ELECTROCHEMICAL CELL

• US 20110177398A1
• Filed: 08/24/2010
• Published: 07/21/2011
• Est. Priority Date: 08/05/2008
• Status: Active Grant

• Current Assignee: Sion Power Corporation
• Original Assignee: Sion Power Corporation
• Inventors: Scordilis-Kelley, Chariclea, Affinito, John D., Mikhaylik, Yuriy V.
• Granted Patent: US 10,629,947 B2
• Time in Patent Office: Days
• US Class Current: 429/325
• 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 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• 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 4/366 as layered products
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/405 Alloys based on lithium
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Electrochemical cells including components and configurations for electrochemical cells, such as rechargeable lithium batteries, are provided. The electrochemical cells described herein may include a combination of components arranged in certain configurations that work together to increase performance of the electrochemical cell. In some embodiments, such combinations of components and configurations described herein may minimize defects, inefficiencies, or other drawbacks that might otherwise exist inherently in prior electrochemical cells, or that might exist inherently in prior electrochemical cells using the same or similar materials as those described herein, but arranged differently.

Claims

1. An electrochemical cell, comprising:

a first electrode comprising;

a first base electrode material layer comprising a first active electrode species;

a second base electrode material layer comprising the first active electrode species;

at least one protective layer positioned between the first and second base electrode material layers;

a current collector;

a release layer, wherein the current collector is positioned between the release layer and the first base electrode material layer;

a second electrode comprising a second active electrode species;

a polymer gel layer positioned between the first and second electrodes; and

an electrolyte,

wherein the electrochemical cell is constructed and arranged to apply, during at least one period of time during charge and/or discharge of the cell, an anisotropic force with a component normal to a surface of the first electrode.

4. An electrochemical cell as in claim 1, wherein the first electrode is an anode and the second electrode is a cathode.

5. An electrochemical cell as in claim 1, wherein the first active electrode species comprises lithium.

6. An electrochemical cell as in claim 1, wherein the first active electrode species comprises lithium metal.

7. An electrochemical cell as in claim 1, wherein the second base electrode material layer is positioned so as to reside between the first base electrode material layer and the electrolyte, the second base electrode material layer comprising sufficient active electrode species to participate in a full discharge of the electrochemical cell.

8. An electrochemical cell as in claim 1, wherein the second base electrode material layer is positioned so as to reside between the first base electrode material layer and the electrolyte, the second layer consisting essentially of lithium metal.

9. An electrochemical cell as in claim 1, wherein at least one of the first and second base electrode material layers comprises a Li—

Z alloy, where Z is a metal or semiconductor and is present in an amount greater than 100 ppm but less than or equal to 10 wt % of the alloy.

10. An electrochemical cell as in claim 9, wherein Z is substantially uniformly dispersed throughout a bulk portion of the anode prior to 10^th discharge of the electrochemical cell.

12. An electrochemical cell as in claim 1, wherein the protective layer is a single-ion conductive layer.

13. An electrochemical cell as in claim 1, wherein the protective layer is a polymer layer.

14. An electrochemical cell as in claim 1, comprising a plurality of protective layers separating the first and second base material electrode layers of the first electrode.

15. An electrochemical cell as in claim 14, wherein the plurality of protective layers comprises a single-ion conductive layer and a polymer layer.

16. An electrochemical cell as in claim 1, wherein the electrolyte comprises an external additive having the formula LiR or (Li—

X)_nR′

, wherein

R comprises a heteroalkyl or heteroaryl group, optionally substituted;

R′

comprises an alkyl or aryl group, optionally substituted,

X is a heteroatom; and

n is an integer equal to or greater than 1.

17. An electrochemical cell as in claim 1, wherein the electrolyte comprises a lithium compound additive that can be produced through reaction between the lithium of the anode and at least one other species of the electrochemical cell during charge and/or discharge of the electrochemical cell, which reaction is substantially irreversible under normal charge and/or discharge of the electrochemical cell.

18. An electrochemical cell as in claim 1, wherein the first electrode and the electrolyte together have a maximum thickness of 500 microns or less.

19. An electrochemical cell as in claim 1, wherein the electrolyte comprises one or more N—

O additives.

20. An electrochemical cell as in claim 1, wherein the electrolyte comprises one or more N—

O additives, the one or more N—

O additives comprising one or more of inorganic nitrates, organic nitrates, organic nitrites, and organic nitro compounds.

21. An electrochemical cell as in claim 1, wherein the electrolyte comprises lithium nitrate.

22. An electrochemical cell as in claim 1, wherein the electrolyte comprises a solvent comprising one or more of acyclic ethers, cyclic ethers, polyethers, and sulfones.

23. An electrochemical cell as in claim 1, wherein the electrolyte comprises one or more lithium salts.

24. An electrochemical cell as in claim 1, wherein the electrolyte comprises one or more of LiSCN, LiCF₃SO₃, and LiN(CF₃SO₂)₂.

25. An electrochemical cell as in claim 1, wherein the second electrode comprises a sulfur-containing material as the second active electrode species, and the electrochemical cell exhibits utilization of the sulfur-containing material of at least 60% and a charge-discharge efficiency of at least 80% over at least 10 cycles at a discharge current density of about 0.4 mA/cm².

26. An electrochemical cell as in claim 1, wherein the electrolyte comprises a first electrolyte solvent and a second electrolyte solvent, wherein, in use, the first electrolyte solvent is present disproportionately at the first electrode, and the second electrolyte solvent is present disproportionately at the second electrode, wherein the second electrolyte solvent includes at least one species which reacts adversely with the first electrode.

27. An electrochemical cell as in claim 1, wherein the electrolyte comprises a first electrolyte solvent and a second electrolyte solvent, wherein, in use, the first electrolyte solvent is present disproportionately at the first electrode, and the second electrolyte solvent is present disproportionately at the second electrode, wherein the polymer gel layer is in contact with at least one of the first and second electrodes, the polymer gel layer disproportionately containing one of the first and second electrolyte solvents.

28. An electrochemical cell as in claim 1, wherein the second active electrode species comprises sulfur in the form of at least one of elemental sulfur, a sulfide of the first active electrode species, and a polysulfide of the first active electrode species.

29. An electrochemical cell as in claim 1, wherein the second electrode comprises a sulfur-containing material as the second electrode active species, and a conductive carbon-containing material.

30. An electrochemical cell as in claim 1, wherein the second electrode comprises particles having a maximum diameter of between about 0.1 microns and about 10 microns, wherein the particles comprise a sulfur-containing material.

31. An electrochemical cell as in claim 1, wherein the second electrode comprises a porous structure comprising a plurality of pores having a total pore volume defined by the total of each of the individual pores volumes, and at least about 50% of the total pore volume is occupied by particles having a maximum diameter of between about 0.1 microns and about 10 microns.

32. An electrochemical cell as in claim 31, wherein the porous structure comprises at least one of carbon, a metal, a polymer, and a ceramic.

33. An electrochemical cell as in claim 31, wherein the second electrode comprises a porous structure having a porosity of at least about 30% during the application of an anisotropic force with a component normal to the first base electrode material layer of the first electrode defining a pressure of at least about 98 Newtons per square centimeter of the first base electrode material layer.

34. An electrochemical cell as in claim 1, wherein the electrochemical cell is exposed to a force with a component defining a pressure of at least about 78 Newtons/cm².

35. An electrochemical cell as in claim 1, wherein the second active electrode species comprises sulfur, the second electrode comprising a porous structure having a void volume of at least about 1 cm³ per gram of sulfur.

38. An electrochemical cell as in claim 1, comprising a primer layer positioned adjacent the current collector, the primer layer comprising less than 30% by weight of a crosslinked polymeric material.

39. An electrochemical cell as in claim 38, wherein the primer layer comprises hydroxyl functional groups.

40. An electrochemical cell as in claim 1, comprising a primer layer positioned adjacent a cathode.

41. An electrochemical cell as in claim 1, wherein the electrochemical cell has an area specific resistance of less than 50 ohm-cm².

42. An electrochemical cell as in claim 1, wherein the electrochemical cell capacity decreases by less than about 0.2% per charge and discharge cycle over at least 10 cycles subsequent to the first charge and discharge cycle.

49. An electrochemical cell as in claim 26, wherein the first active electrode species comprises lithium metal, and wherein the second solvent includes at least one species which interacts with the lithium metal to substantially irreversibly form a lithium-containing impurity.

2. An electrochemical cell, comprising:

an anode comprising;

a first base electrode material layer comprising lithium as an active electrode species;

a second base electrode material layer comprising lithium as an active electrode species;

a first multi-layered structure comprising a polymer layer and a lithium ion conductive layer positioned between the first and second base electrode material layers;

a second multi-layered structure comprising a polymer layer and a lithium ion conductive layer positioned between the second base electrode material layer and an electrolyte;

a cathode comprising sulfur as an active electrode species; and

an electrolyte comprising an N—

O additive,

wherein the electrochemical cell is constructed and arranged to apply, during at least one period of time during charge and/or discharge of the cell, an anisotropic force with a component normal to a surface of the anode.

11. An electrochemical cell as in claim 2, wherein the anode further comprises a current collector and a release layer, wherein current collector is positioned between the release layer and the first base electrode material layer.

43. An electrochemical cell as in claim 2, wherein the cathode has an electrolyte accessible conductive area of at least about 1 m² per gram of sulfur in the cathode.

46. An electrochemical cell as in claim 2, wherein the electrochemical cell is capable of achieving a discharge current density of at least about 0.4 mA per square centimeter of the cathode surface.

47. An electrochemical cell as in claim 2, wherein the electrochemical cell is capable of achieving a current density of at least about 100 mA per gram of sulfur in the cathode during charge or discharge.

48. An electrochemical cell as in claim 2, wherein the ratio of the mass of electrolyte in the electrochemical cell to the mass of sulfur in the cathode is less than about 6:

1.

3. An electrochemical cell, comprising:

an anode comprising;

a first base electrode material layer comprising lithium as an active electrode species;

a second base electrode material layer comprising lithium as an active electrode species;

at least one protective layer positioned between the first and second base electrode material layers; and

a cathode comprising a base electrode material layer comprising sulfur as an active electrode species, wherein the base electrode material layer of the cathode comprises a sulfur loading of at least 1.2 mg S/cm² and has a thickness of less than or equal to about 100 microns.

36. An electrochemical cell as in claim 3, wherein the electrochemical cell is capable of utilizing at least about 65% of the total sulfur in the electrochemical cell, wherein 100% utilization corresponds to 1675 mAh per gram of total sulfur in the electrochemical cell.

37. An electrochemical cell as in claim 3, wherein the electrochemical cell is constructed and arranged to apply, during at least one period of time during charge and/or discharge of the cell, an anisotropic force with a component normal to the active surface of the anode.

44. An electrochemical cell as in claim 3, wherein the cathode has a porosity of at least about 30% during discharge of the electrochemical cell.

45. An electrochemical cell as in claim 3, wherein the cathode contains less than about 20% binder by weight.