Nonaqueous electrolyte and nonaqueous electrolyte secondary battery

• US 20020086216A1
• Filed: 12/27/2001
• Published: 07/04/2002
• Est. Priority Date: 09/28/2000
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hasebe, Hiroyuki, Sekino, Masahiro, Fujiwara, Masashi, Satoh, Asako
• Granted Patent: US 6,861,175 B2
• Time in Patent Office: Days
• US Class Current: 429/330
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• 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 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/004 Three solvents
• CPC Class Codes: H01M 6/164 by the solvent
• CPC Class Codes: H01M 6/40 Printed batteries , e.g. thin film batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Disclosed is a nonaqueous electrolyte secondary battery, comprising a nonaqueous electrolyte containing ethylene carbonate and γ-butyrolactone, wherein, when a charge-discharge cycle test satisfying conditions (A) to (D) given below is performed under an environment of 45° C., the capacity retention rate at 100-th charge-discharge cycle is at least 85% based on the discharge capacity in the first charge-discharge cycle, (A) for the charging, the constant current-constant voltage charging to 4.2V is performed for 3 hours under a current of 1C, (B) the discharging is performed to 3V under a current of 1C, (C) after the charging, the secondary battery is left to stand for 10 minutes, followed by performing the discharging, and (D) after the discharging, the secondary battery is left to stand for 10 minutes, followed by performing the charging.

Claims

1. A nonaqueous electrolyte comprising a nonaqueous solvent and a solute dissolved in said nonaqueous solvent,

wherein said nonaqueous solvent contains a main solvent including 20 to 50% by volume of ethylene carbonate and 40 to 80% by volume of γ

-butyrolactone and a third solvent including at least one kind of solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate.

2. A nonaqueous electrolyte secondary battery, comprising:

a case having a wall thickness not larger than 0.3 mm;

a positive electrode provided in said case;

a negative electrode provided in said case; and

a nonaqueous electrolyte provided in said case and comprising a nonaqueous solvent containing ethylene carbonate and γ

-butyrolactone and a solute dissolved in the nonaqueous solvent,

wherein, when a charge-discharge cycle test satisfying conditions (A) to (D) given below is performed under an environment of 45°

C., the capacity retention rate at 100-th charge-discharge cycle is at least 85% based on the discharge capacity in the first charge-discharge cycle;

(A) for the charging, the constant current-constant voltage charging to 4.2V is performed for 3 hours under a current of 1C;

(B) the discharging is performed to 3V under a current of 1C;

(C) after the charging, the secondary battery is left to stand for 10 minutes, followed by performing the discharging; and

(D) after the discharging, the secondary battery is left to stand for 10 minutes, followed by performing the charging.

3. The nonaqueous electrolyte secondary battery according to claim 2, wherein the amount of said ethylene carbonate based on said nonaqueous solvent falls within a range of between 20% by weight and 50% by weight, and the amount of said γ

-butyrolactone based on said nonaqueous electrolyte falls within a range of between 40% by weight and 80% by weight.

4. A nonaqueous electrolyte secondary battery comprising a case having a wall thickness not larger than 0.3 mm, a positive electrode provided in said case, a negative electrode provided in said case;

and a nonaqueous electrolyte provided in said case and comprising a nonaqueous solvent and a solute dissolved in said nonaqueous solvent,

wherein said nonaqueous solvent contains a main solvent including 20 to 50% by volume of ethylene carbonate and 40 to 80% by volume of γ

-butyrolactone and a third solvent including at least one kind of solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate.

5. The nonaqueous electrolyte secondary battery according to claim 4, wherein said nonaqueous electrolyte is substantially in the form of a liquid or a gel.

6. The nonaqueous electrolyte secondary battery according to claim 4, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 5% by weight.

7. The nonaqueous electrolyte secondary battery according to claim 4, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 3% by weight in the case where said third solvent includes at least one kind of solvent selected from the group consisting of phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate.

8. The nonaqueous electrolyte secondary battery according to claim 4, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 1.5% by weight in the case where said third solvent includes at least one kind of solvent selected from the group consisting of 2-methylfuran, furan, thiophene and catechol carbonate.

9. The nonaqueous electrolyte secondary battery according to claim 4, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 2% by weight in the case where said third solvent includes ethylene sulfite.

10. The nonaqueous electrolyte secondary battery according to claim 4, wherein said third solvent consists essentially of at least one kind of solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, catechol carbonate and vinylethylene carbonate.

11. The nonaqueous electrolyte secondary battery according to claim 4, wherein said third solvent further includes at least one kind of solvent selected from the group consisting of propylene carbonate, vinylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, γ

-valerolactone, methyl propionate and ethyl propionate, the amount of said third solvent based on the nonaqueous solvent is not larger than 5% by weight, and the amount of propylene carbonate based on the nonaqueous electrolyte is smaller than 2% by volume (including 0% by volume).

12. The nonaqueous electrolyte secondary battery according to claim 4, wherein said third solvent further includes vinylene carbonate and at least one kind of solvent selected from the group consisting of propylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, γ

-valerolactone, methyl propionate and ethyl propionate, the amount of said third solvent based on the nonaqueous solvent is not larger than 5% by weight, and the amount of propylene carbonate based on the nonaqueous electrolyte is smaller than 2% by volume (including 0% by volume).

13. The nonaqueous electrolyte secondary battery according to claim 4, wherein said solute includes at least one lithium salt selected from the group consisting of LiClO₄, LiPF₆, LiBF₄, LiAsF₆, LiCF₃SO₃, LiN(CF₃SO₂)₂ and LiN(C₂F₅SO₂)₂.

14. The nonaqueous electrolyte secondary battery according to claim 4, wherein said negative electrode contains a carbonaceous material capable of absorbing-desorbing lithium ions.

15. The nonaqueous electrolyte secondary battery according to claim 14, wherein said carbonaceous material includes mesophase pitch based carbon fiber.

16. The nonaqueous electrolyte secondary battery according to claim 4, wherein said case is formed essentially of a metal plate, a metal film or a sheet including a resin layer.

18. The nonaqueous electrolyte secondary battery according to claim 17, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 5% by weight.

19. The nonaqueous electrolyte secondary battery according to claim 17, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 3% by weight in the case where said third solvent includes at least one kind of solvent selected from the group consisting of phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate.

20. The nonaqueous electrolyte secondary battery according to claim 17, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 1.5% by weight in the case where said third solvent includes at least one kind of solvent selected from the group consisting of 2-methylfuran, furan, thiophene and catechol carbonate.

21. The nonaqueous electrolyte secondary battery according to claim 17, wherein the amount of said third solvent based on the nonaqueous solvent is not larger than 2% by weight in the case where said third solvent includes ethylene sulfite.

22. The nonaqueous electrolyte secondary battery according to claim 17, wherein said third solvent consists essentially of at least one kind of solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, catechol carbonate and vinylethylene carbonate.

23. The nonaqueous electrolyte secondary battery according to claim 17, wherein said third solvent further includes at least one kind of solvent selected from the group consisting of propylene carbonate, vinylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, γ

-valerolactone, methyl propionate and ethyl propionate, the amount of said third solvent based on the nonaqueous solvent is not larger than 5% by weight, and the amount of propylene carbonate based on the nonaqueous solvent is smaller than 2% by volume (including 0% by volume).

24. The nonaqueous electrolyte secondary battery according to claim 17, wherein said third solvent further includes vinylene carbonate and at least one kind of solvent selected from the group consisting of propylene carbonate, diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, γ

-valerolactone, methyl propionate and ethyl propionate, the amount of said third solvent based on the nonaqueous solvent is not larger than 5% by weight, and the amount of propylene carbonate based on the nonaqueous solvent is smaller than 2% by volume (including 0% by volume).

27. The nonaqueous electrolyte secondary battery according to claim 26, wherein said at least one third solvent is contained in an amount of 5% by weight or less based on the total amount of said nonaqueous solvent.

28. The nonaqueous electrolyte secondary battery according to claim 26, wherein, when said at least one third solvent is formed of at least one solvent selected from the group consisting of phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate, the mixing amount of said at least one third solvent is not larger than 3% by weight based on the total amount of said nonaqueous solvent.

29. The nonaqueous electrolyte secondary battery according to claim 26, wherein, when said at least one third solvent is formed of at least one solvent selected from the group consisting of 2-methylfuran, furan, thiophene, and catechol carbonate, the mixing amount of said at least one third solvent is not larger than 1.5% by weight based on the total amount of said nonaqueous solvent.

30. The nonaqueous electrolyte secondary battery according to claim 26, wherein, when ethylene sulfite is used as said at least one third solvent, the mixing amount of said at least one third solvent is not larger than 2% by weight based on the total amount of said nonaqueous solvent.

31. The nonaqueous electrolyte secondary battery according to claim 26, wherein said at least one third solvent is formed of at least one solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, catechol carbonate and vinylethylene carbonate.

17. A nonaqueous electrolyte secondary battery comprising a case having a wall thickness not larger than 0.3 mm, a positive electrode provided in said case, a negative electrode provided in said case, and a nonaqueous electrolyte layer arranged between said positive electrode and said negative electrode, and said nonaqueous electrolyte layer containing a nonaqueous electrolyte and a polymer capable of gelling said nonaqueous electrolyte,

wherein said nonaqueous electrolyte contains a nonaqueous solvent including a main solvent comprising 20% to 50% by volume of ethylene carbonate and 40% to 80% by volume of γ

-butyrolactone and a third solvent comprising at least one kind of solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate.

25. A nonaqueous electrolyte, comprising:

a nonaqueous solvent containing ethylene carbonate (EC), γ

-butyrolactone (BL), and at least one third solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate, the EC content falling within a range of 20 to 50% by volume based on the total amount of the EC and the BL, and the BL content falling within a range of 40 to 80% by volume based on the total amount of the EC and the BL; and

a solute dissolved in said nonaqueous solvent.

26. A nonaqueous electrolyte secondary battery, comprising:

a case having a wall thickness not larger than 0.3 mm;

a positive electrode provided in said case;

a negative electrode provided in said case; and

a nonaqueous electrolyte which is provided in said case and comprises a nonaqueous solvent and a solute dissolved in said nonaqueous solvent, said nonaqueous solvent containing ethylene carbonate (EC), γ

-butyrolactone (BL), and at least one third solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate, the EC content falling within a range of 20 to 50% by volume based on the total amount of the EC and the BL, and the BL content falling within a range of 40 to 80% by volume based on the total amount of the EC and the BL.

32. A nonaqueous electrolyte secondary battery, comprising:

a case having a wall thickness not larger than 0.3 mm;

a positive electrode provided in said case;

a negative electrode provided in said case; and

a nonaqueous electrolyte layer which is arranged between said positive electrode and said negative electrode and comprises a nonaqueous electrolyte and a polymer for gelling said nonaqueous electrolyte, said nonaqueous electrolyte comprising a nonaqueous solvent containing ethylene carbonate (EC), γ

-butyrolactone (BL), and at least one third solvent selected from the group consisting of ethylene sulfite, phenylethylene carbonate, 2-methylfuran, furan, thiophene, catechol carbonate and vinylethylene carbonate, the EC content falling within a range of 20 to 50% by volume based on the total amount of the EC and the BL, and the BL content falling within a range of 40 to 80% by volume based on the total amount of the EC and the BL.