Electrolyte for use in electrochemical devices

• US 7,588,859 B1
• Filed: 03/25/2004
• Issued: 09/15/2009
• Est. Priority Date: 02/11/2004
• Status: Active Grant

• Current Assignee: Bookeun Oh, Khalil Amine, Robert C. West
• Original Assignee: Bookeun Oh, Khalil Amine, Robert C. West
• Inventors: West, Robert C., Amine, Khalil, Oh, Bookeun
• Primary Examiner(s): Yuan; Dah-Wei D
• Assistant Examiner(s): HAN, KWANG S
• Application Number:
  US10/810,080
• Time in Patent Office: 2,000 Days
• Field of Search: None
• US Class Current: 429/188
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01G 11/56 Solid electrolytes, e.g. gels; Additives therein
• CPC Class Codes: H01G 11/58 Liquid electrolytes
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 10/0566 Liquid materials
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

The electrolyte includes one or more polysiloxanes, one or more alkali metal salts, and one or more silanes. At least one polysiloxane includes side chains having poly(alkylene oxide) moieties. At east one silane includes at least one moiety selected from a first group consisting of an alkyl group, a halogenated alkyl group, an aryl group, a halogenated aryl group, an alkoxy group and an oxyalkylene group and at least one moiety selected from a second group consisting of an alkoxy group, an oxyalkylene group and a carbonate group. In one example, the electrochemical device is a secondary battery.

Claims

1. An electrochemical device, comprising:

an electrolyte including one or more polysiloxanes, one or more alkali metal salts, and one or more silanes,

the silane and the polysiloxane being included in different compounds, and

the silane including at least one substituent that includes a poly(alkylene oxide) moiety.

2. The device of claim 1, wherein at least one polysiloxane is cyclic.

3. The device of claim 1, wherein at least one polysiloxane has a backbone that includes one or more silicons linked to one or more side chains that include a poly(alkylene oxide) moiety.

4. The device of claim 3 wherein the backbone includes one or more silicons linked to one or more side chains that include a carbonate moiety.

5. The device of claim 3, wherein one or more of the backbone silicons are linked to a plurality of side chains that each include a poly(alkylene oxide) moiety.

6. The device of claim 3, wherein an organic spacer is positioned between the backbone silicons and the poly(alkylene oxide) moiety.

7. The device of claim 6, wherein the spacer includes oxygen linked directly to the backbone silicons.

8. The device of claim 1, wherein the silane includes at least one substituent that includes a moiety selected from a second group consisting of an alkoxy group, a carbonate group, and an alkylene oxide group.

9. The device of claim 1, wherein at least one polysiloxane has a structure selected from a group consisting of structures represented by formula I-a through formula I-d:

formula I-a;

10. The device of claim 9, wherein m is 0.

11. The device of claim 9, wherein R₄, R₁₀, R₁₄, R₂₉, R₃₈ and R₄₀, are nil.

12. The device of claim 9, wherein R₄, R₁₀, R₁₄, R₂₀, and R₃₈ are an organic spacer.

13. The device of claim 9 wherein the polysiloxane is represented by formula I-d and the organic spacer represented by R₄₀ includes an oxygen linked directly to a silicon on the backbone of the polysiloxane.

14. The device of claim 9, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-a.

15. The device of claim 9, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-b.

16. The device of claim 9, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-c.

17. The device of claim 9, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-d.

18. The device of claim 17, wherein p is 0.

19. The device of claim 1, wherein at least one silane has a structure selected from a group consisting of structures represented by formula II-a through formula I′

-c;

formula II-A;

20. The device of claim 19, wherein at least one silane has a structure selected from a group consisting of structures represented by formula II-a.

21. The device of claim 19, wherein at least one silane has a stricture selected from a group consisting of structures represented by formula II-b.

22. The device of claim 19, wherein at least one silane has a structure selected from a group consisting of structures represented by formula II-c.

23. The device of claim 19, wherein at least one of the R₁, R₂, R₃, Z₁ Z₂, and Z₃ includes an organic spacer, the organic spacer being an alkylene, alkylene oxide or a bivalent ether group.

24. The device of claim 19, wherein at least one of the R₁, R₂, R₃ includes a halogenated alkyl, a halogenated aryl or a halogenated alkoxy.

25. The device of claim 1, wherein the salt is a lithium salt.

26. The device of claim 1, wherein the concentration of alkali metal salt is about 0.3 to 2.0 M.

27. The device of claim 1, wherein the salt is chosen from the group consisting of:

LiClO₄, LiBF₄, LiAsF₆, LiPF₆, LiCF₃SO₃, Li(CF₃SO₂)₂N, Li(CF₃SO₂)₃C, LiN(SO₂C₂F₅)₂, lithium alkyl fluorophosphates, lithium bis(chelato)borates, and mixtures thereof.

28. The device of claim 1, wherein the electrolyte further includes:

at least one additive selected from the group consisting of;

vinyl carbonate, vinyl ethylene carbonate, ethylene sulfite, 1,3 dimethyl butadiene, styrene carbonate, aromatic carbonates, vinyl pyrrole, vinyl piperazine, vinyl piperidine, vinyl pyridine, and mixtures thereof.

29. The device of claim 1, wherein the electrolyte includes a lithium(oxalato)borate (LiBOB) salt and one or more additives selected from a group consisting of VC and VEC.

30. The device of claim 1, wherein the device is lithium secondary battery comprising:

a lithium metal oxide cathode;

a porous separator; and

a carbon or lithium metal anode.

31. The device of claim 30, wherein the cathode includes a material chosen from the group consisting of:

Li_xVO_y, LiCoO₂, LiNiO₂, LiNi_1-xCo_yMe_zO₂, LiMn_0.5Ni_0.5O₂, LiMn_0.3Co_0.3Ni_0.3O₂, LiFePO₄, LiMn₂O₄, LiFeO₂, LiMc_0.5Mn_1.5O₄, vanadium oxide, and mixtures thereof, wherein Me is Al, Mg, Ti, B, Ga, or Si, and Mc is a divalent metal.

32. The device of claim 30, wherein the anode includes a material chosen from the group consisting of:

graphite, carbon, Li₄Ti₅O₁₂, tin alloys, silica alloys, intermetallic compounds, lithium metal, and mixtures thereof.

33. The device of claim 1, wherein the electrolyte is a liquid.

34. The device of claim 1, wherein the electrolyte is a solid.

35. The device of claim 1, wherein the electrolyte includes an interpenetrating network.

36. The device of claim 35, wherein the interpenetrating network includes a cross-linked polyacrylates or a cross-linked polymethacrylates.

37. The device of claim 35, wherein a compound selected from the group consisting of an acrylate having two or more functionalities and a methacrylates having two or more functionalities serves as a monomer for a member of the interpenetrating network.

38. The device of claim 37, wherein the monomer is a dialkyl acrylate, dimethacrylate, a diallyl terminated compound or a dialkyl methacrylate.

39. The device of claim 37, wherein the electrolyte includes one or more solid polymers.

40. The device of claim 39, wherein at least one of the solid polymers is selected from the group consisting of polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA), poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-hexafluoropropylene), polystyrene, polyvinyl chloride, poly(alkyl methacrylate), poly(alkyl acrylate), styrene butadiene rubber (SBR), poly(vinyl acetate), poly(ethylene oxide) (PEO) and mixtures thereof.

41. The device of claim 1, wherein the electrolyte has an ionic conductivity greater than 1.0×

10<sup>−

4</sup> S/cm at 25°

C.

42. The device of claim 1, wherein the electrolyte has an ionic conductivity greater than 4.0×

10⁴ S/cm at 25°

C.

72. The device of claim 17, wherein m is 0;

R₃₈ is an organic spacer; and

the organic spacer represented by R₄₀ includes an oxygen linked directly to a silicon on the backbone of the polysiloxane.

73. The device of claim 20, wherein the variable R₉₄ in the substituent represented by Z₁ is nil.

43. A method of forming an electrochemical device, comprising:

forming an electrolyte including one or more polysiloxanes, one or more alkali metal salts, and one or more silanes,

the silane and the polysiloxane being included in different compounds, and

the silane including at least one substituent that includes a poly(alkylene oxide) moiety; and

activating at least one anode and at least one cathode with the electrolyte.

44. The method of claim 43, wherein at least one polysiloxane is cyclic.

45. The method of claim 43, wherein at least one polysiloxane has a backbone that includes one or more silicons linked to one or more side chains that include a poly(alkylene oxide) moiety.

46. The method of claim 45, wherein one or more of the backbone silicons are linked to a plurality of side chains that each include a poly(alkylene oxide) moiety.

47. The method of claim 45, wherein an organic spacer is positioned between the backbone silicons and the poly(alkylene oxide) moiety.

48. The method of claim 45, wherein the spacer includes an oxygen linked to the backbone silicons.

49. The method of claim 43, wherein the silane includes at least one substituent that includes a moiety selected from a first group consisting of an alkyl group, a halogenated alkyl group, an aryl group, a halogenated aryl group, an alkoxy group and an oxyalkylene group and at least one substituent that includes a moiety selected from a second group consisting of an alkoxy group, an oxyalkylene group or a cyclic carbonate group.

50. The method of claim 49, wherein the silane includes four substituents that each includes a moiety selected from the first group or from the second group.

51. The method of claim 43, wherein at least one polysiloxane has a structure selected from a group consisting of structures represented by formula I-a through formula I-d:

formula I-a;

52. The method of claim 51, wherein m is 0.

53. The method of claim 51, wherein R₄, R₁₀, R1₁₄, R₂₉, R₃₈ and R₄₀, are nil.

54. The method of claim 51, wherein R₄, R₁₀, R1₁₄, R₂₉, R₃₆ and R₄₀, are an organic spacer.

55. The method of claim 54, wherein the organic spacer includes an oxygen linked to a silicon on the backbone of the polysiloxane.

56. The method of claim 51, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-a.

57. The method of claim 51, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-b.

58. The method of claim 51, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-c.

59. The method of claim 51, wherein at least one polysiloxane has a structure selected from the group consisting of structures represented by formula I-d.

60. The method of claim 59, wherein p is 0.

61. The method of claim 43, wherein at least one silane is selected from a group represented by formula II-a through formula II-c:

formula II-A;

62. The method of claim 61, wherein at least one silane has a structure selected from a group consisting of structures represented by formula II-a.

63. The method of claim 61, wherein at least one silane has a structure selected from a group consisting of structures represented by formula II-b.

64. The method of claim 61, wherein at least one silane has a structure selected from a group consisting of structures represented by formula II-c.

65. The method of claim 43, wherein the electrolyte includes at least one additive selected from the group consisting of:

vinyl carbonate, vinyl ethylene carbonate, ethylene sulfite, 1,3 dimethyl butadiene, styrene carbonate, aromatic carbonates, vinyl pyrrole, vinyl piperazine, vinyl piperidine, vinyl pyridine, and mixtures thereof.

66. The method of claim 43, wherein at least one cathode is a lithium metal oxide cathode and at least one anode is a carbon or lithium metal anode.

67. The method of claim 43, wherein at least one cathode includes a material chosen from the group consisting of:

LiCoO₂, LiNiO₂, LiNi_1-xCo_yMe_zO₂, LiMn_0.5Ni_0.5O₂, LiMn_0.3Ni_0.3O₂, LiFePO₄, LiMn₂O₄, LiFeO₂, LiMc_0.5Mn_1.5O₄, vanadium oxide, and mixtures thereof, wherein Me is Al, Mg, Ti, B, Ga or Si, and Mc is a divalent metal.

68. The method of claim 43, wherein at least one anode includes a material chosen from the group consisting of:

graphite, carbon, Li₄Ti₅O₁₂, tin alloys, silica alloys, intermetallic compounds, lithium metal, and mixtures thereof.

69. The method of claim 43, wherein the electrolyte is a liquid.

70. The method of claim 43, wherein the electrolyte is a solid.

71. The method of claim 43, wherein forming the electrolyte includes forming an interpenetrating network.