Electrolyte for rechargeable lithium battery and rechargeable lithium battery comprising same

• US 7,745,055 B2
• Filed: 11/01/2004
• Issued: 06/29/2010
• Est. Priority Date: 10/31/2003
• Status: Active Grant

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Kim, Jin-Sung, Kim, Jin-Hee
• Primary Examiner(s): Weiner; Laura S
• Application Number:
  US10/980,116
• Publication Number:
  US 20050142448A1
• Time in Patent Office: 2,066 Days
• Field of Search: 429/307, 429/330, 429/332, 429/338, 429/342, 429/327, 429/326, 252/62.2
• US Class Current: 429/307
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0567 characterised by the additives
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 10/4235 Safety or regulating additives or arrangements in electrodes, separators or electrolyte H01M10/4242 takes precedence
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0034 Fluorinated solvents
• CPC Class Codes: H01M 2300/0037 Mixture of solvents
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 6/164 by the solvent
• CPC Class Codes: H01M 6/168 by additives
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed is an electrolyte for a rechargeable lithium battery including: a first additive having an oxidation potential of 4.1 to 4.6V; a second additive having an oxidation potential of 4.4 to 5.0V; a non-aqueous organic solvent; and a lithium salt.

Claims

1. An electrolyte for a rechargeable lithium battery, comprising:

a first additive having an oxidation potential from 4.1 to 4.6V, wherein the first additive comprises a compound selected from the group consisting of Formula 1, Formula 2, and combinations thereof;

2. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the first additive has an oxidation potential from 4.1 to 4.4V.

3. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the first additive has an oxidation potential from 4.2 to 4.4V.

4. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the second additive has an oxidation potential from 4.6 to 5.0V.

5. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the second additive has an oxidation potential from 4.7 to 4.9V.

6. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the oxidation potential of the first additive is from 0.1 to 0.7V less than the oxidation potential of the second additive.

7. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the oxidation potential of the first additive is from 0.3 to 0.7V less than the oxidation potential of the second additive.

8. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the electrolyte has an oxidation potential from 4.4 to 4.9V.

9. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the electrolyte has an oxidation potential from 4.5 to 4.7V.

10. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the first additive comprises a compound selected from the group consisting of Formulae 2 to 4, and combinations thereof:

11. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the first additive comprises a compound of Formula 2.

12. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the second additive comprises at least one compound selected from the group consisting of compounds represented by Formulae 5 to 9:

13. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the second additive comprises at least one compound selected from the group consisting of compounds represented by Formulae 5, and 10 to 13:

14. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the second additive is represented by Formula 5:

15. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the combined amount of the first additive and the second additive is 0.01 to 20% by weight based on the total weight of the non-aqueous organic solvent and the lithium salt.

16. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the combined amount of the first additive and the second additive is 0.1 to 10% by weight based on the total weight of the non-aqueous organic solvent and the lithium salt.

17. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the combined amount of the first additive and the second additive is 5 to 10% by weight based on the total weight of the non-aqueous organic solvent and the lithium salt.

18. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the second additive and the first additive are mixed at a weight ratio of 20:

0.1 to 3;

2.

19. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the electrolyte comprises 0.1 to 5% by weight of the first additive and 1 to 20% by weight of the second additive.

20. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the non-aqueous organic solvent is selected from the group consisting of carbonates, esters, ethers, ketones and combinations thereof.

21. The electrolyte for a rechargeable lithium battery according to claim 20, wherein the non-aqueous organic solvent is a carbonate selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate and combinations thereof.

22. The electrolyte for a rechargeable lithium battery according to claim 20, wherein the non-aqueous organic solvent comprises a mixed solvent of cyclic carbonates and chain carbonates.

23. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the non-aqueous organic solvent is a mixed solvent of a carbonate solvent and an aromatic hydrocarbon organic solvent.

24. The electrolyte for a rechargeable lithium battery according to claim 23, wherein the aromatic hydrocarbon organic solvent is a compound represented by Formula 14:

25. The electrolyte for a rechargeable lithium battery according to claim 23, wherein the aromatic hydrocarbon organic solvent is selected from the group consisting of benzene, fluorobenzene, chlorobenzene, nitrobenzene, toluene, fluorotoluene, trifluorotoluene, xylene and mixtures thereof.

26. The electrolyte for a rechargeable lithium battery according to claim 23, wherein the carbonate solvent and an aromatic hydrocarbon organic solvent are mixed in a volume ratio between 1:

1 and 30;

1.

27. The electrolyte for a rechargeable lithium battery according to claim 1, wherein the lithium salt is selected from the group consisting of LiPF₆, LiBF₄, LiSbF₆, LiAsF₆, LiClO₄, CF₃SO₃Li, LiN(SO₂CF₃)₂, LiC₄F₉SO₃, LiAIO₄, LiAlOCI₄, LiN(SO₂C₂F₅)₂), LiN(C_xF_2x+1SO₂)(C_yF_2y+1SO₂) where x and y are natural numbers, LiCl, LiI and combinations thereof.

28. An electrolyte for a rechargeable lithium battery, comprising:

a first additive having an oxidation potential of 4.1 to 4.5V, wherein the first additive comprises a compound selected from the group consisting of Formula 1, Formula 2, and combinations thereof;

29. The electrolyte for a rechargeable lithium battery according to claim 28, wherein the electrolyte has an oxidation potential from 4.5 to 4.7V.