All-solid rechargeable battery

Abstract

This all-solid rechargeable battery includes a first electrode, a second electrode located on the first electrode, a first solid electrolyte layer located between the first electrode and the second electrode, and a reference electrode corresponding to an end portion of the first solid electrolyte layer.

Description

All-solid-state secondary battery

[0001] It is about all-solid-state secondary batteries.

[0002] Recent reports of explosion risks in batteries using liquid electrolytes have led to the development of all-solid-state secondary batteries. All-solid-state secondary batteries are batteries composed entirely of solid materials and utilize solid electrolytes.

[0003] These all-solid-state secondary batteries are safe because there is no risk of explosion due to electrolyte leakage, and they have the advantage of being easy to manufacture thin batteries.

[0004] An all-solid-state secondary battery includes a first electrode, a second electrode, and a solid electrolyte layer positioned between the first electrode and the second electrode.

[0005] In a conventional all-solid-state secondary battery, the potential of the first electrode, which may be a working electrode, and the second electrode, which may be a counter electrode, change during charging and discharging, making it difficult to measure the potential of each electrode.

[0006] One embodiment is directed to providing an all-solid-state secondary battery including a reference electrode capable of precisely measuring the potentials of positive and negative electrodes while preventing short circuiting with other electrodes.

[0007] One aspect provides an all-solid-state secondary battery including a first electrode, a second electrode positioned on the first electrode, a first solid electrolyte layer positioned between the first electrode and the second electrode, and a reference electrode corresponding to an end of the first solid electrolyte layer.

[0008] The reference electrode may overlap an end of the first solid electrolyte layer in a vertical direction in which the first electrode, the first solid electrolyte layer, and the second electrode overlap each other.

[0009] The reference electrode may not overlap with the central region of the first solid electrolyte layer in the vertical direction.

[0010] It may further include a second solid electrolyte layer positioned between the first solid electrolyte layer and the second electrode.

[0011] The reference electrode may be located between an end of the first solid electrolyte layer and an end of the second solid electrolyte layer.

[0012] The reference electrode may include an insulating tape adjacent to an end of the first solid electrolyte layer and an end of the second solid electrolyte layer.

[0013] It may further include a third electrode positioned on the second electrode, and a third solid electrolyte layer positioned between the second electrode and the third electrode.

[0014] It may further include a first gasket surrounding the edge of the second electrode.

[0015] The reference electrode can be in contact with the first gasket between an end of the first solid electrolyte layer and an end of the third solid electrolyte layer.

[0016] The reference electrode may be spaced apart from the second electrode.

[0017] The third solid electrolyte layer includes a first extension portion extending from a rear surface of the third electrode facing the second electrode past an end of the third electrode to a front surface of the third electrode, and the reference electrode can be positioned on the first extension portion.

[0018] The above reference electrode can be in contact with the first extension portion.

[0019] The first solid electrolyte layer includes a second extension portion extending from a rear surface of the second electrode opposite the first electrode to a front surface of the second electrode past an end of the second electrode, and the reference electrode can be positioned on the second extension portion.

[0020] The above reference electrode can be in contact with the second extension portion.

[0021] It may further include a second gasket surrounding the edge of the first electrode.

[0022] The first solid electrolyte layer may include a tail extending in a horizontal direction intersecting the vertical direction in which the first electrode, the first solid electrolyte layer, and the second electrode overlap each other.

[0023] The above reference electrode can be in contact with the tail portion.

[0024] The above tail portion may include a cutting line.

[0025] The above first electrode may be a cathode.

[0026] The above first electrode may be an anode.

[0027] According to one embodiment, an all-solid-state secondary battery is provided that includes a reference electrode capable of precisely measuring the potentials of positive and negative electrodes while preventing short circuiting with other electrodes.

[0028] Figure 1 is a cross-sectional view of an all-solid-state battery.

[0029] Figure 2 is a cross-sectional view of an all-solid-state battery including a precipitated negative electrode.

[0030] Figure 3 is a cross-sectional view showing an all-solid-state secondary battery according to one embodiment.

[0031] Fig. 4 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0032] Figure 5 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0033] Figure 6 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0034] Figure 7 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0035] Figure 8 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0037] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0038] To clearly illustrate various layers and regions in the drawings, their thicknesses are enlarged, and similar parts are designated by the same drawing reference numerals throughout the specification. When an element such as a layer, film, region, or plate is said to be "over" or "on" another element, this includes not only the case where it is "directly over" the other element, but also the case where there is another element in between. Conversely, when an element is said to be "directly over" another element, it means that there is no other element in between.

[0039] Furthermore, the term "layer" here includes not only shapes formed on the entire surface when observed in a plan view, but also shapes formed on a portion of the surface. Here, "or" is not interpreted in an exclusive sense, and for example, "A or B" is interpreted to include A, B, A+B, etc.

[0040] Cathode for all-solid-state secondary batteries

[0041] In one embodiment, a positive electrode for an all-solid-state secondary battery is provided, comprising a current collector and a positive electrode active material layer positioned on the current collector, wherein the positive electrode active material layer includes a positive electrode active material, a sulfide-based solid electrolyte, a fluorine-based resin binder, and vanadium oxide.

[0042] The above-mentioned positive electrode for an all-solid-state secondary battery is manufactured by applying a positive electrode composition including a positive electrode active material, a sulfide-based solid electrolyte, a fluorine-based resin binder, and vanadium oxide to a current collector, and then drying and rolling.

[0043] The above-described positive electrode composition generally exhibits strong alkalinity due to residual lithium such as LiOH and other components, which may result in gelation or aggregation of the fluorine-based resin binder. However, according to one embodiment, the addition of vanadium oxide suppresses gelation of the fluorine-based resin binder, thereby maintaining the viscosity of the positive electrode composition and ensuring processability. Furthermore, since there is no need for a neutralizing agent, deterioration of the sulfide-based solid electrolyte caused by the neutralizing agent can be prevented, thereby improving the performance of the all-solid-state secondary battery.

[0044] vanadium oxide

[0045] The above vanadium oxide is a component that does not dissolve in the solvent of the positive electrode composition, and can control the strong basicity of the positive electrode composition to prevent gelation of the fluorine-based resin binder, while simultaneously suppressing deterioration of the sulfide-based solid electrolyte, thereby improving the ionic conductivity of the positive electrode. It is understood that vanadium oxide controls the pH through physical and / or chemical reactions with the -OH group in the positive electrode composition in a strongly basic state, thereby suppressing gelation of the fluorine-based resin binder. The vanadium oxide has a more excellent ability to suppress gelation of the fluorine-based resin binder by controlling basicity than other transition metal oxides such as titanium oxide or tungsten oxide, has low reactivity with the sulfide-based solid electrolyte, and suppresses deterioration of the sulfide-based solid electrolyte, thereby improving the ionic conductivity of the all-solid-state secondary battery and enhancing the overall performance.

[0046] The above vanadium oxides include, for example, V2O3, VO2, V2O4, V2O 5, Or a combination thereof may be included. In addition, the vanadium oxide may be included in an amount of 0.01 wt% to 5 wt% based on 100 wt% of the positive electrode active material layer, for example, 0.05 wt% to 5 wt%, 0.1 wt% to 5 wt%, 0.5 wt% to 5 wt%, or 0.5 wt% to 3 wt%. When the vanadium oxide is included in such an amount, the viscosity of the positive electrode composition can be appropriately maintained without a decrease in capacity, thereby improving processability and enhancing the ionic conductivity of the positive electrode.

[0047] According to one embodiment, since vanadium oxide is added to the positive electrode composition and dispersed therein, the positive electrode composition is coated on the current collector, so the vanadium oxide may be dispersed within the manufactured positive electrode active material layer. This is distinct from a form in which vanadium oxide is coated on the surface of the positive electrode active material or the sulfide-based solid electrolyte.

[0048] In one example, the vanadium oxide may be pentavalent vanadium oxide (vanadium(V) oxide), in which case the melting point of the vanadium oxide may be 1000°C or lower, for example, 600°C to 800°C, or 650°C to 690°C. The pentavalent vanadium oxide is excellent in suppressing gelation of a fluorine-based resin binder in the positive electrode and is advantageous in improving the overall performance of the battery.

[0049] In addition, the vanadium oxide may be in the form of particles, and the average particle diameter (D50) may be 10 nm to 10 ㎛, for example, 10 nm to 5 ㎛, 10 nm to 3 ㎛, 50 nm to 1 ㎛, 50 nm to 500 nm, or 500 nm to 1 ㎛. Vanadium oxide having such properties is suitable for incorporation into a positive electrode composition, and can effectively suppress gelation of the positive electrode composition without adversely affecting the positive electrode. If the particle diameter of the vanadium oxide is too small, it may not be properly dispersed within the positive electrode, thereby blocking the movement path of electrons and ions, thereby deteriorating battery performance, or may not sufficiently perform its role of suppressing gelation of the binder. On the contrary, if the particle diameter of the vanadium oxide is too large, it may itself block the movement path of electrons and ions, thereby deteriorating battery performance.

[0050] Fluorine resin binder

[0051] The above fluorine-based resin binder may be a general resin binder containing fluorine, and may include, for example, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride-trichloroethylene copolymer, polyvinylidene fluoride-chlorotrifluoroethylene copolymer, polytetrafluoroethylene, or a combination thereof.

[0052] The weight average molecular weight of the fluorinated resin binder may be approximately 50 kDa to 5,000 kDa, or 100 kDa to 2,000 kDa. In addition, the glass transition temperature of the fluorinated resin binder may be -10°C or lower, and the melting point may be 100°C or higher. The melting viscosity of the fluorinated resin binder may be approximately 10 kP to 50 kP. In addition, the fluorinated resin binder may be in the form of particles, and the average particle diameter thereof may be approximately 50 nm to 200 μm. The fluorinated resin binder having such properties can implement excellent adhesive strength even when added in a small amount to the positive electrode composition, and can increase the durability of the battery without adversely affecting the battery performance.

[0053] The fluorine-based resin binder may be included in an amount of 0.1 wt% to 10 wt% based on 100 wt% of the positive electrode active material layer, for example, 0.1 wt% to 8 wt%, 0.1 wt% to 6 wt%, 0.1 wt% to 5 wt%, 0.5 wt% to 4 wt%, or 1 wt% to 3 wt%. When the fluorine-based resin binder is included in the above content range, it can exhibit excellent adhesive strength without adversely affecting the positive electrode.

[0054] positive electrode active material

[0055] The above-mentioned positive electrode active material can be applied without limitation as long as it is generally used in all-solid-state secondary batteries. For example, the above-mentioned positive electrode active material may be a compound capable of reversible intercalation and deintercalation of lithium, and may include a compound represented by any one of the following chemical formulas.

[0056] Li a A 1-b X b D2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5);

[0057] Li a A 1-b Xb O 2-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05);

[0058] Li a HAVE BEEN 1-b X b O 2-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05);

[0059] Li a HAVE BEEN 2-b X b O 4-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05);

[0060] Li a Ni 1-b-c Co b X c D α (0.90 ≤ a ≤1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.5, 0 <α ≤ 2);

[0061] Li a Ni 1-b-c Co b X c O 2-α T α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2);

[0062] Li a Ni 1-b-c Co b X c O 2-α T2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2);

[0063] Li a Ni 1-b-c Mr b X c D α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2);

[0064] Li a Ni 1-b-c Mr b X c O 2-α T α (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2);

[0065] Li a Ni 1-b-c Mr b X c O 2-α T2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α < 2);

[0066] Li a Ni b HAVE BEEN c G d O2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1);

[0067] Li a Ni b Co c Mr d G e O2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤0.5, 0.001 ≤ e ≤ 0.1);

[0068] Li a NiG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0069] Li a CoG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0070] Li a Mr 1-b G b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0071] Li a Mn2G bO4(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0072] Li a Mn 1-g G g PO4(0.90 ≤ a ≤ 1.8, 0 ≤ g ≤ 0.5);

[0073] QO2; QS2; LiQS2;

[0074] V2O5; LiV2O5;

[0075] LiZO2;

[0076] LiNiVO4;

[0077] Li (3-f) J2(PO4)3(0 ≤ f ≤ 2);

[0078] Li (3-f) Fe2(PO4)3(0 ≤ f ≤ 2);

[0079] Li a FePO4(0.90 ≤ a ≤ 1.8).

[0080] In the above chemical formulas, A is selected from the group consisting of Ni, Co, Mn, and combinations thereof; X is selected from the group consisting of Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements, and combinations thereof; D is selected from the group consisting of O, F, S, P, and combinations thereof; E is selected from the group consisting of Co, Mn, and combinations thereof; T is selected from the group consisting of F, S, P, and combinations thereof; G is selected from the group consisting of Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, and combinations thereof; Q is selected from the group consisting of Ti, Mo, Mn, and combinations thereof; Z is selected from the group consisting of Cr, V, Fe, Sc, Y, and combinations thereof; J is selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, and combinations thereof.

[0081] The above-mentioned positive electrode active material may be, for example, lithium cobalt oxide (LCO), lithium nickel oxide (LNO), lithium nickel cobalt oxide (NC), lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium nickel manganese oxide (NM), lithium manganese oxide (LMO), or lithium iron phosphate (LFP).

[0082] The above positive electrode active material may include a lithium nickel-based oxide represented by the following chemical formula 1, a lithium cobalt-based oxide represented by the following chemical formula 2, a lithium iron phosphate-based compound represented by the following chemical formula 3, or a combination thereof.

[0083] [Chemical Formula 1]

[0084] Li a1 Ni x1 M 1 y1 M 2 1-x1-y1 O2

[0085] In the above chemical formula 1, 0.9≤a1≤1.8, 0.3≤x1≤1, 0≤y1≤0.7, and M 1 and M 2 is one or more elements independently selected from the group consisting of Al, B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, and Zr.

[0086] [Chemical Formula 2]

[0087] Li a2 Co x2 M 3 1-x2 O2

[0088] In the above chemical formula 2, 0.9≤a2≤1.8, 0.6≤x2≤1, and M 3 is one or more elements selected from the group consisting of Al, B, Ba, Ca, Ce, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, and Zr.

[0089] [Chemical Formula 3]

[0090] Li a3 Fe x3 M 4 (1-x3) PO4

[0091] In the above chemical formula 3, 0.9≤a3≤1.8, 0.6≤x3≤1, and M 4 is one or more elements selected from the group consisting of Al, B, Ba, Ca, Ce, Co, Cr, Cu, F, Fe, Mg, Mn, Mo, Nb, P, S, Si, Sr, Ti, V, W, and Zr.

[0092] The average particle diameter (D50) of the positive electrode active material may be 1 μm to 25 μm, for example, 3 μm to 25 μm, 5 μm to 25 μm, 5 μm to 20 μm, 8 μm to 20 μm, or 10 μm to 18 μm. A positive electrode active material having such a particle diameter range can be harmoniously mixed with other components within the positive electrode active material layer and can realize high capacity and high energy density.

[0093] The above-mentioned positive electrode active material may be in the form of a secondary particle formed by agglomeration of a plurality of primary particles, or may be in the form of a single particle. In addition, the above-mentioned positive electrode active material may be spherical or nearly spherical in shape, or may be polyhedral or irregular in shape.

[0094] Sulfide-based solid electrolyte

[0095] Sulfide-based solid electrolytes include, for example, Li2S-P2S5, Li2S-P2S5--LiX (where X is a halogen element, for example, I or Cl), Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z. m Sn (m, n are integers, Z is Ge, Zn or Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li p MO q (p, q are integers, and M is P, Si, Ge, B, Al, Ga or In), or a combination thereof.

[0096] Such sulfide-based solid electrolytes can be obtained, for example, by mixing Li2S and P2S5 in a molar ratio of 50:50 to 90:10, or 50:50 to 80:20, and optionally heat-treating them. Within the above mixing ratio range, a sulfide-based solid electrolyte having excellent ionic conductivity can be produced. Here, the ionic conductivity can be further improved by further including other components such as SiS2, GeS2, and B2S3.

[0097] Methods for mixing sulfur-containing raw materials for producing sulfide-based solid electrolytes include mechanical milling or the solution method. Mechanical milling involves placing the starting raw materials in a reactor and vigorously stirring them with a ball mill or similar device to finely atomize and mix them. Using the solution method, the starting raw materials are mixed in a solvent to obtain a solid electrolyte as a precipitate. Furthermore, heat treatment after mixing can solidify the crystals of the solid electrolyte and improve ionic conductivity. For example, a sulfide-based solid electrolyte can be produced by mixing sulfur-containing raw materials and heat-treating them twice or more, resulting in a sulfide-based solid electrolyte with high ionic conductivity and robustness.

[0098] For example, the sulfide-based solid electrolyte particles may include argyrodite-type sulfides. The argyrodite-type sulfides may include, for example, Li a M b P c S d A e(wherein a, b, c, d, and e are all 0 or more and 12 or less, M is Ge, Sn, Si, or a combination thereof, and A is F, Cl, Br, or I) and can be expressed by the chemical formula, and a specific example is Li 7-x PS 6-x A x (x is 0.2 or more and 1.8 or less, and A is F, Cl, Br, or I) can be expressed by the chemical formula. The above argyrodite-type sulfide is specifically Li3PS4, Li7P3S 11 , Li7PS6, Li6PS5Cl, Li6PS5Br, Li 5.8 PS 4.8 Cl 1.2 , Li 6.2 PS 5.2 Br 0.8 It could be the back.

[0099] Sulfide-based solid electrolyte particles containing these argyrodite-type sulfides have an ionic conductivity of 10, which is the ionic conductivity of a typical liquid electrolyte at room temperature. -4 10 inland -2 It has a high ionic conductivity approaching the S / cm range, can form a close bond between a positive electrode active material and a solid electrolyte without causing a decrease in ionic conductivity, and can further form a close interface between an electrode layer and a solid electrolyte layer. An all-solid-state battery including this can have improved battery performance, such as rate characteristics, Coulombic efficiency, and cycle life characteristics.

[0100] An argyrodite-type sulfide-based solid electrolyte can be prepared, for example, by mixing lithium sulfide, phosphorus sulfide, and optionally, a lithium halide. After mixing, a heat treatment may be performed. The heat treatment may include, for example, two or more heat treatment steps.

[0101] According to one embodiment, the average particle diameter (D50) of the sulfide-based solid electrolyte particles may be 5.0 ㎛ or less, for example, 0.1 ㎛ to 5.0 ㎛, 0.1 ㎛ to 4.0 ㎛, 0.1 ㎛ to 3.0 ㎛, 0.5 ㎛ to 2.0 ㎛, or 0.1 ㎛ to 1.5 ㎛. Alternatively, the sulfide-based solid electrolyte particles may be small particles having an average particle diameter (D50) of 0.1 ㎛ to 1.0 ㎛, or may be large particles having an average particle diameter (D50) of 1.5 ㎛ to 5.0 ㎛, depending on the location or purpose of use. The sulfide-based solid electrolyte particles having such a particle diameter range can effectively penetrate between solid particles in a battery, and have excellent contact with an electrode active material and connectivity between solid electrolyte particles. The average particle size of the sulfide-based solid electrolyte particles may be measured from a microscope image, for example, by measuring the sizes of about 20 particles in a scanning electron microscope image to obtain a particle size distribution and calculating D50 from this.

[0102] The content of the solid electrolyte in the positive electrode for the all-solid-state battery may be 0.5 wt% to 35 wt%, for example, 1 wt% to 35 wt%, 5 wt% to 30 wt%, 8 wt% to 25 wt%, or 10 wt% to 20 wt%. This is the content relative to the total weight of components in the positive electrode, and specifically, it can be said to be the content relative to the total weight of the positive electrode active material layer.

[0103] In one embodiment, the positive electrode active material layer may include 50 wt% to 99.35 wt% of the positive electrode active material, 0.5 wt% to 35 wt% of the sulfide-based solid electrolyte, 0.1 wt% to 10 wt% of the fluorine-based resin binder, and 0.05 wt% to 5 wt% of the vanadium oxide, based on 100 wt% of the positive electrode active material layer. When the above content ranges are satisfied, the positive electrode for an all-solid-state secondary battery can maintain high adhesiveness while implementing high capacity and high ionic conductivity, and the viscosity of the positive electrode composition can be maintained at an appropriate level, thereby improving processability.

[0104] Challenge

[0105] The above-described positive electrode active material layer may further include a conductive material. The conductive material is used to impart conductivity to the electrode, and may include, for example, carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, and carbon nanotubes; metal-based materials containing copper, nickel, aluminum, silver, and the like in the form of metal powder or metal fibers; conductive polymers such as polyphenylene derivatives; or combinations thereof.

[0106] The conductive material may be included in an amount of 0.1 wt% to 5 wt%, or 0.1 wt% to 3 wt%, based on the total weight of each component of the positive electrode for the all-solid-state battery, or based on the total weight of the positive electrode active material layer. Within the above content range, the conductive material can improve electrical conductivity without degrading battery performance.

[0107] When the positive electrode active material layer further includes a conductive material, the positive electrode active material layer may include 45 wt% to 99.25 wt% of the positive electrode active material, 0.5 wt% to 35 wt% of the sulfide-based solid electrolyte, 0.1 wt% to 10 wt% of the fluorine-based resin binder, 0.05 wt% to 5 wt% of the vanadium oxide, and 0.1 wt% to 5 wt% of the conductive material, based on 100 wt% of the positive electrode active material layer.

[0108] Meanwhile, the positive electrode for the lithium secondary battery may further include an oxide-based inorganic solid electrolyte in addition to the above-described solid electrolyte. The oxide-based inorganic solid electrolyte may be, for example, Li 1+x Ti 2-x Al(PO4)3(LTAP)(0≤x≤4), Li 1+x+y Al x Ti 2-x Si y P 3-y O 12 (0 <x<2, 0≤y<3), BaTiO3, Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT)(0≤x<1, 0≤y<1), PB(Mg3Nb 2 / 3 )O3-PbTiO3(PMN-PT), HfO2, SrTiO3, SnO2, CeO2, Na2O, MgO, NiO, CaO, BaO, ZnO, ZrO2, Y2O3, Al2O3, TiO2, SiO2, lithium phosphate (Li3PO4), lithium titanium phosphate (Li x Ti y (PO4)3, 0 <x<2, 0<y<3), Li 1+x+y (Al, Ga) x (Ti, Ge) 2-x Si y P 3-y O 12 (0≤x≤1, 0≤y≤1), lithium lanthanum titanate (Li x La yTiO3, 0 <x<2, 0<y<3), Li2O, LiAlO2, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2계 세라믹스, 가넷(Garnet)계 세라믹스 Li 3+x La3M2O 12 (M= Te, Nb, or Zr; x is an integer from 1 to 10), or a combination thereof.

[0109] All-solid-state secondary battery

[0110] In one embodiment, an all-solid-state secondary battery is provided, which includes the aforementioned positive electrode and negative electrode and a solid electrolyte layer positioned between the positive electrode and negative electrode. The all-solid-state secondary battery may also be referred to as an all-solid-state battery or an all-solid-state lithium secondary battery.

[0111] Figure 1 is a cross-sectional view of an all-solid-state battery.

[0112] Referring to FIG. 1, the all-solid-state battery (1000) may have a structure in which an electrode assembly in which a negative electrode (40) including a negative electrode collector (41) and a negative electrode active material layer (43), a solid electrolyte layer (30), and a positive electrode (20) including a positive electrode active material layer (23) and a positive electrode collector (21) are laminated is housed in a case such as a pouch. The all-solid-state battery (1000) may further include an elastic layer (50) on the outer side of at least one of the positive electrode (20) and the negative electrode (40). Although FIG. 1 illustrates one electrode assembly including a negative electrode (40), a solid electrolyte layer (30), and a positive electrode (20), an all-solid-state battery may be manufactured by laminating two or more electrode assemblies.

[0113] cathode

[0114] An anode for an all-solid-state battery may include, for example, a current collector and a negative electrode active material layer positioned on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder, a conductive material, and / or a solid electrolyte.

[0115] The above negative active material may include a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0116] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in an amorphous, plate-like, flake-like, spherical, or fibrous form, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0117] As the above lithium metal alloy, an alloy of lithium and one or more metals selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn can be used.

[0118] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used, and the Si-based negative electrode active material may be silicon, a silicon-carbon composite, or SiO. x(0<x<2), Si-Q 합금(상기 Q는 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 15족 원소, 16족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Si은 아님), 상기 Sn계 음극 활물질로는 Sn, SnO2, Sn-R 합금(상기 R은 알칼리 금속, 알칼리 토금속, 13족 원소, 14족 원소, 15족 원소, 16족 원소, 전이금속, 희토류 원소 및 이들의 조합으로 이루어진 군에서 선택되는 원소이며, Sn은 아님) 등을 들 수 있고, 또한 이들 중 적어도 하나와 SiO2를 혼합하여 사용할 수도 있다. 상기 원소 Q 및 R로는 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, 및 이들의 조합으로 이루어진 군에서 선택되는 것을 사용할 수 있다.

[0119] The silicon-carbon composite may be, for example, a silicon-carbon composite including a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core. The crystalline carbon may be artificial graphite, natural graphite, or a combination thereof. As the amorphous carbon precursor, coal pitch, mesophase pitch, petroleum pitch, coal oil, petroleum heavy oil, or a polymer resin such as a phenol resin, a furan resin, or a polyimide resin may be used. At this time, the content of silicon may be 10 wt% to 50 wt% with respect to the total weight of the silicon-carbon composite. In addition, the content of the crystalline carbon may be 10 wt% to 70 wt% with respect to the total weight of the silicon-carbon composite, and the content of the amorphous carbon may be 20 wt% to 40 wt% with respect to the total weight of the silicon-carbon composite. In addition, the thickness of the amorphous carbon coating layer may be 5 nm to 100 nm.

[0120] The average particle diameter (D50) of the above silicon particles may be 10 nm to 20 μm, for example, 10 nm to 500 nm. The silicon particles may exist in an oxidized form, and at this time, the atomic content ratio of Si:O in the silicon particles, which indicates the degree of oxidation, may be 99:1 to 33:67. The silicon particles may be SiO x It can be a particle, in which case SiO x In the range of x, it can be greater than 0 and less than 2. Here, the average particle diameter (D50) is measured by a particle size analyzer using laser diffraction and means the diameter of particles having a cumulative volume of 50% by volume in the particle size distribution.

[0121] The above Si-based negative electrode active material or Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material. The mixing ratio of the Si-based negative electrode active material or Sn-based negative electrode active material and the carbon-based negative electrode active material can be 1:99 to 90:10 by weight.

[0122] The content of the negative active material in the above negative active material layer may be 95 wt% to 99 wt% with respect to the total weight of the negative active material layer.

[0123] In one embodiment, the negative electrode active material layer further includes a binder and may optionally further include a conductive material. The content of the binder in the negative electrode active material layer may be 1 wt% to 5 wt% based on the total weight of the negative electrode active material layer. In addition, when the negative electrode active material layer further includes a conductive material, the negative electrode active material layer may include 90 wt% to 98 wt% of the negative electrode active material, 1 wt% to 5 wt% of the binder, and 1 wt% to 5 wt% of the conductive material.

[0124] The above binder serves to adhere the negative active material particles well to each other and also to adhere the negative active material well to the current collector. The binder may include an insoluble binder, a water-soluble binder, or a combination thereof.

[0125] The above-described non-aqueous binder may include, for example, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer comprising ethylene oxide, an ethylene propylene copolymer, polystyrene, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyamideimide, polyimide, or a combination thereof.

[0126] The water-soluble binder may be a rubber-based binder or a polymer resin binder. The rubber-based binder may be selected from styrene-butadiene rubber, acrylated styrene-butadiene rubber, acrylonitrile-butadiene rubber, acrylic rubber, butyl rubber, fluororubber, and combinations thereof. The polymer resin binder may be selected from polyethylene oxide, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, ethylene propylene diene copolymer, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenol resin, epoxy resin, polyvinyl alcohol, and combinations thereof.

[0127] When a water-soluble binder is used as the negative electrode binder, a thickener capable of imparting viscosity may be used together, and the thickener may include, for example, a cellulose-based compound. The cellulose-based compound may include carboxymethyl cellulose, hydroxypropylmethyl cellulose, methyl cellulose, an alkali metal salt thereof, or a combination thereof. Na, K, or Li may be used as the alkali metal. The amount of the thickener used may be 0.1 to 3 parts by weight based on 100 parts by weight of the negative electrode active material.

[0128] The conductive material is used to provide conductivity to the electrode, and may include, for example, carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, and carbon nanotubes; metal-based materials in the form of metal powder or metal fibers, including copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or mixtures thereof.

[0129] The negative electrode current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0130] As another example, the negative electrode for the all-solid-state battery may be a precipitation-type negative electrode. The precipitation-type negative electrode refers to a negative electrode that does not include a negative electrode active material when the battery is assembled, but in which lithium metal or the like is precipitated when the battery is charged, and this acts as a negative electrode active material.

[0131] Figure 2 is a cross-sectional view of an all-solid-state battery including a precipitated negative electrode.

[0132] Referring to FIG. 2, the precipitation-type negative electrode (40') may include a current collector (41) and a negative electrode coating layer (45) positioned on the current collector. An all-solid-state battery having such a precipitation-type negative electrode (40') starts initial charging in a state in which no negative electrode active material is present, and during charging, high-density lithium metal or the like is precipitated between the current collector (41) and the negative electrode coating layer (45) to form a lithium metal layer (44), which may function as a negative electrode active material. Accordingly, in an all-solid-state battery that has been charged at least once, the precipitation-type negative electrode (40') may include a current collector (41), a lithium metal layer (44) positioned on the current collector, and a negative electrode coating layer (45) positioned on the metal layer. The lithium metal layer (44) refers to a layer in which lithium metal or the like is precipitated during the charging process of the battery, and may be referred to as a metal layer or a negative electrode active material layer.

[0133] The above cathode coating layer (45) may include a metal, carbon material, or a combination thereof that acts as a catalyst.

[0134] The metal may include, for example, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, or a combination thereof, and may be composed of one type of these or may be composed of an alloy of several types. When the metal is present in the form of particles, the average particle diameter (D50) thereof may be about 4 μm or less, for example, 10 nm to 4 μm.

[0135] The carbon material may be, for example, crystalline carbon, amorphous carbon, or a combination thereof. The crystalline carbon may be, for example, natural graphite, artificial graphite, mesophase carbon microbeads, or a combination thereof. The amorphous carbon may be, for example, carbon black, activated carbon, acetylene black, Denka black, Ketjen black, or a combination thereof.

[0136] When the above-described negative electrode coating layer (45) includes both the metal and the carbon material, the mixing ratio of the metal and the carbon material may be, for example, a weight ratio of 1:10 to 2:1. In this case, the precipitation of lithium metal can be effectively promoted and the characteristics of the all-solid-state battery can be improved. The above-described negative electrode coating layer (45) may include, for example, a carbon material supported with a catalytic metal, or may include a mixture of metal particles and carbon material particles.

[0137] The above cathode coating layer (45) may include, for example, the metal and amorphous carbon, in which case it can effectively promote the precipitation of lithium metal.

[0138] The above cathode coating layer (45) may further include a binder, and the binder may be a conductive binder. In addition, the above cathode coating layer (45) may further include general additives such as fillers, dispersants, and ionic conductive agents.

[0139] The thickness of the cathode coating layer (45) may be, for example, 100 nm to 20 ㎛, or 500 nm to 10 ㎛, or 1 ㎛ to 5 ㎛.

[0140] The above-described precipitated negative electrode (40') may further include, for example, a thin film on the surface of the current collector, i.e., between the current collector and the negative electrode coating layer. The thin film may include an element capable of forming an alloy with lithium. The element capable of forming an alloy with lithium may be, for example, gold, silver, zinc, tin, indium, silicon, aluminum, bismuth, etc., and may be composed of one type thereof or may be composed of multiple types of alloys. The thin film may further flatten the precipitated form of the lithium metal layer (44) and further improve the characteristics of the all-solid-state battery. The thin film may be formed by, for example, a vacuum deposition method, a sputtering method, a plating method, etc. The thickness of the thin film may be, for example, 1 nm to 500 nm.

[0141] solid electrolyte layer

[0142] The solid electrolyte layer (30) may include a sulfide-based solid electrolyte, an oxide-based solid electrolyte, etc. The specific details of the sulfide-based solid electrolyte and the oxide-based solid electrolyte are as described above.

[0143] In one example, the solid electrolyte included in the positive electrode (20) and the solid electrolyte included in the solid electrolyte layer (30) may include the same compound or different compounds. For example, when both the positive electrode (20) and the solid electrolyte layer (30) include an argyrodite-type sulfide-based solid electrolyte, the overall performance of the all-solid-state secondary battery may be improved. In addition, for example, when both the positive electrode (20) and the solid electrolyte layer (30) include the above-described coated solid electrolyte, the all-solid-state secondary battery may implement high capacity and high energy density while implementing excellent initial efficiency and lifespan characteristics.

[0144] Meanwhile, the average particle diameter (D50) of the solid electrolyte included in the positive electrode (20) may be smaller than the average particle diameter (D50) of the solid electrolyte included in the solid electrolyte layer (30). In this case, the energy density of the all-solid-state battery can be maximized while increasing the mobility of lithium ions, thereby improving the overall performance. For example, the average particle diameter (D50) of the solid electrolyte included in the positive electrode (20) may be 0.1 ㎛ to 1.0 ㎛, or 0.1 ㎛ to 0.8 ㎛, and the average particle diameter (D50) of the solid electrolyte included in the solid electrolyte layer (30) may be 1.5 ㎛ to 5.0 ㎛, or 2.0 ㎛ to 4.0 ㎛, or 2.5 ㎛ to 3.5 ㎛. When this particle size range is satisfied, the energy density of the all-solid-state secondary battery can be maximized while lithium ion transport is facilitated, resistance is suppressed, and the overall performance of the all-solid-state secondary battery can be improved. Here, the average particle diameter (D50) of the solid electrolyte can be measured using a particle size analyzer using laser diffraction. Alternatively, the particle size can be measured by selecting 20 or so random particles from a microscope image such as a scanning electron microscope, obtaining a particle size distribution, and calculating the D50 value from this.

[0145] The above solid electrolyte layer may further include a binder in addition to the solid electrolyte. At this time, the binder may be styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, an acrylate polymer, or a combination thereof, but is not limited thereto, and any binder used in the relevant technical field may be used. The acrylate polymer may be, for example, butyl acrylate, polyacrylate, polymethacrylate, or a combination thereof.

[0146] The above solid electrolyte layer can be formed by adding a solid electrolyte to a binder solution, coating the same on a base film, and drying the same. The solvent of the binder solution may be isobutyryl isobutyrate, xylene, toluene, benzene, hexane, or a combination thereof. Since the solid electrolyte layer formation process is widely known in the art, a detailed description thereof will be omitted.

[0147] The thickness of the solid electrolyte layer may be, for example, 10 μm to 150 μm.

[0148] The solid electrolyte layer may further include an alkali metal salt, and / or an ionic liquid, and / or a conductive polymer.

[0149] The above alkali metal salt may be, for example, a lithium salt. The content of the lithium salt in the solid electrolyte layer may be 1 M or more, for example, 1 M to 4 M. In this case, the lithium salt may improve ion conductivity by enhancing the lithium ion mobility of the solid electrolyte layer.

[0150] The above lithium salts include, for example, LiSCN, LiN(CN)2, Li(CF3SO2)3C, LiC4F9SO3, LiN(SO2CF2CF3)2, LiCl, LiF, LiBr, LiI, LiB(C2O4)2, LiBF4, LiBF3(C2F5), lithium bis(oxalato)borate (LiBOB), lithium oxalyldifluoroborate (LIODFB), lithium difluoro(oxalato)borate (LiDFOB), lithium bis(trifluoro methanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2), lithium bis(fluorosulfonyl)imide (LiFSI, It may include LiN(SO2F)2), LiCF3SO3, LiAsF6, LiSbF6, LiClO4 or mixtures thereof.

[0151] In addition, the lithium salt may be an imide-based one, and for example, the imide-based lithium salt may include lithium bis(trifluoro methanesulfonyl)imide (LiTFSI, LiN(SO2CF3)2), lithium bis(fluorosulfonyl)imide (LiFSI, LiN(SO2F)2). The lithium salt may maintain or improve ionic conductivity by appropriately maintaining chemical reactivity with an ionic liquid.

[0152] The above ionic liquid has a melting point below room temperature and is a salt or room-temperature molten salt that is liquid at room temperature and consists only of ions.

[0153] The above ionic liquid may be a compound including a) one or more cations selected from ammonium-based, pyrrolidinium-based, pyridinium-based, pyrimidinium-based, imidazolium-based, piperidinium-based, pyrazolium-based, oxazolium-based, pyridazinium-based, phosphonium-based, sulfonium-based, triazolium-based, and mixtures thereof, and b) one or more anions selected from BF4-, PF6-, AsF6-, SbF6-, AlCl4-, HSO4-, ClO4-, CH3SO3-, CF3CO2-, Cl-, Br-, I-, BF4-, SO4-, CF3SO3-, (FSO2)2N-, (C2F5SO2)2N-, (C2F5SO2)(CF3SO2)N-, and (CF3SO2)2N-.

[0154] The ionic liquid may be at least one selected from the group consisting of, for example, N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylpyrrolidinium bis(3-trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide.

[0155] In the above solid electrolyte layer, the weight ratio of the solid electrolyte and the ionic liquid may be 0.1:99.9 to 90:10, for example, 10:90 to 90:10, 20:80 to 90:10, 30:70 to 90:10, 40:60 to 90:10, or 50:50 to 90:10. A solid electrolyte layer satisfying the above range can maintain or improve ionic conductivity by improving the electrochemical contact area with the electrode. Accordingly, the energy density, discharge capacity, rate characteristics, etc. of the all-solid-state battery can be improved.

[0156] The above-mentioned all-solid-state battery may be a unit battery having a structure of positive electrode / solid electrolyte layer / negative electrode, a bi-cell having a structure of positive electrode / solid electrolyte layer / negative electrode / solid electrolyte layer / positive electrode, or a laminated battery in which the structure of the unit battery is repeated.

[0157] The shape of the above-mentioned all-solid-state battery is not particularly limited, and may be, for example, coin-shaped, button-shaped, sheet-shaped, stacked, cylindrical, flat, etc. In addition, the above-mentioned all-solid-state battery can be applied to large-scale batteries used in electric vehicles, etc. For example, the above-mentioned all-solid-state battery can be used in hybrid vehicles such as plug-in hybrid electric vehicles (PHEVs). In addition, it can be used in fields requiring large amounts of power storage, and for example, it can be used in electric bicycles or power tools.

[0158] Hereinafter, an all-solid-state secondary battery according to one embodiment will be described with reference to FIG. 3.

[0159] Figure 3 is a cross-sectional view showing an all-solid-state secondary battery according to one embodiment.

[0160] Referring to FIG. 3, an all-solid-state secondary battery (1000) according to one embodiment is a secondary battery capable of being charged and discharged. Hereinafter, the first electrode includes a cathode, and the second electrode includes an anode, but is not limited thereto, and the first electrode may include a cathode, and the second electrode may include an anode.

[0161] An all-solid-state secondary battery (1000) according to one embodiment includes a first electrode (100), a second electrode (200), a first solid electrolyte layer (300), a second solid electrolyte layer (400), and a reference electrode (500).

[0162] The first electrode (100) may include the anode described above, but is not limited thereto. The first electrode may have a plate or foil shape, but is not limited thereto.

[0163] The second electrode (200) is positioned on the first electrode (100). The second electrode (200) may include the cathode described above, but is not limited thereto. The second electrode (200) may have a plate or foil shape, but is not limited thereto.

[0164] The first solid electrolyte layer (300) is positioned between the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) may include the above-described solid electrolyte layer, but is not limited thereto. The first solid electrolyte layer (300) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto.

[0165] The second solid electrolyte layer (400) is positioned between the first solid electrolyte layer (300) and the second electrode (200). The second solid electrolyte layer (400) may include the above-described solid electrolyte layer, but is not limited thereto. The second solid electrolyte layer (400) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto. The second solid electrolyte layer (400) may include the same material as or a different material from the first solid electrolyte layer (300), but is not limited thereto. The second solid electrolyte layer (400) is in contact with the first solid electrolyte layer (300), and a reference electrode (500) is positioned corresponding to an end of the first solid electrolyte layer (300).

[0166] The reference electrode (500) corresponds to an end of the first solid electrolyte layer (300).

[0167] For example, the reference electrode is positioned on the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer, or the reference electrode is positioned below the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer, or the reference electrode is positioned between the ends of a plurality of solid electrolyte layers corresponding to the end of the solid electrolyte layer, or the reference electrode is positioned on an extension extending from the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer, or the reference electrode is positioned below the extension extending from the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer, or the reference electrode is positioned on a tail extending in one direction from the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer and is removed together with the tail after inspection, or the reference electrode is positioned below the tail extending in one direction from the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer and is removed together with the tail after inspection, or the reference electrode is positioned on the side of the tail extending in one direction from the end of the solid electrolyte layer corresponding to the end of the solid electrolyte layer The reference electrode may be positioned within an imaginary line crossing the end in one direction. The configuration corresponding to the end of the solid electrolyte layer may include all of the configurations described above.

[0168] The reference electrode (500) is located between an end of the first solid electrolyte layer (300) and an end of the second solid electrolyte layer (400). The reference electrode (500) overlaps the end of the first solid electrolyte layer (300) in the vertical direction (VD) in which the first electrode (100), the first solid electrolyte layer (300), the second solid electrolyte layer (400), and the second electrode (200) overlap each other. The reference electrode (500) does not overlap the central region of the first solid electrolyte layer (300) and the central region of the second solid electrolyte layer (400) in the vertical direction (VD). Here, the end of the first solid electrolyte layer (300) and the end of the second solid electrolyte layer (400) may be ends in the horizontal direction (HD) intersecting the vertical direction (VD), but is not limited thereto. In addition, the central region of the first solid electrolyte layer (300) and the central region of the second solid electrolyte layer (400) may be central regions in the horizontal direction (HD), but are not limited thereto. The reference electrode (500) includes lithium (Li), but is not limited thereto and may include various known materials. The reference electrode (500) includes an insulating tape (510) adjacent to an end of the first solid electrolyte layer (300) and an end of the second solid electrolyte layer (400), and the insulating tape (510) prevents the reference electrode (500) from being short-circuited with the first electrode (100) or the second electrode (200).

[0169] In one embodiment, an all-solid-state secondary battery (1000) is configured such that the interfaces between each of the first electrode (100), the first solid electrolyte layer (300), the second solid electrolyte layer (400), and the second electrode (200) are maintained closely by pressurization according to the unique characteristics of the all-solid-state secondary battery, and a reference electrode (500) overlaps the end of the first solid electrolyte layer (300) and the end of the second solid electrolyte layer (400) in the vertical direction (VD) between the first solid electrolyte layer (300) and the second solid electrolyte layer (400), thereby suppressing the reference electrode (500) from being short-circuited with the first electrode (100) or the second electrode (200) by pressurization.

[0170] In addition, since the all-solid-state secondary battery (1000) according to one embodiment has a structure in which ions move but electrons do not move between the reference electrode (500) and the first electrode (100), which may be a working electrode, and between the reference electrode (500) and the second electrode (200), which may be a counter electrode, by positioning the reference electrode (500) corresponding to the end of the first solid electrolyte layer (300), the potential of each of the first electrode (100) and the second electrode (200) can be precisely measured using the reference electrode (500) that can maintain the potential constant, thereby improving the reliability of the potential measurement for the all-solid-state secondary battery (1000).

[0171] That is, even if the space between the first electrode (100) and the second electrode (200) is pressurized, an all-solid-state secondary battery (1000) is provided in which the reference electrode (500) is prevented from being short-circuited with the first electrode (100) or the second electrode (200), and at the same time, the potential of each of the first electrode (100) and the second electrode (200) can be precisely measured using the reference electrode (500).

[0172] Hereinafter, an all-solid-state secondary battery according to another embodiment will be described with reference to FIG. 4. Below, differences from the above-described embodiment will be described.

[0173] Fig. 4 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0174] Referring to FIG. 4, an all-solid-state secondary battery (1000) according to another embodiment includes a first electrode (100), a second electrode (200), a first solid electrolyte layer (300), a third electrode (600), a third solid electrolyte layer (700), a first gasket (800), and a reference electrode (500).

[0175] The first electrode (100) may include the cathode described above, but is not limited thereto. The first electrode may have a plate or foil shape, but is not limited thereto.

[0176] The second electrode (200) is positioned on the first electrode (100). The second electrode (200) may include the anode described above, but is not limited thereto. The second electrode (200) may have a plate or foil shape, but is not limited thereto.

[0177] The first solid electrolyte layer (300) is positioned between the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) may include the above-described solid electrolyte layer, but is not limited thereto. The first solid electrolyte layer (300) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto.

[0178] The third electrode (600) is positioned on the second electrode (200). The third electrode (600) may include the cathode described above, but is not limited thereto. The third electrode (600) may have a plate or foil shape, but is not limited thereto.

[0179] The third solid electrolyte layer (700) is positioned between the second electrode (200) and the third electrode (600). The third solid electrolyte layer (700) may include the solid electrolyte layer described above, but is not limited thereto. The third solid electrolyte layer (700) may have a layer form between the second electrode (200) and the third electrode (600), but is not limited thereto. The third solid electrolyte layer (700) may include the same material as or a different material from the first solid electrolyte layer (300), but is not limited thereto. The third solid electrolyte layer (700) is in contact with the second electrode (200) and the third electrode (600), and a reference electrode (500) is positioned corresponding to an end of the first solid electrolyte layer (300).

[0180] The first gasket (800) surrounds the edge of the second electrode (200). The first gasket (800) has a loop shape that surrounds the edge of the second electrode (200) in a planar manner, but is not limited thereto. The first gasket (800) includes various known insulating materials.

[0181] The reference electrode (500) corresponds to an end of the first solid electrolyte layer (300). The reference electrode (500) contacts the first gasket (800) between the end of the first solid electrolyte layer (300) and the end of the third solid electrolyte layer (700). The reference electrode (500) is positioned in a space where the end of the first gasket (800) is cut off and overlaps the end of the first solid electrolyte layer (300) in the vertical direction (VD), and the reference electrode (500) overlaps the end of the first solid electrolyte layer (300) and the end of the third solid electrolyte layer (700) in the vertical direction (VD) while being in contact with the first gasket (800). The reference electrode (500) does not overlap the central region of the first solid electrolyte layer (300) and the central region of the third solid electrolyte layer (700) in the vertical direction (VD). Here, the end of the first solid electrolyte layer (300) and the end of the third solid electrolyte layer (700) may be ends in the horizontal direction (HD) intersecting the vertical direction (VD), but are not limited thereto. In addition, the central region of the first solid electrolyte layer (300) and the central region of the third solid electrolyte layer (700) may be central regions in the horizontal direction (HD), but are not limited thereto. The reference electrode (500) includes an insulating tape (510) adjacent to the end of the first solid electrolyte layer (300) and the end of the third solid electrolyte layer (700), and the insulating tape (510) suppresses the reference electrode (500) from being short-circuited with the first electrode (100) or the second electrode (200).

[0182] In another embodiment, an all-solid-state secondary battery (1000) is provided in which, according to the unique characteristics of an all-solid-state secondary battery, the interfaces between each of the first electrode (100), the first solid electrolyte layer (300), the second electrode (200), the third solid electrolyte layer (700), and the third electrode (600) are closely maintained by pressurization, and the reference electrode (500) is brought into contact with the first gasket (800) between the end of the first solid electrolyte layer (300) and the end of the third solid electrolyte layer (700), thereby suppressing the reference electrode (500) from being short-circuited with the first electrode (100), the second electrode (200), or the third electrode (600) by pressurization.

[0183] In addition, since the all-solid-state secondary battery (1000) according to another embodiment has a structure in which ions move but electrons do not move between the reference electrode (500) and each of the first electrode (100), the second electrode (200), and the third electrode (600) by positioning the reference electrode (500) corresponding to the end of the first solid electrolyte layer (300), the potential of each of the first electrode (100), the second electrode (200), and the third electrode (600) can be precisely measured using the reference electrode (500) capable of maintaining a constant potential, thereby improving the reliability of potential measurement for the all-solid-state secondary battery (1000).

[0184] That is, even if the space between each of the first electrode (100), the second electrode (200), and the third electrode (600) is pressurized, a reference electrode (500) is prevented from being short-circuited with the first electrode (100), the second electrode (200), or the third electrode (600), and at the same time, an all-solid-state secondary battery (1000) is provided that can precisely measure the potential of each of the first electrode (100), the second electrode (200), and the third electrode (600) using the reference electrode (500).

[0185] Hereinafter, an all-solid-state secondary battery according to another embodiment will be described with reference to FIG. 5. Below, differences from the above-described embodiment will be described.

[0186] Figure 5 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0187] Referring to FIG. 5, an all-solid-state secondary battery (1000) according to another embodiment includes a first electrode (100), a second electrode (200), a first solid electrolyte layer (300), a third electrode (600), a third solid electrolyte layer (700), a first gasket (800), and a reference electrode (500).

[0188] The first electrode (100) may include the cathode described above, but is not limited thereto. The first electrode may have a plate or foil shape, but is not limited thereto.

[0189] The second electrode (200) is positioned on the first electrode (100). The second electrode (200) may include the anode described above, but is not limited thereto. The second electrode (200) may have a plate or foil shape, but is not limited thereto.

[0190] The first solid electrolyte layer (300) is positioned between the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) may include the above-described solid electrolyte layer, but is not limited thereto. The first solid electrolyte layer (300) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto.

[0191] The third electrode (600) is positioned on the second electrode (200). The third electrode (600) may include the cathode described above, but is not limited thereto. The third electrode (600) may have a plate or foil shape, but is not limited thereto.

[0192] The third solid electrolyte layer (700) is positioned between the second electrode (200) and the third electrode (600). The third solid electrolyte layer (700) may include the above-described solid electrolyte layer, but is not limited thereto. The third solid electrolyte layer (700) may have a layer form between the second electrode (200) and the third electrode (600), but is not limited thereto. The third solid electrolyte layer (700) may include the same material as or a different material from the first solid electrolyte layer (300), but is not limited thereto. The third solid electrolyte layer (700) is in contact with the second electrode (200) and the third electrode (600). The third solid electrolyte layer (700) includes a first extension portion (710) that extends from the rear surface of the third electrode (600) facing the second electrode (200) to the front surface of the third electrode (600) past the end of the third electrode (600) in the horizontal direction (HD). The first extension portion (710) may be positioned at the uppermost portion in the vertical direction (VD) of the all-solid-state secondary battery (1000) corresponding to the end of the first solid electrolyte layer (300), but is not limited thereto.

[0193] The first gasket (800) surrounds the edge of the second electrode (200). The first gasket (800) has a loop shape that surrounds the edge of the second electrode (200) in a planar manner, but is not limited thereto. The first gasket (800) includes various known insulating materials.

[0194] The reference electrode (500) corresponds to an end of the first solid electrolyte layer (300). The reference electrode (500) is located on the first extension portion (710) of the third solid electrolyte layer (700). The reference electrode (500) is in contact with the first extension portion (710). The reference electrode (500) overlaps the end of the first solid electrolyte layer (300) and the end of the third solid electrolyte layer (700) in the vertical direction (VD) on the first extension portion (710) of the third solid electrolyte layer (700). The reference electrode (500) does not overlap the central region of the first solid electrolyte layer (300) and the central region of the third solid electrolyte layer (700) in the vertical direction (VD). Here, the ends of the first solid electrolyte layer (300) and the ends of the third solid electrolyte layer (700) may be ends in the horizontal direction (HD) intersecting the vertical direction (VD), but are not limited thereto. In addition, the central region of the first solid electrolyte layer (300) and the central region of the third solid electrolyte layer (700) may be central regions in the horizontal direction (HD), but are not limited thereto.

[0195] According to another embodiment, an all-solid-state secondary battery (1000) is provided in which, according to the unique characteristics of an all-solid-state secondary battery, the interfaces between each of the first electrode (100), the first solid electrolyte layer (300), the second electrode (200), the third solid electrolyte layer (700), and the third electrode (600) are closely maintained by pressurization, and the reference electrode (500) is positioned on the first extension portion (710) of the third solid electrolyte layer (700) corresponding to the end of the first solid electrolyte layer (300), thereby suppressing the reference electrode (500) from being short-circuited with the first electrode (100), the second electrode (200), or the third electrode (600) by pressurization.

[0196] In addition, since the all-solid-state secondary battery (1000) according to another embodiment has a structure in which ions move but electrons do not move between the reference electrode (500) and each of the second electrode (200) and the third electrode (600) by positioning the reference electrode (500) on the first extension portion (710) of the third solid electrolyte layer (700) corresponding to the end of the first solid electrolyte layer (300), the potential of each of the second electrode (200) and the third electrode (600) can be precisely measured using the reference electrode (500) capable of maintaining a constant potential, thereby improving the reliability of potential measurement for the all-solid-state secondary battery (1000).

[0197] That is, even if the space between each of the first electrode (100), the second electrode (200), and the third electrode (600) is pressurized, a solid-state secondary battery (1000) is provided in which the reference electrode (500) is prevented from being short-circuited with the first electrode (100), the second electrode (200), or the third electrode (600), and at the same time, the potential of each of the positive electrode, the second electrode (200), and the negative electrode, the third electrode (600), can be precisely measured using the reference electrode (500).

[0198] Hereinafter, an all-solid-state secondary battery according to another embodiment will be described with reference to FIG. 6. Below, differences from the above-described embodiment will be described.

[0199] Figure 6 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0200] Referring to FIG. 6, an all-solid-state secondary battery (1000) according to another embodiment includes a first electrode (100), a second electrode (200), a first solid electrolyte layer (300), a second gasket (900), and a reference electrode (500).

[0201] The first electrode (100) may include the anode described above, but is not limited thereto. The first electrode may have a plate or foil shape, but is not limited thereto.

[0202] The second electrode (200) is positioned on the first electrode (100). The second electrode (200) may include the cathode described above, but is not limited thereto. The second electrode (200) may have a plate or foil shape, but is not limited thereto.

[0203] The first solid electrolyte layer (300) is positioned between the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) may include the above-described solid electrolyte layer, but is not limited thereto. The first solid electrolyte layer (300) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto. The first solid electrolyte layer (300) is in contact with the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) includes a second extension portion (310) that extends from the rear surface of the second electrode (200) facing the first electrode (100) past the end of the second electrode (200) in the horizontal direction (HD) to the front surface of the second electrode (200). The second extension (310) may be positioned at the uppermost part in the vertical direction (VD) of the all-solid-state secondary battery (1000) corresponding to the end of the first solid electrolyte layer (300), but is not limited thereto.

[0204] The second gasket (900) surrounds the edge of the first electrode (100). The second gasket (900) has a loop shape that surrounds the edge of the first electrode (100) in a planar manner, but is not limited thereto. The second gasket (900) includes various known insulating materials.

[0205] The reference electrode (500) corresponds to an end of the first solid electrolyte layer (300). The reference electrode (500) is located on the second extension portion (310) of the first solid electrolyte layer (300). The reference electrode (500) is in contact with the second extension portion (310). The reference electrode (500) overlaps the end of the first solid electrolyte layer (300) in the vertical direction (VD) on the second extension portion (310) of the first solid electrolyte layer (300). The reference electrode (500) does not overlap with the central region of the first solid electrolyte layer (300) in the vertical direction (VD). Here, the end of the first solid electrolyte layer (300) may be an end in the horizontal direction (HD) intersecting the vertical direction (VD), but is not limited thereto. Additionally, the central region of the first solid electrolyte layer (300) may be a central region in the horizontal direction (HD), but is not limited thereto.

[0206] According to another embodiment, an all-solid-state secondary battery (1000) is provided in which, according to the unique characteristics of an all-solid-state secondary battery, the interfaces between each of the first electrode (100), the first solid electrolyte layer (300), and the second electrode (200) are maintained closely by pressurization, and the reference electrode (500) is positioned on the second extension portion (310) of the first solid electrolyte layer (300) corresponding to an end of the first solid electrolyte layer (300), thereby suppressing the reference electrode (500) from being short-circuited with the first electrode (100) or the second electrode (200) by pressurization.

[0207] In addition, since the all-solid-state secondary battery (1000) according to another embodiment has a structure in which ions move but electrons do not move between the reference electrode (500) and each of the first electrode (100) and the second electrode (200) by positioning the reference electrode (500) on the second extension portion (310) of the first solid electrolyte layer (300) corresponding to the end of the first solid electrolyte layer (300), the potential of each of the first electrode (100) and the second electrode (200) can be precisely measured using the reference electrode (500) capable of maintaining a constant potential, thereby improving the reliability of the potential measurement for the all-solid-state secondary battery (1000).

[0208] That is, even if the space between the first electrode (100) and the second electrode (200) is pressurized, an all-solid-state secondary battery (1000) is provided in which the reference electrode (500) is prevented from being short-circuited with the first electrode (100) or the second electrode (200), and at the same time, the potential of each of the positive electrode, the first electrode (100), and the negative electrode, the second electrode (200), can be precisely measured using the reference electrode (500).

[0209] Hereinafter, an all-solid-state secondary battery according to another embodiment will be described with reference to FIG. 7. Below, differences from the above-described embodiment will be described.

[0210] Figure 7 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0211] Referring to FIG. 7, an all-solid-state secondary battery (1000) according to another embodiment includes a first electrode (100), a second electrode (200), a first solid electrolyte layer (300), and a reference electrode (500).

[0212] The first electrode (100) may include the cathode described above, but is not limited thereto. The first electrode may have a plate or foil shape, but is not limited thereto.

[0213] The second electrode (200) is positioned on the first electrode (100). The second electrode (200) may include the anode described above, but is not limited thereto. The second electrode (200) may have a plate or foil shape, but is not limited thereto.

[0214] The first solid electrolyte layer (300) is positioned between the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) may include the above-described solid electrolyte layer, but is not limited thereto. The first solid electrolyte layer (300) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto. The first solid electrolyte layer (300) is in contact with the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) includes a second extension portion (310) that extends from the rear surface of the second electrode (200) facing the first electrode (100) past the end of the second electrode (200) in the horizontal direction (HD) to the front surface of the second electrode (200). The second extension (310) may be positioned at the uppermost part in the vertical direction (VD) of the all-solid-state secondary battery (1000) corresponding to the end of the first solid electrolyte layer (300), but is not limited thereto.

[0215] The reference electrode (500) corresponds to an end of the first solid electrolyte layer (300). The reference electrode (500) is located on the second extension portion (310) of the first solid electrolyte layer (300). The reference electrode (500) is in contact with the second extension portion (310). The reference electrode (500) overlaps the end of the first solid electrolyte layer (300) in the vertical direction (VD) on the second extension portion (310) of the first solid electrolyte layer (300). The reference electrode (500) does not overlap with the central region of the first solid electrolyte layer (300) in the vertical direction (VD). Here, the end of the first solid electrolyte layer (300) may be an end in the horizontal direction (HD) intersecting the vertical direction (VD), but is not limited thereto. Additionally, the central region of the first solid electrolyte layer (300) may be a central region in the horizontal direction (HD), but is not limited thereto.

[0216] According to another embodiment, an all-solid-state secondary battery (1000) is provided in which, according to the unique characteristics of an all-solid-state secondary battery, the interfaces between each of the first electrode (100), the first solid electrolyte layer (300), and the second electrode (200) are maintained closely by pressurization, and the reference electrode (500) is positioned on the second extension portion (310) of the first solid electrolyte layer (300) corresponding to an end of the first solid electrolyte layer (300), thereby suppressing the reference electrode (500) from being short-circuited with the first electrode (100) or the second electrode (200) by pressurization.

[0217] In addition, since the all-solid-state secondary battery (1000) according to another embodiment has a structure in which ions move but electrons do not move between the reference electrode (500) and each of the first electrode (100) and the second electrode (200) by positioning the reference electrode (500) on the second extension portion (310) of the first solid electrolyte layer (300) corresponding to the end of the first solid electrolyte layer (300), the potential of each of the first electrode (100) and the second electrode (200) can be precisely measured using the reference electrode (500) capable of maintaining a constant potential, thereby improving the reliability of the potential measurement for the all-solid-state secondary battery (1000).

[0218] That is, even if the space between the first electrode (100) and the second electrode (200) is pressurized, an all-solid-state secondary battery (1000) is provided in which the reference electrode (500) is prevented from being short-circuited with the first electrode (100) or the second electrode (200), and at the same time, the potential of each of the first electrode (100), which is a negative electrode, and the second electrode (200), which is a positive electrode, can be precisely measured using the reference electrode (500).

[0219] Hereinafter, an all-solid-state secondary battery according to another embodiment will be described with reference to FIG. 8. Below, differences from the above-described embodiment will be described.

[0220] Figure 8 is a cross-sectional view showing an all-solid-state secondary battery according to another embodiment.

[0221] Referring to FIG. 8, an all-solid-state secondary battery (1000) according to another embodiment includes a first electrode (100), a second electrode (200), a first solid electrolyte layer (300), and a reference electrode (500).

[0222] The first electrode (100) may include the anode described above, but is not limited thereto. The first electrode may have a plate or foil shape, but is not limited thereto.

[0223] The second electrode (200) is positioned on the first electrode (100). The second electrode (200) may include the cathode described above, but is not limited thereto. The second electrode (200) may have a plate or foil shape, but is not limited thereto.

[0224] The first solid electrolyte layer (300) is positioned between the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) may include the above-described solid electrolyte layer, but is not limited thereto. The first solid electrolyte layer (300) may have a layer form between the first electrode (100) and the second electrode (200), but is not limited thereto. The first solid electrolyte layer (300) is in contact with the first electrode (100) and the second electrode (200). The first solid electrolyte layer (300) includes a tail portion (320) extending in a horizontal direction (HD) intersecting with a vertical direction (VD) in which the first electrode (100), the first solid electrolyte layer (300), and the second electrode (200) overlap each other. The tail portion (320) does not overlap with the first electrode (100), the first solid electrolyte layer (300), and the second electrode (200) in the vertical direction (VD). The tail portion (320) includes a cutting line (321), and the tail portion (320) can be cut along the cutting line (321). The tail portion (320) can be selectively cut from the first solid electrolyte layer (300).

[0225] The reference electrode (500) corresponds to an end of the first solid electrolyte layer (300). The reference electrode (500) contacts the tail portion (320) on the tail portion (320). The reference electrode (500) does not overlap with the first solid electrolyte layer (300), the first electrode (100), and the second electrode (200) in the vertical direction (VD). The reference electrode (500) can be selectively cut from the first solid electrolyte layer (300) along a cutting line (321) together with the tail portion (320).

[0226] In another embodiment, an all-solid-state secondary battery (1000) is provided in which, according to the unique characteristics of an all-solid-state secondary battery, the interface between each of the first electrode (100), the first solid electrolyte layer (300), and the second electrode (200) is maintained closely by pressurization, and the reference electrode (500) is brought into contact with the tail portion (320) of the first solid electrolyte layer (300), thereby suppressing the reference electrode (500) from being short-circuited with the first electrode (100) or the second electrode (200) by pressurization.

[0227] In addition, since the all-solid-state secondary battery (1000) according to another embodiment has a structure in which ions move between the reference electrode (500) and the first electrode (100) and between the reference electrode (500) and the second electrode (200) by positioning the reference electrode (500) on the tail portion (320) corresponding to the end of the first solid electrolyte layer (300), but electrons do not move, the reliability of the potential measurement for the all-solid-state secondary battery (1000) is improved by precisely measuring the potential of each of the first electrode (100) and the second electrode (200) using the reference electrode (500) that can maintain the potential constant.

[0228] In addition, since the all-solid-state secondary battery (1000) according to another embodiment can optionally cut the tail portion (320) along the cutting line (321) together with the reference electrode (500) from the first solid electrolyte layer (300), the reference electrode (500) can be easily separated from the all-solid-state secondary battery (1000) as needed.

[0229] That is, even if the space between the first electrode (100) and the second electrode (200) is pressurized, an all-solid-state secondary battery (1000) is provided in which the reference electrode (500) is prevented from being short-circuited with the first electrode (100) or the second electrode (200), and at the same time, the potential of each of the first electrode (100) and the second electrode (200) can be precisely measured using the reference electrode (500).

[0230] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

[0231] [Explanation of symbols]

[0232] First electrode (100), second electrode (200), first solid electrolyte layer (300), second solid electrolyte layer (400), reference electrode (500)

Claims

1. First electrode; A second electrode positioned on the first electrode; a first solid electrolyte layer positioned between the first electrode and the second electrode; and A reference electrode corresponding to the end of the first solid electrolyte layer An all-solid-state secondary battery comprising:

2. In paragraph 1, An all-solid-state secondary battery in which the reference electrode overlaps an end of the first solid electrolyte layer in a vertical direction in which the first electrode, the first solid electrolyte layer, and the second electrode overlap each other.

3. In paragraph 2, An all-solid-state secondary battery wherein the reference electrode does not overlap with the central region of the first solid electrolyte layer in the vertical direction.

4. In paragraph 1, An all-solid-state secondary battery further comprising a second solid electrolyte layer positioned between the first solid electrolyte layer and the second electrode.

5. In paragraph 4, An all-solid-state secondary battery wherein the reference electrode is located between an end of the first solid electrolyte layer and an end of the second solid electrolyte layer.

6. In paragraph 5, An all-solid-state secondary battery, wherein the reference electrode includes an insulating tape adjacent to an end of the first solid electrolyte layer and an end of the second solid electrolyte layer.

7. In paragraph 1, a third electrode positioned on the second electrode; and A third solid electrolyte layer positioned between the second electrode and the third electrode An all-solid-state secondary battery further comprising:

8. In paragraph 7, An all-solid-state secondary battery further comprising a first gasket surrounding a rim of the second electrode.

9. In paragraph 8, An all-solid-state secondary battery wherein the reference electrode is in contact with the first gasket between an end of the first solid electrolyte layer and an end of the third solid electrolyte layer.

10. In paragraph 9, The above reference electrode is an all-solid-state secondary battery spaced apart from the second electrode.

11. In paragraph 7, The third solid electrolyte layer includes a first extension portion extending from the rear surface of the third electrode opposite the second electrode past the end of the third electrode to the front surface of the third electrode, The above reference electrode is an all-solid-state secondary battery located on the first extension portion.

12. In paragraph 11, The above reference electrode is an all-solid-state secondary battery in contact with the first extension portion.

13. In paragraph 1, The first solid electrolyte layer includes a second extension portion extending from the rear surface of the second electrode opposite the first electrode past the end of the second electrode to the front surface of the second electrode, The above reference electrode is an all-solid-state secondary battery located on the second extension portion.

14. In paragraph 13, The above reference electrode is an all-solid-state secondary battery in contact with the second extension portion.

15. In paragraph 13, An all-solid-state secondary battery further comprising a second gasket surrounding a rim of the first electrode.

16. In paragraph 1, An all-solid-state secondary battery, wherein the first solid electrolyte layer includes a tail extending in a horizontal direction intersecting with a vertical direction in which the first electrode, the first solid electrolyte layer, and the second electrode overlap each other.

17. In paragraph 16, The above reference electrode is an all-solid-state secondary battery in contact with the tail portion.

18. In paragraph 17, An all-solid-state secondary battery wherein the tail portion includes a cutting line.

19. In paragraph 1, A secondary battery in which the first electrode is a cathode.

20. In paragraph 1, A secondary battery in which the above first electrode is an anode.

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