COMPOSITE SOLID ELECTROLYTE FOR PROTECTION OF ACTIVE METAL ANODES

• US 20070172739A1
• Filed: 12/19/2006
• Published: 07/26/2007
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: PolyPlus Battery Company
• Original Assignee: PolyPlus Battery Company
• Inventors: Nimon, Yevgeniy, Visco, Steven, DeJonghe, Lutgard
• Granted Patent: US 8,182,943 B2
• Time in Patent Office: Days
• US Class Current: 429/322
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/056 characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
• CPC Class Codes: H01M 10/0561 the electrolyte being constituted of inorganic materials only
• CPC Class Codes: H01M 10/0566 Liquid materials
• CPC Class Codes: H01M 12/04 composed of a half-cell of the fuel-cell type and of a half-cell of the primary-cell type
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 2300/0005 Acid electrolytes
• CPC Class Codes: H01M 2300/0017 Non-aqueous electrolytes
• CPC Class Codes: H01M 2300/0065 Solid electrolytes
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 2300/0071 Oxides
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 2300/0091 in the form of mixtures
• CPC Class Codes: H01M 4/04 Processes of manufacture in general
• CPC Class Codes: H01M 4/0416 involving impregnation with a solution, dispersion, paste or dry powder H01M4/0438 takes precedence
• CPC Class Codes: H01M 4/08 Processes of manufacture
• 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 4/131 : Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/133 : Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 : Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/139 : Processes of manufacture
• CPC Class Codes: H01M 4/242 : Hydrogen storage electrodes
• CPC Class Codes: H01M 4/32 : Nickel oxide or hydroxide electrodes
• CPC Class Codes: H01M 4/38 : of elements or alloys
• CPC Class Codes: H01M 4/383 : Hydrogen absorbing alloys
• CPC Class Codes: H01M 4/385 : of the type LaNi5
• CPC Class Codes: H01M 4/387 : Tin or alloys based on tin
• CPC Class Codes: H01M 4/62 : Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/86 : Inert electrodes with catalytic activity, e.g. for fuel cells
• CPC Class Codes: H01M 50/46 : Separators, membranes or diaphragms characterised by their combination with electrodes
• CPC Class Codes: H01M 6/04 : Cells with aqueous electrolyte
• CPC Class Codes: H01M 6/16 : with organic electrolyte H01M6/18 takes precedence
• CPC Class Codes: H01M 6/181 : with polymeric electrolytes
• CPC Class Codes: H01M 6/185 : with oxides, hydroxides or oxysalts as solid electrolytes
• CPC Class Codes: H01M 6/188 : Processes of manufacture
• CPC Class Codes: H01M 6/24 : Cells comprising two different electrolytes
• CPC Class Codes: H01M 6/34 : Immersion cells, e.g. sea-water cells
• CPC Class Codes: H01M 8/08 : Fuel cells with aqueous electrolytes
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells

Abstract

A composite solid electrolyte include a monolithic solid electrolyte base component that is a continuous matrix of an inorganic active metal ion conductor and a filler component used to eliminate through porosity in the solid electrolyte. In this way a solid electrolyte produced by any process that yields residual through porosity can be modified by the incorporation of a filler to form a substantially impervious composite solid electrolyte and eliminate through porosity in the base component. Methods of making the composites is also disclosed. The composites are generally useful in electrochemical cell structures such as battery cells and in particular protected active metal anodes, particularly lithium anodes, that are protected with a protective membrane architecture incorporating the composite solid electrolyte. The protective architecture prevents the active metal of the anode from deleterious reaction with the environment on the other (cathode) side of the architecture, which may include aqueous, air and organic liquid electrolytes and/or electrochemically active materials.

Claims

1. A substantially impervious composite solid electrolyte, comprising:

a base component comprising a continuous inorganic solid electrolyte matrix having through pores;

a filler component contained in the base component through pores and providing a fluid barrier;

wherein the composite layer has metal ion conductivity of at least 10<sup>−

6</sup> S/Cm.

2. The composite solid electrolyte layer of claim 1, having metal ion conductivity in the range of at least 10⁻

6 S/cm to about 10<sup>−

2</sup> S/cm.

3. The composite solid electrolyte layer of claim 1, wherein the conductive metal ion is an alkali metal ion.

4. The composite solid electrolyte layer of claim 3, wherein the alkali metal ion is Li.

5. The composite solid electrolyte layer of claim 1, having a thickness of at least 10 microns.

6. The composite solid electrolyte layer of claim 1, wherein the base component has metal ion conductivity of at least 10⁻

6 S/cm.

7. The composite solid electrolyte layer of claim 1, wherein the base component has metal ion conductivity in the range of at least 10⁻

6 S/cm to about 10<sup>−

2</sup> S/cm.

8. The composite solid electrolyte layer of claim 7, wherein the conductive metal ion is an alkali metal ion.

9. The composite solid electrolyte layer of claim 8, wherein the alkali metal ion is Li.

10. The composite solid electrolyte layer of claim 1, wherein the density of the base component is greater than 50% and less than 75% of the theoretical density of the base component material.

11. The composite solid electrolyte layer of claim 1, wherein the density of the base component is greater than 75% and less than 95% of the theoretical density of the base component material.

12. The composite solid electrolyte layer of claim 1, wherein the density of the base component is greater than 95% of the theoretical density of the base component material.

13. The composite solid electrolyte layer of claim 1, wherein the base component comprises a material selected from the group consisting of glassy or amorphous active metal ion conductors, ceramic active metal ion conductors, and glass-ceramic active metal ion conductors.

14. The composite solid electrolyte layer of claim 1, wherein the base component comprises a material selected from the group consisting of sodium and lithium beta-alumina, glass ceramic alkali metal ion conductors, Nasiglass, LISICON, NASICON, Li_0.3La_0.7TiO₃ and silicate glasses.

15. The composite solid electrolyte layer of claim 14, wherein the base component comprises LISICON selected from the group consisting of lithium metal phosphates.

16. The composite solid electrolyte layer of claim 13, wherein the base component comprises

17. The composite solid electrolyte layer of claim 15, wherein the base component material comprises Li_1+xM_xHf_2-x(PO₄)₃, where M is Cr, In, Fe, Ta, Sc, Lu or Y, and where 0<

x≦

0.5.

18. The composite solid electrolyte layer of claim 13, wherein base component material is a lithium lanthanum titanate.

19. The composite solid electrolyte layer of claim 18, wherein the lithium lanthanum titanate is Li_3xLa_(2/3)-xTiO₃ (0<

x<

0.16).

20. The composite solid electrolyte of claim 1 wherein the filler component comprises a material selected from the group consisting of polymers, glasses, ceramics, glass ceramics and metals.

21. The composite solid electrolyte of claim 20, wherein the filler component is not conductive to metal ions.

22. The composite solid electrolyte of claim 21, wherein the filler component comprises a polymer.

23. The composite solid electrolyte of claim 22, wherein the polymer is selected from the group consisting of polyisobutylene, epoxy, polyethylene, polypropylene, polytetraflouroethylene and combinations thereof.

24. The composite solid electrolyte of claim 22, wherein the filler component comprises an alkali metal ion conductive polymer.

25. The composite solid electrolyte layer of claim 24, wherein the polymer is selected from the group consisting of PEO, cross-linked PEO and amorphous PEO and combinations thereof.

26. The composite solid electrolyte layer of claim 20, wherein the filler component comprises a ceramic selected from the group consisting of Al₂O₃, ZrO₂, SiO₂, CeO₂, Al₂TiO₅ and combinations thereof.

37. A protected anode, comprising:

an active metal anode having a first and second surface;

a protective membrane architecture on at least the first surface of the anode, the architecture having ionic conductivity of the active metal of at least 10<sup>−

6</sup> S/cm; and

,

wherein the protective membrane architecture comprises a substantially impervious composite solid electrolyte according to claim 1.

38. The protected anode of claim 37 wherein active metal anode comprises an alkali metal.

39. The protected anode of claim 38 wherein the alkali metal is Li.

40. The protected anode of claim 37, wherein the anode comprises active metal intercalating material.

41. The protected anode of claim 40, wherein the active metal intercalating material comprises carbon.

42. The protected anode of claim 37, wherein the protective membrane architecture further comprises an active metal ion conducting separator layer comprising a non-aqueous anolyte, the separator layer being chemically compatible with the active metal and in contact with the anode, and wherein the composite solid electrolyte is in contact with the separator layer.

43. The protected anode of claim 42, wherein the separator layer comprises a semi-permeable membrane impregnated with a non-aqueous anolyte.

44. The protected anode of claim 43, wherein the semi-permeable membrane is a micro-porous polymer.

45. The protected anode of claim 43, wherein the anolyte is in the liquid phase.

46. The protected anode of claim 45, wherein the anolyte comprises a solvent selected from the group consisting of organic carbonates, ethers, esters, formates, lactones, sulfones, sulfolane, 1,3-dioxolane and combinations thereof.

47. The protected anode of claim 46, wherein the anolyte comprises a solvent selected from the group consisting of EC, PC, DEC, DMC, EMC, THF, 2MeTHF, 1,2-DME or higher glymes, sufolane, methyl formate, methyl acetate, and combinations thereof and a supporting salt selected from the group consisting of LiPF₆, LiBF₄, LiAsF₆, LiClO₄, LiSO₃CF₃, LiN(CF₃SO₂)₂ and LiN(SO₂C₂F₅)₂.

48. The protected anode of claim 43, wherein the anolyte is in the gel phase.

49. The protected anode of claim 48, wherein the anolyte comprises a gelling agent selected from the group consisting of PVdF, PVdF-HFP copolymer, PAN, and PEO and mixtures thereof;

a plasticizer selected from the group consisting of EC, PC, DEC, DMC, EMC, THF, 2MeTHF, 1,2-DME and mixtures thereof; and

a Li salt selected from the group consiting of LiPF₆, LiBF₄, LiAsF₆, LiClO₄, LiSO₃CF₃, LiN(CF₃SO₂)₂ and LiN(SO₂C₂F₅)₂.

50. The protected anode of claim 42 wherein active metal anode comprises an alkali metal.

51. The protected anode of claim 50 wherein the alkali metal is Li.

52. The protected anode of claim 42, wherein the anode comprises active metal intercalating material.

53. The protected anode of claim 52, wherein the active metal intercalating material comprises carbon.

54. The protected anode of claim 37, wherein the protective membrane architecture comprises a laminate, the laminate comprising, a first material layer in contact with the anode, the first material being ionically conductive and chemically compatible with the active metal;

and a second material layer in contact with the first material layer, the second material layer comprising the composite solid electrolyte according to claim 1.

55. The protected anode of claim 54 wherein the first material layer comprises a material selected from the group consisting of a composite reaction product of active metal with Cu₃N, active metal nitrides, active metal phosphides, active metal halides, active metal phosphorus sulfide glass and active metal phosphorous oxynitride glass.

56. The protected anode of claim 55 wherein active metal anode comprises an alkali metal.

57. The protected anode of claim 56 wherein the alkali metal is Li.

58. The protected anode of claim 57 wherein the first material layer comprises a material selected from the group consisting of a composite reaction product of alkali metal with Cu₃N, L₃N, Li₃P, LiI, LiF, LiBr, LiCl and LiPON.

59. The protected anode of claim 58 wherein the active metal anode comprises lithium and the first material layer comprises the composite reaction product of Li with Cu₃N.

60. The protected anode of claim 59 wherein the active metal anode comprises lithium and the first material layer comprises LiPON.

62. A battery cell, comprising:

a protected anode in accordance with claim 37;

and

a cathode structure.

63. The cell of claim 62, wherein the cathode structure comprises an electronically conductive component, an ionically conductive component, and an electrochemically active component, wherein at least one cathode structure component comprises an aqueous constituent.

64. The cell of claim 63, wherein the cathode structure comprises an aqueous electrochemically active component.

65. The cell of claim 64, wherein the aqueous electrochemically active component is water.

66. The cell of claim 64 wherein the aqueous electrochemically active component is seawater.

67. The cell of claim 64, wherein the aqueous electrochemically active component comprises water soluble oxidant selected from the group consisting of gaseous, liquid and solid oxidants and combinations thereof.

68. The cell of claim 67, wherein the water soluble gaseous oxidants are selected from the group consisting of O₂, SO₂ and NO₂, and the water soluble solid oxidants are selected from the group consisting of NaNO₂, KNO₂, Na₂SO₃ and K₂SO₃.

69. The cell of claim 67, wherein the water soluble oxidant is hydrogen peroxide.

70. The cell of claim 63, wherein the ionically conductive component and the electrochemically active component are comprised of an aqueous electrolyte.

71. The cell of claim 70 wherein the aqueous electrolyte is selected from the group consisting of strong acid solutions, weak acid solutions, basic solutions, neutral solutions, amphoteric solutions, peroxide solutions and combinations thereof.

72. The cell of claim 71, wherein the aqueous electrolyte comprises members selected from the group consisting of aqueous solutions of HCl, H₂SO₄, H₃PO₄ acetic acid/Li acetate, LiOH;

sea water, LiCl, LiBr, LiI, NH₄Cl, NH₄Br and hydrogen peroxide, and combinations thereof.

73. The cell of claim 72, wherein the aqueous electrolyte is seawater.

74. The cell of claim 73, wherein the aqueous electrolyte comprises seawater and hydrogen peroxide.

75. The cell of claim 63, wherein the cathode structure electronically conductive component is a porous catalytic support.

76. The cell of claim 64, wherein the cathode structure electrochemically active material comprises air.

77. The cell of claim 76, wherein the ionically conductive material comprises an aqueous constituent.

78. The cell of claim 77, wherein the ionically conductive material comprises a neutral or acidic aqueous electrolyte.

79. The cell of claim 78, wherein the aqueous electrolyte comprises LiCl.

80. The cell of claim 78, wherein the aqueous electrolyte comprises one of NH₄Cl, and HCl.

81. The cell of claim 63, wherein the cathode structure comprises an air diffusion membrane, a hydrophobic polymer layer, an oxygen reduction catalyst, an electrolyte, and an electronically conductive component/current collector.

82. The cell of claim 63, wherein the cathode structure electrochemically active component comprises a metal hydride alloy.

83. The cell of claim 82, wherein the cathode structure ionically conductive component comprises an aqueous electrolyte.

84. The cell of claim 83, wherein the metal hydride alloy comprises one of an AB₅ and an AB₂ alloy.

85. The cell of claim 63, wherein the cell is a primary cell.

86. The cell of claim 63, wherein the cell is a rechargeable cell.

87. The cell of claim 64, wherein the active metal is lithium and the cathode structure comprises an aqueous ionically conductive component and a transition metal oxide electrochemically active component.

88. The cell of claim 87, wherein the transition metal oxide is selected from the group consisting of NiOOH, AgO, iron oxide, lead oxide and manganese oxide.

89. The cell of claim 63 wherein the ionically conductive component is a non-aqueous catholyte comprising at least one non-aqueous solvent and non-aqueous solvents comprise more than 50% of the catholyte solvent volume, and wherein the electrochemically active component is O₂ obtained from ambient air.

90. The cell of claim 89, wherein the non-aqueous solvent is selected from the group of aprotic solvents including N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), dimethylsulfoxide (DMSO), hexamethylphosphoramide (HMPA), and acetonitrile (AN).

91. The cell of claim 89 wherein the non-aqueous solvent is a non-aqueous protic solvent selected from the group consisting of alcohols, diols and liquid polyols.

92. The cell of claim 63, wherein the ionically conductive component comprises a non-aqueous catholyte selected from the group consisting of organic liquids and ionic liquids.

93. The cell of claim 92, wherein the catholyte is a solution of a Li salt in an aprotic solvent selected from the group consisting of organic carbonates, ethers, lactones, sulfones esters, formats and combinations thereof.

94. The cell of claim 93, wherein the catholyte is selected from the group consisting of EC, PC, DEC, DMC, EMC, THF, 2MeTHF, 1,2-DME and higher glymes,1,3 dioxolane, sufolane, methyl formate, methyl acetate, and combinations thereof, and a supporting salt selected from the group consisting of LiPF₆, LiBF₄, LiAsF₆, LiClO₄, LiSO₃CF₃, LiN(CF₃SO₂)₂, LiN(SO₂C₂F₅)₂ and combinations thereof.

95. The cell of claim 94, further comprising a dissolved a solid, liquid or gaseous oxidant selected from the group consisting of lithium polysulfides, NO₂, SO₂, SOCl₂.

27. A method of fabricating a substantially impervious composite solid electrolyte, the method comprising:

providing a base component comprising a continuous inorganic solid electrolyte matrix having through pores; and

impregnating the base component with filler material forming a fluid barrier filler component in the through pores of the base component such that the composite solid electrolyte is rendered substantially impervious.

28. The method of claim 27 wherein the filler component comprises a non-conductive polymer.

29. The method of claim 28 wherein the non-conductive polymer is selected from the group consisting of polyisobutylene, epoxy, polyethylene, polypropylene, polytetraflouroethylene and combinations thereof.

30. The method of claim 27 wherein the filler component is impregnated into the base component under vacuum.

31. The method of claim 27 wherein the filler component is impregnated into the base component by thermoplastic infusion.

32. The method of claim 27 wherein the filler component comprises a monomer and at least one polymerization initiator and the filler component is cured within the pores of the base component.

33. The method of claim 32 wherein the curing method is chosen from the group consisting of thermal curing, radiation curing, photo-curing, e-beam curing and combinations thereof.

34. The method of claim 29 wherein the filler material comprises epoxy and at least one hardener and the filler material is heat-treated within the pores of the base component in order to harden the epoxy.

35. The method of claim 34 comprising the steps of impregnating the base component with a low viscosity solvent followed by sequential impregnation with mixtures of epoxy and solvent whereby in each sequential step the concentration of epoxy is increased relative to the concentration of solvent in the mixture.

36. The method of claim 27 wherein the impregnation of the filler component into the through pores is followed by a surface treatment selected from the group consisting of plasma etching, UVOC, and mechanical grinding.

61. A method of fabricating a protected anode, the method comprising:

forming a laminate of an active metal anode, a first component layer adjacent to the active metal anode that is ionically conductive and chemically compatible with an active metal, and a composite solid electrolyte layer adjacent to the first layer that is substantially impervious, active metal ion conductive and chemically compatible with the first layer material;

wherein the ionic conductivity of the protective membrane architecture is at least 10<sup>−

6</sup> S/cm; and

wherein the composite solid electrolyte layer comprises a continuous inorganic solid electrolyte matrix having through pores, and wherein the through pores contain a filler component that provides a fluid barrier.