Composite solid electrolyte, method of preparing the same, and electrochemical device including the same

1. A composite solid electrolyte comprising:

a first solid electrolyte layer comprising a halide solid electrolyte;

a second solid electrolyte layer comprising an oxide solid electrolyte; and a lithium ion-conductive interlayer between the first solid electrolyte layer and the second solid electrolyte layer,

wherein the lithium ion-conductive interlayer comprises a composition in which a reaction energy of the lithium ion-conductive interlayer with respect to the first solid electrolyte is about −50 millielectron-volts per atom or greater,

wherein the reaction energy of the lithium ion-conductive interlayer with respect to the first solid electrolyte is represented as Equation 1 (E1)

E 1=(Thermodynamic energy of reaction product of the first solid electrolyte and the interlayer)−(Thermodynamic energy of the first solid electrolyte (reaction product 1)+Thermodynamic energy of the interlayer (reaction product 2))

wherein the thermodynamic energies are values obtained through density functional theory calculation.

2. The composite solid electrolyte of claim 1 ,

wherein the lithium ion-conductive interlayer has an ionic conductivity of about 10 −3 mS/cm or greater.

3. The composite solid electrolyte of claim 1 ,

wherein the lithium ion-conductive interlayer comprises a lithium oxide comprising boron, carbon, or a combination thereof.

4. The composite solid electrolyte of claim 1 ,

wherein the lithium ion-conductive interlayer comprises Li 2+x C 1−x B x O 3 wherein 0<x<1, LiF, Li 2 SO 4 , Li 3 AsO 4 , Li 2 CO 3 , Li 3 PO 4 , LiPO 4 , LiCl, Li 4 VO 4 F, Li 3 VO 4 , LiBO 2 , Li 3 BO 3 , Li 2 B 4 O 7 , LiPON, or a combination thereof.

5. The composite of claim 4 , wherein the lithium ion-conductive interlayer comprises lithium fluoride-doped lithium metaborate, silicon-doped lithium tetraborate, lithium metaborate-doped lithium carbonate, lithium orthoborate-doped lithium carbonate, lithium carbonate-doped lithium orthoborate, silicon dioxide-doped lithium orthoborate-lithium carbonate, lithium fluoride-doped lithium orthoborate-lithium carbonate, or a combination thereof.

6. The composite solid electrolyte of claim 1 ,

wherein the lithium ion-conductive interlayer comprises a compound exhibiting peaks at diffraction angles of about 21° 2θ to about 22° 2θ, about 23° 2θ to about 24° 2θ, about 29.5° 2θ to about 30° 2θ, about 30.5° 2θ to about 31° 2θ, about 31.5° 2θ to about 32° 2θ, about 34° 2θ to about 34.5° 2θ, about 36° 2θ, about 37° 2θ, or about 39° 2θ to about 40° 2θ, when analyzed by X-ray diffraction analysis with Cu Kα radiation, or the lithium ion-conductive interlayer comprises a compound exhibiting peaks at diffraction angles of about 21° 2θ to about 22° 2θ, about 23° 2θ to about 24° 2θ, about 29.5° 2θ to about 30° 2θ, about 30.5° 2θ to about 31° 2θ, about 31.5° 2θ to about 32° 2θ, about 34° 2θ to about 34.5° 2θ, about 36° 2θ, about 37° 2θ, and about 39° 2θ to about 40° 2θ, when analyzed by X-ray diffraction analysis with Cu Kα radiation.

7. The composite solid electrolyte of claim 1 , wherein the lithium ion-conductive interlayer comprises Li 2.1 C 0.9 B 0.1 O 3 , Li 2.15 C 0.85 B 0.15 O 3 , Li 2.175 C 0.825 B 0.175 O 3 , Li 2.2 C 0.8 B 0.2 O 3 , Li 2.5 C 0.75 B 0.25 O 3 , Li 2.275 C 0.725 B 0.275 O 3 , Li 2.3 C 0.7 B 0.3 O 3 , Li 2.5 C 0.65 B 0.35 O 3 , Li 2.375 C 0.625 B 0.375 O 3 , Li 2.4 C 0.6 B 0.4 O 3 , Li 2.45 C 0.55 B 0.45 O 3 , Li 2.475 C 0.525 B 0.475 O 3 , Li 2.5 C 0.5 B 0.5 O 3 , Li 2.55 C 0.45 B 0.55 O 3 , Li 2.575 C 0.425 B 0.575 O 3 , or a combination thereof.

8. The composite solid electrolyte of claim 1 , wherein the lithium ion-conductive interlayer has a thickness of about 1 micrometers to about 10 micrometers.

9. The composite solid electrolyte of claim 1 ,

wherein the halide solid electrolyte comprises a compound represented by Formula 1, and the compound represented by Formula 1 has a glass transition temperature of −30° C. or less and a glass or a glass-ceramic structure:

ALi q Q 1−q X—Ga 1−z MzF 3−3z Z 3z   Formula 1

wherein, in Formula 1, Q is Na, K, or a combination thereof,

M is a trivalent cationic element, or a combination thereof,

X is a halogen element other than fluorine, a pseudohalogen, or a combination thereof,

Z is a monovalent anionic element or a combination thereof,

1<A<5, 0<q≤1, and 0≤z<1.

10. The composite solid electrolyte of claim 1 ,

wherein the first solid electrolyte comprises a compound represented by Formula 2:

ALiX-Ga 1-z M z F 3-3z Z 3z   Formula 2

wherein, in Formula 2,

M is a trivalent cationic element or a combination thereof,

X is a halogen element other than fluorine, or a combination thereof,

Z is a monovalent anion element or a combination thereof,

1<A<5, and 0≤z<1.

11. The composite solid electrolyte of claim 1 ,

wherein the first solid electrolyte comprises a compound represented by Formula 3:

ALi q Q 1−q X− a M z Z 3z −b Ga 1−z F 3−3z   Formula 3

wherein, in Formula 3, Q is Na, K, or a combination thereof,

M is a trivalent cationic element or a combination thereof,

X is a halogen element other than fluorine, or a combination thereof,

Z is a monovalent anion or a combination thereof,

0<a≤1, 0<b≤1, 0<a+b, a+b=4−A, 1<A≤3, 0<q≤1, and 0≤z<1, with the proviso that a and b are not both 1.

12. The composite solid electrolyte of claim 1 ,

wherein the first solid electrolyte comprises a compound represented by Formula 4:

ALiX− a M z Z 3z −b Ga 1-z F 3-3z   Formula 4

wherein, in Formula 4, M is a trivalent cationic element, or a combination thereof,

X is a halogen element other than fluorine, or a combination thereof,

Z is a monovalent anionic element, or a combination thereof,

0<a≤1, 0<b≤1, 0<a+b, a+b=4−A, 1<A≤3, and 0≤z<1, with the proviso that a and b are not both 1.

13. The composite solid electrolyte of claim 9 ,

wherein, in Formula 1,

M is In, Sc, Al, TI, Y, B, La, or a combination thereof, and

Z is Cl, Br, I, SCN, OCN, CN, OH, N 3 , or a combination thereof.

14. The composite solid electrolyte of claim 9 ,

wherein, in Formula 1, X is Cl, Br, I, or a combination thereof, and Z is Cl, Br, I, SCN, OCN, CN, OH, N 3 , or a combination thereof.

15. The composite solid electrolyte of claim 9 ,

wherein the compound of Formula 1 is one compound of Formulas 5 to 7:

ALiCl—GaF 3   Formula 5

wherein, in Formula 5, A is 2, 3, or 4,

ALiBr—GaF 3   Formula 6

wherein, in Formula 6, A is 2, 3, or 4,

ALiCl− a M z Z 3z −b GaF 3   Formula 7

wherein, in Formula 7, A is 2 or 3,

Z is Cl or OH,

M is La, In, Sc, Al, TI, Y, B, La, or a combination thereof,

0<a<1, 0<b<1, 0<a+b, a+b=4−A, and 0<z<1.

16. The composite solid electrolyte of claim 9 ,

wherein, the compound of Formula 1 is 2LiCl—GaF 3 , 3LiCl—GaF 3 , 4LiCl—GaF 3 , 3LiBr-GaF 3 , 2LiCl—LiOH—GaF 3 , 3LiCl−0.1LaCl 3 −0.9GaF 3 , 3LiCl−0.1InCl 3 −0.9GaF 3 , 3LiCl−0.1ScCl 3 −0.9GaF 3 , 3LiCl−0.1AlCl 3 −0.9GaF 3 , 3LiCl−0.1TlCl 3 −0.9GaF 3 , 3LiCl−0.1YCl 3 −0.9GaF 3 , 3LiCl−0.1BCl 3 −0.9GaF 3 , 2LiBr—GaF 3 , 4LiBr—GaF 3 , 2LiClO 4 −GaF 3 , 2LiClO 4 −LiOH—GaF 3 , 2LiCl—NaCl—Ga F 3 , 3LiCl—NaCl—GaF 3 , 3LiCl−0.2LaCl 3 −0.8GaF 3 , 3LiCl−0.2InCl 3 −0.8GaF 3 , 3LiCl−0.3LaCl 3 −0.7GaF 3 , 3LiCl−0.3InCl 3 −0.7GaF 3 , 3LiCl−0.5LaCl 3 −0.5GaF 3 , 3LiCl−0.5InCl 3 −0.5GaF 3 , 3LiCl−0.2ScCl 3 −0.8GaF 3 , 3LiCl−0.3ScCl 3 −0.7GaF 3 , 3LiCl−0.5ScCl 3 −0.5GaF 3 , 3LiCl− 0.2 AlCl 3 −0.8GaF 3 , 3LiCl−0.3AlCl 3 −0.7GaF 3 , 3LiCl−0.5AlCl 3 −0.5GaF 3 , 3LiCl−0.2BCl 3 −0.8GaF 3 , 3LiCl−0.3BCl 3 −0.7GaF 3 , 3LiCl−0.5BCl 3 −0.5GaF 3 , 3LiCl−0.2TlCl 3 −0.8GaF 3 , 3LiCl−0.3TlCl 3 −0.7GaF 3 , 3LiCl−0.5TlCl 3 −0.5GaF 3 , 3LiCl−0.2YCl 3 −0.8GaF 3 , 3LiCl−0.3YCl 3 −0.7GaF 3 , 3LiCl−0.5YCl 3 −0.5GaF 3 , or a combination thereof.

17. The composite solid electrolyte of claim 9 ,

wherein the compound of Formula 1 exhibits a Cl 2p peak at about 199 eV to about 203 eV, when analyzed by X-ray photoelectron spectroscopy.

18. The composite solid electrolyte of claim 9 ,

wherein the compound of Formula 1 exhibits a primary peak at a diffraction angle of about 25° 2θ to about 35° 2θ, and a secondary peak at a diffraction angle of about 48° 2θ to about 65° 2θ, when analyzed by X-ray diffraction analysis with Cu Kα radiation.

19. The composite solid electrolyte of claim 9 ,

wherein the compound of Formula 1 exhibits peaks at a diffraction angles of about 29° 2θ to about 31° 2θ, about 33° 2θ to about 35° 2θ, and about 49° 2θ to about 51° 2θ, when analyzed by X-ray diffraction analysis with Cu Kα radiation, or

the compound of Formula 1 exhibits peaks at diffraction angles of about 29° 2θ to about 31° 2θ, about 33° 2θ to about 35° 2θ, about 59° 2θ to about 61° 2θ, and about 62° 2θ to about 64° 2θ, when analyzed by XRD analysis with Cu Kα radiation.

20. The composite solid electrolyte of claim 1 ,

wherein the oxide solid electrolyte is garnet ceramic of the formula Li 3+x La 3 M 2 O 12 wherein M is Te, Nb, or Zr, and x is an integer of 1 to 10, a lithium phosphorus oxynitride of the formula Li x PO y N, wherein 0<x<1, 0<y<1, and 0<z<1, Li X P Y O Z N K wherein 2.7≤x≤3.3, 0.8≤y≤1.2, 3.5≤z≤3.9, and 0.1≤k≤0.5), Li w PO x N y S z wherein 0<w<1, 0<x<1, 0<y<1, and 0<z<1), 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 a Ti 1−a )O 3 0≤a≤1 (PZT), 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 (PMN-PT), 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 , SiC, a lithium phosphate Li 3 PO 4 , a lithium titanium phosphate of the formula Li x Ti y (PO 4 ) 3 wherein 0<x<2 and 0<y<3, a lithium aluminum titanium phosphate of the formula 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 a Ga 1−a ) x (Ti b Ge 1−b ) 2−x Si y P 3−y O 12 wherein 0≤a≤1, 0≤b≤1, 0≤x≤1 and 0≤y≤1, a lithium lanthanum titanate of the formula Li x La y TiO 3 wherein 0<x<2 and 0<y<3, a lithium germanium thiophosphate Li x Ge y P z S w wherein 0<x<4, 0<y<1, 0<z<1, and 0<w<5, a lithium nitride-based glass of the formula Li x N y wherein 0<x<4 and 0<y<2, Li x Si y S z wherein 0<x<3, 0<y<2, and 0<z<4), a P 2 S 5 glass of the formula Li x P y S z wherein 0<x<3, 0<y<3, and 0<z<7), Li 2 O, LiF, LiOH, Li 2 CO 3 , LiAlO 2 , a Li 2 O—Al 2 O 3 —SiO 2 —P 2 O 5 —TiO 2 —GeO 2 ceramic, or a combination thereof.

21. The composite solid electrolyte of claim 9 ,

wherein a clay characteristic maintenance temperature of the compound of Formula 1 is about −60° C. to about 160° C.

22. The composite solid electrolyte of claim 9 ,

wherein the compound of Formula 1 has a glass-ceramic structure, and the glass-ceramic structure has ceramic content of 0.1 weight percent to 30 weight percent, based on a total weight of the compound of Formula 1.

23. An electrochemical device comprising the composite solid electrolyte of claim 1 .

24. The electrochemical device of claim 23 ,

wherein the electrochemical device is a storage battery, a super capacitor, a fuel cell, a sensor, or a chromic device.

25. An electrochemical cell comprising the composite solid electrolyte of claim 1 .

26. The electrochemical cell of claim 25 ,

wherein the electrochemical cell is a secondary battery comprising a cathode, an anode, and the composite solid electrolyte between the cathode and the anode.

27. The electrochemical cell of claim 26 ,

wherein the composite solid electrolyte comprises a compound represented by Formula 1, wherein the compound represented by Formula 1 has a glass or glass-ceramic structure:

ALi q Q 1-q X—Ga 1-z M z F 3-3z Z 3z   Formula 1

wherein, in Formula 1, Q is Na, K, or a combination thereof,

M is a trivalent cationic element, or a combination thereof,

X is a halogen element other than fluorine, a pseudohalogen, or a combination thereof,

Z is a monovalent anionic element or a combination thereof,

1<A<5, 0<q≤1, and 0≤z<1.

28. The electrochemical cell of claim 26 ,

wherein the anode comprises lithium metal or a lithium alloy.

29. A method of manufacturing an electrochemical cell, the method comprising:

providing a cathode;

providing an anode; and

disposing the composite solid electrolyte of claim 1 between the cathode and the anode to manufacture the electrochemical cell.