NOVEL SEPARATORS FOR ELECTROCHEMICAL SYSTEMS

• US 20130224632A1
• Filed: 01/10/2013
• Published: 08/29/2013
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: ROUMI, Farshid
• Granted Patent: US 9,379,368 B2
• Time in Patent Office: Days
• US Class Current: 429/516
• CPC Class Codes: H01G 11/52 Separators
• CPC Class Codes: H01G 9/0029 Processes of manufacture
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/0562 Solid materials
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 10/0569 characterised by the solvents
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• 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 2004/028 Positive electrodes
• CPC Class Codes: H01M 2300/0037 Mixture of solvents
• CPC Class Codes: H01M 2300/004 Three solvents
• CPC Class Codes: H01M 2300/0071 Oxides
• 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 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/382 Lithium H01M4/405 takes precedence
• CPC Class Codes: H01M 4/525 : of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/5825 : Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/587 : for inserting or intercalating light metals
• CPC Class Codes: H01M 4/625 : Carbon or graphite
• CPC Class Codes: H01M 50/403 : Manufacturing processes of separators, membranes or diaphragms
• CPC Class Codes: H01M 50/411 : Organic material
• CPC Class Codes: H01M 50/414 : Synthetic resins, e.g. thermoplastics or thermosetting resins
• CPC Class Codes: H01M 50/431 : Inorganic material
• CPC Class Codes: H01M 50/434 : Ceramics
• CPC Class Codes: H01M 50/437 : Glass
• CPC Class Codes: H01M 50/446 : Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/449 : having a layered structure
• CPC Class Codes: H01M 50/457 : comprising three or more layers
• CPC Class Codes: H01M 50/463 : Separators, membranes or diaphragms characterised by their shape
• CPC Class Codes: H01M 50/489 : Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: H01M 50/491 : Porosity
• CPC Class Codes: H01M 50/494 : Tensile strength
• CPC Class Codes: H01M 8/02 : Details electrodes H01M4/86 - H01M4/98
• CPC Class Codes: H01M 8/0245 : in the form of layered or coated products
• CPC Class Codes: H01M 8/1016 : characterised by the electrolyte material H01M8/12 takes precedence
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 : Electric battery cell making

Abstract

Provided are separator systems for electrochemical systems providing electronic, mechanical and chemical properties useful for a variety of applications including electrochemical storage and conversion. Embodiments provide structural, physical and electrostatic attributes useful for managing and controlling dendrite formation and for improving the cycle life and rate capability of electrochemical cells including silicon anode based batteries, air cathode based batteries, redox flow batteries, solid electrolyte based systems, fuel cells, flow batteries and semisolid batteries. Disclosed separators include multilayer, porous geometries supporting excellent ion transport properties, providing a barrier to prevent dendrite initiated mechanical failure, shorting or thermal runaway, or providing improved electrode conductivity and improved electric field uniformity. Disclosed separators include composite solid electrolytes with supporting mesh or fiber systems providing solid electrolyte hardness and safety with supporting mesh or fiber toughness and long life required for thin solid electrolytes without fabrication pinholes or operationally created cracks.

Claims

1. An electrochemical cell comprising:

a positive electrode;

a negative electrode;

an ionically conductive and electronically insulating separator positioned between said positive electrode and said negative electrode;

a first electronically and ionically conductive layer positioned between said positive electrode and said separator and in electrical contact with said positive electrode or positioned between said negative electrode and said separator and in electrical contact with said negative electrode; and

one or more electrolytes positioned between said positive electrode and said negative electrode;

wherein said one or more electrolytes are capable of conducting charge carriers.

2. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer comprises a metal, a metal alloy, a carbon material, a semiconductor, an electronically conductive polymer, an electronically conductive ceramic, a metallic or alloy mesh, a metallic or alloy perforated layer, a metal or alloy coating, a carbon coating, a porous layer, a perforated layer, a mesh, a foam, an at least partial coating of a conductive material, Au, Al, Cu, Ti, Zn, Ag, stainless steel, Li, Sn, Si, Ni, steel, Tungsten, Tin, Lead, Constantan, Mercury, Germanium or any of their alloys, graphite, carbon black, graphene, carbon nanotubes, coke, Li alloys, Fe alloys, Indium tin oxide (ITO), lanthanum-doped strontium titanate (SLT), yttrium-doped strontium titanate (SYT), Poly(fluorene)s, polyphenylenes, polypyrenes, polyazulenes, polynaphthalenes, Poly(acetylene)s, Polyp-phenylene vinylene), poly(pyrrole)s, polycarbazoles, polyindoles, polyazepines, polyanilines, poly(thiophene)s, poly(3,4-ethylenedioxythiophene), polyp-phenylene sulfide), polyfluorene-based conducting polymers, PAN, Poly(9,9-dioctylfluorene-co-fluorenone, Poly(9,9-dioctylefluorene-co-fluorenone-co-methylbenzoic ester), polythiophene, polypyrrole, poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate)(PEDOT:

PSS), [(ferocenyl)amidopropyl]pyrrole, pyrrole, polypyrrole, polyaniline, polythiophene, polyfuran, SiO2, Napion, PVC or their doped compositions or their mixtures;

or any combination of these.

5. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer comprises a porous, perforated or foam material having a porosity greater than or equal to 30%.

8. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer comprises a thin film structure deposited on at least one external surface of said separator, said positive electrode or said negative electrode or a coating coated on at least one external surface of said separator, said positive electrode or said negative electrode.

10. The electrochemical cell of claim 1, wherein at least a portion of said first electronically and ionically conductive layer is positioned within an active material of said positive electrode or within an active material of said negative electrode;

wherein said portion of said first electronically and ionically conductive layer that is positioned within said active material of said positive electrode or said active material of said negative electrode is not in physical contact with said separator, or wherein said portion of said first electronically and ionically conductive layer that is positioned within said active material of said positive electrode or said active material of said negative electrode is in physical contact with a current collector of said positive electrode or a current collector of said negative electrode, or wherein said portion of said first electronically and ionically conductive layer that is positioned within said active material of said positive electrode or said active material of said negative electrode is not in physical contact with a current collector of said positive electrode or a current collector of said negative electrode.

14. The electrochemical cell of claim 10, wherein said portion of said first electronically and ionically conductive layer that is positioned within said active material of said positive electrode or said active material of said negative electrode is provided within said active material of said positive electrode or said active material of said negative by a method selected from the group consisting of wet processing, dry processing, mechanical pressing, thermal deposition, coating and any combination of these.

15. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer provides an electronical conductivity greater than or equal to 1 S/cm or provides an ionic resistance less than or equal to 10 Ω

·

cm².

19. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer has a thickness less than or equal to 100 μ

m or has a thickness selected from the range of 10 nm to 10 μ

m.

21. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer is provided in physical contact with said separator, or wherein said first electronically and ionically conductive layer is in physical contact with at least 10% of an exterior surface of said separator.

23. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer is in physical contact with said positive electrode or said negative electrode, wherein said first electronically and ionically conductive layer is in physical contact with said positive electrode or said negative electrode, or wherein said first electronically and ionically conductive layer is in physical contact with at least 10% of an exterior surface of said positive electrode or said negative electrode.

26. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer provides an added path for electron transfer between said positive electrode and a positive electrode current collector or an added path for electron transfer between said negative electrode and a negative electrode current collector or wherein said first electronically and ionically conductive layer increases an electronic conductivity of at least a portion of said negative electrode or said positive electrode.

27. The electrochemical cell of claim 1, further comprising a second electronically and ionically conductive layer;

wherein said first electronically and ionically conductive layer is positioned in electrical contact with said positive electrode and wherein said second electronically and ionically conductive layer is positioned in electrical contact with said negative electrode, and wherein said first and second electronically and ionically conductive layers are not in physical or electrical contact with each other.

29. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer provides a homogeneous electric field adjacent to and within said positive electrode or said negative electrode, thereby providing uniform ion deposition into said positive electrode or said negative electrode;

or wherein said first electronically and ionically conductive layer prevents dendrite growth on or from said positive electrode or said negative electrode.

31. The electrochemical cell of claim 1, wherein said separator comprises a microporous layer comprising a polymer, polyethylene, polypropylene, polyethylene terephthalate, Kapton, polytetrofluoroethylene, glass separator, nonwoven separator, woven separator, a polymer electrolyte, a solid electrolyte, a gel electrolyte, Nafion, ZrO₂, PVDF, PEO, PMMA, LISICON, NASICON, LIPON, NaPON, PE, PP, PET, Kapton or any combination of these.

37. The electrochemical cell of claim 1, wherein said separator comprises a coating coated on at least one external surface of said first electronically and ionically conductive layer, at least one surface of said positive electrode or at least one surface of said negative electrode or wherein said separator comprises a thin film deposited on at least one external surface of said first electronically and ionically conductive layer, at least one surface of said positive electrode or at least one surface of said negative electrode.

40. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer is a coating on said separator;

and wherein said separator has a total thickness less than or equal to 500 μ

m or selected or the range of 10 nm to 200 μ

m.

49. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer comprises an external current collector pole;

or wherein said first electronically and ionically conductive layer reduces one of said positive electrode and said negative electrode;

or wherein said external current collector pole oxidizes one of said positive electrode and said negative electrode.

52. The electrochemical cell of claim 1, wherein said electrochemical cell comprises a secondary battery, a primary battery, a flow battery or a semi-solid battery or a fuel cell or an electrochemical capacitor or a lead acid battery, a lithium ion battery, a lithium metal battery, a zinc battery, a lithium-air battery, a zinc-air battery, an aluminum-air battery, an iron-air battery, a lithium-water battery, a silicon based battery, a sodium battery, a magnesium battery, a sodium ion battery, a magnesium ion battery, an alkaline battery or a lead acid battery, or wherein said electrochemical cell comprises a lithium battery comprising one or more of a silicon based anode, a lithium anode, a metal oxide electrode, a sulfur based cathode, a carbon-based oxygen cathode, and a carbon based water cathode.

196. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer conducts ions via transport of said charge carriers of said electrolyte through one or more apertures or pores in said first electronically and ionically conductive layer.

3-4. -4. (canceled)

6-7. -7. (canceled)

9. (canceled)

11-13. -13. (canceled)

16-18. -18. (canceled)

20. (canceled)

22. (canceled)

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28. (canceled)

30. (canceled)

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38-39. -39. (canceled)

41-48. -48. (canceled)

50-51. -51. (canceled)

53-54. -54. (canceled)

55. An electrochemical cell comprising:

a positive electrode;

a negative electrode;

an ionically conductive and electronically insulating separator positioned between said positive electrode and said negative electrode, wherein said separator comprises;

a first high mechanical strength layer having a plurality of apertures extending entirely through said first high mechanical strength layer and provided in a first pattern; and

a first ionically conductive and electronically insulating material provided in at least a portion of said plurality of apertures of said first high mechanical strength layer;

a first electrolyte positioned between said positive electrode and said separator; and

a second electrolyte positioned between said negative electrode and said separator;

wherein said first and second electrolytes are capable of conducting charge carriers.

56. The electrochemical cell of claim 55, wherein said first ionically conductive and electronically insulating material comprises a solid electrolyte, a gel electrolyte, a polymer electrolyte, Nafion, ZrO₂, LISICON, NASICON, PEO, Li₁₀GeP₂S₁₂, LIPON, PVDF, Li₃N, Li₃P, LiI, LiBr, LiCl, LiF, lithium imide, KOH, NaOH, oxide perovskite, La_0.5, Li_0.5TiO₃, thio-LISICON, Li_3.25Ge_0.25P_0.75S₄, glass ceramics, Li₇P₃S₁₁, glassy materials, Li₂S—

SiS₂—

Li₃PO₄, lithium nitride, polyethylene oxide, Doped Li₃N, Li₂S—

SiS₂—

Li₃PO₄, LIPON, Li₁₄Zn(GeO₄)₄, Li-beta-alumina, Li_3.6Si_0.6P_0.4O₄, Li₂S—

P₂S₅, PEO—

LiClO₄, LiN(CF₃SO₂)₂/(CH₂CH₂O)₈, NaPON, SiO2, alumina, silica glass, ceramics, glass-ceramics, water-stable polymers, glassy metal ion conductors, amorphous metal ion conductors, ceramic active metal ion conductors, glass-ceramic active metal ion conductors, an ion conducting ceramic, an ion conducting solid solution, an ion conducting glass, a solid lithium ion conductor or any combination of these.

57. The electrochemical cell of claim 55, wherein said first ionically conductive and electronically insulating material comprises 20% or more by volume of said separator or occupies 20% or more of a surface area of said separator.

63. The electrochemical cell of claim 55, wherein said first ionically conductive and electronically insulating material has an ionic conductivity selected from the range of 10⁻

7 S/cm to 100 S/cm at an operating temperature of said electrochemical cell.

70. The electrochemical cell of claim 55, wherein said first high mechanical strength layer comprises a mesh or a foam comprising a metal, Ni, stainless steel, tin, Al, Cu, an alloy, a glass, a polymer, Kapton, PE, PP, PET, PTFE, PVDF, SiO₂, a ceramic, aluminum oxide, carbon, graphite, nanocarbon or any combination of these.

75. The electrochemical cell of claim 55, wherein said first high mechanical strength layer comprises Kapton, polyethylene, polypropylene, polyethylene terephthalate, poly(methyl methacrylate), a metal coated with a nonconductive material, an alloy coated with a nonconductive material, a polymer, a glass, an aluminum oxide, a silicon oxide, a titanium oxide, Polyacrylic acid (PAA), Cross-linked polyethylene (PEX, XLPE), Polyethylene (PE), Polyethylene terephthalate (PET, PETE), Polyphenyl ether (PPE), Polyvinyl chloride (PVC), Polyvinylidene chloride (PVDC), Polylactic acid (PLA), Polypropylene (PP), Polybutylene (PB), Polybutylene terephthalate (PBT), Polyamide (PA), Polyimide (PI), Polycarbonate (PC), Polytetrafluoroethylene (PTFE), Polystyrene (PS), Polyurethane (PU), Polyester (PE), Acrylonitrile butadiene styrene (ABS), Poly(methyl methacrylate) (PMMA), Polyoxymethylene (POM), Polysulfone (PES), Styrene-acrylonitrile (SAN), Ethylene vinyl acetate (EVA), Styrene maleic anhydride (SMA), PVDF, PEO, LIPON, LISICON, tetramethylammonium hydroxide pentahydrate, (CH₃)₄NOH.5H₂O , poly(ethylene oxide) (PEO), copolymer of epichlorohydrin and ethylene oxide P(ECH-co-EO) and poly(vinylalcohol), PEO-PVA-glassfibre polymer electrolyte, zinc sulfide, silicon dioxide, PVA and PSA, PVA/V6/PSS;

PVAN6/(PSS+PAA);

V6/PVA/(PSS+PAA);

PVMPSS+PAA(35%))/(PSS+PAA(35%));

(PSS+PAA(35%))/PVA/(PSS+PAA(35%));

or (PSS+PAA (35%))/(PVA(10%)+PSS (20% vs. PVA))/(PSS+PAA (35%)) polyethylene glycol, polypropylene glycol, polybutylene glycol, alkyl-polyethylene glycol, alkyl-polypropylene glycol, PEDOT;

PSS, SiO₂, Lithium nitride, NaPON, PVC, glass fiber mat, alkyl-polybutylene glycol, a copolymer thereof, a PEO material, a PVA material or any combination of these.

77. The electrochemical cell of claim 55, wherein said first pattern of apertures provides a first porosity of said first high mechanical strength layer greater than or equal to 30%.

81. The electrochemical cell of claim 55, further comprising a first electronically and ionically conductive layer positioned between said positive electrode and said separator and in electrical contact with said positive electrode or positioned between said negative electrode and said separator and in electrical contact with said negative electrode, or further comprising a second electronically and ionically conductive layer positioned between said negative electrode and said separator and in electrical contact with said negative electrode or positioned between said positive electrode and said separator and in electrical contact with said positive electrode.

86. The electrochemical cell of claim 81, wherein said first electronically and ionically conductive layer comprises an external current collector pole, wherein said first electronically and ionically conductive layer reduces one of said positive electrode and said negative electrode or wherein said external current collector pole oxidizes one of said positive electrode and said negative electrode.

93. The electrochemical cell of claim 55, wherein said separator further comprises a second high mechanical strength layer having a plurality of apertures extending entirely through said second high mechanical strength layer and provided in a second pattern, said second pattern having an off-set alignment relative to said first pattern such that an overlap of said apertures of said first high mechanical strength layer and said apertures of said second high mechanical strength layer along axes extending perpendicularly from said first high mechanical strength layer through said second high mechanical strength layer is less than or equal to 20%;

and wherein said first high mechanical strength layer and said second high mechanical strength layer are positioned such that ions of an electrolyte provided in contact with said first high mechanical strength layer and said second high mechanical strength layer are able to be transported through said first high mechanical strength layer and said second high mechanical strength layer; and

wherein said separator further comprises a second ionically conductive and electronically insulating material provided in at least a portion of said plurality of apertures of said second high mechanical strength layer.

184. The electrochemical cell of claim 55, wherein said first high mechanical strength layer is used to prevent creation of pinholes during the fabrication of said first ionically conductive and electronically insulating material, or wherein said first high mechanical strength layer is used to prevent creation of cracks due to diffusion of ions in said first ionically conductive and electronically insulating material or wherein said first high mechanical strength layer has a 3-dimensional structure or comprises a 3-dimensional mesh or wherein said first high mechanical strength layer is prestressed or wherein said first high mechanical strength layer is prestressed and thereby provides physical contact between one or more ionically conductive and electronically insulating materials and an electrode.

197. The electrochemical cell of claim 55, wherein said ionically conductive and electronically insulating separator conducts ions via transport of said charge carriers of said electrolyte through said apertures in said first high mechanical strength layer.

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113. A method of making a membrane for an electrochemical cell, the method comprising the steps of:

providing a first high mechanical strength layer having a plurality of apertures extending entirely through said first high mechanical strength layer and provided in a first pattern;

providing a first ionically conductive and electronically insulating material into all or a portion of said plurality of apertures of said first high mechanical strength layer.

114-148. -148. (canceled)

149. An electrochemical cell comprising:

a positive electrode;

a negative electrode;

an ionically conductive and electronically insulating separator positioned between said positive electrode and said negative electrode;

one or more thermally and ionically conductive layers positioned between said positive electrode and said separator or positioned between said negative electrode and said separator; and

one or more electrolytes positioned between said positive electrode and said negative electrode;

wherein said one or more electrolytes are capable of conducting charge carriers.

150-166. -166. (canceled)

167. An electrochemical cell comprising:

a positive electrode;

a negative electrode;

a solid electrolyte comprising;

a first ionically conductive and electronically insulating material; and

a group of mechanically tough fibers positioned inside said a first ionically conductive and electronically insulating material;

wherein said electrolyte is capable of conducting charge carriers.

168-183. -183. (canceled)

185-195. -195. (canceled)