All-solid-state battery, manufacturing method therefor, secondary battery comprising same and monolithic battery module comprising same

1. An all-solid-state battery comprising:

a battery supporting member including an oxide-based solid electrolyte of a garnet structure;

a positive electrode disposed on a first surface of the battery supporting member; and

a negative electrode disposed on a second surface of the battery supporting member,

wherein the positive electrode includes

a positive active material layer in contact with the first surface of the battery supporting member and including a positive active material represented by Chemical Formula 1 and an ion conductor, and a conductive material, and

a positive current collector disposed on the positive active material layer:

Li a1 Ni b1 Co c1 Mn d1 M1 e1 M2 f1 O 2−f1   [Chemical Formula 1]

(in Chemical Formula 1,

0.97≤a1≤1.07, 0.75≤b1≤0.95, 0.03≤c1≤0.13, 0.001≤d1≤0.12, 0≤e1≤0.05, 0≤f1≤0.01, b1+c1+d1+e1+f1=1,

M1 is one selected from Na, Mg, Al, Si, K, Ca, Sc, Ti, V, B, Cr, Cu, Zn, Ga, Ge, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Ba, W, and combinations thereof, and

M2 is one selected from N, F, P, S, Cl, Br, I, and combinations thereof), and

wherein

the ion conductor is trilithium borate (Li 3 BO 3 ) and is included in a 5 volume % to 15 volume % range with reference to a total volume of the positive active material layer and

the positive active material is included in a 60 volume % to 80 volume % range with reference to the total volume of the positive active material layer, and

the conductive material is included in a 10 volume % to 35 volume % range with reference to the total volume of the positive active material layer.

2. The all-solid-state battery of claim 1 , wherein,

in Chemical Formula 1, b1 is 0.8≤b1≤0.95.

3. The all-solid-state battery of claim 1 , wherein

an average particle size of the positive active material is 1 μm to 10 μm.

4. The all-solid-state battery of claim 1 ,

wherein the percentage ratio of the volume of a given material to the total volume of the positive active material layer is assumed to be the volume % of the given material in the positive active material layer, wherein the volume (cm 3 ) of each given material used in the positive active material layer is calculated from the mass (g) and nominal density (g/cm 3 ) of each material, and the sum of the volumes of the materials is used as the total volume of the positive active material layer.

5. The all-solid-state battery of claim 1 , wherein

the oxide-based solid electrolyte of the garnet structure is represented by Chemical Formula 2 below:

Li (7−a2−x) M3 x La 3 Zr 2−y−w Ta y M4 z M5 w O 12   [Chemical Formula 2]

(in Chemical Formula 2,

M3 is selected from a group including Al, Na, K, Rb, Cs, Fr, Mg, Ca, and combinations thereof,

M4 is B,

M5 is selected from a group including Nb, Sb, Sn, Hf, Bi, W, Se, Ga, Ge, and combinations thereof,

0≤a2≤0.1,

0≤x≤0.5,

0.005≤y≤0.5,

0.1≤z≤0.5, and

0≤w<0.15).

6. The all-solid-state battery of claim 1 ,

wherein the percentage ratio of the volume of a given material to the total volume of the positive active material layer is assumed to be the volume % of the given material in the positive active material layer, wherein the volume (cm 3 ) of each given material used in the positive active material layer is calculated from the mass (g) and nominal density (g/cm 3 ) of each material, and the sum of the volumes of the materials is used as the total volume of the positive active material layer.

7. The all-solid-state battery of claim 6 , wherein

the conductive material includes one or more conductive materials selected from a group including cobalt oxide (Co 3 O 4 ), cerium oxide (CeO 2 ), indium tin oxide (ITO), indium zinc oxide (IZO), lanthanum cobalt oxide (LaCoO 3 ), copper manganese oxide (Cu 2 MnO 4 ), and silver (Ag).

8. The all-solid-state battery of claim 1 , wherein

the positive current collector includes one material selected from stainless steel (SUS, steel use stainless), gold (Au), platinum (Pt), nickel (Ni), aluminum (AI), molybdenum (Mo), carbon (C), silver (Ag), indium (In), and tin (Sn), or two or more thereof.

9. The all-solid-state battery of claim 1 , wherein

the negative electrode includes a lithium metal, an alloy of the lithium metal, lithium titanate (Li 4 Ti 5 O 12 ), or a combination thereof.

10. A manufacturing method of an all-solid-state battery comprising:

forming a positive active material layer by coating a positive active material slurry on a first surface of an electrode supporting member including an oxide-based solid electrolyte of a garnet structure;

forming a positive current collector on the positive active material layer; and

forming a negative electrode on a second surface of the electrode supporting member,

wherein the positive active material slurry includes an ion conductor, and a conductive material, and a positive active material represented by Chemical Formula 1 below:

Li a1 Ni b1 Co c1 Mn d1 M1 e1 M2 f1 O 2−f1   [Chemical Formula 1]

(in Chemical Formula 1,

0.97≤a1≤1.07, 0.75≤b1≤0.95, 0.03≤c1≤0.13, 0.001≤d1≤0.12, 0≤e1≤0.05, 0≤f1≤0.01, and b1+c1+d1+e1+f1=1,

M1 is one selected from Na, Mg, Al, Si, K, Ca, Sc, Ti, V, B, Cr, Cu, Zn, Ga, Ge, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Ba, W, and combinations thereof, and

M2 is one selected from N, F, P, S, Cl, Br, I, and combinations thereof), and

wherein

the ion conductor is trilithium borate (Li 3 BO 3 ) and is included in a 5 volume % to 15 volume % range with reference to a total volume of the positive active material layer and

the positive active material is included in a 60 volume % to 80 volume % range with reference to the total volume of the positive active material layer, and

the conductive material is included in a 10 volume % to 35 volume % range with reference to the total volume of the positive active material layer.

11. The manufacturing method of claim 10 , wherein

the oxide-based solid electrolyte of the garnet structure is represented by Chemical Formula 2 below, and

the all-solid-state battery is manufactured by including molding the oxide-based solid electrolyte of the garnet structure into the electrode supporting member having a thickness of 60 μm to 1000 μm:

Li (7−a2−x) M3 x La 3 Zr 2−y−w Ta y M4 z M5 w O 12   [Chemical Formula 2]

(in Chemical Formula 2,

M3 is selected from a group including Al, Na, K, Rb, Cs, Fr, Mg, Ca, and combinations thereof,

M4 is B,

M5 is selected from a group including Nb, Sb, Sn, Hf, Bi, W, Se, Ga, Ge, and combinations thereof,

0≤a2≤0.1,

0≤x≤0.5,

0.005≤y≤0.5,

0.1≤z≤0.5, and

0≤w<0.15).

12. The manufacturing method of claim 10 , wherein

the conductive material includes one or more selected from a group including cobalt oxide (Co 3 O 4 ), cerium oxide (CeO 2 ), indium tin oxide (ITO), indium zinc oxide (IZO), lanthanum cobalt oxide (LaCoO 3 ), copper manganese oxide (Cu 2 MnO 4 ), and silver (Ag).

13. The manufacturing method of claim 10 , wherein

the forming of the negative electrode on the second surface of the electrode supporting member is performed by one of a method of forming the negative electrode of a thin film by vacuum-thermally depositing a negative electrode active material of a lithium metal, an alloy of a lithium metal, lithium titanate (Li 4 Ti 5 O 12 ), or a combination thereof on the second surface of the electrode supporting member, or a method of punching a foil made of the negative electrode active material and applying heat to the second surface of the electrode supporting member to attach the punched foil.

14. A secondary battery comprising:

a unit cell composed of an all-solid-state battery of claim 1 ;

a first exterior material including an opening at one surface and receiving the unit cell; and

a second exterior material sealing the opening of the first exterior material.

15. The secondary battery of claim 14 , wherein

the first exterior material includes at least one material among ceramic, glass, and a metal including an insulation layer at a surface.

16. The secondary battery of claim 14 , wherein

the second exterior material includes at least one metal material of Kovar, Invar, stainless steel, copper, and nickel.