All-solid-state battery

Abstract

An all-solid-state battery includes a substrate, an all-solid-state battery element mounted on the substrate, and a metal case positioned to cover the all-solid-state battery element while being spaced apart from it. The space between the battery element and the metal case is filled with air or an inert gas, which suppresses moisture penetration and mitigates structural damage caused by expansion or contraction of the battery element during operation.

Description

ALL-SOLID-STATE BATTERY

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

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

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

[0004] All-solid-state batteries may expand as the volume of the electrode active material layer changes during charge and discharge. Inside the expanded all-solid-state battery, an electrode may be damaged or the bonding of an electrode-solid electrolyte interface may be damaged, resulting in poor contact, which may deteriorate battery characteristics, particularly, charge / discharge cycle characteristics. Furthermore, cracks may form in the all-solid-state battery due to differences in the expansion rates between the electrode and the solid electrolyte, leading to moisture infiltration.

[0005] The present disclosure attempts to provide an all-solid-state battery capable of suppressing expansion.

[0006] The present disclosure seeks to provide an all-solid-state battery capable of preventing moisture infiltration. However, the objective of the present disclosure is not limited to the aforementioned one, and may be extended in various ways within the spirit and scope of the present disclosure.

[0007] An all-solid-state battery may include a substrate, an all-solid-state battery element mounted on the substrate, and a metal case spaced apart from the all-solid-state battery element and covering the all-solid-state battery element, where air or inert gas is filled between the all-solid-state battery element and the metal case.

[0008] The all-solid-state battery element include a laminate including a plurality of solid electrolyte layers, a plurality of positive electrode layers and a plurality of negative electrode layers, a first external electrode disposed outside the laminate and connected to the plurality of positive electrode layers, and a second external electrode disposed outside the laminate and connected to the plurality of negative electrode layers.

[0009] The substrate may comprise a first electrode pad connected to the first external electrode, and a second electrode pad connected to the second external electrode.

[0010] The all-solid-state battery may additionally include a first conductive bonding member connecting the first external electrode to the first electrode pad, and a second conductive bonding member connecting the second external electrode to the second electrode pad.

[0011] The first conductive bonding member and the second conductive bonding member may include silver (Ag).

[0012] The substrate may include a first major surface and a second major surface opposing each other, the first electrode pad is exposed from the first major surface, and the second electrode pad is exposed from the first major surface.

[0013] The substrate may further include a third electrode pad exposed from the second major surface, a fourth electrode pad exposed from the second major surface, a first conductive via electrically connecting the first electrode pad to the third electrode pad, and a second conductive via electrically connecting the second electrode pad to the fourth electrode pad.

[0014] The substrate may include a first major surface and a second major surface opposing each other, the all-solid-state battery element may be mounted on the first major surface of the substrate, and the metal case may be connected to the first major surface of the substrate.

[0015] The all-solid-state battery may additionally include a bonding portion that connects the metal case to the substrate. The bonding portion may include a first bonding portion disposed on the first major surface of the substrate, and a second bonding portion connected to the first bonding portion and in contact with the metal case.

[0016] The first bonding portion may comprise copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.

[0017] The second bonding portion may comprise solder.

[0018] The bonding portion may comprise a third bonding portion embedded in the substrate, and a fourth bonding portion connected to the third bonding portion and in contact with the metal case.

[0019] The third bonding portion may comprise copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.

[0020] The fourth bonding portion may comprisesolder.

[0021] The metal case may comprise copper (Cu), nickel (Ni), tin (Sn), zinc (Zn) or an alloy thereof.

[0022] According to the all-solid-state battery according to the embodiment, expansion during charging and discharging of the all-solid-state battery can be suppressed.

[0023] According to the all-solid-state battery according to the embodiment, the inflow of moisture can be prevented.

[0024] FIG. 1 is an exploded perspective view schematically showing an all-solid-state battery according to an embodiment.

[0025] FIG. 2 is a perspective view schematically showing an all-solid-state battery element of the all-solid-state battery of FIG. 1.

[0026] FIG. 3 is a perspective view schematically showing a laminate of the all-solid-state battery element of FIG. 2.

[0027] FIG. 4 is a cross-sectional view taken along line I-I' of FIG. 2.

[0028] FIG. 5 is an exploded perspective view schematically showing an internal structure of the laminate of FIG. 3.

[0029] FIG. 6 is a partial cross-sectional view schematically showing a positive electrode layer of the all-solid-state battery element of FIG. 2.

[0030] FIG. 7 is a partial cross-sectional view schematically showing a negative electrode layer of the all-solid-state battery element of FIG. 2.

[0031] FIG. 8 is a cross-sectional view schematically showing the all-solid-state battery of FIG. 1.

[0032] FIG. 9A is an enlarged cross-sectional view schematically showing the region A of FIG. 8.

[0033] FIG. 9B is another enlarged cross-sectional view schematically showing the region A of FIG. 8.

[0034] FIG. 10A is a top plan view schematically showing a manufacturing process of an all-solid-state battery according to an embodiment.

[0035] FIG. 10B is a top plan view schematically showing a manufacturing process of an all-solid-state battery according to an embodiment.

[0036] FIG. 10C is a top plan view schematically showing a manufacturing process of an all-solid-state battery according to an embodiment.

[0037] FIG. 10D is a top plan view schematically showing a manufacturing process of an all-solid-state battery according to an embodiment.

[0038] FIG. 11 is a graph illustrating discharge capacity of an all-solid-state battery according to an embodiment.

[0039] FIG. 12 is a graph representing discharge capacity of an all-solid-state battery according to Comparative Example.

[0040] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the disclosure are shown. The drawings and description are to be regarded as illustrative in nature and not restrictive. Similar reference numerals designate like elements throughout the specification. In addition, some components are exaggerated, omitted, or briefly illustrated in the added drawings, and sizes of the respective constituent elements do not reflect the actual sizes.

[0041] The accompanying drawings are provided only in order to allow embodiments disclosed in the present specification to be easily understood and are not to be interpreted as limiting the spirit disclosed in the present specification, and it is to be understood that the present disclosure includes all modifications, equivalents, and substitutions without departing from the scope and spirit of the present disclosure.

[0042] Terms with ordinal numbers such as first, second, and the like are used solely to describe various constituent elements and should not be interpreted as limiting these elements. The terms are only used to differentiate one constituent element from other constituent elements.

[0043] It should be understood that when an element such as a layer, film, region, area, or substrate is referred to as being "on" or "above" another element, it can be directly on the other element or intervening elements may also be present. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements present. Further, in the specification, the word "on" or "above" means disposed on or below the object portion, and does not necessarily mean disposed on the upper side of the object portion based on a gravitational direction.

[0044] Throughout the specification, it should be understood that the term "include", "comprise", "have", or "configure" indicates that a feature, a number, a step, an operation, a constituent element, a part, or a combination thereof described in the specification is present, but does not exclude a possibility of presence or addition of one or more other features, numbers, steps, operations, constituent elements, parts, or combinations, in advance. Unless explicitly stated otherwise, the term "comprise" and its variations, such as "comprises" or "comprising," will be understood to imply the inclusion of the stated elements but not the exclusion of other elements. 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.

[0045] Furthermore, throughout the specification, "connected" does not only mean when two or more elements are directly connected, but also when two or more elements are indirectly connected through other elements, and when they are physically connected or electrically connected, and further, it may be referred to by different names depending on a position or function, and may also be referred to as a case in which respective parts that are substantially integrated are linked to each other.

[0046] FIG. 1 is an exploded perspective view schematically showing an all-solid-state battery according to an embodiment, FIG. 2 is a perspective view schematically showing an all-solid-state battery element of the all-solid-state battery of FIG. 1, and FIG. 3 is a perspective view schematically showing the laminate of the all-solid-state battery element of FIG. 2.

[0047] Referring to FIG. 1, FIG. 2 and FIG. 3, an all-solid-state battery 1000 may include an all-solid-state battery element 1100, a substrate 1200, and a metal case 1300.

[0048] The all-solid-state battery element 1100 may comprise a laminate 100, a first external electrode 200 and a second external electrode 300.

[0049] First, as for directions defined for describing the present embodiment, L-axis, W-axis, and T-axis shown in the drawings indicates axes indicating a length direction, a width direction, and a thickness direction of the all-solid-state battery element 1100, respectively.

[0050] The thickness direction (T-axis direction) may refer to a direction perpendicular to a wide surface (major surface) of sheet-like constituent elements. For example, the thickness direction (T-axis direction) may be used as the same concept as a direction in which components of the laminate 100 are stacked.

[0051] The length direction (L-axis direction) refers to a direction parallel to the wide surfaces (main surfaces) of the sheet-like components, and may be a direction that intersects (or is orthogonal to) the thickness direction (T-axis direction). For example, the length direction (L-axis direction) may refer to a direction in which the first external electrode 200 and the second external electrode 300 face each other.

[0052] The width direction (W-axis direction) refers to a direction parallel to the wide surface (main surface) of the sheet-like components, and may refer to a direction that simultaneously intersects (or crosses) the thickness direction (T-axis direction) and the length direction (L-axis direction).

[0053] 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 complete hexahedral shape, but may have a substantially hexahedral shape. For example, the laminate 100 has a substantially rectangular hexahedral shape, but corner or vertex portions may have a round shape.

[0054] In the present embodiment, for convenience of description, surfaces opposing each other in the length direction (L-axis direction) of the laminate 100 may be defined as a first surface S1 and a second surface S2, surfaces opposing each other in the width direction (W-axis direction) of the laminate 100 and connecting the first surface S1 and the second surface S2 may be defined as a third surface S3 and a fourth surface S4, and surfaces opposing each other in the thickness direction (T-axis direction) of the laminate 100 and connecting the first surface S1 and the second surface S2 may be defined as a fifth surface S5 and a sixth surface S6.

[0055] Therefore, a first direction, which is a direction in which the first surface S1 and the second surface S2 face each other, may be the length direction (L-axis direction), and a second direction and a third direction that are 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), respectively, or the width direction (W-axis direction) and the thickness direction (T-axis direction), respectively.

[0056] A length of the laminate 100 may refer to, based on an optical microscope or scanning electron microscope (SEM) photograph of a cross-section in the length direction (L-axis direction)-the thickness direction (T-axis direction) at a center of the width direction (W-axis direction) of the laminate 100, a maximum value of lengths of a plurality of line segments that connect two outermost boundary lines facing each other in the length direction (L-axis direction) of the laminate 100 shown in the above cross-sectional photograph and are parallel to the length direction (L-axis direction). Meanwhile, the length of the laminate 100 may also refer to a minimum value of lengths of a plurality of line segments that connect two outermost boundary lines facing each other in the length direction (L-axis direction) of the laminate 100 shown in the above cross-sectional photograph and are parallel to the length direction (L-axis direction). On the other hand, the length of the laminate 100 may also refer toan arithmetic average value of lengths of at least two of a plurality of line segments that connect two outermost boundary lines facing each other in the length direction (L-axis direction) of the laminate 100 shown in the above cross-sectional photograph and are parallel to the length direction (L-axis direction).

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

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

[0059] FIG. 4 is a cross-sectional view taken along line I-I' of FIG. 2, and FIG. 5 is an exploded perspective view schematically showing an internal structure of the laminate of FIG. 3.

[0060] Referring to FIG. 3, FIG. 4 and FIG. 5, the laminate 100 may include a solid electrolyte layer 110, a positive electrode layer 130, a negative electrode layer 150, an upper protective layer 160, a lower protective layer 170 and a margin portion 180.

[0061] The solid electrolyte layer 110, the positive electrode layer 130, and the negative electrode layer 150 may each be plural. The positive electrode layer 130 and the negative electrode layer 150 may be alternately stacked in the thickness direction (T-axis direction) with the solid electrolyte layer 110 interposed therebetween. Such a laminated structure may repeat within the laminate 100, and the electrode layer closest to the fifth surface S5 of the laminate 100 may be the positive electrode layer 130 or the negative electrode layer 150, and the electrode layer closest to the sixth surface S6 may be the negative electrode layer 150 or the positive electrode layer 130.

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

[0063] The solid electrolyte layer 110 includes a solid electrolyte, which 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 lithium halide (LiX, where X is a halogen element such as F, Br, Cl, I, or the like). The glass-ceramic (or crystallization glass) refers to that a crystallographic mixture of amorphous and crystalline materials from which peaks and halos are observed in X-ray diffraction, electron beam diffraction, etc. Therefore, the glass-ceramic-based electrolyte is an electrolyte that has undergone partial crystallization through sintering and in which amorphous and crystalline materials are mixed.

[0064] The glass-ceramic-based electrolyte may include a mixture of an amorphous material and two or more types of crystalline materials. In addition, the crystalline material included in the glass-ceramic-based electrolyte may include a lithium compound crystalline phase containing lithium.

[0065] When the glass-ceramic-based electrolyte is included in the solid electrolyte layer 110, sufficient densification is achieved after sintering, whereby it is possible to realize high ionic conductivity.

[0066] As an example, 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 a lithium-chloroboracite-based electrolyte doped with aluminum, and as a specific example, the glass-ceramic electrolyte may include Li2O-B2O3-LiCl-Al2O3or Li4B4Al3O12Cl.

[0067] As another example, the solid electrolyte in the solid electrolyte layer 110 may contain a lithium-borosilicate-based electrolyte (hereinafter referred to as the LBSO-based electrolyte). The LBSO-based electrolyte is a glass-state electrolyte, and glass refers to a crystallographically amorphous material, from which halos are observed in the X-ray diffraction or electron beam diffraction.

[0068] When the LBSO-based electrolyte is included in the solid electrolyte layer 110, it is possible to keep the amorphous state during sintering while lowering the sintering temperature.　 Therefore, there is an advantage that it is possible to realize high ionic conductivity, and reactivity with the electrode is not high. The LBSO-based electrolyte may include lithium (Li), boron (B), silicon (Si), aluminum (Al), phosphorus (P), germanium (Ge), and sulfur (S).

[0069] Alternatively, the solid electrolyte included in the solid electrolyte layer 110 may be one or more types selected from the group consisting of a Garnet-type, a Na super ionic conductor (NASICON)-type, a lithium super ionic conductor (LISICON)-type, a Perovskite-type, and a lithium phosphorus oxynitride (LiPON)-type.

[0070] In an area where the margin portion 180, described later, is disposed, either a material with low ionic and electrical conductivity (i.e., an insulating material) or a material with ionic (or electrical) conductivity similar to that of the solid electrolyte may be present. For example, when a material having ionic conductivity (or electrical conductivity) similar to the ionic conductivity (or electrical conductivity) of the solid electrolyte is present in the margin portion, the material may be a material that is identical to or different from the solid electrolyte in other regions. In another example, a material with ionic (or electrical) conductivity similar to that of the solid electrolyte and an insulating material may coexist in the margin portion.

[0071] The Garnet-type solid electrolyte may refer to lithium lanthanum zirconium oxide (LLZO) represented by LiaLabZrcO12such as Li7La3Zr2O12, and the NASICON-type solid electrolyte may include lithium-aluminum-titanium-phosphate (LATP) of Li1+xAlxTi2-x(PO4)3(wherein 0<x<1) produced by introducing Ti to Li1+xAlxM2-x(PO4)3(LAMP) (wherein 0<x<2, M is Zr, Ti, or Ge)-type compound, lithium-aluminum-germanium-phosphate (LAGP) represented by Li1+xAlxGe2-x(PO4)3(wherein 0<x<1), such as Li1.3Al0.3Ge1.7(PO4)3containing an excessive amount of lithium, and / or lithium-zirconium-phosphate (LZP) of LiZr2(PO4)3.

[0072] In addition, the LISICON-type solid electrolyte may include solid solution oxide represented by xLi3AO4-(1-x)Li4BO4(wherein A is P, As, V, etc., and B is Si, Ge, Ti, etc.), such as Li4Zn(GeO4)4, Li10GeP2O12(LGPO), Li3.5Si0.5P0.5O4, and Li10.42Si(Ge)1.5P1.5Cl0.08O11.92, etc., and solid solution sulfide represented by Li4-xM1-yM'yS4(wherein M is Si or Ge and M' is P, Al, Zn, or Ga), such as Li2S-P2S5, Li2S-SiS2, Li2S-SiS2-P2S5, or Li2S-GeS2.

[0073] Further, the Perovskite-type solid electrolyte may include lithium lanthanum titanate (LLTO) represented by Li3xLa2 / 3-x□1 / 3-2xTiO3(wherein 0<x<0.16, and □ is vacancy), such as Li1 / 8La5 / 8TiO3, and the LiPON-type solid electrolyte may include nitride such as lithium phosphorous oxynitride of Li2.8PO3.3N0.46.

[0074] The positive electrode layer 130 may be exposed outside of the laminate 100 from the first surface S1, and connected to the first external electrode 200.

[0075] FIG. 6 is a partial cross-sectional view schematically illustrating a positive electrode layer of the all-solid-state battery element shown in FIG. 2. Referring to FIG. 4, FIG. 5, and FIG. 6, the positive electrode layer 130 may include a positive electrode current collector 133, a first positive electrode active material layer 135, and a second positive electrode active material layer 136.

[0076] For example, the positive electrode current collector 133 may be made of a plate-shape member or a thin member. As another example, the positive electrode current collector 133 may be a porous body having a reticulate shape, a mesh shape, or the like.

[0077] The positive electrode current collector 133 may include a first surface 133a and a second surface 133b. The first surface 133a and the second surface 133b oppose each other in the thickness direction (T-axis direction).

[0078] The positive electrode current collector 133 may include, but not limited to, a porous metal plate made of stainless steel, nickel (Ni), copper (Cu), tin (Sn), aluminum (Al), or an alloy thereof.

[0079] In addition, the positive electrode current collector 133 may be coated with an oxidation-resistant metal or an oxidation-resistant metal alloy film to prevent oxidation.

[0080] The positive electrode current collector 133 may include a carbon-based plate-shaped, thin, or linear member. The positive electrode current collector 133 may include a conductive carbon material. The conductive carbon material may include graphite, conductive fiber such as carbon nanotube (CNT) or vapor grown carbon fiber (VGCF), or conductive carbon such as carbon black.

[0081] Additionally,, the positive electrode current collector may also include one or more types of solid electrolyte.

[0082] The first positive electrode active material layer 135 and the second positive electrode active material layer 136 may include positive electrode active materials and be disposed on a surface of the positive electrode current collector 133. The first positive electrode active material layer 135 and the second positive electrode active material layer 136 may be formed by printing a positive electrode active material on one or both surfaces of the positive electrode current collector 133, but the method for forming the positive electrode active material layer is not limited thereto.

[0083] The positive electrode active material included in the positive electrode active material layers 135 and 136 may comprise 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 may contain lithium ions and serve to provide the lithium ions to the negative electrode when the all-solid-state battery is being charged. The positive electrode active material may influence the capacity and output of the all-solid-state battery.

[0084] For example, the positive electrode active material may include at least one selected from the group consisting of compounds represented by the following formula: LiaAl-bMbD2(where, 0.90≤a≤1.8, 0≤b≤0.5); LiaEl-bMbO2-cDc(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); LiE2-bMbO4-cDc(where, 0≤b≤0.5, 0≤c≤0.05); LiaNi1-b-cCobMcDα(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); LiaNi1-b-cCobMcO2-αXα(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); LiaNi1-b-cCobMcO2-αX2(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05,0<α<2); LiaNi1-b-cMnbMcDα(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α≤2); LiaNi1-b-cMnbMcO2-αXα(where,0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); LiaNi1-b-cMnbMcO2-αX2(where, 0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05, 0<α<2); LiaNibEcGdO2(where, 0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0.001≤d≤0.1); LiaNibCocMndGeO2(where,0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0.001≤e≤0.1); LiaNiGbO2(where, 0.90≤a≤1.8, 0.001≤b≤0.1); LiaCoGbO2(where, 0.90≤a≤1.8, 0.001≤b≤0.1); LiaMnGbO2 (where, 0.90≤a≤1.8, 0.001≤b≤0.1); LiaMn2GbO4(where, 0.90≤a≤1.8, 0.001≤b≤0.1); QO2; QS2; LiQS2; V2O5; LiV2O2; LiRO2; LiNiVO4; Li(3-f)J2(PO4)3(0≤f≤2); Li(3-f)Fe2(PO4)3(where, 0≤f≤2); and LiFePO4, in which formula, A may be Ni, Co, or Mn; M may be Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, Nb, Ti or a rare-earth element; D may be O, F, S, or P; E may be Co or Mn; X may be F, S, or P; G may be Al, Cr, Mn, Fe, Mg, La, Ce, Sr, or V; Q may be Ti, Mo or Mn; R may be Cr, V, Fe, Sc, or Y; and J may be V, Cr, Mn, Co, Ni, or Cu.

[0085] Additionally, the positive electrode active material may also include LiCoO2, LiMnxO2x(where, x is 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.

[0086] The positive electrode active material may optionally include a conductive material and a binder. However, because an organic substance such as a binder decomposes during sintering process, the organic material may not remain on the positive electrode active material layer of the obtained positive electrode current collector.

[0087] The conductive material is not particularly limited as long as it has conductivity without causing chemical changes in the all-solid-state battery 1000. For example, graphite such as natural graphite and artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjenblack®, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers, metal fibers, etc.; carbon fluoride; metal components such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), copper (Cu), etc., oxides thereof, nitrides thereof, or fluorides thereof; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; conductive materials such as polyphenylene derivatives, etc., may be used.

[0088] The binder may be used to improve the bonding strength of the active material, the conductive material, or similar components . The binder may include, but not limited to, 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 (SBR), fluorine rubber, various copolymers, etc.

[0089] Additionally, the positive electrode layer 130 may further contain a solid electrolyte component. The solid electrolyte component may contain one or more of the above-described components, and may serve as an ionic conduction channel in the positive electrode layer. Therefore, it is possible to reduce interface resistance.

[0090] The negative electrode layer 150 may be exposed outside of the laminate 100 from the second surface S2, and connected to the second external electrode 300.

[0091] FIG. 7 is a partial cross-sectional view schematically showing a negative electrode layer of the all-solid-state battery element of FIG. 2.

[0092] Referring to FIG. 4, FIG. 5, and FIG. 7, the negative electrode layer 150 may include a negative electrode current collector 153, a first negative electrode active material layer 155, and a second negative electrode active material layer 156.

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

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

[0095] For example, the negative electrode current collector 153 may include, but is not limited to, a porous metal plate made of stainless steel, nickel (Ni), copper (Cu), tin (Sn), aluminum (Al), or an alloy thereof.

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

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

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

[0099] The negative electrode active material included in the negative electrode active material layers 155 and 156 may store the lithium ions that have moved from the positive electrode and release the lithium ions when the all-solid-state battery is discharged, thereby generating electrical energy. 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. The negative electrode active material may contain a lithium metal and / or a lithium metal alloy.

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

[0101] The element AM may include 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.

[0102] Additionally, the oxide of the metal / metalloid capable of making an alloy with lithium may include lithium titanium oxide, vanadium oxide, lithium vanadium oxide, SnO2, SiOx(wherein 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 the elements in group 13 to 16 of the periodic table of elements. For example, the negative electrode active material may contain one or more elements selected from the group consisting of Si, Ge, and Sn.

[0103] The carbon-based material may include crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite such as natural graphite or artificial graphite that is in a shapeless, disc-shaped, flake-shaped, globular, or fibrous form. In addition, the amorphous carbon may include, but not limited to, soft carbon (low-temperature calcined carbon), hard carbon, mesophase pitch carbide, calcined cokes, graphene, carbon black, fullerene soot, carbon nanotube, carbon fiber, etc.

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

[0105] The negative active material may optionally comprise a conductive material and a binder.

[0106] The conductive material is not particularly limited as long as it has conductivity without causing chemical changes in the all-solid-state battery 1000. For example, graphite such as natural graphite and artificial graphite; carbon-based materials such as carbon black, acetylene black, Ketjenblack®, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers, metal fibers, etc.; carbon fluoride; metal components such as lithium (Li), tin (Sn), aluminum (Al), nickel (Ni), copper (Cu), etc., oxides thereof, nitrides thereof, or fluorides thereof; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; conductive materials such as polyphenylene derivatives, etc., may be used.

[0107] The binder may be used to improve the bonding strength of the active material, the conductive material, or the like. The binder may include, but not limited to, 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 (SBR), fluorine rubber, various copolymers, etc.

[0108] Additionally, the negative electrode layer 150 may further contain a solid electrolyte component. The solid electrolyte component may contain one or more of the above-described components and may serve as an ionic conduction channel in the negative electrode layer. Therefore, it is possible to reduce interface resistance.

[0109] The upper protective layer 160 and the lower protective layer 170 may be outermost layers disposed on the fifth surface S5 and the sixth surface S6 of the laminate 100, respectively. That is, the upper protective layer 160 may be the outermost layer toward the fifth surface S5 of the laminate 100, and the lower protective layer 170 may be the outermost layer toward the sixth surface S6 of the laminate 100. The upper protective layer 160 and the lower protective layer 170 may improve moisture resistance by preventing moisture penetration, and prevent damage from physical and chemical impacts.

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

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

[0112] The margin portion 180 may be positioned along the edges of the positive electrode layer 130 and the negative electrode layer 150. It may contact the remaining edges of the positive electrode layer 130, except where it connects to the first external electrode 200. Similarly, it may contact the remaining edges of the negative electrode layer 150, except where it connects to the second external electrode 300. For example, the margin portion 180 may be disposed on the solid electrolyte layer 110 in a region other than the region where the positive electrode layer 130 or the negative electrode layer 150 is disposed. When the positive electrode layer 130 is disposed on the solid electrolyte layer 110, the margin portion 180 may be disposed in a region other than the region where the positive electrode layer 130 is disposed. Likewise, when the negative electrode layer 150 is disposed on the solid electrolyte layer 110, the margin portion 180 may be disposed in a region other than the region where the negative electrode layer 150 is disposed.

[0113] Referring to FIG. 4, the margin portion 180 may comprise a portion of the first surface S1 and a portion of the second surface S2 of the laminate 100. Additionally, although not illustrated, the margin portion 180 may also comprise a portion of the third surface S3 and a portion of the fourth surface S4 of the laminate 100.

[0114] The margin portion 180 may be disposed to compensate for a level difference between the solid electrolyte layer 110 and the positive electrode layer 130 and a level difference between the solid electrolyte layer 110 and the negative electrode layer 150. For example, the margin portion 180 may be disposed on the same surface as the positive electrode layer 130 and the negative electrode layer 150. The margin portion 180 may compensate for a level difference between the solid electrolyte layer 110 and the positive electrode layer 130 or a level difference between the solid electrolyte layer 110 and the negative electrode layer 150. This increases the density between the solid electrolyte layer 110 and the electrode layers, which may prevent interlayer delamination or warping caused by sintering during a process of manufacturing the all-solid-state battery.

[0115] Meanwhile, the margin portion 180 may be made of a material that is resistant to moisture and has low lithium (Li) ion conductivity. In this case, the margin portion 180 may protect the active material layers 135, 136, 155, and 156 from moisture infiltration or lithium (Li) ion leakage. For example, the margin portion 180 may include an insulating material or electrolyte material, and may include a material with an ionic conductivity of 1.0x10-10S / cm or less.

[0116] The margin portion 180 may include an insulating material, i.e., a material that is not electrically or ionically conductive.

[0117] The margin portion 180 may include, but not limited to, at least one selected from the group consisting of ceramic materials, e.g., alumina (Al2O3), aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silica (SiO2), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), barium titanate (BaTiO3), zirconium dioxide (ZrO2), mixtures thereof, oxides thereof and / or nitrides thereof, or any other suitable ceramic materials.

[0118] Additionally,, the margin portion 180 may optionally include a solid electrolyte that is the same as or different from the solid electrolyte included in the above-described solid electrolyte layer, and may include one or more types of solid electrolytes, but is not limited thereto.

[0119] Additionally,, a material having a low ionic conductivity and electrical conductivity, i.e., an insulating material, may be present in the margin portion 180, or a material having an ionic conductivity (or electrical conductivity) similar to the ionic conductivity (or electrical conductivity) of a solid electrolyte may be present in the margin portion 180. For example, when a material having ionic conductivity (or electrical conductivity) similar to the ionic conductivity (or electrical conductivity) of the solid electrolyte is present in the margin portion, the material may be a material that is identical to or different from the solid electrolyte in other regions. In another example, a material having ionic conductivity (or electrical conductivity) similar to the ionic conductivity (or electrical conductivity) of the solid electrolyte and an insulating material may coexist in the margin portion.

[0120] The first external electrode 200 and the second external electrode 300 may be positioned outside the laminate 100.

[0121] The first external electrode 200 is connected to the positive electrode layer 130 and the solid electrolyte layer 110 on the first surface S1 of the laminate 100. For example, the first external electrode 200 may cover the first surface S1 of the laminate 100, and the first external electrode 200 may extend onto the third surface S3, the fourth surface S4, the fifth surface S5 and the sixth surface S6 of the laminate 100, to partially cover the respective surfaces.

[0122] Additionally, in another embodiment, the first external electrode 200 may extend onto one surface of the fifth surface S5 and the sixth surface S6 of the laminate 100, to partially cover the corresponding surface.

[0123] The first external electrode 200 may be formed by baking a conductive paste. For example, the conductive paste may include glass and a metal such as silver (Ag) or copper (Cu).

[0124] The second external electrode 300 is connected to the negative electrode layer 150 and the solid electrolyte layer 110 on the second surface S2 of the laminate 100. For instance, the second external electrode 300 may cover the second surface S2 and extend onto the third surface S3, fourth surface S4, fifth surface S5, and sixth surface S6 of the laminate 100, partially covering these surfaces. Additionally, in another embodiment, the second external electrode 300 may extend onto one surface of the fifth surface S5 and the sixth surface S6 of the laminate 100, to partially cover the corresponding surface.

[0125] The second external electrode 300 may be formed by baking a conductive paste. For example, the conductive paste may include glass and a metal such as silver (Ag) or copper (Cu).

[0126] For example, the first surface S1 and the second surface S2 of the laminate 100 are dipped into the conductive paste and then blotted to form the first external electrode 200 and the second external electrode 300. As another example, a conductive paste may be applied to the first surface S1 and the second surface S2 of the laminate 100, to form the first external electrode 200 and the second external electrode 300. As still another example, a dry film obtained by drying a conductive paste may be transferred to the laminate 100 and then baked, to form the first external electrode 200 and the second external electrode 300, but the method for forming the first external electrode 200 and the second external electrode 300 is not limited to the above-described method. For example, the conductive metal in the conductive paste may comprise at least one of copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), or an alloy thereof but is not limited to these.

[0127] FIG. 8 is a cross-sectional view schematically showing the all-solid-state battery of FIG. 1.

[0128] Referring to FIG. 8, the all-solid-state battery element 1100 may be mounted on the substrate 1200.

[0129] The substrate 1200 may be a circuit board, such as a multi-layered circuit board, a single-layered double-sided printed circuit board, or the like, with no particular kind of limitation.

[0130] The substrate 1200 may include a first major surface 1210 and a second major surface 1220 that are opposite to each other in the thickness direction (T-axis direction). The all-solid-state battery element 100 may be mounted on the first major surface 1210 of the substrate 1200.

[0131] The substrate 1200 may include a first electrode pad 1230 and a second electrode pad 1240.

[0132] The first electrode pad 1230 may be exposed from the first major surface 1210 of the substrate 1200. The first electrode pad 1230 may be electrically connected to the first external electrode 200 of the all-solid-state battery element 100. For example, the first external electrode 200 may be electrically connected to the first electrode pad 1230 via a first conductive bonding member 400. The first conductive bonding member may include, for example, silver (Ag).

[0133] The second electrode pad 1240 may be exposed on the first major surface 1210 of the substrate 1200. The second electrode pad 1240 may be electrically connected to the second external electrode 300 of the all-solid-state battery element 100. For example, the second external electrode 300 may be electrically connected to the second electrode pad 1240 via a second conductive bonding member 500. The second conductive bonding member may include, for example, silver (Ag).

[0134] The substrate 1200 may further include a third electrode pad 1250, a fourth electrode pad 1260, a first conductive via V1 and a second conductive via V2.

[0135] The third electrode pad 1250 and the fourth electrode pad 1260 may be exposed on the second major surface 1220 of the substrate 1200. The first electrode pad 1230 and the third electrode pad 1250 may be electrically connected to each other by the first conductive via V1. The second electrode pad 1240 and the fourth electrode pad 1260 may be electrically connected to each other by the second conductive via V2.

[0136] Referring to FIG. 1 and FIG. 8, the metal case 1300 may be spaced apart from the all-solid-state battery element 1100, and may cover the all-solid-state battery element 1100. That is, the metal case 1300 may be disposed on the substrate 1200 in such a way as to accommodate the all-solid-state battery element 1100 inside.

[0137] The metal case 1300 may be made of a metal or an alloy. For example, the metal case 1300 may include copper (Cu), nickel (Ni), tin (Sn), zinc (Zn) or an alloy thereof.

[0138] The metal case 1300 may be formed by machining a plate material, or by joining plates, but the present embodiment is not limited thereto.

[0139] The metal case 1300 may include an opposing portion 1310 and a side portion 1320.

[0140] The opposing portion 1310 may face the all-solid-state battery element 1100 in the thickness direction (T-axis direction) and be spaced apart from it. The side portion 1320 may be a portion extending from an edge of the opposing portion 1310 in the thickness direction (T-axis direction).

[0141] The side portion 1320 may include a first side portion 1321, a second side portion 1322, a third side portion 1323, and a fourth side portion 1324.

[0142] The first side portion 1321 and the second side portion 1322 may be disposed on opposite sides in the length direction (L-axis direction).

[0143] The first side portion 1321 may face the first external electrode 200 of the all-solid-state battery element 1100, in the length direction (L-axis direction), and may be spaced apart from the first external electrode 200.

[0144] The second side portion 1322 may face the second external electrode 300 of the all-solid-state battery element 1100, in the length direction (L-axis direction), and may be spaced apart from the second external electrode 300.

[0145] The third side portion 1323 and the fourth side portion 1324 may be disposed on opposite sides in the width direction (W-axis direction). The third side portion 1323 and the fourth side portion 1324 may be spaced apart from the all-solid-state battery element 1100.

[0146] Additionally, the metal case 1300 may be connected to the first major surface 1210 of the substrate 1200. The metal case 1300 may be fixed on the first major surface 1210 of the substrate 1200.

[0147] FIG. 9A is an enlarged cross-sectional view schematically showing the region A of FIG. 8.

[0148] Referring to FIG. 8 and FIG. 9A, the metal case 1300 and the substrate 1200 may be connected by a bonding portion 600. An internal space S of the metal case 1300 may be sealed by the bonding portion 600. That is, the metal case 1300 and the substrate 1200 may form an enclosed internal space S.

[0149] The bonding portion 600 may include a first bonding portion 610 and a second bonding portion 620.

[0150] The first bonding portion 610 may be disposed on the first major surface 1210 of the substrate 1200. For example, the first bonding portion 610 may include copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.

[0151] The second bonding portion 620 may be connected to the first bonding portion 610, and may be in contact with the first side portion 1321 of the metal case 1300. For example, the second bonding portion 620 may include solder.

[0152] The remaining side portions 1322, 1323, and 1324 of the metal case 1300 are also connected to the substrate 1200 in the same way as the first side portion 1321, and redundant description thereon will be omitted.

[0153] FIG. 9B is another enlarged cross-sectional view schematically showing the region A of FIG. 8.

[0154] Referring to FIG. 8 and FIG. 9B, the metal case 1300 and the substrate 1200 may be connected by a bonding portion 700. The internal space S of the metal case 1300 may be sealed by the bonding portion 700. That is, the metal case 1300 and the substrate 1200 may form an enclosed internal space S.

[0155] The bonding portion 700 may consist of a third bonding portion 710 and a fourth bonding portion 720. The third bonding portion 710 may be embedded in the substrate 1200. That is, the third bonding portion 710 may be surrounded by the substrate 1200 except for the portion exposed from the first major surface 1210 of the substrate 1200. The portion of the third bonding portion 710 exposed from the first major surface 1210 of the substrate 1200 may be flush with the first major surface 1210.

[0156] For example, the third bonding portion 710 may include copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.

[0157] The fourth bonding portion 720 may be connected to the third bonding portion 710, and may be in contact with the first side portion 1321 of the metal case 1300. For example, the fourth bonding portion 720 may include solder.

[0158] The remaining side portions 1322, 1323, and 1324 of the metal case 1300 are also connected to the substrate 1200 in the same way as the first side portion 1321, and redundant description thereon will be omitted.

[0159] The metal case 1300 and the substrate 1200 form a sealed internal space S, which prevents moisture infiltration, thereby improving the moisture resistance reliability of the all-solid-state battery 1000.

[0160] Additionally, the internal space S formed by the metal case 1300 and the substrate 1200 may be filled with air or an inert gas. The inert gas may include, for example, nitrogen (N2) or Argon (Ar), but the present embodiment is not limited thereto.

[0161] Since the internal space S is filled with gas and is sealed, the all-solid-state battery element 1100 may be pressurized by the surrounding gas. Therefore, even if expansion or contraction of the positive electrode active material or the negative active material occurs as the all-solid-state battery element 1100 is charged and discharged, cracks in the positive electrode layer 130 or negative electrode layer 150 caused by this expansion or contraction may be suppressed. Furthermore, the volume change of the positive electrode layer 130 and the negative electrode layer 150 can be suppressed, inhibiting delamination of the positive or negative electrode layers from the current collector.

[0162] Hereinafter, a manufacturing process of the all-solid-state battery according to an embodiment will be briefly described.

[0163] FIG. 10A is a top plan view schematically showing a manufacturing process of the all-solid-state battery according to an embodiment, and FIG. 10B is a top plan view schematically showing a manufacturing process of the all-solid-state battery according to an embodiment. In addition, FIG. 10C is a top plan view schematically showing a manufacturing process of the all-solid-state battery according to an embodiment, and FIG. 10D is a top plan view schematically showing a manufacturing process of the all-solid-state battery according to an embodiment.

[0164] Referring to FIG. 10A, the first bonding portion 610 is formed on the substrate 1200 with the first electrode pad 1230 and the second electrode pad 1240. The first bonding portion 610 may be disposed to surround a region where the all-solid-state battery element is to be disposed. That is, the first bonding portion 610 may be formed to surround the first electrode pad 1230 and the second electrode pad 1240.

[0165] The first bonding portion 610 may be formed by plating a conductive metal on a surface of the substrate 1200. The conductive metal may include copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.

[0166] Alternatively, a paste comprising a conductive metal may be applied to the surface of the substrate 1200 to form the first bonding portion 610.

[0167] In other embodiments, a trench may be formed on the substrate 1200 and filled with a conductive metal to create the first bonding portion. Referring to FIG. 10B, the all-solid-state battery element 1100 may be mounted on the surface of the substrate 1200. That is, the all-solid-state battery element 1100 is disposed on the substrate 1200, such that the first external electrode 200 of the all-solid-state battery element 1100 corresponds to the first electrode pad 1230 and the second external electrode 300 corresponds to the second electrode pad 1240.

[0168] Here, a conductive bonding member (not shown) is disposed between the first external electrode 200 and the first electrode pad 1230 and between the second external electrode 300 and the second electrode pad 1240, respectively.

[0169] Referring to FIG. 10C, the second bonding portion 620 may be formed on the first bonding portion 610. For example, the second bonding portion 620 may be formed by disposing solders on the first bonding portion 610.

[0170] Referring to FIG. 10D, the metal case 1300 may be disposed on the second bonding portion 620. That is, the metal case 1300 is disposed such that the opposing portion 1310 of the metal case 1300 covers the all-solid-state battery element 1100 and the side portions 1321, 1322, 1323, and 1324 of the metal case 1300 is in contact with the second bonding portion 620. This process is conducted in an inert gas atmosphere to ensure no air or moisture remains in the internal space of the metal case 1300. Alternatively, when this process is performed in a dry room, moisture may be minimized even if air remains in the internal space of the metal case 1300.

[0171]

[0172] [Preparation Example: manufacture of all-solid-state battery]

[0173] (Example)

[0174] A plurality of striped positive electrode layers were formed by printing on a solid electrolyte layer (green sheet) in the order of a positive electrode active material layer, a positive electrode current collector, and a positive electrode active material layer, and then filling a space between the positive electrode layers with an insulating material to form a positive electrode sheet.

[0175] A plurality of striped negative electrode layers were formed by printing on a solid electrolyte layer (green sheet) in the order of a negative electrode active material layer, a negative electrode current collector, and a negative electrode active material layer, and then filling a space between the negative electrode layers with an insulating material to form a negative electrode sheet.

[0176] A green chip was created by stacking the positive electrode sheet and the negative electrode sheet so that they intersect each other. A laminate was formed by dicing the green chip.

[0177] The laminate was calcined at 300 °C to 400 °C in an air or nitrogen atmosphere.

[0178] After the calcination, the laminate was sintered at 400°C - 550°C in an air or nitrogen atmosphere.

[0179] An all-solid-state battery element was prepared by applying a conductive paste for external electrodes to the surface of the sintered laminate, and then sequentially placing the laminate in a curing oven at 50 °C, 80 °C, and 200 °C for 30 minutes each, followed by cooling to form the external electrodes.

[0180] A conductive paste was applied to the surface of the substrate to form a first junction.

[0181] An all-solid-state battery element was mounted on the substrate, and a second bonding portion was formed by solder on the first bonding portion.

[0182] An all-solid-state battery was manufactured by disposing a metal case to be in contact with the second bonding portion of the substrate and performing a reflow process.

[0183]

[0184] (Comparative Example)

[0185] A plurality of striped positive electrode layers were formed by printing on a solid electrolyte layer (green sheet) in the order of a positive electrode active material layer, a positive electrode current collector, and a positive electrode active material layer, and then filling a space between the positive electrode layers with an insulating material to form a positive electrode sheet.

[0186] A plurality of striped negative electrode layers were created by printing on a solid electrolyte layer (green sheet) in the sequence of a negative electrode active material layer, a negative electrode current collector, and another negative electrode active material layer. The space between the negative electrode layers was filled with an insulating material to form a negative electrode sheet. A green chip was formed by stacking the positive electrode sheet and the negative electrode sheet so that the positive electrode sheet and the negative electrode sheet intersect each other.

[0187] A laminate was formed by dicing the green chip.

[0188] The laminate was calcined at 300 °C to 400 °C in an air or nitrogen atmosphere.

[0189] After the calcination, is the laminate was sintered at 400°C - 550°C in an air or nitrogen atmosphere.

[0190] An all-solid-state battery element was prepared by applying a conductive paste for external electrodes to the surface of the sintered laminate, and then sequentially placing the laminate in a curing oven at 50 °C, 80 °C, and 200 °C for 30 minutes each, followed by cooling to form the external electrodes.

[0191] An all-solid-state battery was manufactured by mounting the all-solid-state battery element on a substrate.

[0192]

[0193] [Experimental Example: performance of all-solid-state battery]

[0194] Five all-solid-state batteries of Example and Comparative Example were manufactured for each, and initial charge and discharge test was performed for one representative sample. The results are shown in FIG. 11 and FIG. 12.

[0195] Referring to FIG. 11, charge and discharge proceeded normally in the all-solid-state battery manufactured according to Example.

[0196] Referring to FIG. 12, charge and discharge did not occur normally in the all-solid-state battery manufactured according to the Comparative Example. In other words, the all-solid-state battery was rendered unusable by the rapid voltage drop during discharge. In Comparative Example, the all-solid-state battery element appears to have cracked due to accelerated contraction / expansion caused by moisture penetration, resulting in a sharp increase in internal resistance.

[0197] While this disclosure has been described with reference to practical embodiments, it is understood that the disclosure is not limited to the described embodiments but is intended to encompass various modifications and equivalent arrangements within the spirit and scope of the appended claims.

[0198] <Description of symbols>

[0199] 1000: all-solid-state battery

[0200] 1100: all-solid-state battery element

[0201] 1200: substrate

[0202] 1210: first major surface

[0203] 1220: second major surface

[0204] 1230: first electrode pad

[0205] 1240: second electrode pad

[0206] 1300: metal case

[0207] 1310: opposing portion

[0208] 1320: side portion

[0209] 100: laminate

[0210] 110: solid electrolyte layer

[0211] 130: positive electrode layer

[0212] 150: negative electrode layer

[0213] 160: upper protective layer

[0214] 170: lower protective layer

[0215] 180: margin portion

[0216] 200: first external electrode

[0217] 300: second external electrode

Claims

1.An all-solid-state battery, comprising:a substrate;an all-solid-state battery element mounted on the substrate; anda metal case spaced apart from the all-solid-state battery element and covering the all-solid-state battery element,wherein air or inert gas is filled between the all-solid-state battery element and the metal case.2.The all-solid-state battery of claim 1, wherein the all-solid-state battery element comprises:a laminate comprising a plurality of solid electrolyte layers, a plurality of positive electrode layers and a plurality of negative electrode layers;a first external electrode positioned outside the laminate and connected to the plurality of positive electrode layers; anda second external electrode positioned outside the laminate and connected to the plurality of negative electrode layers.3.The all-solid-state battery of claim 2, wherein the substrate comprises:a first electrode pad connected to the first external electrode; anda second electrode pad connected to the second external electrode.4.The all-solid-state battery of claim 3, further comprising:a first conductive bonding member connecting the first external electrode to the first electrode pad; anda second conductive bonding member connecting the second external electrode to the second electrode pad.5.The all-solid-state battery of claim 4, wherein the first conductive bonding member and the second conductive bonding member comprise silver (Ag).6.The all-solid-state battery of claim 3, wherein:the substrate comprises a first major surface and a second major surface opposing each other;the first electrode pad is exposed on the first major surface; andthe second electrode pad is exposed on the first major surface.7.The all-solid-state battery of claim 6, wherein the substrate further comprises:a third electrode pad exposed on the second major surface;a fourth electrode pad exposed on the second major surface;a first conductive via electrically connecting the first electrode pad to the third electrode pad; anda second conductive via electrically connecting the second electrode pad to the fourth electrode pad.8.The all-solid-state battery of claim 1, wherein:the substrate comprises a first major surface and a second major surface opposing each other;the all-solid-state battery element is mounted on the first major surface of the substrate; andthe metal case is connected to the first major surface of the substrate.9.The all-solid-state battery of claim 8, further comprising a bonding portion configured to connect the metal case to the substrate.10.The all-solid-state battery of claim 9, wherein the bonding portion comprise:a first bonding portion disposed on the first major surface of the substrate; anda second bonding portion connected to the first bonding portion and configured to contact the metal case.11.The all-solid-state battery of claim 10, wherein the first bonding portion comprises copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.12.The all-solid-state battery of claim 10, wherein the second bonding portion comprises solder.13.The all-solid-state battery of claim 9, wherein the bonding portion comprises:a third bonding portion embedded in the substrate; anda fourth bonding portion connected to the third bonding portion and configured to contact the metal case.14.The all-solid-state battery of claim 13, wherein the third bonding portion comprises copper (Cu), aluminum (Al), nickel (Ni), gold (Au), or an alloy thereof.15.The all-solid-state battery of claim 13, wherein the fourth bonding portion comprises solder.16.The all-solid-state battery of claim 1, wherein the metal case comprises copper (Cu), nickel (Ni), tin (Sn), zinc (Zn) or an alloy thereof.17.An all-solid-state battery comprising:a substrate;an all-solid-state battery element mounted on the substrate, the all-solid-state battery element including a laminate comprising a plurality of solid electrolyte layers, a plurality of positive electrode layers, and a plurality of negative electrode layers;a metal case spaced apart from the all-solid-state battery element and covering the all-solid-state battery element, the metal case including an opposing portion and a side portion extending from the opposing portion; anda margin portion disposed along the edges of the positive electrode layers and the negative electrode layers;wherein the margin portion includes an insulating material.18.The all-solid-state battery of claim 17, wherein the margin portion is disposed in contact with solid electrolyte layers and is configured to fill spaces between the positive electrode layers and the negative electrode layers.19.The all-solid-state battery of claim 17, wherein the insulating material of the margin portion comprises at least one ceramic material selected from the group consisting of alumina (Al₂O₃), silicon carbide (SiC), and zirconium dioxide (ZrO₂).

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