Classifications

• • 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
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/134—Electrodes based on metals, Si or alloys
• • 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
• • 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
  • H01M10/052—Li-accumulators
  • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• • 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
  • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• • 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
  • H01M4/049—Manufacturing of an active layer by chemical means
• • 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
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• • 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
  • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
  • H01M4/139—Processes of manufacture
  • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
• • 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
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/362—Composites
• • 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
  • H01M4/36—Selection of substances as active materials, active masses, active liquids
  • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
  • H01M4/386—Silicon or alloys based on silicon
• • 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
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• • 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
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
• • 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
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/624—Electric conductive fillers
  • H01M4/625—Carbon or graphite
• • 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
  • H01M2004/021—Physical characteristics, e.g. porosity, surface area
• • 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
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/027—Negative electrodes
• • 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
  • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
  • H01M2004/028—Positive electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2220/00—Batteries for particular applications
  • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M2220/00—Batteries for particular applications
  • H01M2220/30—Batteries in portable systems, e.g. mobile phone, laptop
• • 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

Definitions

• the present disclosure relates to compositions useful as anodes for rechargeable batteries and methods for preparing and using the same.
• an anode composition in some embodiments, includes an electrochemically active material comprising silicon; and
• a method of making an anode composition includes combining (i) precursor materials of an electrochemically active material comprising silicon; and (ii) a base source to form a mixture.
• the method may further include milling the mixture to form a milled mixture; combining the milled mixture and an acid source to form a second mixture; and subjecting the second mixture to a heat treatment to form an acid-base cement monolith.
• a rechargeable battery in some embodiments, includes a cathode; an electrolyte; and an anode that includes an electrochemically active material comprising silicon, and a cement.
• an electronic device is provided. The electronic device includes a rechargeable battery that includes a cathode; an electrolyte; and an anode that includes an electrochemically active material comprising silicon, and a cement.
• Figure 1 depicts the XRD pattern of the composite particles of Example 1.
• Figure 2 depicts an SEM image of the composite particles of Example 1.
• Figure 3 depicts a voltage curve of a coin cell that included, as an anode material, the composite particles of Example 1.
• Figure 4 depicts the cycling characteristics of a coin cell that included, as an anode material, the composite particles of Example 1.
• Figure 5 depicts an SEM image of the composite particles of Example 2.
• Figure 6 depicts the cycling characteristics of a coin cell that included, as an anode material, the composite particles of Example 2.
• Figure 7 depicts an SEM image of the particles of Comparative Example 1.
• Figure 8 depicts the cycling characteristics of a coin cell that included, as an anode material, the particles of Comparative Example 1.
• Figure 9 depicts an SEM image of the particles of Comparative Example 2.
• Figure 10 depicts the cycling characteristics of a coin cell that included, as an anode material, the particles of Comparative Example 2.
• Figure 1 1 depicts the XRD pattern of the composite particles of Example 3.
• Figure 12 depicts the cycling characteristics of a coin cell that included, as an anode material, the composite particles of Example 3.
• Alloy based materials e.g., silicon based alloy materials
• electrochemically active particles typically consist of small particles having a particle size distribution with a D50 value of 3 um in diameter or less.
• Electrode coatings made from such fine particles have high surface areas (for example, > 3.6 m 2 /g), which may lead to poor thermal stability and poor cycling characteristics as a result of increased reactivity between the active material particles and the battery electrolyte.
• Prior approaches to increasing the size of the alloy active material particles include sintering a collection of the particles together (for example, by subjecting the particles to temperatures above 600° €). However, at such temperatures, any
• the present disclosure is directed, in part, to decreasing the surface area of alloy active material particles for negative electrode compositions by the inclusion of acid-base cements in the compositions.
• acid-base cement refers to any cement that comprises an acid source and a base source capable of reacting to form a cementitious material.
• an "amorphous phase” is a phase that lacks long range atomic order and whose x-ray diffraction pattern lacks sharp, well-defined peaks.
• a "nanocrystalline phase” is a phase having crystallites no greater than about 50 nanometers that exhibits long range atomic order and has an x-ray diffraction pattern characterized by well-defined peaks.
• electrochemically active phase refers to a phase or domain that includes at least one electrochemically active metal and which reversibly alloys with Li when used in the negative electrode of a full cell.
• electrochemical ly inactive phase refers to a phase or domain that includes at least one electrochemically inactive metal and does not reversibly alloy with Li when used in the negative electrode of a full cell.
• conducting phase refers to a domain that has substantially high electrical conductivity, including metallic conductors, semi-metals and semiconductors, but is not substantially electrochemically active.
• insulating phase refers to a phase or domain that does not substantially conduct electricity and is not substantially electrochemically active.
• electrochemical ly active refers to materials or phases that can electrochemically react or alloy with lithium at voltages between 0 V and 2 V versus lithium metal.
• electrochemically active material refers to a substance that is electrochemically active, comprises least one electrochemically active phase and may additionally include conducting phases and insulating phases.
• composite anode particles refers to secondary particles that consist of electrochemically active material primary particles that are coupled together with an acid-base cement.
• electrochemical ly inactive refers to materials or phases that are not electrochemically reactive or do not alloy with lithium at voltages between 0 V and 2 V versus lithium metal.
• lithiumate and “lithiation” refer to a process for adding lithium to an electrode material or electrochemically active phase.
• delivery and “delithiation” refer to a process for removing lithium from an electrode material or electrochemically active phase.
• charge and “charging” refer to a process for providing electrochemical energy to a cell.
• discharge and “discharging” refer to a process for removing electrochemical energy from a cell, e.g., when using the cell to perform desired work.
• positive electrode refers to an electrode (often called a cathode) where electrochemical reduction and lithiation occurs during a discharging process in a full cell
• negative electrode refers to an electrode (often called an anode) where electrochemical oxidation and delithiation occurs during a discharging process in a full cell.
• binder refers to a material which exists in a particulate form comprising a plurality of particles wherein the average size of the particles is below 200 micrometers.
• primary particles refers to discrete particles that are substantially non-porous, normally do not reduce in particle size during grinding; and are made up of a single crystal lite or an aggregation of cry stallites that are tightly bound together.
• secondary particles refers to particles whose formation results from a bonding of two or more primary particles (e.g., physical, chemical, ionic, or covalent bonding of primary particles). Secondary particles normally include some porosity and are typically less dense than primary particles.
• the present disclosure is directed to use of cements as components in electrochemically active material compositions useful in electrodes for rechargeable batteries.
• the present disclosure relates to an anode composition for a rechargeable battery.
• the anode composition may include an electrochemically active material and a cement (e.g., in the form of composite anode particles).
• the anode composition may include an electrochemically active material that includes silicon.
• silicon may be present in one or more of the following forms: elemental silicon, a metal silicide, a silicon carbide, or a silicon oxide. In some embodiments, silicon may be present as at least elemental silicon.
• the electrochemically active material may be in the form of multiphase particles, the multiphase particles including each of: (i) an electrochemically active phase that includes silicon; (ii) an insulating phase; and (iii) a conductive phase.
• the electrochemically active phase may consist essentially of elemental silicon, or may also include aluminum, carbon, zinc, gallium, germanium, silver, cadmium, indium, tin, antimony, gold, mercury, lead, bismuth, or combinations thereof.
• the insulating phase may include a ceramic material
• the ceramic material may be an inorganic, non-metallic solid that can be prepared by the action of heat and subsequent cooling of constituent materials.
• the ceramic materials can have a crystalline or partly crystalline structure, or may be amorphous (e.g., a glass).
• the insulating phase can include a borate, a phosphate, a carbonate, an oxide, a sulphate, a silicate, a halide and combinations thereof.
• Insulating phases that are useful in the provided composite particles include oxides of Li, Na, Mg, Ca, La, Ce, Ti, Zr, , Al, Si,
• the provided composite particles include an insulating phase that is selected from AI2O3, CaO, gO, MgAkC , LiA10 2 , Li 2 CO3 ⁇ 4, S1O2, B2O3, LiF, and combinations thereof.
• the insulating phase can be stoichiometric, primarily if it is crystalline, or can be non-stoichiometric.
• stoichiometric it is meant that the atomic ratios of the components of the phase can be represented by ratios of integers. Typically th ese components are solids and contain crystalline domains or grains. By non-stoichiometric it is meant that the atomic ratios of the components of the phase cannot be represented by a ratio of integers. Typically, non- stoichiometric phases are either partially crystalline or amorphous,
• the conducting phase of the provided composite particles may include a metal, a semi-metal, or a semiconductor.
• the composite particles may include a metal element, an alloy, a carbide, an aluminide, a silicide, a boride, a nitride, or a combination thereof.
• Exemplary conducting phases include Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and their alloys.
• Exemplar ⁇ ' carbide conducting phases include TiC and SiC.
• Exemplary silicide conducting phases include FeSi, FeSi?., CrSi 2 , NiSi?., CoSi 2 , TiSi 2 , CusSi, ZrSi 2 , and their ternary and higher order intermetallic compounds.
• Other exemplary conducting phases include T1B2, TiN, FeA.h. and T1AI3.
• the conducting phase can be stoichiometric or nonstoichiometric in a similar fashion to the insulating phase.
• the anode composition may include an electrochemically active material having a formula (I):
• M is one or more metals selected from the group consisting of manganese, molybdenum , niobium , tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, or combinations thereof;
• Q is one or more elements selected from the group consisting of sodium, lithium, potassium, magnesium, calcium, titanium, boron, aluminum, a rare earth metal, or combinations thereof; and
• E is one or more elements selected from the group consisting of boron or nitrogen.
• the Si, Sn, M, C, Q, E, and O elements may be arranged in the form of a multiphase microstructure comprising: (i) an amorphous or nanocrystallme phase comprising silicon; (ii) optionally a conducting nanocrystallme phase; (iii) a phase comprising silicon carbide when d > 0; (iv) optionally an insulating nanocrystallme or amorphous phase, and (v) an amorphous or nanocrystallme phase comprising Sn when b > 0.
• a ⁇ 60 or 70, and d 0 or ⁇ 10 or 15.
• f ⁇ 20, 15, 10, or 5.
• M is one or more metals selected from the group consisting of iron, titanium, nickel, cobalt, molybdenum, and combinations thereof.
• f 0. In some embodiments
• b ::::: 0, d ::::: 0, e ::: 0, f 0 and g :: 0.
• the anode composition may include an electrochemically active material having a formula (II):
• M is one or more metals selected from the group consisting of manganese, molybdenum, niobium, tungsten, tantalum, iron, copper, titanium, vanadium, chromium, nickel, cobalt, zirconium, yttrium, and combinations thereof.
• the Si, Sn, M, and C elements may be arranged in the form of a multi-phase microsti icture comprising: (i) an amorphous phase comprising silicon; (ii) a
• nanocrystallme phase comprising a metal si iicide; (iii) a phase comprising si licon carbide when z > 0; and (iv) an amorphous phase comprising Sn when q > 0.
• M is one or more metals selected from the group consisting of iron, titanium , nickel, cobal t, molybdenum, or combinations thereof.
• y 0.
• any phases present in the electrochemically active material of the present disclosure may be amorphous or nanocrystalline.
• the cement may be a dual-cured cement (e.g., acid- base cement), photo-initiated cement (e.g., UV-curable cement), tri-cure cement
• the cement may be an acid-base cement, such as those acid-base cements that are employed in dental
• an acid source and a base source may be chosen such that may react so as to form the acid-base cement.
• a broad variety of acid sources and base sources may be suitable in the anode compositions of the present disclosure.
• suitable acid sources include pQry(acrylic) acid, magnesium chloride (MgCh), potassium phosphate monobasic ( H2PO4), phosphoric acid (H3PO4), magnesium sulfate i MuSO i !. and ammonium phosphate monobasic (NH2PO4).
• suitable base sources include magnesium oxide (MgO), calcium oxide (CaO), zinc oxide (ZnO) and ammonia (NH3), silicon oxide (S1O2), and SiCh-AkCb-CaO glasses.
• a broad variety of the acid-base cements may be employed including, for example, phosphate cements, oxy-chloride and oxy-sulfate cements.
• Phosphate cements may include without limitation, an acid source that is a monobasic, dibasic, and/or tribasic phosphate salt with counterions sodium, potassium, magnesium, zinc, aluminum or combinations thereof.
• Further examples of suitable acid-base cements include polyalkenoate cements, oxysalt cements, and nonaqueous cements. These acid/base sources may be in the form of a powdered solid, an aqueous solution, and aqueous slurry, a nonaqueous solution or a nonaqueous slurry. Examples of suitable acid-base cements are also described in "Acid-base cements" by A.D. Wilson and J.W. Nicholson, Cambridge University Press, 1993, which is
• the anode composition of the present disclosure may be in the form of secondary composite particles.
• the anode composite particles may be manufactured to achieve any desired size.
• the anode composite particles may have an average size (average major axial diameter or longest straight line between two points on a composite particle) of greater than 1 ⁇ , greater than 5 ⁇ , or greater than 10 ⁇ ; or between 1 - 3 ⁇ , between 5 - 20 ⁇ , or between 20 - 50 ⁇ .
• the anode composite particles may have an average surface area of less than 10 m 2 /g, less than 2 m 2 /g, or less than 1 m 2 /g; or between 0.2 - 1 m 2 /g, between 1 - 3 m 2 /g, or between 2 - 5 m 2 /g.
• the amount of acid-base cement in the anode composite particles may be at least 40 wt. %, at least 20 wt. %, or at least 10 wt. % based upon the total weight of the anode composite particle; or between 10 - 20 wt. %, between 15 - 30 wt. %, or between 30 - 40 wt. % based upon the total weight of the anode composite particle.
• the amount of acid-base cement in the anode composite particles may be at least 40 wt. %, at least 20 wt. %, or at least 10 wt. % based upon the total weight of the ano
• the acid-base cement may comprise less than
• the present disclosure further relates to negative electrode compositions that include the above-described anode composite particles.
• the above- described anode composite particles may be combined with one or more materials to form an electrode composition.
• the electrode composition may include an electrically conductive diluent to facilitate electron transfer from the composition to a current collector.
• Electrically conductive diluents include, for example, carbons, powdered metal, metal nitrides, metal carbides, metal silicides, and metal borides.
• Representative electrically conductive carbon diluents include carbon blacks such as Super P and Super S carbon blacks (both from M M Carbon, Belgium), Shawanigan Black (Chevron
• the amount of conductive diluent in the electrode composition may be at least 2 wt. %, at least 6 wt. %, or at least 8 wt. % based upon the total weight of the electrode coating.
• the negative electrode compositions may include graphite to improve the density and cycling performance, especially in calendered coatings, as described in U.S. Patent Application
• the graphite may be present in the negative electrode composition in an amount of greater than 20 wt. %, greater than 50 wt. %, greater than 70 wt. % or even greater, based upon the total weight of the negative electrode composition.
• the negative electrode compositions may include a binder. Suitable binders include oxo-acids and their salts, such as sodium carboxymethylcellulose, polyacrylic acid and lithium polyacrylate.
• Suitable binders include polyolefms such as those prepared from ethylene, propylene, or butylene monomers; fluorinated polyolefms such as those prepared from vinylidene fluoride monomers; perfluorinated polyolefms such as those prepared from hexafluoropropylene monomer; perfluorinated poly(alkyl vinyl ethers); perfluorinated poly(alkoxy vinyl ethers); or combinations thereof.
• Other suitable binders include polyimides such as the aromatic, aliphatic or cycloaliphatic polyimides and polyacrylates. The binder may be crosslinked. In some embodiments, the amount of binder in the electrode composition may be at least 5 wt.
• the amount of binder in the electrode composition may be less than 30 wt. %, less than 20 wt. %, or less than 10 wt. % based upon the total weight of the electrode coating.
• the present disclosure further relates to methods of making the above-described anode compositions.
• the method may include providing appropriate precursor materials (based on the desired anode composition), combining the precursor materials with a cement precursor (e.g., a base source or an acid source), and mechanically milling the resulting mixture.
• a cement precursor e.g., a base source or an acid source
• Precursor materials may include, for example, Si, FeSi 2 , Fe, A1 2 0 3 , MgAl 2 0 3 , LiA10 2 , Li 2 C0 3 , Si0 2 , B 2 0 3 , and LiF, FeSi 2 , CrSi 2 , NiSi 2 , CoSi 2 , TiSi 2 , Cu 3 Si, ZrSi 2 , TiB 2 , TiN, FeAl 3 , TiAb, CaO, MgO, Sn, C, and combinations thereof.
• the acid or base source may include any of the above described acid or base sources.
• the base or acid source may be present in the mill base in an amount of at least 30 wt. %, at least 20 wt.
• % or at least 10 wt. % based upon the total weight of the mill base; less than 40 wt. %, less than 30 wt. %, or less than 15 wt. % based upon the total weight of the mill base.
• the mechanical milling can include various methods of ball milling, such as high energy ball milling, attritor milling, Sweco milling, planetary milling and low energy ball milling as described in U.S. Patent No. 8,287,772 (Le et al), which is herein incorporated by reference in its entirety.
• Mechanical milling can be performed under an inert atmosphere or under reactive atmospheres including gases such as nitrogen or hydrogen.
• Other methods known to make composite materials may also be used such as sputter deposition or sintering a powdered compact.
• the milled composition may be further process to form a cement.
• a base source or an acid source (depending on which source type was included in the previous step) may be added to the milled composition to form an acid-base cement.
• the base or acid source may be added such that it is present in an amount of at least 20 wt. %, at least 10 wt. %, or at least 5 wt. % based upon the total weight of the anode composite particles; less than 30 wt. %, less than 20 wt. %, or less than 10 wt. % based upon the total weight of the anode composite particles.
• This mixture may then be subjected to heat treatment to form a cement monolith.
• the cement is, for example, a UV-curable cement
• the mixture may be subjected to a UV treatment to form a cement monolith.
• the monolith may be processed (e.g., fractured (e.g., hammered, crushed, ground) and sieved) to obtain anode composite particles of any desired size or surface area.
• the monolith may be processed to obtain anode composite particles having an average size or average surface area as described above.
• the present disclosure is further directed to methods of making negative electrodes that include the above-described anode compositions.
• the anode composite particles optionally containing coating viscosity modifiers such as carboxymethylcellulose and other additives known by those skilled in the art such as a conductive diluent, may be mixed in a suitable coating solvent such as water, ethanol, methanol, isopropanol, n-propanol or N-methylpyrrolidinone with a polymeric binder to form a coating dispersion or coating mixture.
• the dispersion may then be mixed thoroughly and applied to a metal foil current collector by any appropriate dispersion coating technique (e.g., knife coating, notched bar coating, slot-die coating, dip coating, spray coating, electrospray coating, or gravure coating).
• the current collectors are typically thin foils of conductive metals such as, for example, copper, stainless steel, or nickel foil. After the slurry is coated onto the current collector foil, it may be allowed to dry followed usually by drying in a heated oven to remove solvent.
• the negative electrode can be compressed by pressing between two plates or rollers, as known by those skilled in the art.
• the electrode may also be provided with a raised pattern as disclosed in U.S.
• Patent Application Publication No. 2008/0248386 (Obrovac et al).
• the present disclosure is further directed to lithium-ion electrochemical cells that include a positive electrode and the above-described negative electrodes.
• Exemplary positive electrode materials include lithium transition metal oxide intercalation compounds such as L1C0O2, LiCOo.2Nio.8O2, LiMm04, LiFeP0 4 , LiNi02, or lithium mixed metal oxides of manganese, nickel, and cobalt in any proportion. Blends of these materials can also be used in positive electrodes.
• Other exemplary cathode materials are disclosed in
• U.S. Patent No. 6,680,145 (Obrovac et al.) and include transition metal grains in combination with lithium-containing grains.
• Suitable transition metal grains include, for example, iron, cobalt, chromium, nickel, vanadium, manganese, copper, zinc, zirconium, molybdenum, niobium, or combinations thereof with a grain size no greater than about 50 nanometers.
• Suitable lithium-containing grains can be selected from lithium oxides, lithium sulfides, lithium halides (e.g., chlorides, bromides, iodides, or fluorides), or combinations thereof.
• the positive electrode and negative electrode can be combined with an electrolyte to form a lithium ion electrochemical cell.
• the electrolyte may be in contact with both the positive electrode composition and the negative electrode composition, and the positive electrode and the negative electrode are not in physical contact with each other; typically, they are separated by a polymeric separator film sandwiched between the electrodes.
• the electrolyte may be liquid, solid, or a gel.
• solid electrolytes examples include polymeric electrolytes such as polyethylene oxide, polytetrafluoroethylene, fluorine-containing copolymers, and combinations thereof.
• liquid electrolyte solvents examples include ethylene carbonate (EC), 1-fluoroethylene carbonate (FEC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), vinyl carbonate (VC), propylene carbonate (PC), and combinations thereof.
• the electrolyte solvent may be provided with a lithium electrolyte salt to make an electrolyte.
• suitable lithium electrolyte salts include LiPF 6 , L1BF4, L1CIO4, lithium bis(oxalato)borate, LiN(CF 3 S0 2 ) 2 , LiN(C 2 F 5 S0 2 ) 2 , LiAsFe, LiC(CF 3 S0 2 ) 3 , and combinations thereof.
• a large particle size and low surface area secondary active material particle may be obtained.
• Such secondary particles are believed to have improved resistance to fracture during processing and to maintain their integrity during repeated charge/discharge cycles in a battery. Furthermore, the low surface area obtained for such secondary particles is believed to result in improved thermal stability.
• lithium-ion electrochemical cells that incorporate the negative electrodes of the present disclosure may exhibit a capacity retention at cycle 50, 100, or 500 of better than 90%, better than 95%, better than 98%, or even better than 99%.
• lithium-ion electrochemical cells that incorporate the negative electrodes of the present disclosure may exhibit an average coulombic efficiency over at least 20 cycles, at least 30 cycles, or at least 40 cycles of better than 99.7%, better than 99.8%, or even better than 99.9%.
• the anode composite particles have a larger volumetric capacity than graphite (720 Ah/L) when fully lithiated in electrochemical cells.
• the anode particles may have fully lithiated volumetric capacities of at least 800 Ah/L, 1500 Ah/L, or at least 2000 Ah/L.
• the disclosed electrochemical cells can be used in a variety of devices including, without limitation, portable computers, tablet displays, personal digital assistants, mobile telephones, motorized devices (e.g., personal or household appliances and vehicles), instruments, illumination devices (e.g., flashlights) and heating devices.
• One or more electrochemical cells of this invention can be combined to provide battery pack.
• X-ray diffraction was used to identify the crystalline structure of the exemplary composites below.
• the divergence and anti-scatter slits used were set both at 2/3°, while the receiving slit was set at 0.3 mm.
• the X-ray tube was powered to 45 kV at 40 mA.
• a Phenom G2-pro Scanning Electron Microscope (SEM) (Nanoscience, Arizona) was used to study the particle size and morphology of the exemplary composites.
• a Micromeritics Flowsorb II 2300 surface area analyzer was used to determine the surface area of the exemplary composites by the single-point Brunauer, Emmett, and Teller (B.E.T) method.
• Electrodes were prepared by the following procedure. 0.8 g of alloy powder or alloy composite particles, 0.12 g of Super-P carbon black (MMM Carbon, Belgium), and 0.4 g of polyimide binder (PI-2555, HD Microsystems), a 20 weight percent solution in N- methyl pyrrolidinone (NMP, Aldrich) were mixed in a 30 mL Nalgene vessel. Electrode slurries were mixed in a Kurabo Mazerustar (Osaka, Japan) K -50S planetary mixer for two cycles (600 s total). Each cycle on the Mazerustar consisted of three sets of 100 s where the revolution was set to 1140 rpm and the rotation was set to 680 rpm.
• the resulting slurry was hand spread onto an 18-micrometer thick Cu foil using a plastic coating bar with a 0.004 inch gap.
• the coating was dried in an oven at 120 °C for 1.5 hours in air.
• Half cells were prepared using 2325 coin-type cells. All cell assembly procedures were performed in an argon-filled glovebox (VAC, USA). The cells were constructed from the following components and in the following order. Negative terminal/Cu spacer/Li metal film/Separator/alloy electrode/Cu spacer/Positive terminal. Each cell consisted of two 18 mm diameterx0.76 mm thick disks of Cu spacer, a 12.7 mm diameter disk of alloy electrode, two 21 mm diameter micro porous separators (Celgard 2300, 3M), 18 mm diameterx0.38 mm thick disk of Li foil (lithium ribbon available from Aldrich
• the electrolyte was a 1M LiPF6 in EC/DEC/FEC 30/60/10 by volume solution (EC, ethylene carbonate; DEC, diethyl carbonate; FEC, fluoroethylene carbonate, all from BASF).
• EC ethylene carbonate
• DEC diethyl carbonate
• FEC fluoroethylene carbonate
• Si/FeSi/FeSi 2 /Fe/[Si0 2 /Al 2 03/CaO/PAA] was prepared by milling 2.145 g of Si (Aldrich 98% -325 mesh), 1.225 g of Fe ( ⁇ 10 ⁇ , Alfa Aesar), 0.0739 g of Si02 (0.007 ⁇ , Aldrich), 0.1244 g of A1203 (Aldrich), and 0.1361 g of CaO (Sigma Aldrich) with 115 g of 3/16" tungsten carbide balls under an argon atmosphere for two hours in a 40 ml
• Spex mill container using a SPEX MILL (Model 8000-D, Spex Certiprip, Metuchen, N.J.). The speed of the Spex mill was 975 ⁇ 15 rpm. As-milled material was passed through a sieve with a mesh 53 ⁇ opening. And then 2.58 g of as-obtained powder was mixed with 1.2 g of 35 wt% poly(acrylic) acid solution in a mortar and a pestle. Next, the mixture was cured at 60 °C overnight in an oven. The resulting hard monolith was broken with a hammer, then ground by hand and sieved to a 53 ⁇ particle size.
• the XRD pattern of the resulting alloy composite particles showed peaks characteristic of crystalline Si, Fe, FeSi and FeSi 2 phases as shown in Figure 1.
• the X-ray diffraction pattern did not contain peaks from Si0 2 , A1 2 0 3 , and CaO phases indicating that these phases were amorphous.
• the SEM image showed that the particle size range was between 10 and 40 ⁇ and the large secondary particles were composed of small primary particles, as shown in Figure 2.
• the alloy composite particles had a reversible capacity of about 727 mAh/g after 50 cycles.
• V6/[Si02/A1203/CaO/PAA] was prepared using the procedure described in Example 1, except that 3.33 g of V6 alloy powder (L-20772 V6 Si alloy powder, 3M Company) was used instead of 2.145 g of Si (Aldrich 98% -325 mesh) and 1.225 g of Fe
• the SEM image showed that the particle size range was between 15 and 50 ⁇ and the large alloy composite secondary particles were composed of small electrochemically active material primary particles as shown in Figure 5.
• the BET measurement shows that the surface area was 0.6 m2/g.
• Electrodes and coin cells were prepared and tested according to the Procedure for
• Si/FeSi/FeSi2/Fe was prepared by milling 2.145 g of Si (Aldrich 98% -325 mesh) and 1.225 g of Fe ( ⁇ 10 ⁇ , Alfa Aesar) with 115 g of 3/16" tungsten carbide balls under an argon atmosphere for two hours in a 40 ml Spex mill container using a SPEX MILL (Model 8000-D, Spex Certiprip, Metuchen, N.J.). The speed of the Spex mill was 975 ⁇ 15 rpm. As-milled material was passed through a sieve with a mesh 53 ⁇ opening. The XRD pattern of the resulting powder showed peaks characteristic of crystalline Si, Fe,
• V6 alloy was used as received from 3M Company.
• the SEM image shows many fine particles with a diameter about 3 ⁇ along with a few large particles as shown in Figure 9.
• the BET measurement shows that the surface area was 3.6 m2/g.
• Si/FeSi/FeSi2/Fe/[PAA] powder was prepared in the same way as the
• the XRD pattern of the resulting anode composite particles showed peaks characteristic of crystalline Si, Fe, SiFe, and FeSi2 phases as shown in Figure 11.
• a BET surface area measurement shows that the surface area was 0.7 m2/g.

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