Lithium secondary cell with high charge and discharge rate capability and low impedance growth

• US 20070166617A1
• Filed: 09/11/2006
• Published: 07/19/2007
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: A123 Systems Incorporated
• Original Assignee: A123 Systems Incorporated
• Inventors: Lin, Roger, Riley, Gilbert, Chiang, Yet-Ming, Fulop, Ricardo, Chu, Andrew, Gozdz, Antoni
• Granted Patent: US 8,617,745 B2
• Time in Patent Office: Days
• US Class Current: 429/231.950
• 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 10/0569 characterised by the solvents
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A lithium-ion battery is provided that has a fast charge and discharge rate capability and low rate of capacity fade during high rate cycling. The battery can exhibit low impedance growth and other properties allowing for its use in hybrid electric vehicle applications and other applications where high power and long battery life are important features.

Claims

1. A lithium secondary cell comprising:

a positive electrode including a lithium transition metal phosphate compound;

a negative electrode including carbon;

an electrolyte in contact with and separating the positive electrode and negative electrode;

a positive electrode current collector in electronic communication with the positive electrode; and

a negative electrode current collector in electronic communication with the negative electrode,

wherein the cell exhibits impedance growth of no more than about 10% for every 1000 deep discharge charge-discharge cycles at a temperature of up to about 60°

C.

2. The lithium secondary cell of claim 1, wherein the cell exhibits a total cell energy capacity decrease of no more than about 20% from the initial cell energy for every 500 deep discharge charge-discharge cycles at a temperature of up to about 60°

C.

3. The lithium cell of claim 1, wherein the lithium transition metal phosphate is a compound having the formula Li_1-xM(PO)₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel;

and 0≦

x≦

1.

4. The lithium cell of claim 1, wherein the lithium transition metal phosphate is a compound having the formula Li_xM′

_yM″

_a(PO)₄, wherein M″

is selected from the group consisting of Group IIA, IIIA, IVA, VA, VIA and IIIB metals having an ionic radius less than the ionic radius of Fe²⁺, x is equal to or greater than 0 and a and y are greater than 0.

5. The lithium cell of claim 1, wherein the lithium transition metal phosphate is a compound having the formula (Li_1-xZ_x)MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to about 0.05.

6. The lithium secondary cell of claim 1, wherein the lithium transition metal phosphate compound has a specific surface area of greater than about 10 m²/g.

7. The lithium secondary cell of claim 1, wherein the negative electrode includes graphitic carbon.

8. The lithium secondary cell of claim 1, wherein the carbon is selected from the group consisting of graphite, spheroidal graphite, mesocarbon microbeads and carbon fibers.

9. The lithium secondary cell of claim 1, wherein the electrolyte includes about 1.0 M to about 1.3 M LiPF₆ and an organic solvent including about 30 wt % to about 50 wt % ethylene carbonate, about 10 wt % to about 20 wt % propylene carbonate, about 20 wt % to about 35 wt % dimethyl carbonate, about 20 wt % to about 30 wt % ethyl methyl carbonate, with an additional about 1 wt % to about 3 wt % vinylene carbonate.

10. The lithium secondary cell of claim 1, wherein the impedance growth of the cell is logarithmic with respect to time at temperatures of up to about 55°

C.

11. A lithium secondary cell comprising:

a positive electrode comprising a lithium transition metal phosphate;

a negative electrode comprising carbon;

an electrolyte in contact with and separating the positive electrode and negative electrode;

a positive current collector in electronic communication with the positive electrode;

a negative current collector in electronic communication with the negative electrode;

wherein the impedance growth of the cell is logarithmic with respect to time at temperatures of up to about 55°

C.

12. The lithium secondary cell of claim 11, wherein the slope of a curve of impedance growth versus time is steeper at the beginning of battery life than at the end of battery life.

13. The lithium secondary cell of claim 11, wherein the cell exhibits impedance growth of no more than about 10% for every 1000 deep discharge charge-discharge cycles at a temperature of up to about 60°

C.

14. The lithium secondary cell of claim 11, wherein the cell exhibits a total cell energy capacity decrease of no more than about 20% from the initial cell energy capacity for every 500 deep discharge charge-discharge cycles at a temperature of up to about 60°

C.

15. The lithium cell of claim 11, wherein the lithium transition metal phosphate is a compound having the formula Li_1-xM(PO)₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel;

and 0≦

x≦

1.

16. The lithium cell of claim 11, wherein the lithium transition metal phosphate is a compound having the formula Li_xM′

_yM″

_a(PO)₄, wherein M″

is selected from the group consisting of Group IIA, IIIA, IVA, VA, VIA and IIIB metals having an ionic radius less than the ionic radius of Fe²⁺, x is equal to or greater than 0 and a and y are greater than 0.

17. The lithium cell of claim 11, wherein the lithium transition metal phosphate is a compound having the formula (Li_1-xZ_x)MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to about 0.05

18. The lithium secondary cell of claim 11, wherein the lithium transition metal phosphate compound has a specific surface area of greater than about 10 m²/g.

19. The lithium secondary cell of claim 11, wherein the negative electrode includes graphitic carbon.

20. The lithium secondary cell of claim 11, wherein the carbon is selected from the group consisting of graphite, spheroidal graphite, mesocarbon microbeads and carbon fibers.

21. The lithium secondary cell of claim 11, wherein the electrolyte includes about 1.0 M to about 1.3 M LiPF₆ and an organic solvent including about 30 wt % to about 50 wt % ethylene carbonate, about 10 wt % to about 20 wt % propylene carbonate, about 20 wt % to about 35 wt % dimethyl carbonate, about 20 wt % to about 30 wt % ethyl methyl carbonate, with an additional about 1 wt % to about 3 wt % vinylene carbonate.

22. A lithium secondary cell comprising:

a positive electrode including a lithium transition metal phosphate having the formula Li_xM′

_yM″

_a(PO)₄, wherein M″

is selected from the group consisting of Group IIA, IIIA, IVA, VA, VIA and IIIB metals having an ionic radius less than the ionic radius of Fe²⁺, x is equal to or greater than 0 and a and y are greater than 0;

a negative electrode including carbon;

an electrolyte in contact with and separating the positive electrode and negative electrode, wherein the electrolyte includes about 0.8 M to about 1.5 M LiPF₆ and an organic solvent including about 30 wt % to about 70 wt % ethylene carbonate, about 0 wt % to about 20 wt % propylene carbonate, about 0 wt % to about 60 wt % dimethyl carbonate, about 0 wt % to about 60 wt % ethyl methyl carbonate, about 0 wt % to about 60 wt % diethyl carbonate, and about 0 wt % to about 5 wt % vinylene carbonate, wherein the sum of the weight percents of ethylene carbonate and propylene carbonate is between about 30 wt % and about 70 wt % of the total organic solvent, and propylene carbonate represents about 30 wt % or less of the sum;

a positive electrode current collector in electronic communication with the positive electrode; and

a negative electrode current collector in electronic communication with the negative electrode.

23. The lithium secondary cell of claim 22, wherein the cell exhibits impedance growth of no more than about 10% for every deep discharge 1000 charge-discharge cycles at a temperature of up to about 60°

C.

24. The lithium secondary cell of claim 22, wherein the cell exhibits a total cell energy capacity decrease of no more than about 20% from the initial cell energy capacity for every deep discharge 500 charge-discharge cycles at a temperature of up to about 60°

C.

25. The lithium secondary cell of claim 22, wherein the impedance growth of the cell is logarithmic with respect to time at temperatures of up to about 55°

C.

26. The lithium cell of claim 22, wherein the lithium transition metal phosphate has a formula of Li_1-xM(PO)₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel;

and 0≦

x≦

1.

27. The lithium cell of claim 22, wherein the lithium transition metal phosphate is a compound having the formula (Li_1-xZ_x)MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to about 0.05

28. The lithium secondary cell of claim 22, wherein the lithium transition metal phosphate compound has a specific surface area of greater than about 10 m²/g.

29. The lithium secondary cell of claim 22, wherein the negative electrode includes graphitic carbon.

30. The lithium secondary cell of claim 22, wherein the carbon is selected from the group consisting of graphite, spheroidal graphite, mesocarbon microbeads and carbon fibers.

31. The lithium secondary cell of claim 22, wherein the electrolyte includes about 1.0 M to about 1.3 M LiPF₆ and an organic solvent including about 30 wt % to about 50 wt % ethylene carbonate, about 10 wt % to about 20 wt % propylene carbonate, about 20 wt % to about 35 wt % dimethyl carbonate, about 20 wt % to about 30 wt % ethyl methyl carbonate, with an additional about 1 wt % to about 3 wt % vinylene carbonate.

32. A battery pack for use in a hybrid electric vehicle comprising a plurality of lithium secondary cells connected in series, in parallel, or in a combination thereof, wherein each cell comprises:

a positive electrode including a lithium transition metal phosphate compound

a negative electrode including carbon;

an electrolyte in contact with and separating the positive electrode and negative electrode, wherein the electrolyte includes about 0.8 M to about 1.5 M LiPF₆ and an organic solvent including about 30 wt % to about 70 wt % ethylene carbonate, about 0 wt % to about 20 wt % propylene carbonate, about 0 wt % to about 60 wt % dimethyl carbonate, about 0 wt % to about 60 wt % ethyl methyl carbonate, about 0 wt % to about 60 wt % diethyl carbonate, and about 0 wt % to about 5 wt % vinylene carbonate, wherein the sum of the weight percents of ethylene carbonate and propylene carbonate is between about 30 wt % and about 70 wt % of the total organic solvent, and propylene carbonate represents about 30 wt % or less of the sum;

a positive electrode current collector in electronic communication with the positive electrode; and

a negative electrode current collector in electronic communication with the negative electrode.

33. The battery pack of claim 32, wherein each cell in the plurality of cells has a discharge capacity of greater than about 1 Ah.

34. The battery pack of claim 32, wherein each cell in the plurality of cells exhibits impedance growth of no more than about 10% for every 1000 deep discharge charge-discharge cycles at a temperature of up to about 60°

C.

35. The battery pack of claim 32, wherein each cell in the plurality of cells exhibits a total cell energy capacity decrease of no more than about 20% from the initial cell energy capacity for every deep discharge 500 charge-discharge cycles at a temperature of up to about 60°

C.

36. The lithium secondary cell of claim 32, wherein the impedance growth of the cell is logarithmic with respect to time at temperatures of up to about 55°

C.

37. The battery pack of claim 32, wherein the lithium transition metal phosphate is a compound having the formula Li_1-xM(PO)₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel;

and 0≦

x≦

1.

38. The battery pack of claim 32, wherein the lithium transition metal phosphate is a compound having the formula Li_xM′

_yM″

_a(PO)₄, wherein M″

is selected from the group consisting of Group IIA, IIIA, IVA, VA, VIA and IIIB metals having an ionic radius less than the ionic radius of Fe²⁺, x is equal to or greater than 0 and a and y are greater than 0.

39. The battery pack of claim 32, wherein the lithium transition metal phosphate is a compound having the formula (Li_1-xZ_x)MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to about 0.05

40. The battery pack of claim 32, wherein the lithium transition metal phosphate compound has a specific surface area of greater than about 10 m²/g.

41. The battery pack of claim 32, wherein the negative electrode includes graphitic carbon.

42. The battery pack of claim 32, wherein the carbon is selected from the group consisting of graphite, spheroidal graphite, mesocarbon microbeads and carbon fibers.

43. The battery pack of claim 32, wherein the electrolyte includes about 1.0 M to about 1.3 M LiPF₆ and an organic solvent including about 30 wt % to about 50 wt % ethylene carbonate, about 10 wt % to about 20 wt % propylene carbonate, about 20 wt % to about 35 wt % dimethyl carbonate, about 20 wt % to about 30 wt % ethyl methyl carbonate, with an additional about 1 wt % to about 3 wt % vinylene carbonate.

44. A battery pack for use in a hybrid electric vehicle comprising a plurality of lithium secondary cells connected in series, in parallel, or in a combination thereof, wherein each cell comprises:

a positive electrode including a lithium transition metal phosphate compound;

a negative electrode including carbon;

an electrolyte in contact with and separating the positive electrode and negative electrode;

a positive electrode current collector in electronic communication with the positive electrode; and

a negative electrode current collector in electronic communication with the negative electrode;

wherein the cell components are selected to achieve impedance growth of no more than about 10% for every deep discharge 1000 charge-discharge cycles at a temperature of up to about 60°

C.; and

a total cell energy capacity decrease of no more than about 20% from the initial cell energy capacity for every deep discharge 500 charge-discharge cycles at a temperature of up to about 60°

C.; and

a total discharge capacity for each cell in the plurality of cells of at least about 1 Ah.

45. The lithium secondary cell of claim 44, wherein the impedance growth of the cell is logarithmic with respect to time at temperatures of up to about 55°

C.

46. The battery pack of claim 44, wherein the lithium transition metal phosphate is a compound having the formula Li_1-xM(PO)₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel;

and 0≦

x≦

1.

47. The battery pack of claim 44, wherein the lithium transition metal phosphate is a compound having the formula Li_xM′

_yM″

_a(PO)₄, wherein M″

is selected from the group consisting of Group IIA, IIIA, IVA, VA, VIA and IIIB metals having an ionic radius less than the ionic radius of Fe²⁺, x is equal to or greater than 0 and a and y are greater than 0.

48. The battery pack of claim 44, wherein the lithium transition metal phosphate is a compound having the formula (Li_1-xZ_x)MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to about 0.05

49. The hybrid electric vehicle of claim 44, wherein the lithium transition metal phosphate compound has a specific surface area of greater than about 10 m²/g.

50. The hybrid electric vehicle of claim 44, wherein the negative electrode includes graphitic carbon.

51. The hybrid electric vehicle of claim 44, wherein the carbon is selected from the group consisting of graphite, spheroidal graphite, mesocarbon microbeads and carbon fibers.

52. The battery pack of claim 44, wherein the electrolyte includes about 1.0 M to about 1.3 M LiPF₆ and an organic solvent including about 30 wt % to about 50 wt % ethylene carbonate, about 10 wt % to about 20 wt % propylene carbonate, about 20 wt % to about 35 wt % dimethyl carbonate, about 20 wt % to about 30 wt % ethyl methyl carbonate, with an additional about 1 wt % to about 3 wt % vinylene carbonate.

53. A battery pack for use in a device comprising a plurality of lithium secondary cells connected in series, in parallel, or in a combination thereof to provide a voltage sufficient to operate a motor, and wherein each cell has an available power at the beginning of life that is no more than 20% greater than a predefined power at end of life.

54. The battery pack of claim 53, wherein the device is a hybrid electric vehicle.

55. The battery pack of claim 53, wherein end of life is the point at which the cell has an available energy of 300 Wh.

56. The lithium secondary cell of claim 53, wherein the cell exhibits impedance growth of no more than about 10% for every 1000 deep discharge charge-discharge cycles at a temperature of up to 60°

C.

57. The lithium secondary cell of claim 53, wherein the cell exhibits a total cell energy capacity decrease of no more than about 20% from the initial cell energy capacity for every 500 deep discharge charge-discharge cycles at a temperature of up to about 60°

C.

58. The lithium secondary cell of claim 53, wherein the impedance growth of the cell is logarithmic with respect to time at temperatures of up to about 55°

C.

59. The battery pack of claim 53, wherein each cell includes a positive electrode, the positive electrode including a lithium transition metal phosphate is a compound having the formula Li_1-xM(PO)₄, wherein M is selected from the group consisting of vanadium, chromium, manganese, iron, cobalt and nickel;

and 0≦

x≦

1.

60. The battery pack of claim 53, wherein the lithium transition metal phosphate is a compound having the formula Li_xM′

_yM″

_a(PO)₄, wherein M″

is selected from the group consisting of Group IIA, IIIA, IVA, VA, VIA and IIIB metals having an ionic radius less than the ionic radius of Fe²⁺, x is equal to or greater than 0 and a and y are greater than 0.

61. The battery pack of claim 53, wherein the lithium transition metal phosphate is a compound having the formula (Li_1-xZ_x)MPO₄, where M is one or more of vanadium, chromium, manganese, iron, cobalt and nickel, Z is one or more of titanium, zirconium, niobium, aluminum, tantalum, tungsten or magnesium, and x ranges from 0 to about 0.05

62. The battery pack of claim 53, wherein the lithium transition metal phosphate compound has a specific surface area of greater than about 10 m²/g.

63. The battery pack of claim 53, wherein each cell includes a negative electrode, the negative electrode including graphitic carbon.

64. The battery pack of claim 53, wherein the carbon is selected from the group consisting of graphite, spheroidal graphite, mesocarbon microbeads and carbon fibers.

65. The battery pack of claim 53, wherein each cell includes an electrolyte, the electrolyte including about 1.0 M to about 1.3 M LiPF₆ and an organic solvent including about 30 wt % to about 50 wt % ethylene carbonate, about 10 wt % to about 20 wt % propylene carbonate, about 20 wt % to about 35 wt % dimethyl carbonate, about 20 wt % to about 30 wt % ethyl methyl carbonate, with an additional about 1 wt % to about 3 wt % vinylene carbonate.