All-solid secondary battery and method of preparing all-solid secondary battery

1 . An all-solid secondary battery comprising:

a positive electrode layer comprising a positive active material;

a negative electrode layer comprising a negative electrode current collector and a first negative active material layer; and

a solid electrolyte layer between the positive electrode layer and the negative electrode layer, the solid electrolyte layer comprising a solid electrolyte,

wherein the first negative active material layer is adjacent to the solid electrolyte layer, and

the first negative active material layer comprises a multi-component metal composite comprises at least one compound represented by Formula 1:

(M1) a (M2) b (M3) c (X) d   Formula 1

wherein, in Formula 1;

an atomic ratio of (b+c+d):(a+b+c+d) in the multi-component metal composite is in a range of about 0.5:1 to about 0.85:1, and

an atomic ratio of (b+c+d): a is in a range of about 1:1 to about 5.51:1,

M1 is a Group 1 element, Group 2 element, or a combination thereof,

M2 is an element of Sc, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Al, Ge, Y, Zr, Hf, Rh, Cd, In, B, Si, P, F, Cl, Br, I, S, As, Re, Hg, Tl, Pb, or a combination thereof, and optionally C, N, or a combination thereof,

M3 is an element of Ti, Nb, Sb, Bi, Ta, Mo, Ru, Pd, Ag, Sn, Se, Te, W, Os, Ir, Pt, Au, or a combination thereof, and

X is O, N, P, or a combination thereof, and

0.1≤a≤1.0<b≤3, 0<c≤2, and 0.5≤d≤2.

2 . The all-solid secondary battery of claim 1 , wherein the at least one compound of Formula 1,

M1 is Li,

M2 is Ge, Ga, Cu, or a combination thereof,

M3 is Te, Nb, Sb, Bi, Ta, Se, or a combination thereof.

3 . The all-solid secondary battery of claim 1 , wherein the first negative active material layer is a compact layer without pores.

4 . The all-solid secondary battery of claim 1 , wherein an atomic ratio of M1M2M3 to X ion in the multi-component metal composite is about 1.2:1 or greater.

5 . The all-solid secondary battery of claim 1 , wherein the at least one compound of Formula 1 comprises Li a Ge b TecOd, Li a Cu b Te c O d , Li a Sb b Te c O d , Li a Ge b Se c O d , Li a Ga b Te c O d , Li a Zn b Te c O d , Li a Bi b Te c O d , Li a Au b Te c O d , wherein 0<b≤2, 0<c<1, Li a As b Te c O d , Li a Sn b Te c O d , wherein 0<b≤1, 0<c≤1, Li a Sr b Te c O d , wherein 0<b≤1, 0<c≤1, Li a Y b Te c O d , Li a Zr b Te c O d , wherein 0<c≤1, —Li a Nb b Te c O d , wherein 0<b≤2, 0<c≤1, Li a Mo b Te c O d , wherein 0<b≤2, 0<c≤1, Li a Ag b Te c O d , wherein, Li a In b Te c O d , —Li a Pd b Te c O d , wherein 0<b≤2, 0<c≤1, or a combination thereof.

6 . The all-solid secondary battery of claim 1 , wherein the at least one compound of Formula 1 comprises a compound of Formula 2 or a compound of Formula 3:

Li a Ge b Te c O d   Formula 2

wherein, in Formula 2, 0<b≤2, and

Li a Cu b Te c O d   Formula 3

wherein, in Formula 3.

7 . The all-solid secondary battery of claim 1 , wherein the at least one compound of Formula 1 is Li 1 Ge 0.79 Te 0.53 O 1.81 , Li 1 Ge 1.25 Te 1.39 O 1.39 , Li 1 Ge 1.07 Te 0.83 O 0.73 , Li 1 Ge 0.55 Te 0.45 O 0.57 , Li 1 Cu 2.34 Te 1.44 O 0.76 , or a combination thereof.

8 . The all-solid secondary battery of claim 1 , further comprising a second negative active material layer between the negative electrode current collector and the first negative active material layer,

wherein a second negative active material of the second negative active material layer comprises a carbonaceous negative active material, and optionally a metal or a metalloid negative active material.

9 . The all-solid secondary battery of claim 8 , wherein the carbonaceous negative active material is in a form of a particle, and an average diameter of the carbonaceous negative active material particle is about 4 micrometers or less.

10 . The all-solid secondary battery of claim 8 , wherein the carbonaceous negative active material comprises amorphous carbon, and

if present, the metal or the metalloid negative active material comprises indium, silicon, gallium, tin, aluminum, titanium, zirconium, niobium, germanium, antimony, bismuth, gold, platinum, palladium, magnesium, palladium, silver, zinc, or a combination thereof.

11 . The all-solid secondary battery of claim 8 , wherein the metal or the metalloid negative active material is present, and the second negative active material layer comprises: a composite of a first particle comprising amorphous carbon and a second particle comprising the metal or the metalloid, wherein a content of the second particle is in a range of about 1 weight percent to about 60 weight percent, based on a total weight of the composite; or a mixture of the first particle comprising amorphous carbon and the second particle comprising the metal or the metalloid, and wherein a content of the second particle is in a range of about 1 weight percent to about 60 weight percent, based on a total weight of the mixture.

12 . The all-solid secondary battery of claim 8 , further comprising a metal layer comprising lithium or lithium alloy disposed between the negative electrode current collector and the second negative active material layer, or between the second negative active material layer and the first negative active material layer.

13 . The all-solid secondary battery of claim 8 , wherein a region between the negative electrode current collector and the first negative active material layer is a lithium metal-free region that does not comprise lithium metal.

14 . The all-solid secondary battery of claim 1 , further comprising a metal layer comprising lithium or lithium alloy between the negative electrode current collector and the first negative active material layer.

15 . The all-solid secondary battery of claim 1 , wherein a reduction potential of a lithium ion in the first negative active material layer is greater than a reduction potential of the solid electrolyte.

16 . The all-solid secondary battery of claim 1 , wherein the solid electrolyte is an oxide solid electrolyte, a sulfide solid electrolyte, or a combination thereof, and

the oxide solid electrolyte is at least one of Li 1+x+y Al x Ti 2−x Si y P 3−y O 12 , wherein 0<x<2 and 0≤y<3, BaTiO 3 , Pb(Zr p Ti 1−p )O 3 , wherein 0≤p≤1, Pb 1−x La x Zr 1−y Ti y O 3 , wherein 0≤x<1 and 0≤y<1, Pb(Mg 1/3 Nb 2/3 )O 3 —PbTiO 3 , HfO 2 , SrTiO 3 , SnO 2 , CeO 2 , Na 2 O, MgO, NiO, CaO, BaO, ZnO, ZrO 2 , Y 2 O 3 , Al 2 O 3 , TiO 2 , SiO 2 , Li 3 PO 4 , Li x Ti y (PO 4 ) 3 , wherein 0<x<2 and 0<y<3, Li x Al y Ti z (PO 4 ) 3 , wherein 0<x<2, 0<y<1, and 0<z<3, Li 1+x+y (Al p Ga 1−p ) x (Ti q Ge 1−q ) 2−x Si y P 3−y O 12 , wherein 0≤x≤1, 0≤y≤1, 0≤p≤1, and 0≤q≤1, Li x La y TiO 3 , wherein 0<x<2 and 0<y<3, Li 2 O, LiOH, Li 2 CO 3 , LiAlO 2 , Li 2 O—Al 2 O 3 —SiO 2 —P 2 O 5 —TiO 2 —GeO 2 , Li 3+x La 3 M 2 O 12 , wherein M is Te, Nb, or Zr, and x is an integer from 1 to 10, and

the sulfide solid electrolyte is at least one of Li 2 S—P 2 S 5 , Li 2 S—P 2 S 5 —LiX, wherein X is a halogen, Li 2 S—P 2 S 5 —Li 2 O, Li 2 S-P 2 Ss-Li 2 O—LiI, Li 2 S—SiS 2 , Li 2 S—SiS 2 —LiI, Li 2 S—SiS 2 —LiBr, Li 2 S—SiS 2 —LiCl, Li 2 S—SiS 2 —B 2 S 3 —LiI, Li 2 S—SiS 2 —P 2 S 5 —LiI, Li 2 S—B 2 S 3 , Li 2 S—P 2 S 5 —Z m S n , wherein m and n are positive integers and Z is Ge, Zn, Ga, or a combination thereof, Li 2 S—GeS 2 , Li 2 S—SiS 2 —Li 3 PO 4 , and Li 2 S—SiS 2 -Li p MO q , wherein p and q are positive integers and Mis P, Si, Ge, B, Al, Ga, In, or a combination thereof, Li 7−x PS 6−x Cl x , wherein 0<x<2, Li 7−x PS 6−x Br x , wherein 0<x<2, Li 7−x PS 6−x I x , wherein 0<x<2.

17 . A method of preparing the all-solid secondary battery of claim 1 , the method comprising:

providing a solid electrolyte layer;

disposing a pre-first negative active material layer on a first surface of the solid electrolyte layer;

heat-treating the pre-first negative active material layer at a temperature of less than about 600° C. to prepare a first negative active material layer;

disposing a negative electrode current collector on the first negative active material layer; and

disposing a positive active material layer on a second surface of the solid electrolyte layer to prepare the all-solid secondary battery.

18 . The method of claim 17 , wherein before the disposing of the negative electrode current collector on the first negative active material layer, a second negative active material layer is formed on the first negative active material layer, and then the negative electrode current collector is disposed on the second negative active material layer.

19 . The method of claim 18 , wherein the second negative active material layer comprises

a composite of a first particle comprising amorphous carbon and a second particle comprising a metal or a metalloid,

wherein a content of the second particle is in a range of about 1 weight percent to about 60 weight percent, based on a total weight of the composite, or

a mixture of the first particle comprising amorphous carbon and the second particle comprising the metal or the metalloid, and

wherein a content of the second particle is in a range of about 1 weight percent to about 60 weight percent, based on a total weight of the mixture.

20 . An all-solid secondary battery comprising:

a positive electrode layer comprising a positive active material;

a negative electrode layer comprising a negative electrode current collector, a first negative active material layer, and a metal layer comprising lithium or lithium alloy between the negative electrode current collector and the first negative active material layer;

a solid electrolyte layer between the positive electrode layer and the negative electrode layer, the solid electrolyte layer comprising a solid electrolyte,

wherein

the first negative active material layer is adjacent to the solid electrolyte layer,

the first negative active material layer comprises a multi-component metal composite comprising M1, M2, M3, and X,

an atomic ratio of M2M3X to M1M2M3X in the multi-component metal composite is in a range of about 0.5:1 to about 0.85:1,

an atomic ratio of M2M3X to M1 ion is in a range of about 1:1 to about 5.51:1, and

an atomic ratio of M1M2M3 to X ion in the multi-component metal composite is about 1.2:1 or greater,

wherein M1 is a Group 1 element, Group 2 element, or a combination thereof,

M2 is Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Al, Ge, Y, Zr, Hf, Rh, Cd, In, B, Si, P, F, Cl, Br, I, S, As, Re, Hg, Tl, Pb, or a combination thereof, and optionally C, N, or a combination thereof,

M3 is an element of Ti, Nb, Sb, Bi, Ta, Mo, Ru, Pd, Ag, Sn, Se, Te, W, Os, Ir, Pt, Au, or a combination thereof, and

X is O, N, P, or a combination thereof.