All-solid-state battery and manufacturing method thereof

Abstract

A disclosed all-solid-state battery includes a solid electrolyte layer, a first electrode unit layer and a second electrode unit layer facing each other with the solid electrolyte layer interposed therebetween, a first external electrode connected to the second electrode unit layer, and a first margin part disposed between the first electrode unit layer and the first external electrode, wherein the first electrode unit layer includes a first current collector, and a first boundary part disposed between the first current collector and the first margin part and including a first active material.

Description

ALL-SOLID-STATE BATTERY AND MANUFACTURING METHOD THEREOF

[0001] The present disclosure relates to an all-solid-state battery and a manufacturing method thereof.

[0002] As the use of portable electronic devices for long periods of time becomes common, batteries are required to have higher capacity, and with the spread of wearable electronic devices, there is a need to ensure battery safety. Therefore, the development of all-solid-state batteries that use solid electrolytes instead of liquid electrolytes is actively underway.

[0003] All-solid-state batteries are batteries that replace the conventional liquid electrolytes with solid electrolytes, which can greatly improve the risk of explosion due to the flammability of the liquid electrolyte, and can operate stably even in harsh environments with relatively high temperatures and pressures because they do not use liquid electrolytes. In addition, it is also expected to be used in the future as cells can be stacked without separate cooling, enabling high energy density in the same volume. In addition, small all-solid-state batteries are being developed in a form that can be mounted on a board, and have great potential in fields where miniaturization is important, such as wearable devices.

[0004] When manufacturing all-solid-state batteries, conventionally, a current collection layer was printed with an active material in between to enhance electrode performance.

[0005] The above structure may cause the current collection layer to be exposed to the outside of the positive electrode layer after sintering due to the difference in physical properties between the active material and the current collecting conductive material. The current collection layer exposed after sintering has a high risk of coming into contact with surrounding electrodes which may cause a short circuit.

[0006] One aspect of the present embodiment attempts to provide an all-solid-state battery capable of preventing short circuit defects.

[0007] An all-solid-state battery according to some embodiments of the present disclosure may include a solid electrolyte layer, a first electrode unit layer and a second electrode unit layer facing each other with the solid electrolyte layer interposed therebetween, a first external electrode connected to the second electrode unit layer, and a first margin part disposed between the first electrode unit layer and the first external electrode, wherein the first electrode unit layer includes a first current collector, and a first boundary part disposed between the first current collector and the first margin part and including a first active material.

[0008] Additionally, the first boundary part may block the first current collector from contacting the first margin part.

[0009] Additionally, the first electrode unit layer may be disposed on the first current collector and on the first boundary part.

[0010] Additionally, the first active material layer may be made of the same material as the first boundary part.

[0011] Additionally, the first active material layer and the first boundary part may satisfy the following conditional expression:

[0012] [Conditional expression]

[0013] 0.01 % ≤ L2 / L1 ≤ 0.1 %

[0014] where

[0015] L1: Length of the first active material layer

[0016] L2: Length of the first boundary part.

[0017] Additionally, the first active material may be a positive electrode active material.

[0018] Additionally, the first boundary part may further include aluminum oxide (Al2O3) and an electrolyte.

[0019] Additionally, the first boundary part may further include an insulating material.

[0020] In addition, the all-solid-state battery may further include a second external electrode connected to the first electrode unit layer, and a second margin part disposed between the second electrode unit layer and the second external electrode, wherein the second electrode unit layer may include a second current collector and a second boundary part disposed between the second current collector and the second margin part.

[0021] Additionally, the second boundary part may include a negative electrode active material.

[0022] Additionally, the second boundary part may block the second current collector from contacting the second margin part.

[0023] In addition, the second electrode unit layer may further include a second active material layer disposed on the second current collector and on the second boundary part, and the second active material layer is made of the same material as the second boundary part.

[0024] An all-solid-state battery according to another embodiments may include a laminate including a solid electrolyte layer, a positive electrode layer and a negative electrode layer disposed with the solid electrolyte layer interposed therebetween, a first external electrode disposed outside the laminate, and a first margin part disposed between the positive electrode layer and the first external electrode, wherein the positive electrode layer includes a positive electrode active material layer, a positive electrode current collector disposed on the positive electrode active material layer, and a first boundary part disposed between the positive electrode current collector and the first margin part and including the positive electrode active material.

[0025] Additionally, the first boundary part may block the positive electrode current collector from contacting the first margin part.

[0026] Additionally, the positive electrode active material layer and the first boundary part may be made of the same material.

[0027] In addition, the all-solid-state battery may include a second external electrode facing the first external electrode with the laminate interposed therebetween, and a second margin part disposed between the negative electrode layer and the second external electrode, wherein the negative electrode layer may include a negative electrode active material layer, a negative electrode current collector disposed on the negative electrode active material layer, and a second boundary part disposed between the negative electrode current collector and the second margin part.

[0028] Additionally, the second boundary part may be made of the same material as the negative electrode active material layer.

[0029] A manufacturing method of an all-solid-state battery according to an embodiment includes applying an active material paste on the solid electrolyte layer to form an active material layer, applying an insulating paste on the solid electrolyte layer to form a first layer of a margin part, applying a conductive paste on the active material layer to form a current collector, and forming a boundary part by applying a paste for a boundary part on a portion of the active material layer where the current collector is not formed.

[0030] The manufacturing method of the all-solid-state battery may further include forming a second layer of the margin part by applying an insulating paste on the first layer of the margin part, wherein the entire second layer of the margin part may be formed to be spaced apart from the entire current collector by the boundary part.

[0031] Additionally, the paste for the boundary part may be made of the same material as the active material paste.

[0032] According to at least one of the embodiments, a boundary part is formed between the current collector and the margin part, thereby preventing short circuit defects caused by the current collector being exposed outside the positive electrode layer.

[0033] However, embodiments of the present disclosure are not limited to those mentioned above, and may be variously extended in the scope of the technical ideas included in the present disclosure.

[0034] FIG. 1 is a perspective view illustrating an all-solid-state battery according to an embodiment.

[0035] FIG. 2 is a perspective view illustrating a laminate of the all-solid-state battery of FIG. 1.

[0036] FIG. 3 is a cross-sectional view taken along III-III' line in FIG. 1.

[0037] FIG. 4 is a partial perspective view illustrating portion A of FIG. 3.

[0038] FIG. 5 is a partial perspective view illustrating part of a positive electrode layer according to an embodiment.

[0039] FIG. 6 is an exploded perspective view of FIG. 5.

[0040] FIG. 7 is a partial cross-sectional view taken along line VII-VII' of FIG. 4.

[0041] FIG. 8 is a cross-sectional view illustrating the lengths of the positive electrode active material layer and the first boundary part.

[0042] FIG. 9 is a partial perspective view illustrating portion B of FIG. 3.

[0043] FIG. 10 is a cross-sectional view taken along line X-X' of FIG. 9.

[0044] FIGS. 11 to 17 illustrate a manufacturing method of a positive electrode unit layer of an all-solid-state battery according to an embodiment.

[0045] FIG. 18 is a partial perspective view illustrating part of a negative electrode layer of an all-solid-state battery according to another embodiment.

[0046] FIG. 19 is an exploded perspective view of FIG. 18.

[0047] FIG. 20 is a partial cross-sectional view taken along line XX-XX' in FIG. 18.

[0048] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings, in which embodiments of the present disclosure are shown. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification. In the accompanying drawings, some constituent elements are exaggerated, omitted, or schematically illustrated, and the size of each constituent element does not entirely reflect the actual size.

[0049] The accompanying drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and it is to be understood that the technical ideas disclosed herein are not limited by the accompanying drawings and include all modifications, equivalents, or substitutions that are within the range of the ideas and technology of the present disclosure.

[0050] Although terms of "first," "second," and the like are used to explain various constituent elements, the constituent elements are not limited to such terms. These terms are only used to distinguish one constituent element from another constituent element.

[0051] In addition, it will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" 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, when an element is referred to as being "on" or "above" a reference element, it can be positioned above or below the reference element, and it is not necessarily referred to as being positioned "on" or "above" in a direction opposite to gravity.

[0052] Throughout the specification, the terms "comprise" or "have" are intended to specify the presence of stated features, integers, steps, operations, constituent elements, components, or a combination thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, constituent elements, components, and / or groups thereof. Therefore, 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 constituent elements but not the exclusion of any other constituent elements.

[0053] 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.

[0054] Throughout the specification, the term "connected" does not mean only that two or more constituent components are directly connected, but may also mean that two or more constituent components are indirectly connected through another constituent component, that two or more components are electrically connected as well as physically connected, or that two or more constituent components are referred to by different names but are united by location or function.

[0055] In describing the all-solid-state battery in this specification, the direction in which the main components of the all-solid-state battery are stacked is defined as the 'stacking direction', but this may also be the 'thickness direction'. Additionally, a direction parallel to a plane perpendicular to the stacking direction may be defined as a 'plane direction', and the plane direction may include a 'first direction' and a 'second direction' that are orthogonal to each other.

[0056] FIG. 1 is a perspective view illustrating an all-solid-state battery according to an embodiment, FIG. 2 is a perspective view illustrating a laminate of the all-solid-state battery of FIG. 1, and FIG. 3 is a cross-sectional view taken along III-III' line in FIG. 1.

[0057] Referring to FIGS. 1, 2, and 3, an all-solid-state battery 10 according to the embodiment includes a laminate 100, a first external electrode 300, and a second external electrode 400.

[0058] First, defining direction to clearly describe the present embodiment, the L-axis, W-axis, and T-axis shown in the drawings refer to axes representing the length direction, width direction, and thickness direction of the all-solid-state battery 10, respectively.

[0059] The thickness direction (T-axis direction) may be a direction perpendicular to the broad surface (main surface) of sheet-shaped components. For example, the thickness direction (T-axis direction) may be used as the same concept as the direction in which the components of the laminate 100 are stacked.

[0060] The length direction (L-axis direction) is a direction parallel to the wide surface (main surface) of the sheet-shaped components, and may be a direction that intersects or is perpendicular 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 300 and the second external electrode 400 face each other.

[0061] The width direction (W-axis direction) is a direction parallel to the wide surface (main surface) of the sheet-shaped components, and may be a direction that intersects or is perpendicular to the thickness direction (T-axis direction) and the length direction (L-axis direction).

[0062] The laminate 100 may have a substantially hexahedral shape, but the present embodiment is not limited thereto. Due to shrinkage during sintering, the laminate 100 may not have a completely hexahedral shape, but may have a substantially hexahedral shape. For example, the laminate 100 may have a substantially rectangular parallelepiped shape, but portions corresponding to corners or vertices may have a rounded shape.

[0063] For better understanding and ease of description, in this embodiment, the surfaces facing each other in the length direction (L-axis direction) are defined as a first surface S1 and a second surface S2, and the surfaces facing each other in the width direction (W-axis direction) and connecting the first surface S1 and the second surface S2 are defined as a third surface S3 and a fourth surface S4. The surfaces facing each other in the thickness direction (T-axis direction) and connecting the first surface S1 and the second surface S2 are defined as a fifth surface S5 and a sixth surfaces S6.

[0064] Accordingly, a first direction in which the first surface S1 and the second surface S2 face each other may be the length direction (L-axis direction), and second and third directions 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. In the present embodiment, for better understanding and ease of description, the length direction (L-axis direction), the width direction (W-axis direction), and the thickness direction (T-axis direction) are defined as a first direction, a second direction, and a third direction, respectively. However, this is only for better understanding and ease of description, and the first, second, and third directions are not limited thereto. The first, second, and third directions intersect (or are perpendicular to) each other.

[0065] The length of the laminate 100 may refer to, based on an optical microscope or scanning electron microscope (SEM) photograph of the length direction (L-axis direction)-thickness direction (T-axis direction) cross-section at a width direction (W-axis direction) central portion of the laminate 100, the maximum value among the lengths of a plurality of line segments each connecting two outermost boundary lines opposite in the length direction (L-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the length direction (L-axis direction). Hereinafter, the length direction (L-axis direction)-thickness direction (T-axis direction) cross-section refers to a cross-section where the length direction (L-axis direction) and the thickness direction (T-axis direction) intersect (or are perpendicular to) each other. Meanwhile, the length of the laminate 100 may refer to the minimum value among the lengths of a plurality of line segments parallel to the length direction (L-axis direction) and connecting the two outermost boundary lines opposite in the length direction (L-axis direction) as shown in the above-described cross-sectional photograph. Meanwhile, the length of the laminate 100 may refer to an arithmetic average value of the lengths of at least two line segments among a plurality of line segments each connecting two outermost boundary lines opposite in the length direction (L-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the length direction (L-axis direction).

[0066] The thickness of the laminate 100 may refer to, based on an optical microscope or SEM photograph of the length direction (L-axis direction)-thickness direction (T-axis direction) cross-section at a width direction (W-axis direction) central portion of the laminate 100, the maximum value among the lengths of a plurality of line segments each connecting two outermost boundary lines opposite in the thickness direction (T-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the thickness direction (T-axis direction).

[0067] Meanwhile, the thickness of the laminate 100 may refer to the minimum value among the lengths of a plurality of line segments each connecting two outermost boundary lines opposite in the thickness direction (T-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the thickness direction (T-axis direction). Meanwhile, the thickness of the laminate 100 may refer to an arithmetic average value of the lengths of at least two line segments among a plurality of line segments, each connecting two outermost boundary lines opposite in the thickness direction (T-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the thickness direction (T-axis direction).

[0068] The thickness of the laminate 100 may refer to, based on an optical microscope or SEM photograph of the length direction (L-axis direction)-width direction (W-axis direction) cross-section at a thickness direction (T-axis direction) central portion of the ceramic main body 10, the maximum value among the lengths of a plurality of line segments each connecting two outermost boundary lines opposite in the width direction (W-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the width direction (W-axis direction). Hereinafter, the length direction (L-axis direction)-width direction (W-axis direction) cross-section refers to a cross-section where the length direction (L-axis direction) and the width direction (W-axis direction) intersect (or are perpendicular to) each other. Meanwhile, the width of the laminate 100 may refer to the minimum value among the lengths of a plurality of line segments each connecting two outermost boundary lines opposite in the width direction (W-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the width direction (W-axis direction). Meanwhile, the width of the laminate 100 may refer to an arithmetic average value of the lengths of at least two line segments among a plurality of line segments, each connecting two outermost boundary lines opposite in the width direction (W-axis direction) of the laminate 100, which is shown in the above-described cross-sectional photograph, and parallel to the width direction (W-axis direction).

[0069] The laminate 100 may include a solid electrolyte layer 110, a positive electrode unit layer 130, a negative electrode unit layer 150, an upper protective layer 180, and a lower protective layer 190. The positive electrode unit layer 130 and the negative electrode unit layer 150 may be defined as a first unit layer and a second unit layer, or a second unit layer and a first unit layer.

[0070] There may be a plurality of solid electrolyte layers 110, positive electrode unit layers 130, and negative electrode unit layers 150, respectively. The positive electrode unit layer 130 and the negative electrode unit layer 150 may be alternately stacked in the thickness direction (T-axis direction) with the solid electrolyte layer 110 interposed therebetween. The laminate 100 may have a stacking structure of the solid electrolyte layer 110 / negative electrode unit layer 150 / solid electrolyte layer 110 / positive electrode unit layer 130. That is, the positive electrode unit layer 130 and the negative electrode unit layer 150 may face each other with the solid electrolyte layer 110 interposed therebetween. Based on the solid electrolyte layer 110, the positive electrode unit layer 130 may be disposed on one surface of the solid electrolyte layer 110 and the negative electrode unit layer 150 may be disposed on the other surface of the solid electrolyte layer 110.

[0071] The solid electrolyte layer 110 includes a solid electrolyte. A solid electrolyte may serve as a passage for lithium (Li) ions. The solid electrolyte included in the solid electrolyte layer 110 may include a glass-ceramic electrolyte including a lithium halogen (halogen elements such as LiX, X=F, Br, Cl, I). Glass-ceramic (or crystallized glass) means that amorphous and crystalline elements coexist crystallographically. For example, when peaks and halos are observed in X-ray diffraction or electron beam diffraction, it may mean that amorphous and crystalline substances coexist crystallographically. Therefore, the glass-ceramic electrolyte is an electrolyte in which amorphous and crystalline elements are mixed due to partial crystallization through sintering.

[0072] The glass-ceramic electrolyte may contain a mixture of amorphous and two or more types of crystalline. Additionally, the crystalline substance included in the glass-ceramic electrolyte may include a lithium compound crystalline phase containing lithium.

[0073] When the glass-ceramic electrolyte is included, it is possible to implement high ionic conductivity after sufficient densification is achieved through sintering.

[0074] The glass-ceramic electrolyte may include at least one selected from the group consisting of 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 lithium chloride (LiCl). According to some embodiments, 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 lithium chloride (LiCl). As a specific example, the glass-ceramic electrolyte may include Li2O-B2O3-SiO2-P2O5-GeO2-LiCl.

[0075] The solid electrolyte included in the solid electrolyte layer 110 may include lithium borosilicate-based electrolyte (hereinafter referred to as LBSO-based electrolyte). The LBSO-based electrolyte is an electrolyte in a glass state. The glass is crystallographically amorphous, and a halo may be observed in X-ray diffraction or electron beam diffraction. When the solid electrolyte layer 110 includes the LBSO-based electrolyte, the sintering temperature may be lowered and the amorphous state may be maintained during sintering. Accordingly, it is possible to implement high ionic conductivity and secure the advantage of not being highly reactive with the electrode. The LBSO-based electrolyte may include at least one selected from the group consisting of lithium (Li), boron (B), silicon (Si), aluminum (Al), phosphorus (P), germanium (Ge), and sulfur (S). According to some embodiments, the LBSO-based electrolyte may include lithium (Li), boron (B), silicon (Si), aluminum (Al), phosphorus (P), germanium (Ge), and sulfur (S).

[0076] In addition, the solid electrolyte included in the solid electrolyte layer 110 may be one or more types selected from the group consisting of Garnet-type, NASICON-type, LISICON-type, perovskite-type, and LiPON-type.

[0077] The garnet-type solid electrolytes may indicate lithium-lanthanum zirconium oxide (LLZO) represented by LiaLabZrcO12, such as Li7La3Zr2O12. The NASICON-type solid electrolyte may indicate lithium-aluminum-titanium-phosphate (LATP) represented by Li1+xAlxTi2-x(PO4)3(0<x<1) in which Ti is introduced into a Li1+xAlxM2-x(PO4)3(LAMP) (0<x<2, wherein M is Zr, Ti, or Ge)-type compound, lithium-aluminum-germanium-phosphate (LAGP) represented by Li1+xAlxGe2-x(PO4)3(0<x<1), such as Li1.3Al0.3Ti1.7(PO4)3or the likein which excess lithium is introduced, and / or lithium-zirconium-phosphate (LZP) of LiZr2(PO4)3.

[0078] In addition, the LISICON-type solid electrolyte may indicate a solid solution oxide represented by xLi3AO4-(1-x)Li4BO4(wherein A is P, As, or V, etc., B is Si, Ge, or Ti, etc.) and including Li4Zn(GeO4)4, Li10GeP2O12(LGPO), Li3.5Si0.5P0.5O4, Li10.42Si(Ge)1.5P1.5Cl0.08O11.92, etc., and a solid solution sulfide including Li2S-P2S5, Li2S-SiS2, Li2S-SiS2-P2S5, Li2S-GeS2,etc.represented by Li4-xM1-yM'yS4(M= Si, Ge, and M'= P, Al, Zn, Ga).

[0079] The perovskite-type solid electrolyte may indicate lithium-lanthanum-titanium-oxide (LLTO) represented by Li3xLa2 / 3-x□1 / 3-2xTiO3(0<x<0.16, □: vacancy), such as Li1 / 8La5 / 8TiO3or the like, and the LiPON-type solid electrolyte may refer to a nitride such as lithium-phosphorous-oxynitride, such as Li2.8PO3.3N0.46orthe like.

[0080] For example, the minimum length of the solid electrolyte layer 110 in the thickness direction (T-axis direction) may be 28 μm or more.

[0081] The upper protective layer 180 and the lower protective layer 190 may be outermost layers disposed on the fifth surface S5 and sixth surface S6 of the laminate 100, respectively. That is, the upper protective layer 180 may be the outermost layer on the fifth surface S5 of the laminate 100, and the lower protective layer 190 may be the outermost layer on the sixth surface S6 of the laminate 100. The upper protective layer 180 and lower protective layer 190 may improve moisture resistant reliability by preventing moisture from penetrating into the laminate 100. Additionally, the upper protective layer 180 and lower protective layer 190 may prevent damage to the laminate 100 caused by physical or chemical impact.

[0082] The upper protective layer 180 and the lower protective layer 190 may each be an insulating layer made of an insulating material, which is a material that does not have electronic conductivity (or ionic conductivity).

[0083] The upper protective layer 180 and lower protective layer 190 may include ceramic materials, such as aluminum oxide (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silicon dioxide (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), mixtures thereof, oxides and / or nitrides thereof, or any other suitable ceramic materials, but are not limited thereto. Additionally, the upper protective layer 180 and the lower protective layer 190 may optionally include the above-described solid electrolyte and may include one or more types of solid electrolyte, but are not limited thereto.

[0084] The first external electrode 300 and the second external electrode 400 are disposed the outside surfaces of the laminate 100. For example, the first external electrode 300 may be an external positive electrode, and the second external electrode 400 may be an external negative electrode. However, the first external electrode 300 and the second external electrode 400 are not limited thereto.

[0085] The first external electrode 300 is disposed on the first surface S1, and the second external electrode 400 is disposed on the second surface S2. The second first external electrode 300 is in contact with the positive electrode layer 131 on the first surface S1 of the laminate 100, and the second external electrode 400 is in contact with the negative electrode layer 151 on the second surface S2 of the laminate 100. The first external electrode 300 may cover the first surface S1 of the laminate 100 and be connected to the positive electrode layer 131. The second external electrode 400 may cover the second surface S2 of the laminate 100 and be connected to the negative electrode layer 151.

[0086] For example, the first external electrode 300 may extend from the first surface S1 of the laminate 100 to the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 to partially cover each surface. In addition, the second external electrode 400 may extend from the second surface S2 of the laminate 100 to the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 to partially cover each surface.

[0087] As another example, the first external electrode 300 may extend from the first surface S1 to either the fifth surface S5 or the sixth surface S6 to partially cover the corresponding surface, and the second external electrode 400 may extend from the second surface S2 to either the fifth surface S5 or the sixth surface S6 to partially cover the corresponding surface.

[0088] The first external electrode 300 may include a first electrode unit layer 310 and a first plating layer 320, and the second external electrode 400 may include a second electrode layer 410 and a second plating layer 420.

[0089] The first external electrode 300 and the second external electrode 400 described above with reference to FIGS. 1 and 3 are only described for the purpose of distinction, and the configuration is not limited by the terminology. For example, in another description, the first external electrode may be in contact with the second surface S2 and the second external electrode may be in contact with the first surface S1.

[0090] Hereinafter, the first unit layer will be described with reference to FIGS. 3 and 4. The first unit layer includes a first electrode unit layer and a first margin part. The first electrode unit layer may include a first active material layer, a first current collector, and a first boundary layer. For better understanding and ease of description, the first unit layer will be described as the positive electrode unit layer 130, and the first electrode unit layer will be described as the positive electrode layer 131.

[0091] FIG. 4 is a partial perspective view illustrating portion A of FIG. 3.

[0092] Referring to FIGS. 3 and 4, the positive electrode unit layer 130 may be formed on one surface of the solid electrolyte layer 110. The positive electrode unit layer 130 may include the positive electrode layer 131 and a first margin part 133. The positive electrode layer 131 is a portion responsible for electronic conduction, with one end exposed to the first surface S1 of the laminate 100 and in contact with the first external electrode 300.

[0093] The first margin part 133 is a region of the positive electrode unit layer 130 excluding the positive electrode layer 131. The first margin part 133 may be disposed on the second surface S2, third surface S3, and fourth surface S4. That is, the first margin part 133 is a portion parallel to the positive electrode layer 131 in the length direction (L-axis direction) and the width direction (W-axis direction). The first margin part 133 may be formed to be in contact with both surfaces of the positive electrode layer 131 along the length direction (L-axis direction) and be in contact with one surface of the positive electrode layer 131 along the width direction (W-axis direction). Accordingly, the first margin part 133 may be exposed to the second surface S2, third surface S3, and fourth surface S4 of the laminate 100. That is, the first margin part 133 may be formed to surround the positive electrode layer 131 in three directions. For example, the first margin part 133 may have a double curved shape.

[0094] The first margin part 133 may be formed of an insulating material, which is a material that does not have electronic conductivity (or ionic conductivity).

[0095] The first margin part 133 may include a ceramic material. For example, the first margin part 133 may include at least one selected from the group consisting of aluminum oxide (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silicon dioxide (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), mixtures thereof, oxides and / or nitrides thereof, or any other suitable ceramic materials.

[0096] Additionally, the first margin part 133 may include one or more types of solid electrolyte and may optionally include the above-described solid electrolyte.

[0097] The first margin part 133 may include a material with low ionic conductivity and low electronic conductivity, such as an insulating material. Additionally, a material having ionic conductivity (or electronic conductivity) similar to that of the solid electrolyte may be present in the first margin part 133. For example, if the first margin part 133 include a material having ionic conductivity (or electronic conductivity) similar to that of the solid electrolyte, the material may be the same material as or a different material from the solid electrolyte in other regions.

[0098] As another example, the first margin part 133 may include an insulating material and a material having ionic conductivity (or electronic conductivity) similar to that of a solid electrolyte together.

[0099] The first margin part 133 may resolve the height difference between the solid electrolyte layer 110 and the positive electrode layer 131 by forming a portion of the side surface which is parallel to the positive electrode layer 131 in the length direction (L-axis direction) and width direction (W-axis direction) in the positive electrode unit layer 130. Accordingly, it is possible to suppress the occurrence of interlayer peeling or bending due to sintering.

[0100] The first margin part 133 may be formed by applying an insulating paste on the solid electrolyte layer 110. In FIG. 3, the boundary between the first margin part 133 and the solid electrolyte layer 110 is clearly shown, but when the first margin part 133 and the solid electrolyte layer 110 are formed of the same material, it may be difficult to distinguish the boundary in the laminate 100 after sintering.

[0101] FIG. 5 is a partial perspective view illustrating a part of the positive electrode layer 131 of the all-solid-state battery 10 according to some embodiments, FIG. 6 is an exploded perspective view of FIG. 5, and FIG. 7 is a partial cross-sectional view taken along line VII-VII' of FIG. 4.

[0102] Referring to FIGS. 4, 5, 6, and 7, the positive electrode layer 131 may include a positive electrode current collector 1313, a positive electrode active material layer 1311, and a first boundary part 1314.

[0103] One end of the positive electrode current collector 1313 may be exposed in the direction of the first surface S1. For example, the positive electrode current collector 1313 may be formed as a plate-shaped member or a thin-shaped member. As another example, the positive electrode current collector 1313 may be formed of a porous material such as a net-type or mesh shape.

[0104] The positive electrode current collector 1313 may be a porous metal plate made of stainless steel, and may include at least one selected from the group consisting of nickel (Ni), copper (Cu), tin (Sn), aluminum (Al), and alloys thereof. Additionally, the positive electrode current collector 1313 may be coated with an oxidation-resistant metal or alloy film to prevent oxidation.

[0105] The positive electrode current collector 1313 may be formed as a carbon-based plate-shaped, thin-shaped, linear or circular member. The positive electrode current collector 1313 may include a conductive carbon-based material. For example, the conductive carbon material may include conductive fiber such as graphite, carbon nanotubes (CNT) or vapor grown carbon fiber (VGCF), or conductive carbon such as carbon black.

[0106] The positive electrode current collector 1313 may include one or more types of solid electrolyte.

[0107] The first boundary part 1314 may be disposed on the side surface of the positive electrode current collector 1313 in the length direction (L-axis direction) and the width direction (W-axis direction). The first boundary part 1314 may be disposed between the positive electrode current collector 1313 and the first margin part 133. The first boundary part 1314 may contact both ends of the positive electrode current collector 1313 in the width direction (W-axis direction). Additionally, the first boundary part 1314 may contact the end close to the second surface S2 of both ends of the positive electrode current collector 1313 in the length direction (L-axis direction). The first boundary part 1314 may be disposed to surround the ends of the positive electrode current collector 1313 in the length direction (L-axis direction) and the width direction (W-axis direction) excluding the end exposed to the first surface S1. That is, the first boundary part 1314 may be disposed to contact both ends of the positive electrode current collector 1313 disposed along the length direction (L-axis direction) and one end of the both ends disposed along the width direction (W-axis direction). Among the ends of the positive electrode current collector 1313, the end that is not in contact with the first boundary part 1314 may be exposed to the first surface S1 of the laminate 100 and may be in contact with the first external electrode 300. Since the first boundary part 1314 is disposed between the positive electrode current collector 1313 and the first margin part 133, and the positive electrode current collector 1313 and the first margin part 133 are spaced apart from each other. That is, the first boundary part 1314 may block the positive electrode current collector 1313 from contacting the first margin part 133.

[0108] Based on the first margin part 133, the first boundary part 1314 may be disposed to contact the inner surface of the first margin part 133 along the length direction (L-axis direction) and the width direction (W-axis direction). Accordingly, the first boundary part 1314 may be formed to surround the positive electrode current collector 1313 in three directions. Since the positive electrode current collector 1313 surrounds the positive electrode current collector 1313 while contacting the positive electrode current collector 1313 on the third surface S3, the second surface S2, and the fourth surface S4, the entire positive electrode current collector 1313 and the entire first margin part 133 may be spaced apart by the first boundary part 1314. That is, the first boundary part 1314 may block the positive electrode current collector 1313 from contacting the first margin part 133.

[0109] The first boundary part 1314 includes a positive electrode active material. The first boundary part 1314 may be made of the same material as the positive electrode active material layer 1311. For example, the first boundary part 1314 may be formed of a material including lithium (Li) ions. In this case, the first boundary part 1314 may reversibly intercalate and deintercalate lithium ions.

[0110] For example, the first boundary part 1314 may include at least one selected from the group consisting of the compounds represented by the following formulae:

[0111] 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; and J is V, Cr, Mn, Co, Ni, or Cu.

[0112] The first boundary part 1314 may further include aluminum oxide (Al2O3) and an electrolyte. At this time, the first boundary part 1314 may further include an insulating material to reduce lithium (Li) leakage.

[0113] Due to the difference in shrinkage rate between the positive electrode active material and the current collector, if the current collector protrudes further in the length direction (L-axis direction) or width direction (W-axis direction) than the positive electrode active material layer 1311, the risk of contact with surrounding electrodes may increase, resulting in short circuit defects. The first boundary part 1314 may prevent short circuit defects caused by protrusion of the current collector. That is, the first boundary part 1314 may prevent short circuit defects in the all-solid-state battery 10 by preventing the current collector from protruding as described above.

[0114] The positive electrode active material layer 1311 includes a positive electrode active material. The positive electrode active material layer 1311 may be disposed on the positive electrode current collector 1313 and the first boundary part 1314. The positive electrode active material layer 1311 may be formed by printing a positive electrode active material on one or both surfaces of the positive electrode current collector 1313 and the first boundary part 1314. However, the method of forming the positive electrode active material layer 1311 is not limited thereto.

[0115] The positive electrode active material included in the positive electrode active material layer 1311 may be a material containing lithium (Li) ions. The positive electrode active material may reversibly intercalate and deintercalate lithium ions. In other words, the positive electrode active material contains lithium ions and may serve to provide lithium ions to the 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.

[0116] The positive electrode active material may include, for example, at least one selected from the group consisting of the compounds represented by the following formulae:

[0117] 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)J2PO43(0≤f≤2); Li(3-f)Fe2PO4)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; and J is V, Cr, Mn, Co, Ni, or Cu.

[0118] The positive electrode active material may also include 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.

[0119] The positive electrode active material may optionally 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 electrode active material layer 1311 on the obtained positive electrode current collector 1313.

[0120] The conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the all-solid-state battery 10. For example, graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fiber and metal fiber; fluorinated carbon; metal components such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), and copper (Cu), and oxides, nitrides, or fluorides thereof; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives may be used.

[0121] The binder may be used to improve the bonding strength between the active material and the conductive material. Materials that can be used as the binder may include at least one selected from the group consisting of polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, various copolymers, and the like, but are not limited thereto.

[0122] The positive electrode active material layer 1311 may additionally include a solid electrolyte component. The solid electrolyte component may use one or more of the above-described components. The solid electrolyte component included in the positive electrode active material layer 1311 may function as an ion conduction channel in the positive electrode active material layer 1311. Through this, the interface resistance may be reduced.

[0123] For example, the first boundary part 1314 and the positive electrode active material layer 1311 may include the same material. Additionally, the first boundary part 1314 and the positive electrode active material layer 1311 may be formed using the same paste.

[0124] FIG. 8 is a cross-sectional view illustrating the lengths of the positive electrode active material layer and the first boundary part.

[0125] In FIG. 8, L1, L2, and L3 represent the length of the positive electrode active material layer 1311, the length of the first boundary part 1314, and the length of the positive electrode current collector 1313 in the length direction (L-axis direction), respectively.

[0126] The ratio of the length L2 of the first boundary part 1314 to the length L1 of the positive electrode active material layer 1311 in the length direction (L-axis direction) may be 0.01 % or more and 0.1 % or less. That is, the positive electrode active material layer 1311 and the first boundary part 1314 may satisfy the following conditional expression:

[0127] [Conditional expression]

[0128] 0.01 % ≤ L2 / L1 ≤ 0.1 %

[0129] where

[0130] L1: Length of the positive electrode active material layer in the length direction

[0131] L2: Length of the first boundary part in the length direction.

[0132] If the ratio of the length L2 of the first boundary part 1314 to the length L1 of the positive electrode active material layer 1311 in the length direction (L-axis direction) exceeds 0.1 %, battery capacity may significantly decrease. Additionally, if the ratio of the length L2 of the first boundary part 1314 to the length L1 of the positive electrode active material layer 1311 is less than 0.01 %, a short circuit may occur. For example, the minimum length of the solid electrolyte layer 110 in the thickness direction (T-axis direction) may be 28 μm or more.

[0133] For example, the length of the positive electrode active material layer 1311 in the length direction (L-axis direction) may refer to the maximum value of a plurality of line segments parallel to the length direction (L-axis direction) and connecting the two outermost boundary lines facing in the length direction (L-axis direction) of the positive electrode active material layer 1311 shown in the above cross-sectional photograph, based on the optical microscope or scanning electron microscope (SEM) image (cross-sectional photograph) of the length direction (L-axis direction)-thickness direction (T-axis direction) cross-section taken at the central part of the width direction (W-axis direction) of the laminate 100. As another example, the length of the positive electrode active material layer 1311 in the length direction (L-axis direction) may refer to the minimum value among the lengths of the plurality of line segments described above. As another example, the length of the positive active material layer 1311 in the length direction (L-axis direction) may refer to the arithmetic mean value of at least two lengths among the lengths of the plurality of line segments described above.

[0134] The length L2 of the first boundary part 1314 in the length direction (L-axis direction) may refer to the difference between the length L1 of the positive electrode active material layer 1311 in the length direction (L-axis direction) and the length L3 of the positive electrode current collector 1313. That is, when the length L1 of the positive electrode active material layer 1311 and the length L3 of the first boundary part 1313 are measured, the difference value L3-L1 may be the length L2 of the first boundary part 1314.

[0135] For example, the length of the positive electrode current collector 1313 in the length direction (L-axis direction) may refer to the maximum value of a plurality of line segments parallel to the length direction (L-axis direction) and connecting the two outermost boundary lines facing in the length direction (L-axis direction) of the positive electrode current collector 1313 shown in the above cross-sectional photograph, based on the optical microscope or scanning electron microscope (SEM) image (cross-sectional photograph) of the length direction (L-axis direction)-thickness direction (T-axis direction) cross-section taken at the central part of the width direction (W-axis direction) of the laminate 100. As another example, the length of the positive electrode current collector 1313 in the length direction (L-axis direction) may refer to the minimum value among the lengths of the plurality of line segments described above. As another example, the length of the positive electrode current collector 1313 in the length direction (L-axis direction) may refer to the arithmetic mean value of at least two lengths among the lengths of the plurality of line segments described above.

[0136] If the boundary part that satisfies the above conditional expression is formed, short circuit defects may be prevented even when the thickness of the solid electrolyte layer 110 is reduced, and battery capacity may be similarly secured. Accordingly, while reducing the thickness of the laminate 100, almost the same battery capacity may be secured without short circuit defects. Additionally, if the thickness of the laminate 100 is kept the same, more positive electrode unit layers 130 and negative electrode unit layers 150 may be formed in the laminate 100, thereby increasing the cell capacity.

[0137] Hereinafter, the second unit layer will be described with reference to FIGS. 9 and 10. The second unit layer includes a second electrode unit layer and a second margin part. For better understanding and ease of description, it is assumed that the second unit layer is the negative electrode unit layer 150.

[0138] FIG. 9 is a partial perspective view illustrating portion B of FIG. 3, and FIG. 10 is a cross-sectional view taken along line X-X' of FIG. 9.

[0139] Referring to FIGS. 3, 9, and 10, the negative electrode unit layer 150 may be formed on one surface of the solid electrolyte layer 110. The negative electrode unit layer 150 includes the negative electrode layer 151 and a second margin part 153. One end of the negative electrode layer 151 is exposed to the second surface S2 of the laminate 100 and is in contact with the second external electrode 400. The second margin part 153 is disposed between the negative electrode layer 151 and the first external electrode 300.

[0140] The second margin part 153 configures a region of the negative electrode unit layer 150 excluding the negative electrode layer 131. That is, the second margin part 153 may be disposed on the first surface S1, the third surface S3, and the fourth surface S4. That is, the second margin part 153 is a portion parallel to the negative electrode layer 151 in the length direction (L-axis direction) and the width direction (W-axis direction). The second margin part 153 may be formed to be in contact with both surfaces of the negative electrode layer 151 along the length direction (L-axis direction) and be in contact with one surface of the negative electrode layer 151 along the width direction (W-axis direction). Accordingly, the second margin part 153 may be exposed to the second surface S2, third surface S3, and fourth surface S4 of the laminate 100. For example, the second margin part 153 may have a double curved shape.

[0141] The second margin part 153 may be formed of an insulating material, that is, a material that does not have electronic conductivity (or ionic conductivity).

[0142] The second margin part 153 may include a ceramic material. For example, the second margin part 153 may include at least one selected from the group consisting of aluminum oxide (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silicon dioxide (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), mixtures thereof, oxides and nitrides thereof, or any other suitable ceramic materials.

[0143] Additionally, the second margin part 153 may include one or more types of solid electrolyte and may optionally include the above-described solid electrolyte.

[0144] The second margin part 153 may include a material with low ionic conductivity and low electronic conductivity, that is, an insulating material. Additionally, a material having ionic conductivity (or electronic conductivity) similar to that of a solid electrolyte and an insulating material may be present in the second margin part 153 together. For example, if the second margin part 153 may include a material having ionic conductivity (or electronic conductivity) similar to that of the solid electrolyte, the material may be the same material as or a different material from the solid electrolyte in other regions. As another example, the second margin part 153 may include an insulating material and a material having ionic conductivity (or electronic conductivity) similar to that of a solid electrolyte and together.

[0145] The first margin part 133 and the second margin part 153 may be formed of the same material. Additionally, the solid electrolyte, the first margin part 133, and the second margin part153 may be formed of the same material.

[0146] The second margin part 153 may be formed by applying an insulating paste on the solid electrolyte layer 110. In FIG. 3, the boundary between the second margin part 153 and the solid electrolyte layer 110 is clearly shown, but when second margin part 153 and the solid electrolyte layer 110 are formed of the same material, it may be difficult to distinguish the boundary in the laminate 100 after sintering.

[0147] The negative electrode layer 151 includes a negative electrode active material. The negative electrode active material included in the negative electrode layer 151 may generate electrical energy by storing and releasing lithium ions that have moved from the positive electrode layer 131 when the all-solid-state battery 10 is discharged. A carbon-based material, silicon, a 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 may be used as the negative electrode active material, and lithium metal and / or a lithium metal alloy may be included.

[0148] The lithium metal alloy may include lithium and a metal / metalloid capable of alloying with lithium. For example, the metal / metalloid capable of alloying with lithium may include Si, Sn, Al, Ge, Pb, Bi, Sb, a Si-AM alloy (where AM is an alkali metal, alkaline earth metal, group 13 to 16 elements, a transition metal, a rare earth element, or combinations thereof, and does not contain Si), a Sn-AM alloy (where AM is an alkali metal, alkaline earth metal, group 13 to 16 elements, a transition metal, a transition metal oxide of lithium titanium oxide (Li4Ti5O12), etc., a rare earth element, or a combination of elements thereof, and does not include Sn), MnOx(0<x≤2), etc.

[0149] 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 combinations thereof.

[0150] Further, the oxide of the metal / metalloid capable of alloying 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 of Elements. For example, the negative electrode active material may include one or more elements selected from the group consisting of Si, Ge, and Sn.

[0151] The carbon-based material may be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite such as amorphous, plate-like, flake-like, spherical, or fibrous natural graphite or artificial graphite. In addition, amorphous carbon may be soft carbon (low temperature sintered carbon) or hard carbon, mesophase pitch carbide, sintered coke, graphene, carbon black, fullerene soot, carbon nanotubes, carbon fiber, or the like, but is not limited thereto.

[0152] The silicon may include at least one selected form the group consisting of Si, SiOx(0<x<2, for example 0.5 to 1.5), Sn, SnO2, or a silicon-containing metal alloy and mixtures thereof. The silicon-containing metal alloy may include, for example, silicon and at least one selected from the group consisting of Al, Sn, Ag, Fe, Bi, Mg, Zn, In, Ge, Pb, and Ti.

[0153] The negative electrode active material may optionally include a conductive material and a binder.

[0154] The conductive material is not particularly limited as long as it has conductivity without causing chemical changes in the all-solid-state battery 10. For example, graphite such as natural graphite or artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fiber and metal fiber; fluorinated carbon; metal components such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), and copper (Cu), and oxides, nitrides, or fluorides thereof; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives may be used.

[0155] The binder may be used to improve the bonding strength between the active material and the conductive material. For example, the binder may include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine rubber, various copolymers, and the like.

[0156] The first electrode layer 310 of the first external electrode 300 may be electrically connected to the positive electrode layer 131, and the second electrode layer 410 of the second external electrode 400 may be electrically connected to the negative electrode layer 151.

[0157] For example, the first electrode layer 310 and the second electrode layer 410 may be a sintered electrode containing a conductive metal and glass, or a resin-based electrode containing a conductive metal and a resin.

[0158] For example, the first electrode layer 310 and the second electrode layer 410 may be formed by applying a terminal electrode paste containing a conductive metal to the first surface S1 and the second surface S2 of the laminate 100, respectively. As another example, the first electrode layer 310 and the second electrode layer 410 may be formed by transferring a dried film of a conductive paste to the laminate 100 and then sintering the dried film. However, the method of forming the first electrode layer 310 and the second electrode layer 410 is not limited thereto. The conductive metal may include one or more selected from the group consisting of copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), and alloys thereof.

[0159] The first plating layer 320 covers the first electrode layer 310, and the second plating layer 420 covers the second electrode layer 410. The first plating layer 320 and the second plating layer 420 may serve to improve the mounting characteristics of the external electrode. The first plating layer 320 and the second plating layer 420 may include at least one type selected from the group consisting of copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), and alloys thereof. The first plating layer 320 and the second plating layer 420 may each be formed of one or more layers.

[0160] Next, a manufacturing method of the positive electrode unit layer 130 in the all-solid-state battery 10 of the above-described configuration will be described.

[0161] FIGS. 11 to 17 illustrate a manufacturing method of a positive electrode unit layer 130 of an all-solid-state battery according to an embodiment.

[0162] Referring to FIG. 11, the solid electrolyte layer 110 is prepared, and a first positive electrode active material layer 1311a may be formed by applying an active material paste on the solid electrolyte layer 110 by printing, and then drying.

[0163] Referring to FIG. 12, next, a first layer of a margin part 133a may be formed by applying an insulating paste on the solid electrolyte layer 110 by printing, and then drying. The insulating paste may be applied to the remaining portion of the solid electrolyte where the first layer of the margin part 133a is not formed. The first layer of the margin part 133a may contact the edge of the first positive electrode active material layer 1311a on a plane. The first layer of the margin part 133a may contact three of the four edge surfaces of the first positive electrode active material layer 1311a in the length direction (L-axis direction) and the width direction (W-axis direction). The first layer of the margin part 133a may be formed to contact both edge surfaces disposed along the length direction (L-axis direction) among the four edge surfaces of the first positive electrode active material layer 1311a. Among the edges of the first positive electrode active material layer 1311a, the edges that are not in contact with the first layer of the margin part 133a may be exposed to the first surface S1 after sintering the laminate 100.

[0164] Referring to FIG. 13, the positive electrode current collector 1313 may be formed by applying a conductive paste by printing on the first positive electrode active material layer 1311a, and then drying.

[0165] Referring to FIG. 14, the first boundary part 1314 may be formed by applying a paste for the first boundary part on the first positive electrode active material layer 1311a by printing, and then drying. The paste for the first boundary part may be applied to a portion of the first positive electrode active material layer 1311a where the positive electrode current collector 1313 is not formed. The first boundary part 1314 may contact the edge surface of the positive electrode current collector 1313 on a plane. That is, the first boundary part 1314 may be disposed along the edge of the positive electrode current collector 1313 in the length direction (L-axis direction). Additionally, the first boundary part 1314 may be disposed along one of both edges of the positive electrode current collector 1313 facing in the length direction (L-axis direction). At this time, the edge of the positive electrode current collector 1313 in contact with the first boundary part 1314 is an edge disposed close to the second surface S2. The edge of the positive electrode current collector 1313 that is not in contact with the first boundary part 1314 may be exposed to the first surface S1 of the laminate 100. In other words, the positive electrode current collector 1313 may have an approximate hexahedral shape with two edge surfaces along the length direction (L-axis direction) and two edge surfaces along the width direction (W-axis direction), and the first boundary part 1314 may be formed to contact both edge surfaces disposed along the length direction (L-axis direction) of the positive electrode current collector 1313 and to contact one of the two edge surfaces disposed along the width direction (W-axis direction). That is, the first boundary part 1314 may be formed to surround three of the four surfaces of the positive electrode current collector 1313 in a plane direction. The paste for the first boundary part includes a positive electrode active material. The paste for the first boundary part applied when forming the first boundary part 1314 may include lithium (Li) ions. For example, the paste for the first boundary part may include aluminum oxide (Al2O3) and an electrolyte, and may further include an insulating material. For example, the paste for the first boundary part may be same as the active material paste forming the positive electrode active material layer.

[0166] Referring to FIG. 15, a second layer of a margin part 133b may be formed by applying an insulating paste on the first layer of the margin part 133a by printing, and then drying. The second layer of the margin part 133b may contact the edge of the first boundary part 1314 on a plane. The direction in which the second layer of the margin part 133b contacts the edge of the first boundary part 1314 may be the same as the direction in which the first boundary part 1314 contacts the edge of the positive electrode current collector 1313.

[0167] Referring to FIG. 16, a second positive electrode active material layer 1311b may be formed by applying an active material paste on the positive electrode current collector 1313 and the first boundary part 1314 by printing, and then drying.

[0168] Referring to FIG. 17, a third layer of a margin part 133c may be formed by printing and drying the insulating paste on the second layer of the margin part 133b. The third layer of the margin part 133c may contact the edge of the second positive electrode active material layer 1311b on a plane. That is, the third layer of the margin part 133c may contact three of the four edges of the second positive electrode active material layer 1311b in the length direction (L-axis direction) and the width direction (W-axis direction). Among the edges of the first positive electrode active material layer 1311a, the edges that are not in contact with the first layer of the margin part 133a may be exposed to the first surface S1 after sintering the laminate 100. In this way, the first margin 133 may be formed by applying and drying the first layer of the margin part 133a, the second layer of the margin part 133b, and the third layer of the margin part 133c, respectively.

[0169] [Experimental Example 1]

[0170] While changing the thickness of the solid electrolyte layer (the length of the solid electrolyte layer in the thickness direction (T-axis direction)) and the length of the positive electrode current collector, 20 all-solid-state batteries of Examples 1 to 9 and Comparative Examples 1 to 3 were each prepared. The lengths of the positive electrode active material layer of the all-solid-state batteries of Examples 1 to 9 and Comparative Examples 1 to 3 were measured in the length direction and were all 8 mm. The length of the positive electrode current collector was also measured in the length direction.

[0171] A paste containing 65 wt% (weight percent) of lithium cobalt oxide (LOC) and 35 wt% of solid electrolyte was used to form the positive electrode active material layer. The conductive paste for forming the positive electrode current collector contained 60 wt% of flake graphite and 40 wt% of solid electrolyte. A paste containing 60 wt% of spherical-shaped natural graphite and 40 wt% of solid electrolyte was used to form the negative electrode active material layer. The same material as the positive electrode active material layer was used to form the boundary part of the all-solid-state batteries of Examples 1 to 9. To form the positive electrode layer, the first positive electrode active material layer, the positive electrode current collector, and the second positive electrode active material layer were printed at thicknesses of 50 μm, 10 μm, and 50 μm, respectively, on the solid electrolyte sheet. Additionally, in order to form a negative electrode layer, a negative electrode active material layer with a thickness of 50 μm was printed on the solid electrolyte sheet.

[0172] The laminate was manufactured so that the positive electrode unit layer and negative electrode unit layer formed as above were 25 layers each, totaling 50 layers. The results of measuring the average capacity and short defect rate for the all-solid-state batteries of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 1. In Table 1, the ratio of the first boundary part indicates the ratio of the length of the first boundary part to the length of the positive electrode active material layer.

[0173] Thickness of solid electrolyte layer (μm)Length of positive electrodeactive material layer (mm)Length of positive electrode current collector (mm)Length of first boundary part (μm)Ratio of first boundary part (%)Battery capacity (mAh)Short defect rate (%)Comparative Example 1208800.009.890Example 12087.96200.2513.150Example 22087.92400.5012.730Example 32087.84801.0011.530Comparative Example2258800.0011.560Example 42587.96200.2512.530Example 52587.92400.5012.515Example 62587.84801.0011.715Comparative Example 3308800.0012.420Example 73087.96200.2512.60Example 83087.92400.5012.30Example 93087.84801.0011.60

[0174] As shown in Table 1, it was confirmed that when the thickness of the solid electrolyte layer was the same, the capacity increased as the ratio of the first boundary part increased. Additionally, as the ratio of the first boundary part increased, the short defect rate also decreased.

[0175] However, when the thickness of the solid electrolyte layer was 25 ㎛ or less, short defects occurred even if the ratio of the first boundary part was increased to 1 %. When the thickness of the solid electrolyte layer was 30 ㎛, 20 % of short defects occurred in Comparative Example 3 without the first boundary part, while in Examples 7, 8, and 9 with the ratio of the first boundary part of 0.25 % or higher, no short defects occurred.

[0176] Therefore, it was confirmed that in order to prevent short defects, the thickness of the solid electrolyte layer must be greater than 25 ㎛ and the first boundary part must be formed.

[0177] [Experimental Example 2]

[0178] While changing the length of the positive electrode active material layer (measured in the length direction) and the length of the positive electrode current collector, 100 all-solid-state batteries of Examples 10 to 14 and Comparative Examples 4 to 7 were each prepared. Since it was confirmed in Experimental Example 1 that the thickness of the solid electrolyte layer must be greater than 25 ㎛ to prevent short defects, each of the all-solid-state batteries of Examples 10 to 14 and Comparative Examples 4 to 7 was prepared to have a solid electrolyte layer thickness of 28 ㎛.

[0179] A paste containing 65 wt% (weight percent) of lithium cobalt oxide (LOC) and 35 wt% of solid electrolyte was used to form the positive electrode active material layer. The conductive paste for forming the positive electrode current collector contained 60 wt% of flake graphite and 40 wt% of solid electrolyte. A paste containing 60 wt% of spherical-shaped natural graphite and 40 wt% of solid electrolyte was used to form the negative electrode active material layer. The same material as the positive electrode active material layer was used to form the boundary part of the all-solid-state batteries of Examples 10 to 14. To form the positive electrode layer, the first positive electrode active material layer, the positive electrode current collector, and the second positive electrode active material layer were printed at thicknesses of 50 μm, 10 μm, and 50 μm, respectively, on the solid electrolyte sheet. Additionally, in order to form a negative electrode layer, a negative electrode active material layer with a thickness of 50 μm was printed on the solid electrolyte sheet.

[0180] The laminate was manufactured so that the positive electrode unit layer and the negative electrode unit layer formed as above were 25 layers each, totaling 50 layers, and the results of measuring the average capacity and short defect rate are shown in Table 2. In Table 2, the ratio of the first boundary part indicates the ratio of the length of the first boundary part to the length of the positive electrode active material layer.

[0181] Thickness of solid electrolyte layer (μm)Length of positive electrodeactive material layer (mm)Length of positive electrode current collector (mm)Length of first boundary part (μm)Ratio of first boundary part (%)Battery capacity (mAh)Short defect rate (%)Comparative Example 42813.9714.0400-70.00-0.50116.1027Comparative Example 52814.5014.49871.3000.00916.215Example 102814.1214.11861.4120.01016.170Example 112814.1214.11831.6940.01216.160Example 122814.2214.208611.380.08016.130Example 132814.2214.205814.220.10016.130Example 142813.9613.946013.960.10015.980Comparative Example 62813.9913.974615.390.11015.700Comparative Example 72813.9913.971818.190.13015.680

[0182] As shown in Table 2, short defects occurred in the all-solid-state battery in which the positive electrode current collector was longer than the positive electrode active material layer (Comparative Example 4) and in the all-solid-state battery in which the ratio of the first boundary part was less than 0.01 %. Therefore, it was confirmed that the ratio of the first boundary part must be 0.01 % or more to prevent short defects.

[0183] Meanwhile, as the ratio of the first boundary part increased, battery capacity tended to decrease. In particular, it was confirmed that the battery capacity decreased significantly at the ratio of the first boundary part of 0.1 %. Looking at the measurement results of Examples 10 to 13 (14.12 mAh and 14.22 mAh) in which the lengths of the positive electrode active material layers are similar to each other, as the ratio of the first boundary part increases from 0.01 % to 0.1 %, the battery capacity decreased from 16.17 mAh to 16.13 mAh. On the other hand, looking at the measurement results of Example 14 and Comparative Example 6 (13.96 mAh and 13.99 mAh), where the lengths of the positive electrode active material layers are similar to each other, the battery capacity is significantly reduced compared to the results of Examples 10 to 13 (15.98 mAh and 15.70 mAh, respectively), although the difference is small, with a ratio of the first boundary part of 0.10 % and 0.11 %, respectively. As above, in the section where the ratio of the first boundary ratio was 0.01 % or more and 0.1 % or less had lower decrease in battery capacity than in the section with a ratio exceeding 0.1 %. In other words, it was confirmed that when the ratio of the first boundary part exceeded 0.1 %, the efficiency in terms of battery capacity significantly decreased.

[0184] Hereinafter, an all-solid-state battery according to another embodiment will be described with reference to FIGS. 18 to 20.

[0185] FIG. 18 is a partial perspective view illustrating part of a negative electrode layer 155 of an all-solid-state battery according to another embodiment, FIG. 19 is an exploded perspective view of FIG. 18, and FIG. 20 is a partial cross-sectional view taken along line XX-XX' in FIG. 18. The all-solid-state battery of the embodiment illustrated in FIGS. 18 to 20 is similar to the all-solid-state battery described with reference to FIGS. 1 to 10. Detailed descriptions of the same components are omitted.

[0186] Referring to FIGS. 18 to 20, the negative electrode layer 155 of the all-solid-state battery according to the present embodiment may include a negative electrode active material layer 1551, a negative electrode current collector 1553, and a second boundary part 1554.

[0187] The negative electrode current collector 1553 may be made of, for example, stainless steel, nickel (Ni), copper (Cu), tin (Sn), aluminum (Al), or an alloy thereof. Additionally, the negative electrode current collector 1553 may be coated with an oxidation-resistant metal or alloy film to prevent oxidation.

[0188] The negative electrode current collector 1553 may be formed of the same conductive carbon-based material as the positive electrode current collector 1313. Additionally, the negative electrode current collector 1553 may contain one or more types of solid electrolytes. For example, the negative electrode current collector 1553 may include a sintered oxide glass electrolyte.

[0189] The second boundary part 1554 may be disposed on the side surface of the negative electrode current collector 1553 in the length direction (L-axis direction) and the width direction (W-axis direction). The second boundary part 1554 may be disposed between the negative electrode current collector 1553 and the second margin part 153. The second boundary part 1554 may contact both ends of the negative electrode current collector 1553 in the width direction (W-axis direction). Additionally, the second boundary part 1554 may contact the end close to the first surface S1 of both ends of the negative electrode current collector 1553 in the length direction (L-axis direction). The second boundary part 1554 may be disposed to surround the ends of the negative electrode current collector 1553 in the length direction (L-axis direction) and the width direction (W-axis direction) excluding the end exposed to the first surface S1. That is, the second boundary part 1554 may be disposed to contact both ends of the positive electrode current collector 1553 disposed along the length direction (L-axis direction) and one end of the both ends disposed along the width direction (W-axis direction). Among the ends of the negative electrode current collector 1553, the end that is not in contact with the second boundary part 1554 may be exposed to the second surface S2 of the laminate 100 and may be in contact with the second external electrode 400. Since the second boundary part 1554 is disposed between the negative electrode current collector 1553 and the second margin part 153, the negative electrode current collector 1553 and the second margin part 153 are spaced apart from each other. That is, the second boundary part 1554 may block the negative electrode current collector 1553 from contacting the second margin part 153.

[0190] Based on the second margin 153, the second boundary part 1554 may be disposed to contact the inner surface of the second margin part 153 along the length direction (L-axis direction) and the width direction (W-axis direction). Accordingly, the second boundary part 1554 may be formed to surround the negative electrode current collector 1553 in three directions. Since the negative electrode current collector 1553 surrounds the negative electrode current collector 1553 while contacting the negative electrode current collector 1553 on the third surface S3, the first surface S1, and the fourth surface S4, the entire negative electrode current collector 1553 and the entire second margin part 153 may be spaced apart by the second boundary part 1554.

[0191] For example, the second boundary part 1554 may use a carbon-based material, silicon, a 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 lithium metal and / or a lithium metal alloy. The second boundary part 1554 may be formed of the same material as the negative electrode active material layer 1551.

[0192] Since the length and measurement method of the second boundary part 1554 are the same as the length and measurement method of the first boundary part 1314, overlapping descriptions will be omitted.

[0193] The negative electrode active material layer 1551 includes a negative electrode active material. The negative electrode active material layer 1551 may be disposed on the negative electrode current collector 1553 and the second boundary part 1554. The negative electrode active material layer 1551 may be formed by printing a negative electrode active material on one or both surfaces of the negative electrode current collector 1553 and the second boundary part 1554. That is, the negative electrode active material layer 1551 may include a first negative electrode active material layer 1551a disposed on one surface of the negative electrode current collector 1553 and the second boundary part 1554, and may further include a second negative electrode active material layer 1551b disposed on the other surface of the negative electrode current collector 1553 and the second boundary part 1554. However, the method of forming the negative electrode active material layer 1551 is not limited thereto. Since the negative electrode active material included in the negative electrode active material layer 1551 is the same as the negative electrode active material described with reference to FIGS. 1 to 10, overlapping descriptions will be omitted.

[0194] 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.

[0195] <Description of symbols>

[0196] 10: All-solid-state battery

[0197] 100: Laminate

[0198] 110: Solid electrolyte layer

[0199] 130: Positive electrode unit layer

[0200] 131: Positive electrode layer

[0201] 1311 Positive electrode active material layer

[0202] 1313: Positive electrode current collector

[0203] 1314: First boundary part

[0204] 133: First margin part

[0205] 150: Negative electrode unit layer

[0206] 151: Negative electrode layer

[0207] 153: Second margin part

[0208] 1551: Negative electrode active material layer

[0209] 1553: Negative electrode current collector

[0210] 1554: Second boundary part

[0211] 180: Upper protective layer

[0212] 190: Lower protective layer

[0213] 300: First external electrode

[0214] 310: First electrode layer

[0215] 320: First plating layer

[0216] 400: Second external electrode

[0217] 410: Second electrode layer

[0218] 420: Second plating layer

Claims

1.An all-solid-state battery, comprising:a solid electrolyte layer;a first electrode unit layer and a second electrode unit layer facing each other with the solid electrolyte layer interposed therebetween;a first external electrode disposed on an outer surface of the all-solid-state battery and connected to the second electrode unit layer; anda first margin part disposed between the first electrode unit layer and the first external electrode,wherein the first electrode unit layer comprises a first current collector, and a first boundary part disposed between the first current collector and the first margin part and including a first active material.2.The all-solid-state battery of claim 1, whereinthe first boundary part blocks the first current collector from contacting the first margin part.3.The all-solid-state battery of claim 1, whereinthe first electrode unit layer further comprises a first active material layer disposed on the first current collector and on the first boundary part.4.The all-solid-state battery of claim 3, whereinthe first active material layer comprises the same material as the first boundary part.5.The all-solid-state battery of claim 3, whereinthe first active material layer and the first boundary part satisfy the following conditional expression:[Conditional expression]0.01 % ≤ L2 / L1 ≤ 0.1 %whereL1: Length of the first active material layerL2: Length of the first boundary part.6.The all-solid-state battery of claim 1, whereinthe first active material is a positive electrode active material.7.The all-solid-state battery of claim 1, whereinthe first boundary part further comprises aluminum oxide (Al2O3) and an electrolyte.8.The all-solid-state battery of claim 7, whereinthe first boundary part further comprises an insulating material.9.The all-solid-state battery of claim 1, further comprising:a second external electrode disposed on an outer surface of the all-solid-state battery and connected to the first electrode unit layer; anda second margin part disposed between the second electrode unit layer and the second external electrode,wherein the second electrode unit layer comprises a second current collector and a second boundary part disposed between the second current collector and the second margin part.10.The all-solid-state battery of claim 9, whereinthe second boundary part comprises a negative electrode active material.11.The all-solid-state battery of claim 9, whereinthe second boundary part blocks the second current collector from contacting the second margin part.12.The all-solid-state battery of claim 9, whereinthe second electrode unit layer further comprises a second active material layer disposed on the second current collector and on the second boundary part, andthe second active material layer comprises the same material as the second boundary part.13.An all-solid-state battery, comprising:a laminate including a solid electrolyte layer, and a positive electrode layer and a negative electrode layer disposed with the solid electrolyte layer interposed therebetween;a first external electrode disposed outside the laminate; anda first margin part disposed between the positive electrode layer and the first external electrode,wherein the positive electrode layer comprises a positive electrode active material layer, a positive electrode current collector disposed on the positive electrode active material layer, and a first boundary part disposed between the positive electrode current collector and the first margin part and including the positive electrode active material.14.The all-solid-state battery of claim 13, whereinthe first boundary part blocks the positive electrode current collector from contacting the first margin part.15.The all-solid-state battery of claim 13, whereinthe positive electrode active material layer and the first boundary part comprises the same material.16.The all-solid-state battery of claim 13, comprising:a second external electrode facing the first external electrode with the laminate interposed therebetween; anda second margin part disposed between the negative electrode layer and the second external electrode,wherein the negative electrode layer comprises a negative electrode active material layer, a negative electrode current collector disposed on the negative electrode active material layer, and a second boundary part disposed between the negative electrode current collector and the second margin part.17.The all-solid-state battery of claim 16, whereinthe second boundary part is made of the same material as the negative electrode active material layer.18.A method of manufacturing an all-solid-state battery, comprising:applying an active material paste on the solid electrolyte layer to form an active material layer;applying an insulating paste on the solid electrolyte layer to form a first layer of a margin part;applying a conductive paste on the active material layer to form a current collector; andforming a boundary part by applying a paste for a boundary part on a portion of the active material layer where the current collector is not formed.19.The method of the all-solid-state battery of claim 18, further comprisingforming a second layer of the margin part by applying an insulating paste on the first layer of the margin part,wherein the entire second layer of the margin part is formed to be spaced apart from the entire current collector by the boundary part.20.The method of the all-solid-state battery of claim 18, whereinthe paste for the boundary part comprises the same material as the active material paste.

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