Electrochemical systems with electronically conductive layers

• US 9,379,368 B2
• Filed: 01/10/2013
• Issued: 06/28/2016
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Roumi, Farshid
• Primary Examiner(s): Alejandro, Raymond
• Application Number:
  US13/738,835
• Publication Number:
  US 20130224632A1
• Time in Patent Office: 1,265 Days
• US Class Current: 1/1
• 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 electrochemical systems with electronically and ionically conductive layers that have electronic, mechanical and chemical properties useful for a variety of applications including electrochemical storage and conversion. State of the art electrochemical cells are made with electronically non-conductive separators between the opposite electrodes as the natural choice to prevent any electronic path between the opposite electrodes. Herein, electronically conductive layers are introduced between an electrode and the separator without producing any direct electronic path between the opposite electrodes. 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 electronically and ionically conductive layers 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 electronically and ionically conductive layers between the separator and an electrode include metals, metal alloys, a carbon materials, semiconductors, electronically conductive polymers, electronically conductive ceramics and any combination of these.

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 wherein said first electronically and ionically conductive layer comprises a porous, perforated or foam material having a porosity greater than or equal to 30%, has a thickness selected from the range of 10 nm to 100 μ

m, and comprises a metal, a metal alloy, a carbon material, a semiconductor, or any combination of these; 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;

wherein said first electronically and ionically conductive layer provides an electronic conductivity greater than or equal to 1 S/cm and provides an ionic resistance less than or equal to 10 Ω

·

cm².

2. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer comprises a metallic or alloy mesh, a metallic or alloy perforated layer, a metal or alloy coating, or a carbon coating.

3. 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.

4. 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 said current collector of said positive electrode or a said current collector of said negative electrode.

5. The electrochemical cell of claim 4, 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.

6. The electrochemical cell of claim 1, wherein said first electronically and ionically conductive layer is provided in physical contact with said separator.

7. 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.

8. 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.

9. 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.

10. 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.

11. The electrochemical cell of claim 1, wherein said separator comprises a microporous layer comprising a polymer, polyethylene, polypropylene, polyethylene terephthalate, poly(4,4′

-oxydiphenylene-pyromellitimide), polytetrofluoroethylene, glass separator, nonwoven separator, woven separator, a polymer electrolyte, a solid electrolyte, a gel electrolyte, C₇HF₁₃O₅S.C₂F₄ Nafion, ZrO₂, polyvinylidene difluoride, polyethylene oxide, poly(methyl methacrylate), Li_2+2xZn<sub>1−

x</sub>GeO, Na_1+xZr₂Si_xP<sub>3−

x</sub>O₁₂, 0<

x<

3, Li₂PO₂N, Na₂PO₂N, or any combination of these.

12. 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.

13. 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.

14. 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.

15. The electrochemical cell of claim 1, wherein said electrochemical cell comprises a secondary battery, a primary battery, a flow battery, a semi-solid battery, a fuel cell, an electrochemical capacitor, 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.

16. 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.