Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/14—Metallic material, boron or silicon
  • C23C14/16—Metallic material, boron or silicon on metallic substrates or on substrates of boron or silicon
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/14—Metallic material, boron or silicon
  • C23C14/16—Metallic material, boron or silicon on metallic substrates or on substrates of boron or silicon
  • C23C14/165—Metallic material, boron or silicon on metallic substrates or on substrates of boron or silicon by cathodic sputtering
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/56—Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
  • C23C14/564—Means for minimising impurities in the coating chamber such as dust, moisture, residual gases
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M10/00—Secondary cells; Manufacture thereof
  • H01M10/05—Accumulators with non-aqueous electrolyte
  • H01M10/058—Construction or manufacture
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/04—Processes of manufacture in general
  • H01M4/0402—Methods of deposition of the material
  • H01M4/0421—Methods of deposition of the material involving vapour deposition
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/411—Organic material
  • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M6/00—Primary cells; Manufacture thereof
  • H01M6/14—Cells with non-aqueous electrolyte
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
  • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
  • H01M50/409—Separators, membranes or diaphragms characterised by the material
  • H01M50/446—Composite material consisting of a mixture of organic and inorganic materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/10—Energy storage using batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• the present disclosure relates generally to the field of electrodes for use in electrochemical cells. More specifically, but without limitation, the present disclosure relates to electrodes for use in electrochemical cells comprising a protective layer and processes of forming such electrodes and electrochemical cells.
• Lithium (Li) metal may be particularly useful as the anode of electrochemical cells because of its relatively light weight and high energy density, as compared to other types of anode materials (e.g., carbon, metals).
• Automobiles to portable electronic devices e.g., laptops, cellular phones
• batteries which comprise lithium anodes.
• lithium anodes in electrochemical cells experience decreased performance with power cycling, the decreased performance resulting from self discharge. As a result, lithium anodes have not been adopted for commercial rechargeable batteries.
• Li-salts including (but not limited to) carbonate, oxide, hydroxide.
• the surface layer on the lithium metal which may be non-homogenous in thickness and composition, which may lead to uneven current distribution across the lithium surface, during plating and/or stripping.
• the surface layer under the Li-salts may become non-uniform or roughen with successive cycles charge/discharge.
• non-uniformity of the lithium surface may result in mossy lithium (i.e., lithium not connected to the current collector) or dendrites. Either case may result in reduced battery performance, although the latter is also a potential source of battery self-discharge and even thermal runaway.
• One aspect of the disclosure provides a composition for use in an electrochemical cell.
• the composition includes a clean metal substantially free of impurities and a layer of protective material in contact with the clean metal.
• Another aspect of the disclosure provides an electrochemical cell including a metal film comprising a clean metal substantially free of impurities.
• the electrochemical cell may further include an electrolyte and a layer of protective material disposed between the electrolyte and the metal film.
• FIG. 1 illustrates an apparatus for forming a metal film via vapor deposition
• FIG. 2 illustrates an apparatus for forming a metal film via sputter deposition
• FIG. 3 provides a schematic for plasma cleaning of a metal surface
• FIG. 4 provides impedance data for lithium metal precursor having undergone treatment with tetraethyl orthosilicate (TEOS).
• TEOS tetraethyl orthosilicate
• FIG. 5 provides impedance data for clean lithium having undergone treatment with TEOS.
• a "clean metal" surface generally referred to as a condition whereby the resulting metallic surface is substantially free of carbonate, oxide and hydroxide components or other impurities typically found on a battery grade metal received from a manufacturer.
• Impurities found on a battery grade metal from a manufacturer may comprise about 20% to 80% carbon and/or about 10% to 35% oxygen.
• the difficulties or decreased performance of electrochemical cells, as a result of deposit formation on the metal surface during charge/discharge cycling for example, may be solved by the use of a clean metal surface followed by the addition of a protective layer.
• One layer in an electrochemical cell may be an anode comprising a clean metal, such as lithium, as the anode active material.
• the lithium (Li) metal may be in the form of a lithium metal foil or a thin lithium film that has been deposited on a substrate, as will be described below. If desirable for the electrochemical properties of the cell, the lithium metal may be in the form of a lithium alloy such as, for example, a lithium aluminum alloy. Further, the thickness of the lithium metal layer may be any suitable thickness and may vary from about 5 nanometers (nm) to 50 microns.
• compositions and processes disclosed are also applicable to other metal anodes such as sodium (Na), magnesium (Mg) and aluminum (Al).
• a layer of a protective material may be deposited to the clean metal.
• the protective material may comprise an organic component, inorganic component or combination of organic/inorganic components.
• the protective material may comprise an organic component such as a polymer.
• Suitable polymers for use in the protective material may include, but are not limited to, ionically conductive polymers, sulfonated polymers, hydrocarbon polymers, vinyl polymer, cyanoacrylate based polymers, conjugated polymers such as poly p-phenylene, polyacetylene, polyphenyl vinylene, polyazulene, polyperinapthalene, polyacenes, oxalates (e.g., diethyl oxalates, dimethyl oxalates, dipropyl oxalates, etc.) polysiloxanes, polyphosphagens, polytetrafluoroethylenes, polyvinylpuridine, polyvinyl quinoline, poly-2-vinylpyridine, vinyl naphthalene, polyvinylidene fluorides, polyethylene oxide, vinylidene fluoride- hexafluoropropylene copolymers, tetrafluoroethylene-fluoropopylene copoly
• the polymeric material may also be one that includes phosphorus (P) or nitrogen (N) such as, for example, acrylates or polyacrylates, polyphosphazene, or polyglycols.
• the acrylates may include an ultraviolet curable acrylate or diacrylate (e.g., Tetraethylene Glycol Diacrylate, Polyethylene Glycol 200 Diacrylate, Polyethylene Glycol 400 Diacrylate, Polyethylene Glycol 200 Dimethacrylate, Polyethylene Glycol 400 Dimethacrylate, Polyethylene Glycol 600 Dimethacrylate, Polyethylane Glycol 200 Diacrylate, N- Vinyl-2-Pyrrolidone, Acrylonitrile, Diethylaminoethyl Acrylate, Diethylaminoethyl Methacrylate, Diisopropylaminoethyl Methacrylate, Dimethylaminopropyl Methacrylamide, and Methoxyethyl Acrylate).
• P phosphorus
• N such as
• any suitable polymer or polymeric material of the present disclosure may be formed by any conventional polymerization of one or more monomers selected from alkyl acrylates, glycol acrylates, polyglycol acrylates, polyol polyacrylates, or the like.
• polymers or polymeric material may be formed by cross-linking monomers selected from the group of polyethylene oxide diacrylate, polyethylene oxide dimethacrylate, polypropylene oxide diacrylate, polypropylene oxide dimethacrylate, polymethylene oxide diacrylate, polymethylene oxide dimethacrylate, alkyldiol diacrylate, alkyldiol dimethacrylate, divinylbenzene, derivates or mixtures thereof.
• the selection of the polymer, polymeric material and/or monomer may be dependent on a number of factors including, but not limited to, the properties of electrolyte, anode and cathode used in the cell.
• the protective material layer may comprise an inorganic component selected from a silicate, borate, aluminate, iodide, bromide, chloride, nitride, sulfide, phosphate, carbonate, phosphorus oxynitride, titanium oxide, borosulfide, aluminosulfide, and phosphosulfide, or a derivative or combination thereof.
• an inorganic component selected from a silicate, borate, aluminate, iodide, bromide, chloride, nitride, sulfide, phosphate, carbonate, phosphorus oxynitride, titanium oxide, borosulfide, aluminosulfide, and phosphosulfide, or a derivative or combination thereof.
• the inorganic protective material layer may include anions or salts of a metal such as LJ2O, SiC>2, B2O3, AI2O3, Na2 ⁇ , U2CO3, LiF, LiN, Li 2 S, LiOH, Li 3 N, Li 3 P, LiI, LiBr, LiCI, LiF, LiPON, P 2 S 5 , P 4 S 3 , TiO 2 , , BaTiO 2 , Ba 2 O 3 or the like.
• the protective material may be selected for its ability to conduct ions and/or allow tunneling while limiting the conduction of electrons.
• the thickness of the protective material layer is selected to provide the necessary protection to the clean metal layer. It may be desirable to keep the layer thickness as thin as possible while providing the desired degree of protection so as to not add excess amounts of non-active materials to the electrochemical cell which would increase the weight of the cell and reduce its energy density. Further, thin layers of protective material may exhibit faster ion conduction as compared to thicker layers of the same protective materials. To that end, the thickness of the protective material layer may be any suitable thickness and may vary from about 2 nanometers (nm) to 100 microns according to one implementation and from about 10 microns to 50 microns in another implementation. Further, he protective material may be disposed between the clean metal surface and an electrolyte.
• Various methods of preparing a clean metal or clean metal film are contemplated by the present disclosure including, but not limited to sputtering deposition/processes, ion plating processes, extrusion, electroplating known vapor deposition processes, such as plasma or chemical vapor deposition (CVD) processes. Additional methods may include vacuum deposition techniques and may include treatment of a metal surface with reactive materials in the liquid or gas state to produce a clean metal surface.
• the clean metal layer i.e., to apply a protective material. It should be understood, however, that in the various methods used to treat the clean metal, the clean metal may not be exposed to temperature ranges substantially exceeding its melting temperature. For example, in the case of depositing a protective material to clean lithium, the lithium is not exposed to temperatures exceeding its melting point of 180° C.
• vapor deposition is one possible technique employed to produce a clean metal surface.
• a metal precursor 110 may be heated under vacuum within a sterile environment such as a vacuum chamber 100 to limit the exposure of metal to little or no contaminants.
• a vacuum chamber 100 is shown for the purpose of illustration, the present disclosure also contemplates other sterile or inert environments such as a glove box or the like.
• the metal precursor 110 may be lithium (Li) 1 sodium (Na), magnesium (Mg) or aluminum (Al) in a relatively untreated of unpurified form.
• any of the aforementioned metal precursors may exist in a raw form as received from a manufacturer.
• the metal precursor 110 may be heated to its melting temperature by a heating means such as electrodes 120.
• a heating means such as electrodes 120.
• other conventional heating means may be employed to raise the temperature of the metal precursor 110 to approximately its melting point.
• the temperature range at which the metal precursor 110 is heated varies depending on its melting point. For example, vapor deposition of lithium may occur at or near the melting point of lithium and thus, at a temperature range of at least 180° C.
• the metal precursor 110 When heated to its melting point, the metal precursor 110 may melt, boil or atomize and release particles of clean metal 130 throughout the vacuum chamber 100. Impurities found within or on the surface of the metal precursor 110 typically have higher melting points as compared to the metal precursor 110. Thus, the impurities do not melt but rather stay in contact with the metal precursor 110. Impurities generally associated with the aforementioned metals may include oxides, nitrides, alkyls, carbonates, a combination thereof or the like.
• the vaporized particles of clean metal 130 may be released (e.g., ejected) from the metal precursor 110 and contacted with a substrate 140 disposed within the vacuum chamber 100.
• a suitable substrate 140 used for vapor deposition may be any conventional material/metal such as nickel (Ni), titanium (Ti), for example, which does not alloy with the clean metal.
• Ni nickel
• Ti titanium
• the substrate 140 may be any suitable electronic conductor.
• sputter deposition is shown as another technique used to produce a clean metal surface.
• Sputter deposition or sputtering may also be known as physical vapor deposition (PVD) whereby particles in a metal precursor 110, such as lithium, for example, are ejected into gas phase due to bombardment of the metal precursor 110 by energetic ions or sputtering gas 210.
• PVD physical vapor deposition
• a sterile environment 200 for sputter deposition may comprise an inlet 230 and an outlet 220 for the introduction of sputtering gas 210.
• Sputtering gases 210 used are typically inert gases or gases which do not react with the metal precursor 110. Examples of possible sputtering gases include, but are not limited to, helium, neon and argon.
• the sputtering gas may be a single type of gas or a combination of gases, such as a reaction gas and carrier gas, which may be introduced into the sterile environment 200.
• the sputtering gas 210 bombards the metal precursor 110, causing particles of clean metal 130 to be released from the precursor 110 and deposit onto a substrate 140. Further, sputtering may occur with the bombardment of the metal precursor 110 by energized particles of gas at a high rate of speed. Thus, particles of clean metal 130 which are released from the precursor 100 are drawn by a magnetic field to the substrate 140.
• the substrate 140 employed in a sputter deposition may have characteristics and properties as previously mentioned.
• FIG. 3 provides a schematic illustrating bombardment of the surface layer on the metal, resulting in the removal of the surface impurity layer from the metal surface. Bombardment of plasma 310 or sputtering gas, in certain implementations, may yield a metal precursor 320 with remaining impurities 320 while clean metal is adhered to the surface of a substrate as previously described.
• the clean lithium may then become a substrate for application of a protective material which may be applied to lithium to improve the performance of lithium in rechargeable batteries.
• the protective material may be deposited, as a coating, in contact with the clean metal surface.
• Other contemplated methods for depositing the protective material to the clean metal may include dipping or vapor deposition at room temperature.
• the clean lithium and the protective material may further be formed separately and laminated together.
• Any known inert environment, such as a glove box, for example, may be utilized to facilitate the treatment of clean metal.
• Li lithium
• Li metal was cleaned for approximately 2 minutes. 200 nanometers (nm) of lithium (Li) is deposited on electron beam (e-beam) nickel (Ni) substrate. The Ni substrate with clean Li was soaked for 15 seconds and subsequently, 6% soak power was applied for a soak period of approximately 1 minute. Following a rise to predeposit for approximately 1 minute, 6.5% predeposit power was applied. The Li is deposited on the Ni substrate at a rate of approximately 1 angstrom per second at a power of less than 10.6% deposition power.
• the process for preparing clean lithium described below was performed in an argon filled glove box.
• the surface of battery grade lithium foil available from FMC
• the scraped lithium was punched to a required size and diameter of an electrode to form a lithium electrode.
• To the lithium electrode in a container was added 20 mL tetraethyl orthosilicate (TEOS).
• TEOS tetraethyl orthosilicate
• the lithium electrode was turned over after approximately 2.5 minutes. After submerging the lithium electrode in the TEOS solution for more than 5 minutes, the lithium is removed from the solution. Cell assembly utilizing the resultant lithium is performed within 15 minutes.
• EXAMPLE 3 As can be seen from FIG. 4, impedance of a typical electrochemical cell containing Li precursor treated with TEOS (as in Example 2) may decrease over successive charge/discharge cycles. In the case of an electrochemical cell utilizing a clean lithium electrode with a protective layer, initial impedance is lower as compared to that of a typical electrochemical cell, as shown in FIG. 5. Further, an electrochemical cell utilizing a clean lithium electrode may exhibit relatively constant impedance over successive charge/discharge cycles as compared to a typical electrochemical cell. This implies that the electrode surface area does not change during successive cycles and does not exhibit roughening.
• the present disclosure provides a process for preparing a clean metal anode and applying a layer of protective material directly to the metal, resulting in a homogeneous or semi-homogeneous layer on the surface of the anode.
• the layer of protective material allows more homogeneous current distribution and so allows the metal surface to remain relatively smooth during charge/discharge of the electrochemical cell.
• compositions and processes of the present disclosure may enhance properties of the electrochemical cell such as maintaining relatively constant impedance over successive charge/discharge cycles and improving the homogeneity of metal anode surfaces.

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• 2009
  • 2009-02-27 US US12/395,488 patent/US8703333B2/en active Active
• 2010
  • 2010-03-01 WO PCT/US2010/000636 patent/WO2010098891A2/en not_active Ceased
  • 2010-03-01 JP JP2011552035A patent/JP6005938B2/ja active Active
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