All-solid-state battery

Abstract

An all-solid-state battery according to present disclosure includes a cell stack including a solid electrolyte layer, a positive electrode layer, and a negative electrode layer, wherein the solid electrolyte layer is interposed between the positive electrode layer and the negative electrode layer, and a coating layer located on one or both surfaces in a stacking direction of the cell stack, or on one or both surfaces in a width direction of the cell stack, wherein the coating layer includes a silane-modified acrylic resin, and a surface energy of the coating layer is less than or equal to about 40 dyne / cm.

Description

ALL-SOLID-STATE BATTERY

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

[0002] Recently, the miniaturization and prolonged use of portable electronic devices requires high-capacity batteries, and the spread of wearable electronic devices requires securing the safety of the batteries. Therefore, the development of all-solid-state batteries that use solid electrolytes instead of liquid electrolytes has been actively conducted.

[0003] All-solid-state batteries do not use flammable organic solvents, so additional circuits for safety may be simplified. Therefore, it is expected to be a technology capable of manufacturing high-capacity safe batteries per unit volume.

[0004] In addition, oxide all-solid-state batteries using oxide electrolytes have lower ionic conductivity of the electrolyte (10-4S / cm to 10-6S / cm) than sulfide (10-2S / cm), and require a high-temperature firing process, but they are more stable than sulfide all-solid-state batteries that use sulfide electrolytes that react with oxygen and moisture in the air.

[0005] Stacked oxide all-solid-state batteries are ultra-small batteries that may be mounted on a board like a passive device and are stable even when exposed to high temperatures during a reflow process for this purpose.

[0006] Since the all-solid-state battery is vulnerable to moisture, moisture resistance is generally strengthened by applying exterior materials such as epoxy or ceramic to strengthen water repellency. In addition, fluorine-based coating agents have been used to increase water repellency by lowering surface energy of exterior materials, but due to recent restrictions on the use of perfluoric acid compounds, there is a need to develop materials with a surface energy as low as fluorine-based resin.

[0007] One aspect of the embodiment provides an all-solid-state battery with excellent water repellency and moisture resistance.

[0008] However, the problems that the embodiments are intended to address are not limited to the problems described above and may be expanded in various ways within the scope of the technical ideas included in the embodiments.

[0009] The all-solid-state battery according to the embodiment has the advantage of excellent water repellency and moisture resistance.

[0010] However, the various and beneficial advantages and effects of the present invention are not limited to the foregoing, and will be more easily understood in the process of describing specific embodiments of the present invention.

[0011] FIG. 1 is a perspective view schematically showing an all-solid-state battery according to an embodiment.

[0012] FIG. 2 is a cross-sectional view schematically showing an all-solid-state battery according to an embodiment.

[0013] FIG. 3 is a graph evaluating the moisture resistance reliability of the all-solid-state battery according to Example 5 and Comparative Example 1.

[0014] An all-solid-state battery according to an embodiment includes a cell stack including a solid electrolyte layer, a positive electrode layer, and a negative electrode layer, wherein the solid electrolyte layer is interposed between the positive electrode layer and the negative electrode layer, and

[0015] a coating layer located on one or both surfaces in a stacking direction of the cell stack, or on one or both surfaces in a width direction of the cell stack,

[0016] wherein the coating layer includes a silane-modified acrylic resin, and a surface energy of the coating layer is less than or equal to about 40 dyne / cm.

[0017] The silane-modified acrylic resin may be formed by reacting an acrylic resin including an acrylic oligomer, an acrylic monomer, or a combination thereof with a silane compound.

[0018] A silicone modification content of the silane-modified acrylic resin may be about 0.05 mmol / g to about 100 mmol / g.

[0019] The acrylic monomer may include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, octyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, triisopropylsilyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or a combination thereof.

[0020] The silane compound may include an alkoxy silane compound, a polydimethylsiloxane-based compound, a silicone resin intermediate, silicone oil, or a combination thereof.

[0021] The alkoxy silane compound may include methyl trimethoxysilane, methyl triethoxysilane, dimethyl dimethoxysilane, dimethyl diethoxysilane,　phenyl trimethoxysilane, diphenyl dimethoxysilane, phenyl triethoxysilane, diphenyl diethoxysilane, phenylmethyl dimethoxysilane, cyclohexyl trimethoxysilane, dicyclohexyl dimethoxysilane, cyclohexyl triethoxysilane, dicyclohexyl diethoxysilane, 3-aminopropyl triethoxysilane, 3-methacryloxylpropyl trimethoxysilane, or a combination thereof.

[0022] The polydimethylsiloxane-based compound may include poly(dimethylsiloxane),bis(3-aminopropyl) terminated, poly(dimethylsiloxane), bis(hydroxyalkyl) terminated, poly(dimethylsiloxane),hydroxy terminated, poly(dimethylsiloxane), monohydroxy terminated, poly(dimethylsiloxane),vinyl terminated, or a combination thereof.

[0023] The silane compound may be included in an amount of about 0.08 parts by weight to about 50 parts by weight based on 100 parts by weight of the acrylic resin.

[0024] The silane-modified acrylic resin may further include a melamine compound, an epoxy compound, or a combination thereof.

[0025] The epoxy compound may include bisphenol-based epoxy, naphthalene-based epoxy, biphenyl-based epoxy, novolac-type epoxy, isocyanate epoxy, or a combination thereof.

[0026] A thickness of the coating layer may be about 0.1 μm to about 20 μm.

[0027] An all-solid-state battery according to another embodiment includes a cell stack including a solid electrolyte layer, a positive electrode layer, and a negative electrode layer, wherein the solid electrolyte layer is interposed between the positive electrode layer and the negative electrode layer,

[0028] a coating layer located on one or both surfaces in a stacking direction of the cell stack, or on one or both surfaces in a width direction of the cell stack, and

[0029] a cover layer between the cell stack and the coating layer,

[0030] wherein the coating layer includes a silane-modified acrylic resin, and a surface energy of the coating layer is less than or equal to about 40 dyne / cm.

[0031] The silane-modified acrylic resin may be formed by reacting an acrylic resin including an acrylic oligomer, an acrylic monomer, or a combination thereof with a silane compound.

[0032] The silicone modification content of the silane-modified acrylic resin may be about 0.05 mmol / g to about 100 mmol / g.

[0033] The acrylic monomer may include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, octyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, triisopropylsilyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or a combination thereof.

[0034] The silane compound may include an alkoxy silane compound, a polydimethylsiloxane-based compound, a silicone resin intermediate, silicone oil, or a combination thereof.

[0035] The silane compound may be included in an amount of about 0.08 parts by weight to about 50 parts by weight based on 100 parts by weight of the acrylic resin.

[0036] The silane-modified acrylic resin may further include a melamine compound, an epoxy compound, or a combination thereof.

[0037] A thickness of the coating layer may be about 0.1 μm to about 20 μm.

[0038] A thickness of the cover layer may be about 50 μm to about 300 μm.

[0039] Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail so as to facilitate practice by those having ordinary knowledge in the art to which the present invention belongs. In order to clearly illustrate the invention in the drawings, parts not pertinent to the description have been omitted, and identical or similar components are designated by the same reference numerals throughout the specification. Furthermore, the accompanying drawings are intended only to facilitate an understanding of the embodiments disclosed herein, 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 scope of the ideas and technology of the present invention. In addition, some components are exaggerated, omitted, or schematically depicted in the accompanying drawings, and the dimensions of each component are not necessarily indicative of actual dimensions.

[0040] In addition, unless explicitly described to the contrary, the word “comprise,” and variations such as “comprises” or “comprising,” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0041] Throughout the specification, the "stacking direction" refers to a direction in which the components are stacked sequentially, and may also be a "thickness direction" perpendicular to a wide side (main plane) of the components on the sheet, which corresponds to a T-axis direction in the drawings. In addition, the "lateral direction" refers to a direction that extends from the edge of the component on the sheet, parallel to a wide surface (main surface), which may be a "plane direction" and corresponds to an L-axis direction in the drawings. In addition, a W-axis direction in the drawing may be a "width direction.".

[0042] Hereinafter, various embodiments and modifications will be described in detail with reference to the drawings.

[0043] FIG. 1 is a perspective view schematically showing an all-solid-state battery according to an embodiment, and FIG. 2 is a cross-sectional view of an all-solid-state battery according to an embodiment.

[0044] As an example, the all-solid-state battery 100 may have a roughly hexahedral shape.

[0045] In the present embodiment, for convenience of explanation, in the all-solid-state battery 100, both surfaces opposing each other in a thickness direction (T-axis direction) will be defined as a first surface and a second surface, and both surfaces connected to the first surface and the second surface and opposing each other in a longitudinal direction (L-axis direction) will be defined as a third surface and a fourth surface. For example, the first side and second side of the all-solid-state battery 100 that face each other may be the third surface and the fourth surface.

[0046] The all-solid-state battery 100 according to an embodiment includes a cell stack including a solid electrolyte layer 130, a positive electrode layer 120, and a negative electrode layer 140, wherein the solid electrolyte layer 130 is interposed between the positive electrode layer 120 and the negative electrode layer 140, and a coating layer 160 located on one or both surfaces in a stacking direction of the cell stack, or on one or both surfaces in a width direction of the cell stack.

[0047] Coating Layer

[0048] The coating layer 160 is located on one or both surfaces of the cell stack in the stacking direction, or on one or both surfaces in the width direction of the cell stack. As an example, the coating layer 160 may be located on both surfaces in the stacking direction of the cell stack, or may be positioned on both surfaces in the width direction of the cell stack. As a specific example, the coating layer 160 may be located on both surfaces in the stacking direction of the cell stack and on both surfaces in the width direction of the cell stack.

[0049] As an example, the coating layer 160 may be located on the outermost side in the stacking direction of the cell stack of the all-solid-state battery 100. By being located on the outside of the cell stack, the coating layer 160 can improve water repellency and moisture resistance of the all-solid-state battery.

[0050] As an example, the coating layer 160 may be disposed on the outer surface of the positive electrode layer 120 located at the bottom and the negative electrode layer 140 located at the top in the stacking direction of the cell stack. Herein, the solid electrolyte layer 130 may be disposed between the coating layer 160 and the positive electrode layer 120 or negative electrode layer 140 adjacent thereto.

[0051] The coating layer 160 includes a silane-modified acrylic resin. The coating layer 160 has the advantage of excellent water repellency and moisture resistance reliability as well as excellent mechanical properties due to the silane-modified acrylic resin.

[0052] In an embodiment, the surface energy of the coating layer 160 is less than or equal to about 40 dyne / cm. For example, the surface energy of the coating layer 160 may be less than or equal to about 38 dyne / cm, less than or equal to about 37 dyne / cm, or less than or equal to about 35 dyne / cm. If the surface energy of the coating layer 160 exceeds about 40 dyne / cm, it is difficult to sufficiently secure the water repellency and moisture resistance of the all-solid-state battery.

[0053] The surface energy of the coating layer 160 is determined by dropping purified water and methane iodide on the surface of the coating layer, measuring respective contact angles, and calculating an contact angle according to Owens-Wendt-Label.

[0054] For example, the contact angle of the coating layer 160 with respect to purified water may be greater than or equal to about 80 °, for example, greater than or equal to about 85 °, or greater than or equal to about 90 °. For example, the contact angle of the coating layer 160 with methane iodide may be greater than or equal to about 30 °, for example, greater than or equal to about 40 °, or greater than or equal to about 45 °.

[0055] The silane-modified acrylic resin is not particularly limited as long as it is an acrylic resin modified with silane, and for example, a resin obtained by modifying an acrylic resin with a silane compound.

[0056] In an embodiment, the silane-modified acrylic resin may be formed by reacting an acrylic resin including an acrylic oligomer, an acrylic monomer, or a combination thereof with a silane compound.

[0057] As a specific example, the silane-modified acrylic resin can be prepared by mixing and reacting an acrylic oligomer and a silane compound in the presence of an organic solvent.

[0058] As another specific example, the silane-modified acrylic resin may be prepared by radical polymerization of one or more types of acrylic monomer and a silane compound. At this time, a silane-modified acrylic resin can be prepared by adding a photoinitiator in the presence of an organic solvent.

[0059] The acrylic monomer may include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, octyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, triisopropylsilyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or a combination thereof. For reference, the “(meth)acrylic acid” may include “acrylic acid,” “methacrylic acid,” or a combination thereof.

[0060] The acrylic oligomer may be a polymer that can be prepared by polymerizing the aforementioned acrylic monomers. A weight average molecular weight (Mw) of the acrylic oligomer may be about 150,000 to about 300,000. If the above numerical range is satisfied, an all-solid-state rechargeable battery with excellent mechanical properties can be implemented.

[0061] The acrylic oligomer or the acrylic monomer may have a functional group that can react with a silane compound. The functional groups may include, for example, an isocyanate group, a hydroxy group, an amino group, a carboxyl group, a thiol group, an epoxy group, a hydrosilyl group, an ethynyl group, an ammonium group, an amide group, an imino group, an alkoxysilyl group, an ether group, a sulfonic acid group, a nitrile group, or a combination thereof.

[0062] The silane compound may include, but is not limited to, an alkoxy silane compound, a polydimethylsiloxane-based compound, a silicone resin intermediate, silicone oil, or a combination thereof.

[0063] The alkoxy silane compounds may include methyl trimethoxysilane, methyl triethoxysilane, dimethyl dimethoxysilane, dimethyl diethoxysilane, phenyl trimethoxysilane, diphenyl dimethoxysilane, phenyl triethoxysilane, diphenyl diethoxysilane, phenylmethyl dimethoxysilane, cyclohexyl trimethoxysilane, dicyclohexyl dimethoxysilane, cyclohexyl triethoxysilane, dicyclohexyl diethoxysilane, 3-aminopropyl triethoxysilane, 3-methacryloxylpropyl trimethoxysilane, or a combination thereof.

[0064] As a specific example, the alkoxy silane compound may include 3-aminopropyl triethoxysilane, 3-methacryloxypropyl trimethoxysilane, poly(dimethylsiloxane) (PDMS), or a combination thereof.

[0065] The polydimethylsiloxane-based compound may include poly(dimethylsiloxane), bis(3-aminopropyl) terminated, poly(dimethylsiloxane), bis(hydroxyalkyl) terminated, poly(dimethylsiloxane), hydroxy terminated, poly(dimethylsiloxane), monohydroxy terminated, poly(dimethylsiloxane),vinyl terminated, or a combination thereof.

[0066] As an example, the silicone modification content of the silane-modified acrylic resin may be about 0.05 mmol / g to about 100 mmol / g. As an example, the silicone modification content of the silane-modified acrylic resin may be greater than or equal to about 0.05 mmol / g, greater than or equal to about 0.08 mmol / g, or greater than or equal to about 0.1 mmol / g, and less than or equal to about 100 mmol / g, less than or equal to about 50 mmol / g, less than or equal to about 20 mmol / g, less than or equal to 10 mmol / g, or less than or equal to 2.5 mmol / g.

[0067] The silicone modification content (mmol / g) can be obtained through Equation 1, and may mean an content (mmol) of silyl groups included in 1 g of the silane-modified acrylic resin.

[0068] [Equation 1]

[0069] Silicone modification content = Content of silyl group (mmol) / Silane-modified acrylic resin (g)

[0070] If the silicone modification content of the silane-modified acrylic resin is less than about 0.05 mmol / g, it is difficult to secure water repellency because the surface energy of the silane-modified acrylic resin is high. If it exceeds about 100 mmol / g, the surface energy of the silane-modified acrylic resin is lowered and water repellency is excellent, but there is a problem of poor adherence to the cell stack.

[0071] In an embodiment, the silane compound may be included in an amount of greater than or equal to about 0.08 parts by weight, greater than or equal to about 0.1 parts by weight, greater than or equal to about 1 part by weight, or greater than or equal to about 2 parts by weight, and less than or equal to about 60 parts by weight, less than or equal to about 55 parts by weight, or less than or equal to 50 parts by weight based on 100 parts by weight of the acrylic resin. As an example, the silane compound may be included in an amount of about 0.08 to about 60 parts by weight, for example, about 0.08 to about 50 parts by weight, about 0.1 to about 60 parts by weight, or about 0.1 to about 50 parts by weight based on 100 parts by weight of the acrylic resin.

[0072] When the above numerical range is satisfied, an all-solid-state battery with excellent water repellency and moisture resistance can be implemented.

[0073] The photoinitiator may include 2,2'-azobis(2-methylpropionitrile) (AIBN), 1-hydroxy-cyclohexyl-phenylketone, 2-hydroxy- 2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone, methylbenzoyl formate, α, α-dimethoxy-α-phenylacetophenone, 2-benzoyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, or a combination thereof.

[0074] The organic solvent may include alcohols such as methanol, ethanol, propanol, and isopropanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate, and butyl carbitol acetate; phenols such as phenol, 4-methoxy phenol, and 4-ethoxy phenol; aromatic compounds such as toluene, benzene, and xylene; ethers; or a combination thereof.

[0075] The silane-modified acrylic resin may further include a melamine compound, an epoxy compound, or a combination thereof. When the silane-modified acrylic resin further includes a melamine compound or an epoxy compound, there is an advantage that the mechanical properties such as tensile strength and elongation of the coating layer are superior.

[0076] The silane-modified acrylic resin may further include a melamine (C3H6N6) compound. For example, the melamine compound may be included in an amount of less than or equal to about 30 parts by weight based on 100 parts by weight of the silane-modified acrylic resin, and if it is included in greater than about 30 parts by weight, the water-repellent effect of the silane-modified acrylic resin may be reduced.

[0077] As an example, a melamine-acrylic monomer is prepared by reacting melamine with the acrylic monomer, and then the melamine-acrylic monomer is radically polymerized with the acrylic monomer, thereby producing a silane-modified acrylic resin including a melamine compound.

[0078] As an example, melamine and acrylic monomer may be stirred in the presence of formaldehyde and the organic solvent at about 100 °C to about 150 °C for about 1 to about 2 hours, and then an acid catalyst may be added to prepare melamine-acrylic monomer.

[0079] The silane-modified acrylic resin further including a melamine compound may be prepared by adding a photoinitiator in the presence of the organic solvent and radically polymerizing the prepared melamine-acrylic monomer and the acrylic monomer.

[0080] The acid catalyst may include a sulfonic acid catalyst, a phosphoric acid catalyst, or a combination thereof. The sulfonic acid-based catalyst may include p-toluene sulfonic acid, methane sulfonic acid, dodecylbenzene sulfonic acid, or a combination thereof, and the phosphoric acid-based catalyst may include phosphoric acid, phosphorous acid, or a combination thereof.

[0081] The silane-modified acrylic resin may further include an epoxy compound. For example, the epoxy compound may be included in an amount of less than or equal to about 30 parts by weight based on 100 parts by weight of the silane-modified acrylic resin. If it is included in greater than about 30 parts by weight, the water-repellent effect of the silane-modified acrylic resin may be reduced.

[0082] For example, the epoxy compound may include bisphenol-based epoxy such as bisphenol A-type epoxy and bisphenol F-type epoxy; naphthalene-based epoxy such as bifunctional naphthalene epoxy; biphenyl-based epoxy; novolac-type epoxy; isocyanate epoxy; or a combination thereof.

[0083] The silane-modified acrylic resin may further include one or more additives such as a polymerization accelerator, a curing accelerator, an UV absorber, a lubricant, a leveling agent, an anti-foaming agent, an antioxidant, a flame retardant, an infrared absorber, a surfactant, and a surface modifier.

[0084] A thickness of the coating layer 160 may be about 0.1 μm to about 20 μm. When the above numerical range is satisfied, an all-solid-state battery with excellent water repellency and moisture resistance reliability as well as excellent mechanical properties can be implemented.

[0085] Cover Layer

[0086] The all-solid-state battery according to an embodiment may further include a cover layer (not shown) between the coating layer and the cell stack.

[0087] By being located on the outside of the cell stack, the cover layer can serve to alleviate an impact of the all-solid-state battery, prevent moisture infiltration into the interior, and prevent current leakage.

[0088] In order to provide insulating properties, the cover layer may include an insulating material having an ionic conductivity of less than or equal to about 1.0X10-10S / cm, or less than or equal to about 1.0X10-6S / cm. If the insulating material is commonly used, it can be used without limitation in its type

[0089] For example, the insulating material may include an insulating material such as ceramic or resin.

[0090] The ceramics may include aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), It may include barium titanate (BaTiO3), a mixture thereof, or an oxide and / or a nitride of these materials.

[0091] For example, the resin may include polyolefin such as polyethylene or polypropylene, polyester such as polyethylene terephthalate (PET), polyurethane, or polyimide.

[0092] For example, a thickness of the cover layer may be about 50 μm to about 300 μm. If the above thickness range is satisfied, it is possible to effectively alleviate the impact of the all-solid-state battery, prevent moisture infiltration into the interior, and prevent current leakage.

[0093] Solid Electrolyte Layer

[0094] The solid electrolyte layer 130 may be interposed and stacked between the positive electrode layer 120 and the negative electrode layer 140. Accordingly, the solid electrolyte layer 130 may be disposed adjacent to positive electrode active material layers 121 and 122 of the positive electrode layer 120 and negative electrode active material layers 141 and 142 of the negative electrode layer 140 in a stacking direction.

[0095] Thus, in the all-solid-state battery 100, a plurality of positive electrode layers 120 and negative electrode layer 140 may be alternately disposed and stacked with a plurality of solid electrolyte layers 130 interposed between them. The all-solid-state battery 100 may be a stacked all-solid-state battery 100 manufactured by alternately stacking a plurality of positive electrode layers 120 and negative electrode layers 140, interposing a plurality of solid electrolyte layers 130 between them to manufacture a cell stack, and then firing them at a time.

[0096] The solid electrolyte layer 130 may include an inorganic solid electrolyte including an oxide-based solid electrolyte, a sulfide-based solid electrolyte, or a combination thereof.

[0097] The oxide-based solid electrolytes include Garnet-type, Nasicon-type, LISICON-type, perovskite-type, LiPON-type, and amorphous-type (glass), or a glass-ceramic electrolyte.

[0098] The Garnet-type solid electrolytes may refer to lithium lanthanum zirconium oxide (LLZO), represented by LiaLabZrcO12, such as Li7La3Zr2O12. Nasicon-type solid electrolytes may refer to lithium-aluminum-titanium-phosphate (LATP) of Li1+xAlxTi2-x(PO4)3(0<x<1) where Ti is introduced into a compound of the type Li1+xAlxM2-x(PO4)3(LAMP) (where 0<x<2, and M is Zr, Ti, or Ge), lithium-aluminum-germanium-phosphate (LAGP), represented by Li1+xAlxGe2-x(PO4)3(0<x<1), such as Li1.3Al0.3Ti1.7(PO4)3and / or lithium-zirconium-phosphate (LZP) of LiZr2(PO4)3with an excess of lithium introduced.

[0099] In addition, the LISICON-type solid electrolyte may indicate a solid solution oxide represented by xLi3AO4-(1-x)Li4BO4(A is P, As, V, etc., B is Si, Ge, Ti, etc.) and including Li4Zn(GeO4)4, Li10GeP2O12(LGPO), Li3.5Si0.5P0.5O4, Li10.42Si(Ge)1.5P1.5Cl0.08O11.92, etc., and the solid solution sulfide including Li2S-P2S5, Li2S-SiS2, Li2S-SiS2-P2S5, or Li2S-GeS2,etc.represented by Li4-xM1-yM'yS4(M is Si, Ge, and M' is P, Al, Zn, or Ga).

[0100] The perovskite-type solid electrolytes may refer to lithium-lanthanum titanate (LLTO), represented by Li3xLa2 / 3-x□1 / 3-2xTiO3(0<x<0.16, □: vacancy), such as Li1 / 8La5 / 8TiO3, etc. The LiPON-type solid electrolytes may refer to a nitride, such as lithium-phosphorous oxynitride, such as Li2.8PO3.3N0.46.

[0101] The amorphous electrolyte may include Li2O-B2O3-SiO2, Li2O-B2O3-P2O5, Li3BO3-Li2CO3, or Li3BO3-Li2CO3,or the like.

[0102] The glass-ceramic electrolyte may include lithium halide (LiX, wherein X is a halogen element of F, Br, Cl, I, or a combination thereof), and may be an electrolyte in which amorphous and crystalline elements are mixed. When the solid electrolyte layer 130 includes the glass-ceramic electrolyte, the solid electrolyte may be sufficiently densified after firing to achieve high ionic conductivity.

[0103] 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, and magnesium. (Mg) oxide, lithium chloride (LiCl), or a combination thereof.

[0104] As an example, the glass-ceramic electrolyte may include a lithium chloro boracite (Li2O-B2O3-LiCl-Al2O3)-based electrolyte. As a specific example, the glass-ceramic electrolyte may include Li2O-B2O3-LiCl-Al2O3.

[0105] The sulfide-based solid electrolyte may include sulfur atoms among the electrolyte components and is not particularly limited to specific components, and may include one or more of a crystalline solid electrolyte, an amorphous solid electrolyte (glassy solid electrolyte), or a glass ceramic solid electrolyte.

[0106] For example, the sulfide-based solid electrolyte may include LPS-type sulfides including sulfur and phosphorus (for example, Li2S-P2S5), and Thio-LISICON type compounds, such as Li4-xGe1-xPxS4(where x may be 0.1 to 2, 3 / 4, or 2 / 3), Li10±1MP2X12(where M is Ge, Si, Sn, or Al, and X is S, or Se), Li3.833Sn0.833As0.166S4, Li4SnS4, Li3.25Ge0.25P0.75S4, Li2S-P2S5, B2S3-Li2S, xLi2S-(100-x)P2S5(where x is 70 to 80), Li2S-SiS2-Li3N, Li2S-P2S5-LiI, Li2S-SiS2-LiI, Li2S-B2S3-LiI, Li10SnP2S12, and Li3.25Ge0.25P0.75S4.

[0107] Electrode Layer

[0108] The electrode layers may include a positive electrode layer 120 and a negative electrode layer 140, and may essentially include current collectors 123 and 143 and electrode active material layers 121, 122, and 141, 142 applied to at least one surface of the current collectors 123 and 143.

[0109] Referring to FIG. 2, the positive electrode layer 120 may be formed by applying the positive electrode active material layers 121 and 122 to at least one surface of the positive electrode current collector 123, and the negative electrode layer 140 may be formed by applying the negative electrode active material layers 141 and 142 to at least one surface of the negative electrode current collector 143.

[0110] For example, the electrode layer located at the bottom relative to the stacking direction may be formed by applying the positive electrode active material layer 122 on one surface of the positive electrode current collector 123, and the electrode layer located at the uppermost end may be formed by applying the negative electrode active material layer 141 on one surface of the negative electrode current collector 143.

[0111] Also, the electrode layers located between the uppermost end and the lowermost end may be formed by applying the positive electrode active material layers 121 and 122 to both sides of the positive electrode current collector 123, or by applying the negative electrode active material layers 141 and 142 to both surface of the negative electrode current collector 143.

[0112] The positive electrode active material layers 121 and 122 may include a positive electrode active material and, optionally, a solid electrolyte. Additionally, the positive electrode active material layers 121 and 122 may optionally further include additives such as a binder or a conductive agent.

[0113] As an example, the positive electrode active material is not particularly limited as long as it can secure sufficient capacity of the all-solid-state battery 100. For example, the positive electrode active material may include lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphorus oxide, lithium manganese oxide, or combinations thereof.

[0114] For example, the positive electrode active material may be a compound represented by the following chemical formulas: 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, wherein A is Ni, Co, or Mn; M is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, 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.

[0115] The positive electrode active material may also be LiCoO2, LiMnxO2x(where x = 1 or 2), LiNi1-xMnxO2x(where 0<x<1), LiNi1-x-yCoxMnyO2(where 0≤x≤0.5, 0≤y≤0.5), LiFePO4, TiS2, FeS2, TiS3, or FeS3.

[0116] The solid electrolyte may include a lithium ion conductor according to an embodiment. The content of the solid electrolyte may be 0.1 parts by weight or more, 1 part by weight or more, or 10 parts by weight or more, and may be 80 parts by weight or less, 60 parts by weight or less, or 50 parts by weight or less, based on the total of 100 parts by weight of the positive electrode active material.

[0117] The conductive agent is not particularly limited as long as it has conductivity without causing chemical changes in the all-solid-state battery 100. For example, conductive agent may include graphite, such as natural 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 or metal fiber; carbon fluoride; metal powders, such as aluminum and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and conductive materials, such as polyphenylene derivatives.

[0118] A content of the conductive agent may be about 1 part by weight to about 10 parts by weight, for example, about 2 parts by weight to about 5 parts by weight, based on the total of 100 parts by weight of the positive electrode active material. If the content of the conductive agent is within the above range, the finally obtained electrode may have excellent conductivity properties.

[0119] A binder may be used to improve bonding strength between an active material and a conductive agent. The binders may include, for example, polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diether polymer (EPDM), sulfonated EPDM, a styrene butadiene rubber, a fluorinated rubber, or various copolymers.

[0120] A content of the binder may be about 1 part by weight to about 50 parts by weight, or about 2 parts by weight to about 5 parts by weight, based on the total of 100 parts by weight of the positive electrode active material. If the content of the binder satisfies the above range, the active material layer may have high bonding strength.

[0121] As an example, the positive electrode current collector 123 may be porous, such as a network or mesh-like, and may be a porous metal plate, such as stainless steel, nickel, aluminum, etc., or a two-dimensional carbon-based material (e.g., graphite). In addition, the positive electrode current collector 123 may be coated with an oxidation-resistant metal or alloy film to prevent oxidation.

[0122] The negative electrode active material layers 141 and 142 may include a negative electrode active material and, optionally, a solid electrolyte. Additionally, the negative electrode active material layers 141 and 142 may optionally further include additives such as a binder or a conductive agent.

[0123] The negative electrode active material may be carbon-based material, silicon, silicon oxide, silicon-based alloy, silicon-carbon-based material composite, tin, tin-based alloy, tin-carbon composite, metal oxide, or combinations thereof, and may include a lithium metal and / or a lithium metal alloy. The carbon-based material may include a two-dimensional carbon-based material and as a specific example, the carbon-based material may include graphite.

[0124] The lithium metal alloy may include lithium and metals / metalloids capable of alloying with lithium. For example, metals / metalloids capable of alloying with lithium may include Si, Sn, Al, Ge, Pb, Bi, Sb, Si-Y alloys (where Y is an alkali metal, an alkaline earth metal, an element in groups 13 to 16, a transition metal, rare earth elements or a combination of these elements, but do not include Si), Sn-Y alloy (where Y is an alkali metal, an alkaline earth metal, an element in groups 13 to 16, a transition metal, a transition metal oxide such as lithium titanium oxide (Li4Ti5O12), a rare earth element, or a combination of these elements, but does not include Sn), or MnOx(0<x≤2).

[0125] The element Y may be Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Rh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Tl, Ge, P, As, Sb, Bi, S, Se, Te, Po, or a combination thereof.

[0126] In addition, oxides of metals / metalloids capable of alloying with lithium may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, SnO2, SiOx(0<x<2), etc. For example, the negative electrode active material may include one or more elements selected from elements in groups 13 to 16 of the periodic table of elements. For example, the negative electrode active material may include one or more elements selected from Si, Ge, and Sn.

[0127] The carbon-based material may be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite, such as natural graphite or artificial graphite, in the form of amorphous, platelets, flakes, spheres, or fibers. In addition, the amorphous carbon may be soft carbon (low-temperature calcined carbon) or hard carbon, mesophase pitch carbide, calcined coke, graphene, carbon black, fullerene soot, carbon nanotube, and carbon fiber.

[0128] The silicon may be Si, SiOx(0<x<2, for example 0.5 to 1.5), Sn, SnO2, or a silicon-containing metal alloy and a mixture thereof. The silicon-containing metal alloy may include, for example, silicon and one or more of Al, Sn, Ag, Fe, Bi, Mg, Zn, in, Ge, Pb, and Ti.

[0129] The solid electrolyte may include a lithium ion conductor according to an embodiment. A content of the solid electrolyte may be greater than or equal to about 0.1 parts by weight, greater than or equal to about 1 part by weight, or greater than or equal to about 10 parts by weight, and may be less than or equal to about 80 parts by weight, less than or equal to about 60 parts by weight, or less than or equal to about 50 parts by weight, based on the total of 100 parts by weight of the negative electrode active material.

[0130] As an example, the negative electrode current collector 143 may be porous, such as a network or mesh-like, and may be a porous metal plate, such as stainless steel, nickel, aluminum, etc.

[0131] In addition, the negative electrode current collector 143 may be coated with an oxidation-resistant metal or alloy film to prevent oxidation. Additionally, the negative electrode current collector 143 may be coated with an oxidation-resistant metal or alloy film to prevent oxidation.

[0132] Margin Layer

[0133] Referring to FIG. 2, the all-solid-state battery 100 according to an embodiment may further include a margin layer 150 disposed along the edge of the positive electrode layer 120 and the negative electrode layer 140.

[0134] Referring to FIG. 2, the margin layer 150 may be located on the solid electrolyte layer 130 and may be disposed at edges of the positive electrode active material layers 121 and 122 or the negative electrode active material layers 141 and 142 in a lateral direction. Accordingly, the margin layer 150 may be located in the same layer of the positive electrode layer120 and the negative electrode layer140, respectively.

[0135] The margin layer 150 may include an insulating material having an ionic conductivity of less than or equal to about 1.0X10-10S / cm, or less than or equal to about 1.0X10-6S / cm. If the insulating material is commonly used, it can be used without limitation in its type

[0136] For example, the insulating material may include an insulating material such as ceramic or resin.

[0137] The ceramic may include aluminum nitride (AlN), beryllium oxide (BeO), boron nitride (BN), silicon (Si), silicon carbide (SiC), silicon nitride (Si3N4), gallium arsenide (GaAs), gallium nitride (GaN), barium titanate (BaTiO3), a mixture thereof, or an oxide and / or a nitride of these materials.

[0138] For example, the resin may include polyolefin such as polyethylene or polypropylene, polyester such as polyethylene terephthalate (PET), polyurethane, or polyimide.

[0139] Additionally, the margin layer 150 may further include the solid electrolyte included in the aforementioned solid electrolyte layer 130.

[0140] External Electrode

[0141] The terminal of the positive electrode current collector 123 and the terminal of the negative electrode current collector 143 are exposed on both sides of the cell stack of the all-solid-state battery 100, and external electrodes 112 and 114 may be connected and coupled to the exposed terminals.

[0142] That is, the external electrodes 112 and 114 may be configured to be connected to the terminal of the positive electrode current collector 123 to have a positive electrode, and to be connected to the terminal of the negative electrode current collector 143 to have a negative electrode. If the terminals of the positive electrode current collector 123 and the terminals of the negative electrode current collector 143 are configured to face opposite directions from each other, the external electrodes 112 and 114 may also be located on each side.

[0143] The external electrodes 112 and 114 can cover not only the cell stack but also the lateral direction of the coating layer 160. That is, as the coating layer 160 is manufactured by firing at a time when manufacturing the cell stack, and the external electrodes 112 and 114 are subsequently formed, the external electrodes 112 and 114 may also be located in a lateral direction of the coating layer.

[0144] The external electrodes 112 and 114 may include electrode layers 112a and 114a and plating layers 112b and 114b formed on the electrode layers 112a and 114a.

[0145] For a more specific example of the electrode layers 112a and 114a, the electrode layers 112a and 114a may be fired electrodes including conductive metal and glass, or may be resin-based electrodes including a conductive metal and a resin. Additionally, the electrode layers 112a and 114a may be formed by sequentially forming a fired electrode and a resin-based electrode on both sides of the cell stack.

[0146] The conductive metal included in the electrode layers 112a and 114a may be a material with excellent electrical conductivity and is not particularly limited. The conductive metal may be a conductive metal including, for example, copper (Cu), nickel (Ni), tin (Sn), palladium (Pd), platinum (Pt), gold (Au), silver (Ag), tungsten (W), titanium (Ti), lead (Pb), or an alloy thereof.

[0147] The glass included in the electrode layers 112a and 114a may be a composition of mixed oxides. The glass may include, for example, silicon oxide, boron oxide, aluminum oxide, transition metal oxide, alkali metal oxide, alkaline earth metal oxide, or combinations thereof. Herein, the transition metal may be selected from zinc (Zn), titanium (Ti), copper (Cu), vanadium (V), manganese (Mn), iron (Fe), or nickel (Ni), and the alkali metal may be selected from lithium (Li), sodium (Na), or potassium (K), and the alkaline earth metal may be selected from magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba).

[0148] The plating layers 112b and 114b serve to improve mounting characteristics. The type of the plating layers 112b and 114b is not particularly limited, and may be a plating layer including one or more of Ni, Sn, Pd, and an alloy thereof, and may be formed of a plurality of layers.

[0149] As a specific example, the plating layers 112b and 114b may be a Ni plating layer or a Sn plating layer. A Ni plating layer and a Sn plating layer may be formed sequentially, or a Sn plating layer, a Ni plating layer, and a Sn plating layer may be formed sequentially on the electrode layers 112a and 114a. Additionally, the plating layers 112b and 114b may include a plurality of Ni plating layers and / or a plurality of Sn plating layers.

[0150] A method of forming the external electrodes 112 and 114 is not particularly limited. For example, the external electrodes 112 and 114 may be formed by dipping the cell stack in a conductive paste containing conductive metal and glass, or by printing the conductive paste on the surface of the cell stack, such as by screen printing or gravure printing. In addition, various methods, such as by applying a conductive paste to the surface of the cell stack, or by transferring a dried film of the conductive paste to the cell stack may be used.

[0151] Specific examples of the invention are described below. However, the examples described below are intended only to illustrate or described the invention in detail, and should not be construed as limiting the scope of the invention.

[0152] (Examples)

[0153] Preparation Example 1

[0154] A silane-modified acrylic resin (a silicone modification content: 0.1 mmol / g) according to Preparation Example 1 is prepared by mixing 100 g of an acrylic oligomer (Mw: 180,000) including10 mmole of an isocyanate group as a functional group and 2.3 g of 3-aminopropyl triethoxysilane in a toluene solvent for 1 hour.

[0155] Preparation Example 2

[0156] A silane-modified acrylic resin (a silicone modification content: 0.2 mmol / g) according to Preparation Example 2 is prepared by mixing 100 g of an acrylic oligomer (Mw: 260,000) including 10 mmole of an isocyanate group as a functional group and 46 g of poly(dimethylsiloxane),bis(3-aminopropyl) terminated (hereinafter, referred to as PDMS) in atoluene solvent for 1 hour.

[0157] Preparation Example 3

[0158] A silane-modified acrylic resin (a silicone modification content: 0.15 mmol / g) according to Preparation Example 3 is prepared by adding 1.2 mole (170 g) of isobutyl methacrylate, 0.3 mole (43 g) of n-butyl methacrylate, 1.35 mole (268 g) of octyl methacrylate, and 0.07 mole of 3-methacryloxylpropyl trimethoxysilane to 280 g of a methylethylketone solvent and then, adding 2 g of 2,2′-azobis(2-methylpropinonitrile) (hereinafter, referred to as AIBN) as a photoinitiator for a radical polymerization thereto.

[0159] Preparation Example 4

[0160] A melamine-HEMA monomer is prepared by mixing 1 mole of melamine, 6 mols of formaldehyde, and 6 mols of 2-hydroxyethyl methacrylate (hereinafter, referred to as HEMA) in a 4-methoxyphenol solvent at 110 °C for 1 hour and then, adding p-toluenesulfonic acid thereto.

[0161] Subsequently, 0.3 mole of the melamine-HEMA monomer with1.2 mole of isobutyl methacrylate, 1.35 mole of octyl methacrylate, and 0.07 mole of 3-methacryloxylpropyl trimethoxysilane is added to 280 g of a methylethylketone solvent, and 2 g of AIBN as a photoinitiator is added thereto for radical polymerization to obtain a silane-modified acrylic resin (a silicone modification content: 0.14 mmol / g) according to Preparation Example 4.

[0162] Preparation Example 5

[0163] A silane-modified acrylic resin (a silicone modification content: 1.04 mmol / g) according to Preparation Example 5 is prepared by adding 14 g of a bifunctional naphthalene epoxy compound and 20 g of a bisphenol A type epoxy compound to 10 g of the silane-modified acrylic resin of Preparation Example 2, adding 0.6 g of a curing accelerator thereto, and mixing them in 100 g of a butyl carbitolacetate solvent.

[0164] Comparative Preparation Example 1

[0165] A resin according to Comparative Preparation Example 1 is prepared by adding 0.6 g of a curing accelerator to 14 g of a bifunctional naphthalene epoxy compound and 20 g of a bisphenol A type epoxy compound and then, mixing them in 100 g of a butyl carbitolacetate solvent.

[0166] Comparative Preparation Example 2

[0167] A melamine-HEMA monomer is prepared by mixing 1 mole of melamine, 6 mols of formaldehyde, and 6 mols of 2-hydroxyethyl methacrylate (hereinafter, referred to as HEMA) in a 4-methoxyphenol solvent at 110 °C for 1 hour and then, adding p-toluenesulfonic acid thereto.

[0168] 0.3 mole of the melamine-HEMA monomer with 1.2 mole of isobutyl methacrylate and 1.35 mole of octyl methacrylate is added to 280 g of a methylethylketone solvent, and 2 g of AIBN as a photoinitiator is added thereto for radical polymerization to prepare a resin of Comparative Preparation Example 2.

[0169] Example 1

[0170] A positive electrode layer green sheet is manufactured by mixing LiCoO2as a positive electrode active material, Li2O-B2O3-LiCl-Al2O3(a glass-ceramic-based solid electrolyte) as a solid electrolyte, and carbon black as a conductive material in a volume ratio of 47.5:47.5:5 and then, printing the mixture into a positive electrode active material layer with a screen printer.

[0171] A negative electrode layer green sheet is manufactured by mixing 2 μm graphite as a negative electrode active material and Li2O-B2O3-LiCl-Al2O3(a glass-ceramic-based solid electrolyte) as a solid electrolyte in a volume ratio of 5:5 and using a screen printer.

[0172] A solid electrolyte layer green sheet is manufactured by using Li2O-B2O3-LiCl-Al2O3(a glass-ceramic-based solid electrolyte) as a solid electrolyte.

[0173] The manufactured positive electrode layer green sheet, negative electrode layer green sheet, and solid electrolyte layer green sheet are stacked to obtain a cell stack green sheet, and then, the silane-modified acrylic resin of Preparation Example 1 is coated to be 20 μm thick on the cell stack green sheet, which is compressed and fired to manufacture an all-solid-state battery cell according to Example 1.

[0174] Examples 2 to 5

[0175] An all-solid-state battery cell is manufactured in the same manner as in Example 1 except that each of the silane-modified acrylic resins according to Preparation Examples 2 to 5 is coated on the cell stack green sheet.

[0176] Comparative Examples 1 to 2

[0177] An all-solid-state battery cell is manufactured in the same manner as in Example 1 except that each of the silane-modified acrylic resins according to Comparative Preparation Examples 1 to 2 is coated on the cell stack green sheet.

[0178] (Evaluation Examples)

[0179] Evaluation Example 1: Water Repellency Evaluation (surface energy measurement)

[0180] Each coating layer on the outermost surface of the all-solid-state battery cells of Examples 1 to 5 and Comparative Examples 1 to 2 is measured with respect to surface energy by using a contact angle analyzer tester.

[0181] Specifically, after dropping pure water and methane iodide onto each coating layer on the outermost surface of the all-solid-state battery cells to measure a contact angle, the surface energy is calculated therefrom by using Owens-Wendt-Rabel & Kaelble Model.

[0182] Evaluation Example 2: Evaluation of Mechanical Properties (tensile strength and elongation)

[0183] After milling or polishing each coating layer (20 μm) on the outermost surface of the all-solid-state battery cells of Examples 1 to 5 and Comparative Examples 1 to 2 to extract the coating layer therefrom, tensile strength and elongation are measured by using a dynamic mechanical analyzer (DMA), and the results are shown in Table 1.

[0184] Contact angle(purified water, °)Contact angle(methane iodide, °)Coating layersurface energy(dyne / cm)Tensile strength (MPa)Elongation (%)Example 1102.6855.4631.534.215Example 2104.7260.4428.623.820Example 3107.1680.4517.342.620Example 4100.5650.1234.592215Example 592.145.936.533025Comparative Example 126.8970.132.55Comparative Example 256.825.753.491.86

[0185] Referring to Table 1, each coating layer of the all-solid-state battery cells of Examples 1 to 5 has surface energy of less than or equal to 40 dyne / cm and thus exhibits excellent water repellency. On the contrary, each coating layer of the all-solid-state battery cells of Comparative Examples 1 and 2, which includes no silane-modified acrylic resin, exhibits surface energy of greater than about 50 dyne / cm and thus insufficient water repellency.

[0186] Referring to Table 1, each coating layer of the all-solid-state battery cells of Examples 1 to 5 exhibits superbly excellent tensile strength and elongation and thus excellent mechanical properties, compared with that of the all-solid-state battery cells of Comparative Examples 1 to 2.

[0187] Evaluation Example 3: Evaluation of Moisture Resistance Reliability

[0188] The all-solid-state battery cells of Example 5 and Comparative Example 1 are evaluated with respect to moisture resistance reliability.

[0189] Specifically, each all-solid-state battery sample according to Example 5 and Comparative Example 1 is prepared by 2 to measure moisture resistance reliability at 85 °C under relative humidity (R.H.) of 85 % at 4 V for 48 hours by using ESPEC (PR-3J, 8585) equipment, and the results are shown in FIG. 3.

[0190] Referring to FIG. 3, the all-solid-state battery cell of Example 5 maintains insulation resistance of 108Ω or more after 48 hours, but the all-solid-state battery cell of Comparative Example 1 exhibits sharply decreased insulation resistance after about 10 hours and thus deteriorated moisture resistance reliability.

[0191] It is to be understood that although the preferred embodiment of the present invention has been described above, the present invention is not limited thereto, but can be implemented in various modifications within the scope of the claims, the detailed description of the present invention, and the accompanying drawings, which also fall within the scope of the present invention.

[0192] <Description of Symbols>

[0193] 100: all-solid-state battery

[0194] 112, 114: external electrode

[0195] 112a, 114a: electrode layer

[0196] 112b, 114b: plating layer

[0197] 120: positive electrode layer

[0198] 121, 122: positive electrode active material layer

[0199] 123: positive electrode current collector

[0200] 130: solid electrolyte layer

[0201] 140: negative electrode layer

[0202] 141, 142: negative electrode active material layer

[0203] 143: negative electrode current collector

[0204] 150: margin layer

[0205] 160: coating layer

Claims

1.Anall-solid-state battery, comprisinga cell stack including a solid electrolyte layer, a positive electrode layer, and a negative electrode layer, wherein the solid electrolyte layer is interposed between the positive electrode layer and the negative electrode layer, anda coating layer located on one or both surfaces in a stacking direction of the cell stack, and / or on one or both surfaces in a width direction of the cell stack,wherein the coating layer includes a silane-modified acrylic resin, and a surface energy of the coating layer is less than or equal to about 40 dyne / cm.2.The all-solid-state battery of claim 1, whereinthe silane-modified acrylic resin is formed by reacting an acrylic resin including an acrylic oligomer, an acrylic monomer, or a combination thereof with a silane compound.3.The all-solid-state battery of claim 1, whereina silicone modification content of the silane-modified acrylic resin is about 0.05 mmol / g to about 100 mmol / g.4.The all-solid-state battery of claim 2, whereinthe acrylic monomer includes (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, octyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, triisopropylsilyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or a combination thereof.5.The all-solid-state battery of claim 2, whereinthe silane compound includes an alkoxy silane compound, a polydimethylsiloxane-based compound, a silicone resin intermediate, silicone oil, or a combination thereof.6.The all-solid-state battery of claim 5, whereinthe alkoxy silane compound includes methyl trimethoxysilane, methyl triethoxysilane, dimethyl dimethoxysilane, dimethyl diethoxysilane, phenyl trimethoxysilane, diphenyl dimethoxysilane, phenyl triethoxysilane, diphenyl diethoxysilane, phenylmethyl dimethoxysilane, cyclohexyl trimethoxysilane, dicyclohexyl dimethoxysilane, cyclohexyl triethoxysilane, dicyclohexyl diethoxysilane, 3-aminopropyl triethoxysilane, 3-methacryloxylpropyl trimethoxysilane, or a combination thereof.7.The all-solid-state battery of claim 5, whereinthe polydimethylsiloxane-based compound includes poly(dimethylsiloxane), bis(3-aminopropyl) terminated, poly(dimethylsiloxane), bis(hydroxyalkyl) terminated, poly(dimethylsiloxane), hydroxy terminated, poly(dimethylsiloxane), monohydroxy terminated, poly(dimethylsiloxane), vinyl terminated, or a combination thereof.8.The all-solid-state battery of claim 2, whereinthe silane compound is included in an amount of about 0.08 parts by weight to about 50 parts by weight based on 100 parts by weight of the acrylic resin.9.The all-solid-state battery of claim 1, whereinthe silane-modified acrylic resin further includes a melamine compound, an epoxy compound, or a combination thereof.10.The all-solid-state battery of claim 9, whereinthe epoxy compound includes bisphenol-based epoxy, naphthalene-based epoxy, biphenyl-based epoxy, novolac-type epoxy, isocyanate epoxy, or a combination thereof.11.The all-solid-state battery of claim 1, whereina thickness of the coating layer is about 0.1 μm to about 20 μm.12.An all-solid-state battery, comprisinga cell stack including a solid electrolyte layer, a positive electrode layer, and a negative electrode layer, wherein the solid electrolyte layer is interposed between the positive electrode layer and the negative electrode layer, anda coating layer located on one or both surfaces in a stacking direction of the cell stack, and / or on one or both surfaces in a width direction of the cell stack, anda cover layer between the cell stack and the coating layer,wherein the coating layer includes a silane-modified acrylic resin, and a surface energy of the coating layer is less than or equal to about 40 dyne / cm.13.The all-solid-state battery of claim 12, whereinthe silane-modified acrylic resin is formed by reacting an acrylic resin including an acrylic oligomer, an acrylic monomer, or a combination thereof with a silane compound.14.The all-solid-state battery of claim 12, whereina silicone modification content of the silane-modified acrylic resin is about 0.05 mmol / g to about 100 mmol / g.15.The all-solid-state battery of claim 13, whereinthe acrylic monomer includes (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, octyl (meth)acrylate, cyclohexyl (meth)acrylate, glycidyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, triisopropylsilyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or a combination thereof.16.The all-solid-state battery of claim 13, whereinthe silane compound includes an alkoxy silane compound, a polydimethylsiloxane-based compound, a silicone resin intermediate, silicone oil, or a combination thereof.17.The all-solid-state battery of claim 13, whereinthe silane compound is included in an amount of about 0.08 parts by weight to about 50 parts by weight based on 100 parts by weight of the acrylic resin.18.The all-solid-state battery of claim 12, whereinthe silane-modified acrylic resin further includes a melamine compound, an epoxy compound, or a combination thereof.19.The all-solid-state battery of claim 12, whereina thickness of the coating layer is about 0.1 μm to about 20 μm.20.The all-solid-state battery of claim 12, whereina thickness of the cover layer is about 50 μm to about 300 μm.21.An all-solid-state battery, comprising:external electrodes disposed on length-wise opposing surfaces of a cell stack including a solid electrolyte; anda coating layer disposed on one or more external surfaces of the cell stack other than the length-wise opposing surfaces,wherein the coating layer comprises a silane-modified acrylic resin and has a surface energy less than or equal to 40 dyne / cm.22.The all-solid-state battery of claim 21, wherein a silicone modification content of the silane-modified acrylic resin is about 0.05 mmol / g to about 100 mmol / g.23.The all-solid-state battery of claim 21, wherein the silane-modified acrylic resin further includes a melamine compound, an epoxy compound, or a combination thereof.24.The all-solid-state battery of claim 21, further comprising a cover layer disposed between the cell stack and the coating layer.

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