

[0007] The present disclosure attempts to provide an all-solid-state battery in which a bonding strength of an edge portion of the positive electrode layer and the negative electrode layer is improved.

[0008] However, the objective of the present disclosure is not limited to the aforementioned one, and may be extended in various ways within the spirit and scope of the present disclosure.

[0009] An all-solid-state battery may include a laminate including a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer, where the positive electrode layer and the negative electrode layer have an edge of which at least a portion has a zigzag pattern, where the zigzag pattern may include a plurality unit patterns including a peak and a valley, and where the positive electrode layer and the negative electrode layer is formed such that the zigzag patterns partially overlap in a thickness direction of the laminate.

[0010] With respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate, a horizontal distance between a peak of the unit pattern of the positive electrode layer and a valley of the unit pattern of the negative electrode layer may be 0.2 mm or more and 1 mm or less.

[0011] With respect to the unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate, a horizontal distance between the peak of the unit pattern of the positive electrode layer and a peak of the unit pattern of the negative electrode layer may be 0.2 mm or more and 1 mm or less.

[0012] The zigzag pattern may be formed in at least a portion of an edge that is not exposed through outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.

[0013] The all-solid-state battery may further include a marginal portion disposed to be in contact with an edge that is not exposed through outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.

[0014] The marginal portion may have an edge in contact with the positive electrode layer and the negative electrode layer and having a shape corresponding to an edge shape of the positive electrode layer and the negative electrode layer.

[0015] The marginal portion may include at least one of a solid electrolyte and an insulation material.

[0016] The positive electrode layer may include a positive electrode current collector and a positive electrode active material layer.

[0017] The negative electrode layer may include a negative electrode current collector and a negative electrode active material layer.

[0018] An all-solid-state battery may include a laminate including a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer, where the positive electrode layer and the negative electrode layer have an edge of which at least a portion has a zigzag pattern, where the zigzag pattern may include a plurality unit patterns including a peak and a valley, and where, with respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in a thickness direction of the laminate, a horizontal distance between a peak of the unit pattern of the positive electrode layer and a valley of the unit pattern of the negative electrode layer may be 0.2 mm or more and 1 mm or less.

[0019] With respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate, a horizontal distance between the peak of the unit pattern of the positive electrode layer and a peak of the unit pattern of the negative electrode layer may be 0.2 mm or more and 1 mm or less.

[0020] The zigzag pattern may be formed in at least a portion of an edge that is not exposed through outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.

[0021] The all-solid-state battery may further include a marginal portion disposed to be in contact with an edge that is not exposed through outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.

[0022] An all-solid-state battery may include a laminate including a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer, where the positive electrode layer and the negative electrode layer have an edge of which at least a portion has a zigzag pattern, where the zigzag pattern may include a plurality unit patterns including a peak and a valley, and where, with respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in a thickness direction of the laminate, a horizontal distance between a peak of the unit pattern of the positive electrode layer and a peak of the unit pattern of the negative electrode layer may be 0.2 mm or more and 1 mm or less.

[0023] The zigzag pattern may be formed in at least a portion of an edge that is not exposed through outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.

[0024] The all-solid-state battery may further include a marginal portion disposed to be in contact with an edge that is not exposed through outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.

[0025] According to the all-solid-state battery according to an embodiment, after the bonding strength between the positive electrode layer and the negative electrode layer after plasticization is improved, thereby improving delamination between layers.

[0026] However, it is clear that the effects of the embodiments are not limited to the effects described above, and can be expanded in various ways without departing from the spirit and scope of the present disclosure.

[0027] FIG. 1 is a perspective view schematically showing an all-solid-state battery according to an embodiment.

[0028] FIG. 2 is a perspective view schematically showing the laminate of FIG. 1.

[0029] FIG. 3 is a cross-sectional view taken along line I-I' of FIG. 1.

[0030] FIG. 4 is a partial cross-sectional view schematically showing a positive electrode layer of the all-solid-state battery of FIG. 1.

[0031] FIG. 5 is a partial cross-sectional view schematically showing a negative electrode layer of the all-solid-state battery of FIG. 1.

[0032] FIG. 6 is an exploded perspective view schematically showing an internal structure of the laminate of FIG. 1.

[0033] FIG. 7 is an enlarged exploded perspective view of the structure of a positive electrode layer, a negative electrode layer, and a solid electrolyte layer of the all-solid-state battery of FIG. 1.

[0034] FIG. 8 is a top plan view schematically showing the structure of a positive electrode layer, a negative electrode layer, and a solid electrolyte layer of the all-solid-state battery of FIG. 1.

[0035] FIG. 9 is an enlarged view showing a portion A of FIG. 8.

[0036] FIG. 10 is a drawing showing a state in which a third surface of the laminate of FIG. 2 is polished to the peak of the electrode layer pattern.

[0037] FIG. 11 is a drawing showing a state in which a third surface of the laminate of FIG. 2 is polished to the valley of the electrode layer pattern.

[0038] FIG. 12 is a digital image of cross-section taken along line II-II' of FIG. 2.

[0039] FIG. 13 is a cross-sectional view taken along line II-II' of FIG. 2.

[0040] FIG. 14 is a graph showing discharge capacity of all-solid-state batteries according to Examples and Comparative Examples.

[0041] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the disclosure are shown. In order to clearly describe the present disclosure, parts or portions that are irrelevant to the description are omitted, and identical or similar constituent elements throughout the specification are denoted by the same reference numerals. In addition, some constituent elements are exaggerated, omitted, or briefly illustrated in the added drawings, and sizes of the respective constituent elements do not reflect the actual sizes.

[0042] Further, the accompanying drawings are provided for helping to easily understand exemplary embodiments disclosed in the present specification, and the technical spirit disclosed in the present specification is not limited by the accompanying drawings, and it will be appreciated that the present disclosure includes all of the modifications, equivalent matters, and substitutes included in the spirit and the technical scope of the present disclosure.

[0043] Terms including ordinal numbers such as first, second, and the like will be used only to describe various components, and are not interpreted as limiting these components. The terms are only used to differentiate one component from others.

[0044] It will be understood that when an element such as a layer, film, region, area, or substrate is referred to as being "on" or "above" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. Further, in the specification, the word "on" or "above" means disposed on or below the object portion, and does not necessarily mean disposed on the upper side of the object portion based on a gravitational direction.

[0045] It will be further understood that terms "comprise" and "have" used in the present specification specify the presence of stated features, numerals, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, numerals, steps, operations, components, parts, or combinations thereof. In addition, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises" or "comprising" will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0046] Further, throughout the specification, the phrase "in a plan view" or "on a plane" means viewing a target portion from the top, and the phrase "in a cross-sectional view" or "on a cross-section" means viewing a cross-section formed by vertically cutting a target portion from the side.

[0047] In addition, throughout the specification, "connected" means that two or more components are not only directly connected, but two or more components may be connected indirectly through other components, physically connected as well as being electrically connected, or it may be referred to by different names depending on the location or function but may mean integral.

[0048] FIG. 1 is a perspective view schematically showing an all-solid-state battery according to an embodiment, and FIG. 2 is a perspective view schematically showing the laminate of FIG. 1, and FIG. 3 is a cross-sectional view taken along line I-I' of FIG. 1. In addition, FIG. 4 is a partial cross-sectional view schematically showing a positive electrode layer of the all-solid-state battery of FIG. 1, and FIG. 5 is a partial cross-sectional view schematically showing a negative electrode layer of the all-solid-state battery of FIG. 1.

[0049] Referring to FIG. 1 and FIG. 2, an all-solid-state battery 1000 may include a laminate 100, a first external electrode 200, and a second external electrode 300.

[0050] First, as for directions defined for describing the present embodiment, an L-axis, a W-axis and a T-axis shown in the drawings represent axes indicating a length direction, a width direction, and a thickness direction of the all-solid-state battery 1000, respectively.

[0051] The thickness direction (T-axis direction) may be a direction perpendicular to wide surfaces (i.e., major surface) of sheet-shaped components. For example, the thickness direction (T-axis direction) may be used as the same concept as a direction in which components of the laminate 100 are stacked.

[0052] The length direction (L-axis direction) is a direction parallel to wide surfaces (major surfaces) of sheet-shaped components and may be a direction intersecting (or orthogonal to) the thickness direction (T-axis direction). For example, the length direction (L-axis direction) may be a direction in which the first external electrode 200 and the second external electrode 300 face each other.

[0053] The width direction (W-axis direction) is a direction parallel to wide surfaces (major surfaces) of sheet-shaped components and may be a direction simultaneously intersecting (or orthogonal to) the thickness direction (T-axis direction) and the length direction (L-axis direction).

[0054] The laminate 100 may be formed in a generally hexahedral shape, but the present embodiment is not limited thereto. Due to shrinkage during sintering, the laminate 100 may have a substantially hexahedral shape although not a complete hexahedral shape. For example, the laminate 100 may have a generally rectangular hexahedral shape but a portion corresponding to an edge or a vertex may have a round shape.

[0055] In the present embodiment, for convenience of description, surfaces facing each other in the length direction (L-axis direction) of the laminate 100 may be defined as a first surface S1 and a second surface S2, surfaces facing each other in the width direction (W-axis direction) of the laminate 100 and connecting the first surface S1 and the second surface S2 may be defined as a third surface S3 and a fourth surface S4, and surfaces facing each other in the thickness direction (T-axis direction) of the laminate 100 and connecting the first surface S1 and the second surface S2 may be defined as a fifth surface S5 and a sixth surface S6.

[0056] Therefore, a first direction, which is a direction in which the first surface S1 and the second surface S2 face each other, may be the length direction (L-axis direction), and a second direction and a third direction perpendicular to the first direction and perpendicular to each other may be the thickness direction (T-axis direction) and the width direction (W-axis direction) or the width direction (W-axis direction) and the thickness direction (T-axis direction), respectively.

[0057] A length of the laminate 100 may mean, based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section in the length direction (L-axis direction)-the thickness direction (T-axis direction) at a central portion of the laminate 100 in the width direction (W-axis direction), a maximum value of lengths of a plurality of line segments that connect two outermost boundary lines facing each other in the length direction (L-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the length direction (L-axis direction). Meanwhile, the length of the laminate 100 may mean a minimum value of lengths of the plurality of line segments that connect two outermost boundary lines facing each other in the length direction (L-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the length direction (L-axis direction). On the other hand, the length of the laminate 100 may mean an arithmetic average value of lengths of at least two line segments among the plurality of line segments that connect two outermost boundary lines facing each other in the length direction (L-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the length direction (L-axis direction).

[0058] A thickness of the laminate 100 may mean, based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section in the length direction (L-axis direction)-the thickness direction (T-axis direction) at the central portion of the laminate 100 in the width direction (W-axis direction), a maximum value of lengths of the plurality of line segments that connect two outermost boundary lines facing each other in the thickness direction (T-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the thickness direction (T-axis direction). Meanwhile, the thickness of the laminate 100 may mean a minimum value of lengths of the plurality of line segments that connect two outermost boundary lines facing each other in the thickness direction (T-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the thickness direction (T-axis direction). On the other hand, the thickness of the laminate 100 may mean an arithmetic average value of lengths of at least two line segments among the plurality of line segments that connect two outermost boundary lines facing each other in the thickness direction (T-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the thickness direction (T-axis direction).

[0059] A width of the laminate 100 may mean, based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section in the length direction (L-axis direction)-the width direction (W-axis direction) at a central portion of the laminate 100 in the thickness direction (T-axis direction), a maximum value of lengths of the plurality of line segments that connect two outermost boundary lines facing each other in the width direction (W-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the width direction (W-axis direction). Meanwhile, the width of the laminate 100 may mean a minimum value of lengths of the plurality of line segments that connect two outermost boundary lines facing each other in the width direction (W-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the width direction (W-axis direction). On the other hand, the width of the laminate 100 may mean an arithmetic average value of lengths of at least two line segments among the plurality of line segments that connect two outermost boundary lines facing each other in the width direction (W-axis direction) of the laminate 100 shown in the above-described cross-sectional photograph, respectively, and are parallel to the width direction (W-axis direction).

[0060] Referring to FIG. 2 and FIG. 3, the laminate 100 may include a solid electrolyte layer 110, a positive electrode layer 130, a negative electrode layer 150, an upper protective layer 160, a lower protective layer 170 and a marginal portion 180.

[0061] The solid electrolyte layer 110, the positive electrode layer 130 and the negative electrode layer 150 may be provided in plural quantities, respectively. The positive electrode layer 130 and the negative electrode layer 150 may be alternately stacked in the thickness direction (T-axis direction) interposing the solid electrolyte layer 110. Such a stacking structure may be repeated within the laminate 100, and an electrode layer closest to the fifth surface S5 of the laminate 100 may be the positive electrode layer 130 or the negative electrode layer 150, and an electrode layer closest to the sixth surface S6 may be the negative electrode layer 150 or the positive electrode layer 130.

[0062] The positive electrode layer 130 may be disposed on a first surface of the solid electrolyte layer 110, and the negative electrode layer 150 may be disposed on a second surface of the solid electrolyte layer 110.

[0063] The solid electrolyte layer 110 may include a solid electrolyte. The solid electrolyte may serve as a passage of lithium (Li) ions.

[0064] The solid electrolyte included in the solid electrolyte layer 110 may include a glass-ceramic-based electrolyte including lithium halide (LiX, where X is a halogen element such as F, Br, Cl, I). The glass-ceramic (or crystallized glass) means as shown by peaks and halos observed, a material in which amorphous and crystalline phases coexist, X-ray diffraction or electron beam diffraction. Therefore, the glass-ceramic electrolyte may be an electrolyte in a mixed state of amorphous and crystalline phases, with some crystallization having occurred through sintering.

[0065] An amorphous phase and two or more types of crystalline phases may coexist in the glass-ceramic electrolyte. In addition, the crystalline phase included in the glass-ceramic electrolyte may include a lithium compound crystal phase including lithium.

[0066] When the glass-ceramic electrolyte is included, densifying after sintering may be sufficiently performed, thereby enabling implementation of high ionic conductivity.

[0067] The glass-ceramic electrolyte may include lithium (Li) oxide, boron (B) oxide, silicon (Si) oxide, aluminum (Al) oxide, gallium (Ga) oxide, phosphorus (P) oxide, germanium (Ge) oxide, magnesium (Mg) oxide and chloride lithium (LiCl). As a specific example, the glass-ceramic electrolyte may include a lithium chloroboracite-based electrolyte doped with aluminum, and as a specific example, the glass-ceramic electrolyte may include Li2O-B2O3-LiCl-Al2O3or Li4B4Al3O12Cl.

[0068] On the other hand, the solid electrolyte included in the solid electrolyte layer 110 may include a lithium borosilicate-based electrolyte (hereinafter, referred to as an LBSO-based electrolyte). The LBSO-based electrolyte is an electrolyte in a glass state, and glass means a crystallographically amorphous phase, as shown by halos observed in X-ray diffraction or electron beam diffraction.

[0069] When the solid electrolyte included in the solid electrolyte layer 110 includes the LBSO-based electrolyte, the sintering temperature can be lowered while maintaining an amorphous state during sintering, thereby implementing high ionic conductivity, and there is an advantage of low reactivity with the electrode. The LBSO-based electrolyte may include lithium (Li), boron (B), silicon (Si), aluminum (Al), phosphorus (P), germanium (Ge), and sulfur (S).

[0070] In addition, the solid electrolyte included in the solid electrolyte layer 110 may be one or more selected from the group consisting of garnet-type, NASICON-type, LISICON-type, perovskite-type and LiPON-type.

[0071] In a region where the marginal portion 180 to be described later is disposed, a material having low ionic conductivity and electrical conductivity, i.e., an insulation material may exist, and a material having ionic conductivity (or electrical conductivity) similar to that of the solid electrolyte may exist. For example, when a material having ionic conductivity (or electrical conductivity) similar to that of the solid electrolyte exists in this region, that material may be the same material as the solid electrolyte of other regions, and may be a different material. As another example, a material having ionic conductivity (or electrical conductivity) similar to that of the solid electrolyte may exist in this region together with an insulation material.

[0072] The garnet-type solid electrolyte may mean lithium-lanthanum-zirconium-oxide (LLZO) represented by LiaLabZrcO12, such as Li7La3Zr2O12, and the NASICON-type solid electrolyte may mean lithium-aluminum-titanium-phosphate (LATP) of Li1+xAlxTi2-x(PO4)3(0<x<1) in which Ti is introduced into Li1+xAlxM2-x(PO4)3(LAMP) (0<x<2, M=Zr, Ti, Ge)-type compound, lithium-aluminum-germanium-phosphate (LAGP) represented as Li1+xAlxGe2-x(PO4)3(0<x<1) such as Li1.3Al0.3Ge1.7(PO4)3into which excessive lithium is introduced, and / or lithium-zirconium-phosphate (LZP) of LiZr2(PO4)3.

[0073] In addition, the LISICON-type solid electrolyte may mean a solid solution oxide represented as xLi3AO4-(1-x)Li4BO4(A: P, As, V, or the like, B: Si, Ge, Ti, or the like) and including Li4Zn(GeO4)4, Li10GeP2O12(LGPO), Li3.5Si0.5P0.5O4, Li10.42Si(Ge)1.5P1.5Cl0.08O11.92, or the like and a solid solution sulfide including Li2S-P2S5, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-GeS2, or the like represented as Li4-xM1-yM'yS4(M= Si, Ge, and M' = P, Al, Zn, Ga).

[0074] In addition, the perovskite-type solid electrolyte may mean lithium-lanthanum-titanate (LLTO) represented by Li3xLa2 / 3-x□1 / 3-2xTiO3(0<x<0.16, □ = vacancies), such as Li1 / 8La5 / 8TiO3, and the LiPON-type solid electrolyte may mean nitrides such as lithium-phosphorous-oxynitride such as Li2.8PO3.3N0.46.

[0075] The positive electrode layer 130 may be exposed through the first surface S1 of the laminate 100, and may be connected to the first external electrode 200.

[0076] Referring to FIG. 3 and FIG. 4, the positive electrode layer 130 may include a positive electrode current collector 133, a first positive electrode active material layer 135 and a second positive electrode active material layer 136.

[0077] The positive electrode current collector 133 may be formed of, for example, a plate-shaped member or a thin member. As another example, the positive electrode current collector 133 may be a porous body such as a reticulate or mesh shape.

[0078] The positive electrode current collector 133 may include a first surface 133a and a second surface 133b. The first surface 133a and the second surface 133b may face each other in the thickness direction (T-axis direction).

[0079] The positive electrode current collector 133 may be a porous metal plate formed of, for example, stainless steel, nickel (Ni), copper (Cu), tin (Sn), aluminum (Al), or an alloy thereof, but is not limited thereto.

[0080] In addition, the positive electrode current collector 133 may be coated with an oxidation-resistant metal or alloy film in order to prevent oxidation.

[0081] The positive electrode current collector 133 may be formed of a carbon-based planar, thin, or linear member. The positive electrode current collector 133 may be made of a conductive carbon material, and the conductive carbon material may be, for example, graphite, conductive fiber such as carbon nanotube (CNT) or vapor-grown carbon fiber (VGCF), or conductive carbon such as carbon black.

[0082] Meanwhile, the positive electrode current collector may also include one or more types of solid electrolytes.

[0083] The first positive electrode active material layer 135 and the second positive electrode active material layer 136 may include a positive electrode active material, and may be disposed on a surface of the positive electrode current collector 133. The first positive electrode active material layer 135 and the second positive electrode active material layer 136 may be formed by printing the positive electrode active material on one surface or both surfaces of the positive electrode current collector 133, but the method of forming the positive electrode active material layer is not limited thereto.

[0084] The positive electrode active material included in the positive electrode active material layers 135 and 136 may be a material containing lithium (Li) ions. The positive electrode active material may reversibly intercalate and deintercalate lithium ions. That is, the positive electrode active material may contain lithium ions and serve to provide lithium ions to a negative electrode when charging an all-solid-state battery. The positive electrode active material may affect the capacity and output of an all-solid-state battery.

[0085] The positive electrode active material may be, for example, a compound represented by the following formula: LiaAl-bMbD2(where, 0.90≤a≤1.8, 0≤b≤0.5); LiaEl-bMbO2-cDc(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiE2-bMbO4-cDc(where, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobMcDα(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); LiaNi1-b-cCobMcO2-αXα(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); LiaNi1-b-cCobMcO2-αX2(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05,0<α<2); LiaNi1-b-cMnbMcDα(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); LiaNi1-b-cMnbMcO2-αXα(where,0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); LiaNi1-b-cMnbMcO2-αX2(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); LiaNibEcGdO2(where, 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1); LiaNibCocMndGeO2(where,0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1); LiaNiGbO2(where, 0.90≤a≤1.8, 0.001≤b≤0.1); LiaCoGbO2(where, 0.90≤a≤1.8, 0.001≤b≤0.1); LiaMnGbO2 (where, 0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn2GbO4(where, 0.90≤a≤1.8, 0.001≤b≤0.1); QO2; QS2; LiQS2; V2O5; LiV2O2; LiRO2; LiNiVO4; Li(3-f)J2(PO4)3(0≤f≤2); Li(3-f)Fe2(PO4)3(where, 0≤f≤2); and LiFePO4, in the above formula, A is Ni, Co, or Mn; M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Nb, Ti, or a rare-earth element; D is O, F, S, or P; E is Co or Mn; X is F, S, or P; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, or V; Q is Ti, Mo, or Mn; R is Cr, V, Fe, Sc, or Y; J is V, Cr, Mn, Co, Ni, or Cu.

[0086] In addition, the positive electrode active material may be LiCoO2, LiMnxO2x(where, x =1 or 2), LiNi1-xMnxO2x(where, 0<x<1), LiNi1-x-yCoxMnyO2(where, 0≤x≤0.5, 0≤y≤0.5), LiFePO4, TiS2, FeS2, TiS3, or FeS3, but is not limited thereto.

[0087] The positive electrode active material may selectively include a conductive material and a binder. However, since organic materials such as binders are decomposed during sintering, they may not remain in the positive active material layer of the obtained positive electrode current collector.

[0088] The conductive material is not particularly limited as long as it has conductivity without causing chemical change in the all-solid-state battery 1000. For example, graphite such as natural graphite or artificial graphite; a carbon-based material such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; a conductive fiber such as carbon fiber or metal fiber; fluorinated carbon; a metal component such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), or copper (Cu), an oxide, nitride or fluoride thereof, or the like; a conductive whisker such as zinc oxide or potassium titanate; a conductive metal oxide such as titanium oxide; a conductive material such as polyphenylene derivative, or the like may be used.

[0089] The binder may be used to improve bonding strength between the active material and the conductive material. Examples of the binder may be polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber and various copolymer, or the like, but are not limited thereto.

[0090] Meanwhile, the positive electrode layer 130 may further include a solid electrolyte component. The solid electrolyte component may include at least one component among the above-described components, and may function as an ion conduction channel within the positive electrode layer. Through this, interfacial resistance may be reduced.

[0091] The negative electrode layer 150 may be exposed through the second surface S2 of the laminate 100, and may be connected to the second external electrode 300.

[0092] Referring to FIG. 3 and FIG. 5, the negative electrode layer 150 may include a negative electrode current collector 153, a first negative electrode active material layer 155 and a second negative electrode active material layer 156.

[0093] The negative electrode current collector 153 may be formed of, for example, a plate-shaped member or a thin member. As another example, the negative electrode current collector 153 may use a porous body, e.g., in a reticulate or mesh shape.

[0094] The negative electrode current collector 153 may include a first surface 153a and a second surface 153b. The first surface 153a and the second surface 153b may face each other in the thickness direction (T-axis direction).

[0095] The negative electrode current collector 153 may be a porous metal plate formed of, for example, stainless steel, nickel (Ni), copper (Cu), tin (Sn), aluminum (Al), or an alloy thereof, but is not limited thereto.

[0096] In addition, the negative electrode current collector 153 may be coated with an oxidation-resistant metal or alloy film in order to prevent oxidation.

[0097] The negative electrode current collector 153 may be formed of a conductive carbon-based material, the same as the positive electrode current collector 133, and may include one or more types of solid electrolytes. The negative electrode current collector 153 may be the same as the negative electrode active material layers 155 and 156.

[0098] The first negative electrode active material layer 155 and the second negative electrode active material layer 156 may include a negative electrode active material, and may be disposed on a surface of the negative electrode current collector 153. The first negative electrode active material layer 155 and the second negative electrode active material layer 156 may be formed by printing the negative electrode active material on one surface or both surfaces of the negative electrode current collector 153, but the method of forming the negative electrode active material layer is not limited thereto.

[0099] The negative electrode active material included in the negative electrode active material layers 155 and 156 may store lithium ions that have moved from the positive electrode, and generate electrical energy by releasing the lithium ions when discharging the all-solid-state battery. The negative electrode active material may include a carbon-based material, silicon, silicon oxide, a silicon-based alloy, a silicon-carbon-based material composite, tin, a tin-based alloy, a tin-carbon composite, a metal oxide, or a combination thereof, and may include a lithium metal and / or a lithium metal alloy.

[0100] The lithium metal alloy may include lithium and a metal / metalloid that can be alloyed with lithium. For example, the metal / metalloid capable of forming an alloy with lithium may be Si, Sn, Al, Ge, Pb, Bi, Sb, Si-AM alloy (AM is an alkali metal, an alkaline-earth metal, Group 13 to 16 elements, a transition metal, a rare-earth element or a combination thereof, and does not include Si), Sn-AM alloy (AM is an alkali metal, an alkaline-earth metal, Group 13 to 16 elements, a transition metal, a transition metal oxide such as lithium titanium oxide (Li4Ti5O12), a rare-earth element or a combination thereof, and does not include Sn), MnOx(0 < x ≤ 2), or the like.

[0101] The element AM may be Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, or a combination thereof.

[0102] In addition, oxide of the metal / metalloid that can be alloyed with lithium may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, SnO2, SiOx(0<x<2), or the like. For example, the negative electrode active material may include one or more elements selected from the group consisting of Group 13 to 16 elements of the periodic table. For example, the negative electrode active material may include one or more element selected from the group consisting of Si, Ge, and Sn.

[0103] The carbon-based material may be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite such as natural graphite or artificial graphite in amorphous, platy, flake, spherical or fibrous forms. In addition, the amorphous carbon may be soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, graphene, carbon black, fullerene soot, carbon nanotubes, carbon fibers, and the like, but is not limited thereto.

[0104] The silicon may be one selected from the group consisting of Si, SiOx(0 <x <2, for example, 0.5 to 1.5), Sn, SnO2, or silicon-containing metal alloy, and a mixture thereof. The silicon-containing metal alloy may include, for example, silicon, and at least one of Al, Sn, Ag, Fe, Bi, Mg, Zn, in, Ge, Pb and Ti.

[0105] The negative electrode active material may selectively include a conductive material and a binder.

[0106] The conductive material is not particularly limited as long as it has conductivity without causing chemical change in the all-solid-state battery 1000. For example, graphite such as natural graphite or artificial graphite; a carbon-based material such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, or thermal black; a conductive fiber such as carbon fiber or metal fiber; fluorinated carbon; a metal component such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), or copper (Cu), an oxide, nitride or fluoride thereof, or the like; conductive whiskers such as zinc oxide, potassium titanate, or the like; a conductive metal oxide such as titanium oxide; a conductive material such as polyphenylene derivative, or the like may be used.

[0107] The binder may be used to improve bonding strength between the active material and the conductive material. Examples of the binder may be polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber and various copolymer, or the like, but are not limited thereto.

[0108] Meanwhile, the negative electrode layer 150 may further include a solid electrolyte component. The solid electrolyte component may include at least one component among the above-described components, and may function as an ion conduction channel within the negative electrode layer. Through this, interfacial resistance may be reduced.

[0109] Referring to FIG. 3, the upper protective layer 160 and the lower protective layer 170 may be outermost layers disposed on the fifth surface S5 and the sixth surface S6 of the laminate 100, respectively. That is, the upper protective layer 160 may be an outermost layer toward the fifth surface S5 of the laminate 100, and the lower protective layer 170 may be an outermost layer toward the sixth surface S6 of the laminate 100. The upper protective layer 160 and the lower protective layer 170 may prevent moisture permeation to improve moisture resistance reliability, and may prevent damage due to a physical and chemical impact.

[0110] The upper protective layer 160 and the lower protective layer 170 may be an insulation layer formed of an insulation material, i.e., a material that does not have electrical (ionic) conductivity.

[0111] The upper protective layer 160 and the lower protective layer 170 may include a ceramic material, and for example, may include alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silica (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), nitride gallium (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), a mixture thereof, oxides and / or nitrides of these materials, or any other appropriate ceramic material, but it is not limited thereto. In addition, the upper protective layer 160 and the lower protective layer 170 may optionally include the above-described solid electrolyte, and may include one or more types of solid electrolytes, but is not limited thereto.

[0112] The marginal portion 180 may be disposed along edges of the positive electrode layer 130 and the negative electrode layer 150. The marginal portion 180 may be disposed to be in contact with a remaining edge of the positive electrode layer 130 excluding a portion where the positive electrode layer 130 is connected to the first external electrode 200. In addition, the marginal portion 180 may be disposed to be in contact with a remaining edge of the negative electrode layer 150 excluding a portion where the negative electrode layer 150 is connected to the second external electrode 300.

[0113] For example, the marginal portion 180 may be disposed in a region excluding a region where the positive electrode layer 130 or the negative electrode layer 150 is disposed on the solid electrolyte layer 110. When the positive electrode layer 130 is disposed on the solid electrolyte layer 110, the marginal portion 180 may be disposed in a region excluding a region where the positive electrode layer 130 is disposed. In the same way, when the negative electrode layer 150 is disposed on the solid electrolyte layer 110, the marginal portion 180 may be disposed in a region excluding a region where the negative electrode layer 150 is disposed.

[0114] Referring to FIG. 3, the marginal portion 180 may form a part of the first surface S1 and a part of the second surface S2 of the laminate 100. Meanwhile, although not shown in the drawings, the marginal portion 180 may form a part of the third surface S3 and a part of the fourth surface S4 of the laminate 100.

[0115] The marginal portion 180 may be disposed to resolve a step between the solid electrolyte layer 110 and the positive electrode layer 130 and a step between the solid electrolyte layer 110 and the negative electrode layer 150. The marginal portion 180 may be disposed, for example, on the same plane as the positive electrode layer 130 and the negative electrode layer 150. The marginal portion 180 may resolve a step between the solid electrolyte layer 110 and the positive electrode layer 130 or a step between the solid electrolyte layer 110 and the negative electrode layer 150. Accordingly, the density between the solid electrolyte layer 110 and electrode layer increases, so that delamination or bending between layers due to sintering may be prevented during the manufacturing process of the all-solid battery.

[0116] Meanwhile, the marginal portion 180 may be formed of a material that is resistant to moisture and has low lithium (Li) ion conductivity. In this case, the marginal portion 180 may protect active material layers 135, 136, 155, and 156 from moisture infiltration, lithium (Li) ion leakage, or the like. For example, the marginal portion 180 may include an insulation material or an electrolyte material, and a material with an ionic conductivity of 1.0x10-10S / cm or less.

[0117] The marginal portion 180 may be formed of an insulation material, i.e., a material that does not have electrical (ionic) conductivity.

[0118] The marginal portion 180 may include a ceramic material, and for example, may include alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silica (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), nitride gallium (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), a mixture thereof, oxides and / or nitrides of these materials, or any other appropriate ceramic material, but it is not limited thereto.

[0119] Meanwhile, the marginal portion 180 may include a solid electrolyte that is the same as or different from the solid electrolyte included in the solid electrolyte layer described above, and may include one or more types of solid electrolytes, but is not limited thereto.

[0120] In addition, the marginal portion 180 may include a material having low ionic conductivity and electrical conductivity, i.e., an insulation material, and a material having ionic conductivity (or electrical conductivity) similar to that of the solid electrolyte. For example, when a material having ionic conductivity (or electrical conductivity) similar to that of the solid electrolyte exists in the marginal portion, the material may be the same material as the solid electrolyte of other regions, and may be a different material. As another example, a material having ionic conductivity (or electrical conductivity) similar to that of the solid electrolyte and an insulation material may exist together in the marginal portion.

[0121] The first external electrode 200 and the second external electrode 300 may be disposed outside the laminate 100.

[0122] The first external electrode 200 may be connected to the positive electrode layer 130 and the solid electrolyte layer 110 on the first surface S1 of the laminate 100. For example, the first external electrode 200 may cover the first surface S1 of the laminate 100, and the first external electrode 200 may extend to the third surface S3, the fourth surface S4, the fifth surface S5, and the sixth surface S6 of the laminate 100, to partially cover each of the surfaces.

[0123] Meanwhile, in another embodiment, the first external electrode 200 may extend to one surface of the fifth surface S5 and the sixth surface S6 of the laminate 100, to partially cover a corresponding surface.

[0124] The first external electrode 200 may be formed by baking a conductive paste. The conductive paste may include, for example, a conductive metal such as silver (Ag) or copper (Cu) and glass.

[0125] The second external electrode 300 may be connected to the negative electrode layer 150 and the solid electrolyte layer 110 on the second surface S2 of the laminate 100. For example, the second external electrode 300 may cover the second surface S2 of the laminate 100, and the second external electrode 300 may extend to the third surface S3, the fourth surface S4, the fifth surface S5, and the sixth surface S6 of the laminate 100, to partially cover each of the surfaces.

[0126] Meanwhile, in another embodiment, the second external electrode 300 may extend to one surface of the fifth surface S5 and the sixth surface S6 of the laminate 100, to partially cover a corresponding surface.

[0127] The second external electrode 300 may be formed by baking a conductive paste. The conductive paste may include, for example, a conductive metal such as silver (Ag) or copper (Cu) and glass.

[0128] For example, the first external electrode 200 and the second external electrode 300 may be formed by dipping the first surface S1 and the second surface S2 of the laminate 100 into the conductive paste and blotting it. As another example, the first external electrode 200 and the second external electrode 300 may be formed by applying the conductive paste to the first surface S1 and the second surface S2 of the laminate 100, respectively. As still another example, the first external electrode 200 and the second external electrode 300 may be formed by transferring a dry film formed by drying the conductive paste to the laminate 100 and then sintering it, but the method of forming the first external electrode 200 and the second external electrode 300 is not limited to the method described above. The conductive metal included in the conductive paste may be at least one of, for example, copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb) and an alloy thereof, but is not limited thereto.

[0129] FIG. 6 is an exploded perspective view schematically showing an internal structure of the laminate of FIG. 1, FIG. 7 is a partial enlarged cross-sectional view schematically showing the structure of a positive electrode layer, a negative electrode layer, and a solid electrolyte layer of the all-solid-state battery of FIG. 1, and FIG. 8 is a top plan view schematically showing the structure of a positive electrode layer, a negative electrode layer, and a solid electrolyte layer of the all-solid-state battery of FIG. 1.

[0130] Referring to FIG. 6 and FIG. 7, one solid electrolyte layer 110 may be simultaneously in contact with the positive electrode layer 130 and the negative electrode layer 150. The first surface of the solid electrolyte layer 110 may be in contact with the positive electrode active material layers 135 and 136 of the positive electrode layer 130, and the second surface may be in contact with the negative electrode active material layers 155 and 156 of the negative electrode layer 150. That is, the solid electrolyte layer 110 may be disposed between the positive electrode active material layers 135 and 136 and the negative electrode active material layers 155 and 156.

[0131] The positive electrode layer 130 and the negative electrode layer 150 have an edge of which at least a portion has a zigzag pattern. The zigzag pattern may be formed in at least a portion of an edge that is not exposed through an outer surface of the laminate 100 among the edges of the positive electrode layer 130 and the negative electrode layer 150. That is, in the positive electrode layer 130, the zigzag pattern may be formed in at least a portion among the remaining edge of the positive electrode layer 130 excluding a portion exposed to the first surface S1 of the laminate 100, and in the negative electrode layer 150, the zigzag pattern may be formed in the remaining edge of the negative electrode layer 150 excluding portion exposed to the second surface S2 of the laminate 100.

[0132] In the positive electrode layer 130, the zigzag pattern may be formed in at least a portion among the remaining edge of the positive electrode layer 130 excluding a portion connected to the first external electrode 200. For example, the zigzag pattern may be formed on all or part of an edge where the positive electrode layer 130 is in contact with the marginal portion 180, or may be formed on all or part of a length directional edge or all or part of a width directional edge, among edges where the positive electrode layer 130 is in contact with the marginal portion 180.

[0133] In the negative electrode layer 150, the zigzag pattern may be formed in the remaining edge of the negative electrode layer 150 excluding a portion connected to the second external electrode 300. For example, the zigzag pattern may be formed on all or part of an edge where the negative electrode layer 150 is in contact with the marginal portion 180, or may be formed on all or part of a length directional edge or all or part of a width directional edge, among edges where the negative electrode layer 150 is in contact with the marginal portion 180.

[0134] Referring to FIG. 8, the zigzag pattern formed on the edges of the positive electrode layer 130 and the negative electrode layer 150 may have a shape in which peaks P and valleys V are repeated. The peaks P may be portions of the positive electrode layer 130 and the negative electrode layer 150 that are sharp outward, and the valleys V may be portions of the positive electrode layer 130 and the negative electrode layer 150 that are sharp inward. That is, when the zigzag pattern is considered to be a shape in which two sides of a triangle are repeated, a vertex where the two sides of the triangle meet may be the peak P, and a portion where sides of adjacent two triangles meet may be the valley V. The present embodiment is not limited thereto, and the zigzag pattern may have the shape in which the peak P and the valley V are repeated, and may have, for example, a waved shape, a protrusions-and-depressions pattern, or the like.

[0135] The zigzag pattern formed on the edge of the positive electrode layer 130 and the zigzag pattern formed on the edge of the negative electrode layer 150 may be disposed to partially overlap in the thickness direction of the laminate 100. That is, in the zigzag pattern formed on the edge of the positive electrode layer 130 and the zigzag pattern formed on the edge of the negative electrode layer 150, peaks (and also valleys) may not overlay with each other in the thickness direction of the laminate 100. For example, a peak of the zigzag pattern of the positive electrode layer 130 and a peak of the zigzag pattern of the negative electrode layer 150 may not overlap with each other in the thickness direction. In addition, a valley of the zigzag pattern of the positive electrode layer 130 and a valley of the zigzag pattern of the negative electrode layer 150 may not overlap with each other in the thickness direction, either.

[0136] FIG. 9 is an enlarged view showing a portion A of FIG. 8, and FIG. 10 is a drawing showing a state in which a third surface of the laminate of FIG. 2 is polished to the peak of the electrode layer pattern, and FIG. 11 is a drawing showing a state in which a third surface of the laminate of FIG. 2 is polished to the valley of the electrode layer pattern, and FIG. 12 is a digital image of cross-section taken along line II-II' of FIG. 2.

[0137] Referring to FIG. 9, in the zigzag pattern formed on the edge of the positive electrode layer 130 and the zigzag pattern formed on the edge of the negative electrode layer 150, a horizontal distance a between a peak and a valley may be 0.2 mm or more and 1 mm or less. Here, the horizontal distance a between peaks and valleys of the zigzag pattern of the positive electrode layer 130 and the zigzag pattern of the negative electrode layer 150 indicates a horizontal distance between a peak of the unit pattern of the positive electrode layer 130 and a valley of the unit pattern of the negative electrode layer 150 or a horizontal distance between a valley of the unit pattern of the positive electrode layer 130 and a peak of the unit pattern of the negative electrode layer 150, with respect to unit patterns of the positive electrode layer 130 and the negative electrode layer 150 that are adjacent in the thickness direction of the laminate among the zigzag patterns. Here, the term unit pattern may be a pattern composed of peaks and valleys among the zigzag pattern, and may mean a range from one valley to a subsequent valley in the zigzag pattern of the positive electrode layer 130 or the negative electrode layer 150. That is, one peak range in the repeated peaks in the zigzag pattern may be referred to as the unit pattern. A plurality of unit patterns may be included, and in FIG. 9, Z' may be one of the unit patterns of the positive electrode layer 130, and Z'' may be one of the unit patterns of the negative electrode layer 150.

[0138] A measuring method of the horizontal distance a between a peak and a valley may be as follows. First, one surface among the third surface S3 and the fourth surface S4 of the laminate 100 may be polished. Referring to FIG. 10, the third surface S3 of the laminate 100 may be polished in a cross-section in the length direction (L-axis direction)-the thickness direction (T-axis direction) of the laminate 100 until the peak of the positive electrode layer 130 or the negative electrode layer 150 appears. In a cross-section of the laminate 100 in the L-T direction in which the peak of the positive electrode layer 130 or the negative electrode layer 150 has appeared, the electrode may appear as a dot. A width W' of the laminate 100 remaining after the polishing until the peak of the positive electrode layer 130 or the negative electrode layer 150 appears may be measured by an outer diameter micrometer. The polishing of the laminate 100 is continued. Referring to FIG. 11, the third surface S3 of the laminate 100 may be polished in the cross-section of the laminate 100 in the L-T direction until the valley of the positive electrode layer 130 or the negative electrode layer 150 appear. In the cross-section of the laminate 100 in the L-T direction in which the valley of the positive electrode layer 130 or the negative electrode layer 150 has appeared, the electrode may appear as a solid line. A width W" of the laminate 100 remaining after the polishing until the valley of the positive electrode layer 130 or the negative electrode layer 150 appear may be measured by an outer diameter micrometer. When the width W" of the laminate 100 is subtracted from the width W' of the laminate 100 measured as such, the horizontal distance a between a peak and a valley may be obtained.

[0139] When the horizontal distance a between a peak and a valley is less than 0.2 mm, a crack or delamination may occur in the interface between layers, and when it exceeds 1 mm, the charging and discharging efficiency of the all-solid-state battery may be deteriorated.

[0140] In the zigzag pattern formed on the edge of the positive electrode layer 130 and the zigzag pattern formed on the edge of the negative electrode layer 150, a horizontal distance b between peaks may be 0.2 mm or more and 1 mm or less. Here, the horizontal distance b between peaks of the zigzag pattern of the positive electrode layer 130 and the zigzag pattern of the negative electrode layer 150 indicates a horizontal distance between the peak of the unit pattern of the positive electrode layer 130 and the peak of the unit pattern of the negative electrode layer 150 adjacent thereto, with respect to unit patterns of the positive electrode layer 130 and the negative electrode layer 150 that are adjacent in the thickness direction of the laminate 100.

[0141] The measuring method of the horizontal distance b between peaks may be as follows. First, one surface among the third surface S3 and the fourth surface S4 of the laminate 100 may be polished. The polishing may be performed in a cross-section in the length direction (L-axis direction)-the thickness direction (T-axis direction) of the laminate 100 until a part of the zigzag pattern of the positive electrode layer 130 or the negative electrode layer 150. In the cross-section of the laminate 100 in the L-T direction in which a part of the zigzag pattern of the positive electrode layer 130 or the negative electrode layer 150 has appeared, the electrode may appear as a dotted line. The cross-section of the laminate 100 in the L-T direction in the state that a part of the zigzag pattern of the positive electrode layer 130 or the negative electrode layer 150 has appeared may be photographed by an optical microscope or scanning electron microscope (SEM) to obtain a cross-sectional image of the laminate 100 in the L-T direction. At this time, the cross-sectional image of the laminate 100 in the L-T direction may be an image captured at a magnification of 100 to 1000 times. The horizontal distance b between peaks may be obtained by measuring central distances of the positive electrode layer 130 and the negative electrode layer 150 in the cross-sectional image in the L-T direction and then taking the average of the central distances.

[0142] Referring to FIG. 12, when central distances b1, b2, b3, … bn of the positive electrode layer 130 and the negative electrode layer 150 are measured from the cross-sectional image of the laminate 100 in the L-T direction in which a part of the zigzag pattern of the positive electrode layer 130 or the negative electrode layer 150 appears, and the average of b1, b2, b3, … bn is obtained, that average value may be the horizontal distance b between peaks. Here, n in bn is the number of central distances of the positive electrode layer 130 and the negative electrode layer 150 measured from the cross-sectional image of the laminate 100 in the L-T direction, and may be 10 or more.

[0143] When the horizontal distance b between peaks is less than 0.2 mm, a crack or delamination may occur in the interface between layers, and when it exceeds 1 mm, the charging and discharging efficiency of the all-solid-state battery may be deteriorated.

[0144] The marginal portion 180 may be disposed to be in contact with an edge that is not exposed through the outer surface of the laminate 100 among the edges of the positive electrode layer 130 and the negative electrode layer 150. The marginal portion 180 may have an edge in contact with the positive electrode layer 130 and the negative electrode layer 150 and having a shape corresponding to the edge shape of the positive electrode layer 130 and the negative electrode layer 150. For example, on an edge of the marginal portion 180 in contact with the zigzag pattern formed on the edge of the positive electrode layer 130, a valley may be disposed with respect to the peak of the pattern of the positive electrode layer 130, and a peak may be disposed with respect to the valley of the pattern of the positive electrode layer 130. In addition, on the edge of the marginal portion 180 in contact with the zigzag pattern formed on the edge of the negative electrode layer 150, a valley may be disposed with respect to the peak of the pattern of the negative electrode layer 150, and a peak may be disposed with respect to the valley of the pattern of the negative electrode layer 150.

[0145] FIG. 13 is a cross-sectional view taken along line II-II' of FIG. 2, and represents a cross-section in the length direction (L-axis direction)-the thickness direction (T-axis direction) of the laminate 100 at a generally central portion of the peak and the valley of the zigzag pattern.

[0146] Referring to FIG. 13, on the edge where the zigzag pattern is formed among the edges of the positive electrode layer 130 and the negative electrode layer 150, the marginal portion 180 may be disposed between patterns, and they may partially overlap in the thickness direction of the laminate 100.

[0147] According to the present embodiment, by forming at least a portion among the edges of the positive electrode layer 130 and the negative electrode layer 150 in the zigzag pattern, the bonding area may be increased, and since the zigzag patterns of the positive electrode layer 130 and the negative electrode layer 150 do not completely overlap but partially overlap in the thickness direction of the laminate 100, the bonding strength of the positive electrode layer 130 and the negative electrode layer 150 in the thickness direction may be improved. Accordingly, a crack or delamination occurrence ratio may be significantly reduced in the interface between layers.

[0148] [Experimental Example]

[0149] Hereinafter, referring to FIG. 14 and Table 1, the performance of all-solid-state batteries according to Examples and Comparative Examples will be described.

[0150] FIG. 14 is a graph showing discharge capacity of all-solid-state batteries according to Examples and Comparative Examples, and Table 1 is a table representing whether delamination between layers has occurred and the charging and discharging efficiency depending on the horizontal distance a between a peak and a valley and the horizontal distance b between peaks of Examples and Comparative Examples. Here, the horizontal distance a between a peak and a valley indicates the horizontal distance between the peak of the unit pattern of the positive electrode layer and the valley of the unit pattern of the negative electrode layer or the horizontal distance between the valley of the unit pattern of the positive electrode layer and the peak of the unit pattern of the negative electrode layer, with respect to the unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate. In addition, the horizontal distance b between peaks indicates the horizontal distance between the peak of the unit pattern of the positive electrode layer and the peak of the unit pattern of the negative electrode layer, with respect to the unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate.

[0151] Horizontal distance a between peak and valley [mm]Horizontal distance b between peaks [mm]Whether interlayer delamination has occurredCharging and discharging efficiency [%]Comparative Example 1--○62Comparative Example 20.10.1○62Example 10.20.2△63Example 20.20.5△66Example 30.21.0Ｘ69Example 40.50.2△66Example 50.50.5Ｘ66Example 60.51.0Ｘ63Example 71.00.2Ｘ69Example 81.00.5Ｘ63Example 91.01.0Ｘ60Comparative Example31.51.5Ｘ57

[0152] All-solid-state batteries according to Examples and Comparative Examples were prepared as follows. The solid electrolyte layer was prepared by molding a lithium chloroboracite-based electrolyte (hereinafter, referred to as LCBA) doped with aluminum into a thickness of 30 μm. The positive electrode layer was prepared by mixing lithium cobalt oxide (Lithium cobalt oxide, LCO) on a solid electrolyte layer and LCBA and molding it into a thickness of 30 μm by using a screen printer. The negative electrode layer was prepared by mixing graphite of 2μm and LCBA on a solid electrolyte layer and molding it into a thickness of 30 μm by using a screen printer. The upper protective layer, the lower protective layer, and the marginal portion were applied with LCBA composition, and the upper protective layer and the lower protective layer were applied by preparing 20 sheets. The electrode layer was laminated in a total of 5 layers (negative electrode layer-positive electrode layer-negative electrode layer-positive electrode layer-negative electrode layer). In the case of Comparative Example 1, the edge of the electrode layer was straight, and in the case of Comparative Example 2, Comparative Example 3, Example 1 to Example 9, the edge of the electrode layer was in a zigzag pattern, with different horizontal distances a between a peak and a valley and different horizontal distances b between peaks, based on which experiments for whether delamination between layers occurs after plasticization and the charging and discharging were performed. In FIG. 14, the curved line A represents the charging and discharging efficiency of Comparative Example 3, the curved line B represents that of Example 9, the curved line C represents that of Comparative Example 1 and Comparative Example 2, the curved line D represents that of Example 1, Example 6, and Example 8, the curved line E represents that of Example 2, Example 4, and Example 5, and the curved line F represents that of Example 3 and Example 7.

[0153] Referring to FIG. 14 and Table 1, in the case of Comparative Example 1 in which the edge of the electrode layer is straight, and Comparative Example 2 in which the edge of the electrode layer has a zigzag pattern but the horizontal distance a between a peak and a valley and the horizontal distance b between peaks are both less than 0.2 mm, the charging and discharging efficiency was 62%, which is more than 60%, but the delamination between layers has occurred in all layers. Meanwhile, in the case of Comparative Example 3 in which the edge of the electrode layer has a zigzag pattern but the horizontal distance a between a peak and a valley and the horizontal distance b between peaks are both above 1.0 mm, the delamination between layers did not occurred but the charging and discharging efficiency was 57%, which is low.

[0154] On the other hand, referring to an Example in which the edge of the electrode layer has a zigzag pattern and the horizontal distance a between a peak and a valley is 0.2 mm or more and 1 mm or less or the horizontal distance b between peaks is 0.2 mm or more and 1 mm or less, first, in Example 1 to Example 3 in which the horizontal distance a between a peak and a valley is 0.2 mm, the charging and discharging efficiency was high, at 63%, 66%, and 69%, respectively, and the delamination between layers occurred in some layers in Example 1 in which the horizontal distance b between peaks is 0.2 mm and Example 2 in which the horizontal distance b between peaks is 0.5 mm, but did not occur at all in Example 3 in which the horizontal distance b between peaks is 1.0 mm.

[0155] In Example 4 to Example 6 in which the horizontal distance a between a peak and a valley is 0.5 mm, the charging and discharging efficiency was high, at 66%, 66%, and 63%, respectively, and the delamination between layers occurred in some layers only in Example 4 in which the horizontal distance b between peaks is 0.2 mm, and did not occurred at all in Example 5 in which the horizontal distance b is 0.5 mm and in Example 6 in which it is 1.0 mm.

[0156] In the case of Example 7 to Example 9 in which the horizontal distance a between a peak and a valley is 1.0 mm, the charging and discharging efficiency was high at 69%, 63%, and 60%, respectively, and the delamination between layers did not occur.

[0157] Therefore, it may be seen that, when the horizontal distance a between a peak and a valley is 0.2 mm or more and 1 mm or less and / or the horizontal distance b between peaks is 0.2 mm or more and 1 mm or less while the edge of the electrode layer has a zigzag pattern, the delamination between layers hardly occurs and the charging and discharging efficiency is high at 60% or more.

[0158] While this disclosure has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0159] <Description of symbols>

[0160] 1000: all-solid-state battery

[0161] 100: laminate

[0162] 110: solid electrolyte layer

[0163] 130: positive electrode layer

[0164] 150: negative electrode layer

[0165] 160: upper protective layer

[0166] 170: lower protective layer

[0167] 180: marginal portion

[0168] 200: first external electrode

[0169] 300: second external electrode

Claims

An all-solid-state battery, comprising a laminate comprising a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer,wherein the positive electrode layer and the negative electrode layer have an edge of which at least a portion has a zigzag pattern, wherein the zigzag pattern comprises a plurality of unit patterns comprising a peak and a valley, andwherein the zigzag patterns partially overlap in a thickness direction of the laminate.The all-solid-state battery of claim 1, wherein, with respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate, a horizontal distance between a peak of a unit pattern of the positive electrode layer and a valley of a unit pattern of the negative electrode layer is 0.2 mm or more and 1 mm or less.The all-solid-state battery of claim 1, wherein, with respect to the unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate, a horizontal distance between a peak of a unit pattern of the positive electrode layer and a peak of a unit pattern of the negative electrode layer is 0.2 mm or more and 1 mm or less.The all-solid-state battery of claim 1, wherein the zigzag pattern is formed in at least a portion of an edge that is not exposed through an outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.The all-solid-state battery of claim 1, further comprising a marginal portion disposed to be in contact with an edge that is not exposed through an outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.The all-solid-state battery of claim 5, wherein the marginal portion has an edge in contact with the positive electrode layer and the negative electrode layer and having a shape corresponding to edge shapes of the positive electrode layer and the negative electrode layer.The all-solid-state battery of claim 5, wherein the marginal portion comprises at least one of a solid electrolyte and an insulation material.The all-solid-state battery of claim 1, wherein the positive electrode layer comprises a positive electrode current collector and a positive electrode active material layer.The all-solid-state battery of claim 1, wherein the negative electrode layer comprises a negative electrode current collector and a negative electrode active material layer.An all-solid-state battery, comprising a laminate comprising a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer,wherein the positive electrode layer and the negative electrode layer have an edge of which at least a portion has a zigzag pattern, wherein the zigzag pattern comprises a plurality of unit patterns comprising a peak and a valley, andwherein, with respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in a thickness direction of the laminate, a horizontal distance between a peak of a unit pattern of the positive electrode layer and a valley of a unit pattern of the negative electrode layer is 0.2 mm or more and 1 mm or less.The all-solid-state battery of claim 10, wherein, with respect to the unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in the thickness direction of the laminate, a horizontal distance between the peak of the unit pattern of the positive electrode layer and a peak of the unit pattern of the negative electrode layer is 0.2 mm or more and 1 mm or less.The all-solid-state battery of claim 10, wherein the zigzag pattern is formed in at least a portion of an edge that is not exposed through an outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.The all-solid-state battery of claim 10, further comprising a marginal portion disposed to be in contact with an edge that is not exposed through an outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.An all-solid-state battery, comprising a laminate comprising a solid electrolyte layer, a positive electrode layer in contact with a first surface of the solid electrolyte layer, and a negative electrode layer in contact with a second surface of the solid electrolyte layer,wherein the positive electrode layer and the negative electrode layer have an edge of which at least a portion has a zigzag pattern, wherein the zigzag pattern comprises a plurality of unit patterns comprising a peak and a valley, andwherein, with respect to unit patterns of the positive electrode layer and the negative electrode layer that are adjacent in a thickness direction of the laminate, a horizontal distance between a peak of a unit pattern of the positive electrode layer and a peak of a unit pattern of the negative electrode layer is 0.2 mm or more and 1 mm or less.The all-solid-state battery of claim 14, wherein the zigzag pattern is formed in at least a portion of an edge that is not exposed through an outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.The all-solid-state battery of claim 14, further comprising a marginal portion disposed to be in contact with an edge that is not exposed through an outer surface of the laminate among edges of the positive electrode layer and the negative electrode layer.The all-solid-state battery of claim 14, wherein a peak of the zigzag pattern of the positive electrode layer and a peak of the zigzag pattern of the negative electrode layer do not overlap with each other in the thickness direction of the laminate,and a valley of the zigzag pattern of the positive electrode layer and a valley of the zigzag pattern of the negative electrode layer do not overlap with each other in the thickness direction of the laminate.

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