Lithium metal battery

1. A lithium metal battery comprising:

a lithium metal negative electrode;

a positive electrode; and

an electrolyte between the lithium metal negative electrode and the positive electrode,

wherein the electrolyte comprises a nonaqueous organic solvent, a lithium salt, and an inorganic additive,

wherein the inorganic additive comprises an inorganic oxide,

wherein the inorganic oxide comprises at least one selected from a hydroxyl group and a C 1 -C 10 alkyl group attached to a surface of the inorganic oxide, and

wherein the nonaqueous organic solvent is at least one selected from a glyme solvent and an ether solvent.

2. The lithium metal battery of claim 1 , wherein the glyme solvent is at least one selected from 1,2-dimethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dimethylene glycol dimethyl ether, trimethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether.

3. The lithium metal battery of claim 1 , wherein the ether solvent is at least one selected from 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl ether, and dibutyl ether.

4. The lithium metal battery of claim 1 , wherein the lithium salt is at least one selected from lithium bis(fluorosulfonyl) imide, lithium bis(trifluoromethanesulfonyl) imide, LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiCsPF 6 , LiNO 3 , LiPO 2 F 2 , LiBr, lithium bis(oxalato)borate, lithium difluoro(oxalate)borate, LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 3 CF 3 ) 2 , LiC 4 F 9 SO 3 , LiAlCl 4 , and lithium trifluoromethanesulfonate.

5. The lithium metal battery of claim 1 , wherein the lithium salt is soluble in the nonaqueous organic solvent, and the inorganic additive is insoluble in the nonaqueous organic solvent.

6. The lithium metal battery of claim 1 , wherein the inorganic additive has attractive interactions with at least one selected from the nonaqueous organic solvent and the lithium salt.

7. The lithium metal battery of claim 6 , wherein the attractive interactions comprise at least one selected from intermolecular forces, electrostatic interactions, π-interactions, Van der Waals forces, hydrogen bonds, and anion absorption.

8. The lithium metal battery of claim 1 , wherein the inorganic oxide comprises at least one selected from a compound represented by Formula 1 and a complex thereof:

M x O y   Formula 1

wherein, in Formula 1, 1≤x≤2 and 1≤y≤4, and

M is at least one selected from silicon, aluminum, magnesium, titanium, zirconium, zinc, and barium.

9. The lithium metal battery of claim 8 , wherein the inorganic oxide comprises at least one selected from SiO 2 , TiO 2 , ZnO, Al 2 O 3 , BaTiO 3 , and a complex thereof.

10. The lithium metal battery of claim 1 , wherein an amount of the inorganic additive is in a range of about 0.1 part to about 20 parts by weight, based on 100 parts by weight of a total weight of the nonaqueous organic solvent and the lithium salt.

11. The lithium metal battery of claim 1 , wherein the inorganic additive is in particle form and comprises primary particles having an average particle diameter of about 5 nanometers to about 100 nanometers or agglomerates of the primary particles having an average particle diameter of about 1 micrometer to about 100 micrometers.

12. The lithium metal battery of claim 1 , wherein the lithium metal battery further comprises a protective film on the lithium metal negative electrode, wherein the protective film comprises a portion of the inorganic additive and a lithium metal layer surrounding the portion of the inorganic additive.

13. The lithium metal battery of claim 12 , wherein a thickness of the protective film is in a range of about 1 micrometer to about 100 micrometers.

14. The lithium metal battery of claim 1 , wherein the battery comprises at least one selected from a separator and a solid electrolyte disposed between the lithium metal negative electrode and the positive electrode.

15. An electrolyte for a lithium metal battery, the electrolyte comprising:

a nonaqueous organic solvent;

a lithium salt; and

an inorganic additive, wherein the inorganic additive comprises an inorganic oxide, and wherein the inorganic oxide comprises at least one selected from a hydroxyl group and a C 1 -C 10 alkyl group attached to a surface of the inorganic oxide, and wherein the nonaqueous organic solvent is at least one selected from a glyme solvent and an ether solvent.

16. The electrolyte of claim 15 , wherein the glyme solvent comprises at least one selected from 1,2-dimethoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dimethylene glycol dimethyl ether, trimethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, triethylene glycol dimethyl ether, and triethylene glycol diethyl ether.

17. The electrolyte of claim 15 , wherein the ether solvent comprises at least one selected from 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, dimethyl ether, and dibutyl ether.

18. The electrolyte of claim 15 , wherein the lithium salt comprises at least one selected from lithium bis(fluorosulfonyl) imide, lithium bis(trifluoromethanesulfonyl) imide, LiPF 6 , LiBF 4 , LiAsF 6 , LiClO 4 , LiCsPF 6 , LiNO 3 , LiPO 2 F 2 , LiBr, lithium bis(oxalato)borate, lithium difluoro(oxalate)borate, LiCF 3 SO 3 , LiN(SO 2 CF 3 ) 2 , LiN(SO 2 C 2 F 5 ) 2 , LiC(SO 2 CF 3 ) 3 , LiN(SO 3 CF 3 ) 2 , LiC 4 F 9 SO 3 , LiAlCl 4 , and lithium trifluoromethanesulfonate.

19. The electrolyte of claim 15 , wherein the lithium salt is soluble in the nonaqueous organic solvent, and the inorganic additive is insoluble in the nonaqueous organic solvent.

20. The electrolyte of claim 15 , wherein the inorganic oxide comprises at least one selected from a compound represented by Formula 1 and a complex thereof:

M x O z   Formula 1

wherein, in Formula 1, 1≤x≤2 and 1≤z≤4, and

M is at least one selected from silicon, aluminum, magnesium, titanium, zirconium, zinc, and barium.

21. The electrolyte of claim 15 , wherein an amount of the inorganic additive is about 0.1 part to about 20 parts by weight, based on 100 parts by weight of a total weight of the nonaqueous organic solvent and the lithium salt.

22. A method for producing a lithium metal battery, the method comprising:

providing an electrolyte comprising a nonaqueous organic solvent, a lithium salt, and an inorganic additive; and

combining a lithium metal negative electrode, a positive electrode, and the electrolyte to form the lithium metal battery, wherein the inorganic additive comprises an inorganic oxide, and the inorganic oxide comprises at least one selected from a hydroxyl group and a C 1 -C 10 alkyl group attached to a surface of the inorganic oxide, and

wherein the nonaqueous organic solvent is at least one selected from a glyme solvent and an ether solvent.

23. The method of claim 22 , wherein the lithium salt is dissolved in the nonaqueous organic solvent, and the inorganic additive is insoluble in the nonaqueous organic solvent.

24. The method of claim 22 , wherein the inorganic oxide comprises at least one selected from compound represented by Formula 1 and a complex thereof:

M x O z   Formula 1

wherein, in Formula 1, 1≤x≤2 and 1≤z≤4, and

M is at least one selected from silicon, aluminum, magnesium, titanium, zirconium, zinc, and barium.

25. The method of claim 22 , wherein the inorganic oxide comprises at least one SiO 2 , TiO 2 , ZnO, Al 2 O 3 , BaTiO 3 , and a complex thereof.

26. The method of claim 22 , wherein an amount of the inorganic additive is about 0.1 parts to about 20 parts by weight, based on 100 parts by weight of a total weight of the nonaqueous organic solvent and the lithium salt.