All-solid rechargeable battery module

Abstract

An all-solid rechargeable battery is provided. The all-solid rechargeable battery comprises: unit cells of the all-solid rechargeable battery in which a negative electrode, a solid electrolyte layer, and a positive electrode are laminated; flexible partition walls between the unit cells, at the outer edges thereof in the first and second directions intersecting the lamination direction; and tab members disposed at both ends of the partition walls in the lamination direction to electrically connect the unit cells.

Description

All-solid-state secondary battery module

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

[0002] Recent industrial demands have led to the active development of batteries with high energy density and safety. For example, lithium-ion batteries are being used not only in information and communication devices, but also in the automotive sector. Safety is particularly important in the automotive sector, as it is directly related to life.

[0003] Lithium-ion batteries currently on the market use electrolytes containing flammable organic solvents, which poses a risk of overheating and fire in the event of a short circuit. To address this issue, all-solid-state secondary batteries using solid electrolytes are being proposed.

[0004] All-solid-state secondary batteries do not use flammable organic solvents, significantly reducing the risk of fire or explosion even if a short circuit occurs. Therefore, these all-solid-state batteries significantly improve safety compared to lithium-ion batteries that use electrolytes.

[0005] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present disclosure and may therefore include information that does not constitute prior art.

[0006] One embodiment provides an all-solid-state secondary battery module having flexibility.

[0007] One embodiment provides an all-solid-state secondary battery module having flexibility and lithium ion conductivity.

[0008] An all-solid-state secondary battery module according to one embodiment includes unit cells of an all-solid-state secondary battery in which a negative electrode, a solid electrolyte layer, and a positive electrode are laminated, flexible partition walls arranged on the outer sides in first and second directions intersecting the stacking direction of the unit cells and arranged between the unit cells, and tab members arranged at both ends of the partition walls in the stacking direction to electrically connect the unit cells.

[0009] The above unit cells may have cathodes arranged on one side of the stacking direction and anodes arranged on the other side of the stacking direction.

[0010] The above tab members may include a first connection tab that connects the negative current collectors arranged on one side of the stacking direction to each other, and a second connection tab that connects the positive current collectors arranged on the other side of the stacking direction to each other.

[0011] The above unit cells can have cathodes and anodes arranged alternately in the first direction and the second direction.

[0012] The tab members may include a first connection tab that connects the current collector of the negative electrode and the current collector of the positive electrode, which are arranged on one side of the stacking direction, to each other, and a second connection tab that connects the current collector of the positive electrode and the current collector of the negative electrode, which are arranged on the other side of the stacking direction.

[0013] The above flexible barrier may include a conductive binder of lithium ions.

[0014] The above flexible partition wall may include a skeleton structure made of a porous inorganic or organic material, and an ion-conducting polymer filled in the skeleton structure.

[0015] The above porous inorganic material may include either zeolite or SiO2.

[0016] The above porous organic material may include any one of porous PTFE, PE, and PP materials used as secondary battery separators.

[0017] The above ion conductive polymer can be used alone or has pores, and includes PVdF, PVdF-HFP, H-NBR, an acrylate binder, a PEO series binder, and one of LiTFSI, LiFSI, LiCFSI, LiBF4, LiClO4, LiAsF6, LiCF3SO3, and LiPF6, and as a mixed material with a salt, can have a Li ion conductivity of 10-3 S / cm to 10-6 S / cm.

[0018] In the above flexible bulkhead, the skeleton structure may have a volume ratio of 0% to 40%, and the volume ratio of the organic material, binder, and salt may have a volume ratio of 60% to 100%.

[0019] The above flexible partition wall can have a relative ratio of ionic conductivity of 51% to 100%.

[0020] The above flexible partition wall can be formed of an ion-conducting polymer.

[0021] In the above flexible bulkhead, the ratio of lithium salt to organic matter including binder may be 10 wt% to 200 wt%.

[0022] The above flexible partition wall can have a relative ratio of ionic conductivity of 75% to 100%.

[0023] One embodiment can provide flexibility in an all-solid-state secondary battery module by providing flexible partitions on the periphery of the unit cells.

[0024] The flexible bulkhead of one embodiment includes a conductive binder for lithium ions, thereby imparting flexibility to an all-solid-state battery module while preventing a decrease in cell performance due to a decrease in lithium ion conductivity.

[0025] Figure 1 is a cross-sectional view showing an all-solid-state secondary battery according to one embodiment.

[0026] FIG. 2 is a cross-sectional view showing the formation of a lithium metal layer of an all-solid-state secondary battery according to one embodiment.

[0027] Figure 3 is a plan view of an all-solid-state secondary battery module according to a first embodiment of the present invention.

[0028] Figure 4 is a cross-sectional view taken along line IV-IV of Figure 3.

[0029] Figure 5 is a cross-sectional view of an all-solid-state secondary battery module according to a second embodiment of the present invention.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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; for example, "A or B" is interpreted to include A, B, A+B, etc.

[0034] Cathode for all-solid-state secondary batteries

[0035] 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 comprises a positive electrode active material, a sulfide-based solid electrolyte, a fluorine-based resin binder, and vanadium oxide.

[0036] 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.

[0037] 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.

[0038] vanadium oxide

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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 itself may block the movement path of electrons and ions, thereby deteriorating battery performance.

[0044] Fluorine resin binder

[0045] 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.

[0046] 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.

[0047] 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.

[0048] positive electrode active material

[0049] 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.

[0050] Li a A 1-b X b D2(0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5);

[0051] Li a A 1-b Xb O 2-c D c (0.90 ≤ a ≤ 1.8, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05);

[0052]

[0053] *46 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);

[0054] 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);

[0055]

[0056] *48 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);

[0057] 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);

[0058] 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);

[0059] 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);

[0060] 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);

[0061] 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);

[0062] 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);

[0063] 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);

[0064] Li a NiG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0065] Li a CoG b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0066] Li a Mr 1-b G b O2(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0067] Li a Mn2G b O4(0.90 ≤ a ≤ 1.8, 0.001 ≤ b ≤ 0.1);

[0068] Li a Mn 1-g G g PO4(0.90 ≤ a ≤ 1.8, 0 ≤ g ≤ 0.5);

[0069] QO2; QS2; LiQS2;

[0070] V2O5; LiV2O5;

[0071] LiZO2;

[0072] LiNiVO4;

[0073] Li (3-f) J2(PO4)3(0 ≤ f ≤ 2);

[0074] Li (3-f) Fe2(PO4)3(0 ≤ f ≤ 2);

[0075] Li a FePO4(0.90 ≤ a ≤ 1.8).

[0076] 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.

[0077] 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).

[0078] 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.

[0079] [Chemical Formula 1]

[0080] Li a1 Ni x1 M 1 y1 M 2 1-x1-y1 O2

[0081] 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.

[0082] [Chemical Formula 2]

[0083] Li a2 Co x2 M 3 1-x2 O2

[0084] 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.

[0085] [Chemical Formula 3]

[0086] Li a3 Fe x3 M 4 (1-x3) PO4

[0087] 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.

[0088] 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.

[0089] 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.

[0090] Sulfide-based solid electrolyte

[0091] 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. mS n (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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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 the electrode layer and the 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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 this content range is satisfied, the positive electrode for an all-solid-state secondary battery can implement high capacity and high ionic conductivity while maintaining high adhesiveness, and the viscosity of the positive electrode composition can be maintained at an appropriate level, thereby improving processability.

[0100] Challenge

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] All-solid-state secondary battery

[0106] 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.

[0107] Fig. 1 is a cross-sectional view of an all-solid-state secondary battery according to one embodiment. Referring to Fig. 1, the all-solid-state secondary battery (100) may have a structure in which an electrode assembly in which a negative electrode (400) including a negative electrode current collector (401) and a negative electrode active material layer (403), a solid electrolyte layer (300), and a positive electrode (200) including a positive electrode active material layer (203) and a positive electrode current collector (201) are laminated is housed in a case such as a pouch. The all-solid-state battery (100) may further include an elastic layer (500) on the outer side of at least one of the positive electrode (200) and the negative electrode (400). Although Fig. 1 illustrates one electrode assembly including a negative electrode (400), a solid electrolyte layer (300), and a positive electrode (200), an all-solid-state battery may be manufactured by laminating two or more electrode assemblies.

[0108] cathode

[0109] An anode for an all-solid-state battery may include, for example, a current collector and a layer of anode active material positioned on the current collector. The layer of anode active material includes a cathode active material and may further include a binder, a conductive material, and / or a solid electrolyte.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] In one embodiment, the negative electrode active material layer further comprises a binder and may optionally further comprise 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 comprises a conductive material, the negative electrode active material layer may comprise 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] FIG. 2 is a schematic cross-sectional view of an all-solid-state secondary battery including a precipitation-type negative electrode according to one embodiment. Referring to FIG. 2, the precipitation-type negative electrode (400') may include a current collector (401) and a negative electrode coating layer (405) positioned on the current collector. An all-solid-state battery including such a precipitation-type negative electrode (400') starts initial charging in a state in which no negative electrode active material is present, and upon charging, a high-density lithium metal or the like is precipitated between the current collector (401) and the negative electrode coating layer (405) to form a lithium metal layer (404), 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 (400') may include a current collector (401), a lithium metal layer (404) positioned on the current collector, and a negative electrode coating layer (405) positioned on the metal layer. The above lithium metal layer (404) refers to a layer in which lithium metal, etc. 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.

[0127] The above cathode coating layer (405) may include a metal, a carbon material, or a combination thereof that acts as a catalyst.

[0128] 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.

[0129] 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.

[0130] When the above-described negative electrode coating layer (405) 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 (405) may include, for example, a carbon material supported with a catalytic metal, or may include a mixture of metal particles and carbon material particles.

[0131] The above cathode coating layer (405) may include, for example, the metal and amorphous carbon, in which case it can effectively promote the precipitation of lithium metal.

[0132] The above cathode coating layer (405) may further include a binder, and the binder may be a conductive binder. In addition, the above cathode coating layer (405) may further include general additives such as fillers, dispersants, and ionic conductive agents.

[0133] The thickness of the cathode coating layer (405) may be, for example, 100 nm to 20 ㎛, or 500 nm to 10 ㎛, or 1 ㎛ to 5 ㎛.

[0134] The above-described precipitated negative electrode (400') 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 (404) 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.

[0135] solid electrolyte layer

[0136] The solid electrolyte layer (300) 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.

[0137] In one example, the solid electrolyte included in the positive electrode (200) and the solid electrolyte included in the solid electrolyte layer (300) may include the same compound or different compounds. For example, when both the positive electrode (200) and the solid electrolyte layer (300) 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 (200) and the solid electrolyte layer (300) 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.

[0138] Meanwhile, the average particle diameter (D50) of the solid electrolyte included in the positive electrode (200) may be smaller than the average particle diameter (D50) of the solid electrolyte included in the solid electrolyte layer (300). 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 (200) 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 (300) 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.

[0139] 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.

[0140] 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.

[0141] The thickness of the solid electrolyte layer may be, for example, 10 ㎛ to 150 ㎛.

[0142] The above solid electrolyte layer may further include an alkali metal salt, and / or an ionic liquid, and / or a conductive polymer.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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-.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] FIG. 3 is a plan view of an all-solid-state secondary battery module according to a first embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line IV-IV of FIG. 3. Referring to FIGS. 3 and 4, the all-solid-state secondary battery module (1) of the first embodiment includes unit cells (UC), a flexible partition wall (10), and tab members (20).

[0153] The unit cells (UC) are formed as an all-solid-state secondary battery including a stacked negative electrode (410), a solid electrolyte layer (310), and a positive electrode (210). The single-sided positive electrode (210) has a positive electrode active material layer (213) on one surface of a positive electrode current collector (211). The positive electrode active material layer (213) can be formed by coating a positive electrode active material slurry on one surface of a positive electrode current collector (211) or bonding a solvent-free positive electrode active material.

[0154] The negative electrode (410) may have a negative electrode active material layer (413) on a negative electrode current collector (411). The solid electrolyte layer (300) may be formed as a film by directly coating a solid electrolyte film on the negative electrode active material layer (413).

[0155] The partition wall (10) is arranged on the outer side in the first direction (x-axis direction) and the second direction (y-axis direction) intersecting the stacking direction (z-axis direction) of the unit cells (UC) and is arranged between neighboring unit cells (UC). The partition wall (10) provides flexibility in the first direction (x-axis direction) and the second direction (y-axis direction) in the all-solid-state secondary battery module (1) due to its flexibility.

[0156] Additionally, the bulkhead (10) includes a lithium ion conductive binder. The lithium ion conductive binder compensates for the reduction in lithium ion conductivity in the all-solid-state secondary battery module (1) by imparting flexibility to the bulkhead (10) by including a polymer. Accordingly, a reduction in the performance of the unit cells (UC) is prevented.

[0157] The bulkhead (10) includes both a form in which a skeleton structure made of a porous inorganic or organic material is filled with an ion-conducting polymer and a form made of an ion-conducting polymer.

[0158] The bulkhead (10) does not contain any active material of the positive or negative electrode. The bulkhead (10) is 10 -8 It has an electronic conductivity of less than S / cm. The material that can be used as the partition wall (10) is a porous inorganic material, and a structure with high porosity such as zeolite or SiO2 can be used as the skeleton.

[0159] In addition, the organic skeleton structure includes porous PTFE (70-80% porous product), PE, and PP materials used as secondary battery separators. The ion-conducting materials that can be inserted into the pores or used alone are PVdF, PVdF-HFP, H-NBR, acrylate binder, PEO series binder, and LiTFSI, LiFSI, LiCFSI, LiBF4, LiClO4, LiAsF6, LiCF3SO3, LiPF6, and all salts, as a mixture of 10-3 S / cm~10 -6 It has a Li ion conductivity of S / cm.

[0160] Table 1 shows the results of Experimental Examples 1 to 4 and Comparative Examples 1 to 2 for a partition wall (10) having a skeleton structure made of porous inorganic or organic material and filled with an ion-conducting polymer.

[0161] Volume ratio of structural organic matter / binder + salt ion conductivity relative ratio (%) Experimental example 10100100 Experimental example 2109085 Experimental example 3257564 Experimental example 4406051 Comparative example 155452 Comparative example 265351

[0162] Referring to Table 1, in the case of having a porous partition wall (10), in Experimental Examples 1 to 4, the volume ratio of the skeleton structure is 0% to 40%, and the volume ratio of the organic substance, binder, and salt is 60% to 100%. As the skeleton structure increases from 0% to 40%, the volume ratio of the organic substance, binder, and salt decreases from 100% to 60%. Accordingly, the relative ratio of ionic conductivity decreases from 100% to 51%. The reason why the lower limit of the volume ratio of the skeleton structure is 0% is because when the volume ratio of the skeleton structure becomes 0, the volume ratio of the ion-conductive organic substance, binder, and salt in the partition wall (10) becomes 100%. At this time, the relative ratio of ionic conductivity is 100%. When the volume ratio of the skeletal structure exceeds 40%, the flexible characteristics of the partition wall (10) are lost, and the relative ratio of ion conductivity in the partition wall (10) is proportionally reduced.

[0163] Compared to Experimental Examples 1 to 4, Comparative Examples 1 and 2 have a volume ratio of the skeletal structure of 55% to 65%, and a volume ratio of organic matter, binder, and salt of 45% to 35%. In this case, it can be seen that the relative ratio of ionic conductivity is greatly reduced to 2% and 1%, respectively. The relative ratio of ionic conductivity is based on the relative ratio of ionic conductivity of 100% in Experimental Example 1, where the volume ratio of the skeletal structure is 0%, and the volume ratio of organic matter, binder, and salt is 100%.

[0164] Table 2 shows the results of Experimental Examples 1 to 4 and Comparative Examples 1 to 2 for a partition wall (10) made of an ion-conducting polymer.

[0165] Weight ratio of organic matter / binder salt ion conductivity (%) Experimental example 11001075 Experimental example 21005080 Experimental example 3100100100 Experimental example 410020085 Comparative example 1100050 Comparative example 210025045

[0166] Referring to Table 2, in the case of having a porous partition wall (10), in Experimental Examples 1 to 4, the ratio of the organic material including the binder and the lithium salt varies depending on the type of the organic material, and the lithium salt can be mixed in a ratio of 10% to 200% by weight relative to the organic material. This is because the ionic conductivity decreases when the lithium salt is less than 10% by weight. At this time, the relative ratio of the ionic conductivity is 75%. When the lithium salt exceeds 200% by weight, the lithium salt is precipitated and hardens, so flexibility is lost. At this time, the relative ratio of the ionic conductivity is 95%. Compared to Experimental Examples 1 to 4, Comparative Examples 1 and 2 have a weight ratio of lithium salt of 0% and 250%. In this case, it can be seen that the relative ratio of the ionic conductivity is greatly reduced to 50% and 45%. The relative ratio of ionic conductivity is based on the fact that the relative ratio of ionic conductivity is 100% in the case of Experimental Example 3 where the weight ratio of the organic material including the skeletal binder and the lithium salt is 100 wt%, 100 wt%. The unit cells (UC) have negative electrodes (410) arranged on one side in the stacking direction and positive electrodes (210) arranged on the other side in the stacking direction. The tab members (20) include a first connection tab (21) and a second connection tab (22). The first connection tab (21) connects the current collectors (411) of the negative electrodes (41) arranged on one side (lower side) in the stacking direction to each other, and the second connection tab (22) connects the current collectors (211) of the positive electrodes (210) arranged on the other side (upper side) in the stacking direction to each other.

[0167] The unit cells (UC) are connected in parallel by the first and second tabs (21, 22). Therefore, the all-solid-state secondary battery module (1) has a configuration in which a plurality of unit cells (UC) are connected in parallel, and can supply a large amount of power.

[0168] Below, a second embodiment is described. Compared to the first embodiment, descriptions of identical configurations are omitted, and descriptions of different configurations are provided.

[0169] Fig. 5 is a cross-sectional view of an all-solid-state secondary battery module according to a second embodiment of the present invention. Referring to Fig. 5, the all-solid-state secondary battery module (2) of the second embodiment includes a first unit cell (UC1) and a second unit cell (UC2).

[0170] For example, the first unit cell (UC1) has a structure in which the positive electrode (210) is positioned upward and the negative electrode (410) is positioned downward. The second unit cell (UC2) has a structure in which the negative electrode (410) is positioned upward and the positive electrode (210) is positioned downward.

[0171] Therefore, when the first and second unit cells (UC1, UC2) are arranged sequentially in the first and second directions, the cathode (410) and the anode (210) are arranged alternately in the first and second directions.

[0172] The tab members (30) include a first connection tab (31) and a second connection tab (32). The first connection tab (31) connects the current collectors (411, 211) of the positive and negative electrodes (41) arranged on one side (lower side) in the stacking direction to each other, and the second connection tab (32) connects the current collectors (211, 411) of the positive and negative electrodes (210, 410) arranged on the other side (upper side) in the stacking direction to each other.

[0173] The first and second unit cells (UC1, UC2) are connected in series by the first and second tabs (31, 32). Therefore, the all-solid-state secondary battery module (2) is configured to connect a plurality of first and second unit cells (UC1, UC2) in series, thereby supplying high-output power.

[0174] The above description is only one embodiment for implementing the all-solid-state battery manufacturing method, process plate, and all-solid-state battery according to the present disclosure, and the present disclosure is not limited to the above-described embodiment, and as claimed in the following claims, it will be understood that the technical spirit of the present disclosure encompasses a range in which various modifications can be implemented by anyone having ordinary skill in the art to which the present invention pertains without departing from the gist of the present disclosure.

[0175] - Explanation of symbols -

[0176] 1, 2: All-solid-state secondary battery module 10: Bulkhead

[0177] 20: Absence of tab 21: First connection tab

[0178] 22: Second connection tab 30: Tab members

[0179] 31: First connection tab 32: Second connection tab

[0180] 210: Anode 211: Anode current collector

[0181] 213: Cathode active material layer 310: Solid electrolyte layer

[0182] 410: Cathode 411: Cathode current collector

[0183] 413: Negative active material layer UC: Unit cell

[0184] UC1: First unit cell UC2: Second unit cell

Claims

1. Unit cells of an all-solid-state secondary battery comprising a cathode, a solid electrolyte layer, and a cathode; A flexible partition arranged on the outer side in the first direction and the second direction intersecting the stacking direction of the unit cells and arranged between the unit cells; and An all-solid-state secondary battery module including tab members arranged at both ends of the bulkhead in the stacking direction to electrically connect the unit cells.

2. In paragraph 1, The above unit cells are The cathodes are placed on one side of the above-mentioned stacking direction, An all-solid-state secondary battery module in which the cathodes are arranged on different sides of the stacking direction.

3. In paragraph 1, The above tabs are absent A first connecting tab that connects the current collectors of the negative electrodes arranged on one side of the stacking direction to each other, and An all-solid-state secondary battery module, comprising a second connecting tab for connecting the current collectors of the positive electrodes arranged on the other side of the stacking direction.

4. In paragraph 1, The above unit cells are An all-solid-state secondary battery module in which cathodes and anodes are arranged alternately in the first direction and the second direction.

5. In paragraph 1, The above tabs are absent A first connecting tab that connects the current collector of the negative electrode and the current collector of the positive electrode, which are arranged on one side of the stacking direction, to each other, and An all-solid-state secondary battery module, comprising a second connecting tab that connects the current collector of the positive electrode and the current collector of the negative electrode, which are arranged on the other side of the stacking direction.

6. In paragraph 1, An all-solid-state secondary battery module, wherein the flexible bulkhead comprises a conductive binder of lithium ions.

7. In paragraph 1, The above flexible bulkhead A skeleton structure made of porous inorganic or organic materials, and An all-solid-state secondary battery module comprising an ion-conducting polymer filled in the above-mentioned skeletal structure.

8. In paragraph 7, The above porous inorganic material An all-solid-state secondary battery module comprising either zeolite or SiO2.

9. In paragraph 7, The above porous organic material An all-solid-state secondary battery module comprising porous PTFE, PE, or PP materials used as a secondary battery separator.

10. In paragraph 7, The above ion conductive polymer It includes PVdF, PVdF-HFP, H-NBR, Acrylate binder, PEO series binder and one of LiTFSI, LiFSI, LiCFSI, LiBF4, LiClO4, LiAsF6, LiCF3SO3, LiPF6, which can be used alone or with pores. An all-solid-state secondary battery module having a Li ion conductivity of 10-3 S / cm to 10-6 S / cm as a mixed material with salt.

11. In paragraph 7, In the above flexible bulkhead, An all-solid-state secondary battery module, wherein the skeleton structure has a volume ratio of 0 to 40%, and the volume ratios of the organic material, binder, and salt have a volume ratio of 60 to 100%.

12. In paragraph 11, The above flexible bulkhead An all-solid-state secondary battery module having a relative ratio of ionic conductivities of 51% to 100%.

13. In paragraph 1, The above flexible bulkhead An all-solid-state secondary battery module formed of an ion-conducting polymer.

14. In paragraph 13, In the above flexible bulkhead An all-solid-state secondary battery module having a lithium salt content of 10 to 200 wt% relative to organic matter including a binder.

15. In paragraph 14, The above flexible bulkhead An all-solid-state secondary battery module having a relative ratio of ionic conductivity of 75% to 100%.

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