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
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/621—Binders
  • H01M4/622—Binders being polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/08—Cellulose derivatives
  • C08L1/26—Cellulose ethers
  • C08L1/28—Alkyl ethers
  • C08L1/286—Alkyl ethers substituted with acid radicals, e.g. carboxymethyl cellulose [CMC]
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
  • C08L25/14—Copolymers of styrene with unsaturated esters
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
  • C08L9/10—Latex
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J101/00—Adhesives based on cellulose, modified cellulose, or cellulose derivatives
  • C09J101/08—Cellulose derivatives
  • C09J101/26—Cellulose ethers
  • C09J101/28—Alkyl ethers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J101/00—Adhesives based on cellulose, modified cellulose, or cellulose derivatives
  • C09J101/08—Cellulose derivatives
  • C09J101/26—Cellulose ethers
  • C09J101/28—Alkyl ethers
  • C09J101/284—Alkyl ethers with hydroxylated hydrocarbon radicals
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J101/00—Adhesives based on cellulose, modified cellulose, or cellulose derivatives
  • C09J101/08—Cellulose derivatives
  • C09J101/26—Cellulose ethers
  • C09J101/28—Alkyl ethers
  • C09J101/286—Alkyl ethers substituted with acid radicals
• • 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
• • 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
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2201/00—Properties
  • C08L2201/52—Aqueous emulsion or latex, e.g. containing polymers of a glass transition temperature (Tg) below 20°C
• • 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 presently disclosed and/or claimed inventive process(es), procedure(s), method(s), product(s), result(s), and/or concept(s) (collectively hereinafter referred to as the "presently disclosed and/or claimed inventive concept(s)") relates generally to a composition of a binder for use in battery electrodes and methods of preparing such. More particularly, but not by way of limitation, the presently disclosed and/or claimed inventive concept(s) relates to a binder composition comprising an ionizable water soluble polymer and a redispersible powder containing a latex, a protective colloid, and an anticaking agent for use in the production and manufacture of electrodes of a lithium ion battery.
• the presently disclosed and/or claimed inventive concept(s) relates generally to electrode compositions and methods of making electrodes, both anodes and cathodes, with a binder composition containing an ionizable water soluble polymer and a redispersible powder.
• Lithium ion batteries are used in an array of products including medical devices, electric cars, airplanes, and most notably, consumer products such as laptop computers, cell phones, and cameras. Due to their high energy densities, high operating voltages, and low self-discharges, lithium ion batteries have overtaken the secondary battery market and continue to find new uses in developing industries and products.
• lithium ion batteries comprise an anode, a cathode, and an electrolyte material such as an organic solvent containing a lithium sait.
• the anode and cathode ⁇ collectively, "electrodes" are formed by mixing either an anode active material or a cathode active material with a binder and a solvent to form a paste or slurry which is then coated and dried on a current collector, such as aluminum or copper, to form a film on the current collector.
• a current collector such as aluminum or copper
• the anodes and cathodes are then layered and coiled prior to being housed in a pressurized casing containing an electrolyte material, which all together forms a lithium ion battery.
• the binders used in lithium ion batteries generally consist of a celiulosic rheology modifier and a latex material, such as styrene butadiene (SB), which are mixed with an electrode active materia! and a dispersing agent in a multi-step process.
• SB styrene butadiene
• ce!lulosic materials are generally in powder form, they are not easily soluble in water and require a long time to dissolve unless subjected to a high shear at low concentrations of the ceilulosic material (e.g., less than 3%).
• styrene butadiene latex is not stable at a high shear (and high temperature) and, therefore, cannot be mixed together with both the ceilulosic material(s) and the electrode active material(s) in a single mixing step.
• a latex material in the process typically requires the ceilulosic material and the electrode active material to be separately mixed with water to first form individual solutions, which are then mixed together prior to adding the latex material.
• the number of steps required to produce binders containing a latex material increases the overall cost and time needed to produce lithium ion battery electrodes.
• styrene butadiene latex ⁇ 40 - 60% water
• biocide(s) to store it for longer periods of time.
• it is inconvenient to store and ship styrene butadiene latex for the multi-step process especially during the winter months when temperatures frequently are below room temperature (i.e., below 25°C).
• CMC carboxymethyiceiluiose
• redispersible powder based binder composition comprising carboxymethyl hydroxyethyl cellulose actually improves the capacity of lithium ion batteries comprising silicon despite the tendency of silicon to cause large volume changes during charging. This is due in part to the higher percent elongation and flexibility of carboxymethyl hydroxyethyl cellulose relative to other celluloses presently used in binder compositions, including CMC. Furthermore, the redispersib!e powder based binder composition disclosed herein comprising carboxymethyl hydroxyethyl cellulose is capable of being used in both anodes and cathodes, which demonstrate improved electrochemical properties over the prior art.
• the presently disclosed and/or claimed inventive concept(s) encompasses a binder material that can be in the form of a dry powder capable of reducing the mixing efforts necessary to form a slurry for the production of lithium ion battery electrodes.
• the presently disclosed and/or claimed inventive concept(s) further encompasses a binder precursor composition(s) for use in the preparation of a lithium ion battery comprising an ionizable water soluble polymer and a redispersib!e powder comprising a protective colloid, an anticaking agent, and a latex polymer.
• the ionizable water soluble polymer can be a hydrophiiically modified celiulosic material, for example, but without limitation, carboxyaikyl cellulose and carboxymethyl hydroxyethyl cellulose. It is contemplated that a slurry can be formed by adding water to the above- described binder precursor composition.
• an electrode for use in a lithium ion battery comprising (i) a film
• the ionizable water soluble polymer can be a hydrophiiically modified cellulose, for example, but without limitation, carboxyaikyl cellulose and carboxymethyl hydroxyethyl cellulose.
• the presently disclosed and/or claimed inventive concept(s) also encompasses a method of making an electrode for a lithium ion battery comprising the steps of (1) combining an electrode active material, an ionizable water soluble polymer, a redispersible powder, and water to form a slurry; (2) applying the slurry to a current collector to form a coated current collector comprising a slurry layer on the current collector; and (3) drying the slurry layer on the coated current collector to form a film on the current collector, wherein the film and the current collector comprise the electrode.
• the ionizable water soluble polymer can be a hydrophilically modified cellulose, for example, but without limitation, carboxya!kyl cellulose and carboxymethyi hydroxyethyl cellulose.
• FIG. 1 is a schematic diagram, in accordance with one embodiment, for a method of making a slurry for use in the manufacture of an electrode.
• FIG. 2 is a schematic diagram, in accordance with another embodiment, for a method of making a slurry for use in the manufacture of an electrode.
• FIG. 3 is a schematic diagram, in accordance with an additional embodiment, for a method of making a slurry for use in the manufacture of an electrode.
• FIG. 4 is a graphical representation comparing the viscosities of slurry compositions containing a redispersible powder or styrene butadiene latex emulsion, as described in Examples 1-4 below.
• FIG. 5 is a graphical representation comparing the viscosities of slurry compositions containing a redispersible powder or styrene butadiene latex emulsion, as described in Examples 7-12 below.
• FIG. 6 is a graphical representation comparing the viscosities of slurry compositions containing different carboxymethyi celluloses, as described in Examples 13 18 below.
• FIG. 7 is a graphical representation comparing the viscosities of slurry compositions containing different carboxymethyi celluloses, as described in Examples 17 22 below.
• FIG. 8 is a graphical representation of the adhesion data for Examples 17-24, as described below.
• FIG. 9 is a graphical representation of the electrochemical performance for Samples A-F (35 ⁇ anode film thickness) showing a voltage profile at a 0.05 C rate, as described below.
• FIG. 10 is a graphical representation of the electrochemical performance for Samples A-F (70 ⁇ anode film thickness) showing a voltage profile at a 0.05 C rate, as described below.
• FIG. 11 is a graphical representation of the capacity retention and couiombic efficiency capabilities after 100 cycles for Samples A-F (35 ⁇ anode film thickness), as described below.
• FIG. 12 is a graphical representation of the capacity retention and couiombic efficiency capabilities after 100 cycles for Samples A-F (70 ⁇ anode film thickness), as described below.
• FiG. 13 is a graphical representation of the rate capabilities for Samples A-F (70 ⁇ anode film thickness) as measured by their capacity retentions at rates of 0.05C, 0.2C, and 0.5C for 5 cycles per rate, as described below.
• FIG. 14 is a graphical representation of the impedance of Samples A-F (70 [xm anode film thickness), as described below.
• FIG. 15 is graphical representation of the charge capacity of cycle data of Si Ox/Gra hite (92/5) anode with Aqu D-52S3 and various RDP binders (100/0.66/1.2)
• FIG. 16 is graphical representation of the discharge capacity of cycle data of SiOx/Graphite (92/5) anode with Aqu D-52S3 and various RDP binders (100/0.66/1.2)
• the designated value may vary by plus or minus twelve percent, or eleven percent, or ten percent, or nine percent, or eight percent, or seven percent, or six percent, or five percent, or four percent, or three percent, or two percent, or one percent.
• the use of the term “at least one” will be understood to include one as well as any quantity more than one, including but not limited to, 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc.
• the term “at least one” may extend up to 100 or 1000 or more depending on the term to which it is attached.
• the words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain” ⁇ are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.
• the term “or combinations thereof” as used herein refers to all permutations and combinations of the listed items preceding the term.
• A, B, C, or combinations thereof is intended to include at least one of: A, B, C, AB, AC, BC, or ABC and, if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.
• expressly included are combinations that contain repeats of one or more item or term, such as BB, AAA, MB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth.
• BB BB
• AAA AAA
• MB BBC
• AAABCCCCCC CBBAAA
• CABABB CABABB
• a binder precursor composition of the presently disclosed and/or claimed inventive concept(s) generally comprises, consists of, or consists essentially of an ionizable water soluble polymer and a redispersible powder which can comprise, consist of, or consist essentially of a protective colloid (also referred to as a "redispersing aid"), an anticaking agent, and a latex polymer.
• the ionizable water soluble polymer can be any material selected from the group comprising, consisting of, or consisting essentially of a hydrophilically modified cellulose material, a polyacrylic acid, a polyacrylic acid copolymer, and combinations thereof.
• the binder precursor composition can generally be used in the manufacture of a film for use in the production of an electrode for a lithium ion battery.
• the hydrophilically modified cellulosic material can be a carboxyalkyl cellulose.
• the hydrophilically modified cellulosic material can be carboxymethyl cellulose.
• the degree of substitution of the hydrophilically modified cellulosic material employed in the compositions and methods of the presently disclosed and/or claimed inventive concept(s) can be in a range of from about 0.6 to 1.4, or from about 0.7 to about 1.2, or from about 0.8 to about 1.1.
• the hydrophilically modified cellulosic materia! can be a hydrophilically modified hydroxyalkyi cellulose.
• the hydrophilically modified hydroxyalkyi cellulose can be any hydroxyalkyi cellulose modified with a hydrophilic group.
• the hydroxyalkyi cellulose can be selected from the group comprising, consisting of, or consisting essentially of
• the hydrophilic group can be a carboxyalkyl group.
• the hydrophilically modified hydroxyalkyi cellulose can be selected from the group comprising, consisting of, or consisting essentially of carboxymethyl hydroxyethyl cellulose, carboxymethyl hydroxypropyl cellulose, and combinations thereof.
• the polyacryiic acid copolymer can be a polymer comprising polyacrylic acid and at least one of the following monomers selected from the group comprising, consisting of, or consisting essentially of methacrylic acid, acrylamide, sulfonic acids, and combinations thereof.
• the sulfonic acids are selected from the group comprising, consisting of, or consisting essentially of 2- acrylamido-2-methylpropane sulfonic acid (AMPS ® , The Lubrizol Corporation, Wickliffe, OH) and vinyl sulfonic acid.
• the protective colloid in the redispersible powder can be selected from the group comprising, consisting of, or consisting essentially of polyvinyl alcohol, polyvinyl acetate, a hydroxyalkyi cellulose polymer, and combinations thereof.
• the hydroxyalkyi cellulose polymer can be hydroxyethyl cellulose.
• the anttcaking agent in the redispersible powder can be any material selected from the group comprising, consisting of, or consisting essentially of calcium carbonate, kaolin, silica, carbon, lithium carbonate, and combinations thereof.
• the latex polymer in the redispersible powder can be any materia!
• the latex polymer in the presently disclosed and/or claimed inventive concept can be any polymer effective in a slurry such that it is capable of forming a film on a current collector with reasonable adhesive and electrochemical properties.
• the ionizable water soluble polymer can be present in the binder precursor composition in a range of from about 2 % to about 75 %, or from about 20% to about 60 %, or from about 35% to about 45% by weight.
• the redispersible powder can be present in the binder precursor composition in a range of from about 25% to about 98%, or from about 40% to about 80%, or from about 55% to about 65% by weight.
• the protective colloid can be present in the redispersible powder in a range of from about 0.1% to about 10%, or from about 2% to about 8%, or from about 4% to about 6% by weight;
• the anticaking agent can be present in the redispersible powder in a range of from about 1% to about 35%, or from about 10% to about 30%, or from about 25% to about 35% by weight;
• the latex polymer can be present in the redispersible powder in a range of from about 30% to about 98.9%, or from about 65% to about 90%, or from about 70% to about 85% by weight.
• the redispersible powder can be in the form of particles, wherein the average diameter of the redispersible powder particles is less than about 500 ⁇ , or less than about 300 ⁇ , or less than about 150 ⁇ .
• the binder precursor composition of the presently disclosed and/or claimed inventive concept(s) comprises, consists of, or consists essentially of an electrode active material, an ionizable water soluble polymer, and a redispersible powder which can comprise, consist of, or consist essentially of a protective colloid, an anticaking agent, and a iatex polymer.
• the ionizable water soluble polymer can be present in the binder precursor composition in a range from about 0.25% to about 2.25%, or from about 0.5% to about 1.75%, or from about 0.75% to about 1.25% by weight; the redispersible powder can be present in the binder precursor composition in a range from about 0.25% to about 3.5%, or from about 0.75% to about 2.5%, or from about 1.25% to about 1.75% by weight; and the electrode active material can be present in the binder precursor composition in a range from about 94.25% to about 99.5%, or from about 95% to about 99%, or from about 96.5% to about 98.5% by weight.
• the electrode active material is an anode active material
• the anode active material can be any material comprising, consisting of, or consisting essentially of (1) carbonaceous materials, (2) silicon-based alloys, (3) complex
• the anode active material in one non-limiting embodiment, can be a carbonaceous material wherein the material comprises, consists of, or consists essentially of an artificial graphite, a natural graphite, surface modified graphite, coke, carbon fiber, and combinations thereof.
• the anode active material can be a complex compound comprising, consisting of, or consisting essentially of a carbonaceous material and silicon.
• the anode active material in another non-limiting embodiment, can comprise, consist of, or consist essentially of lithium titanate oxide ⁇ LTO ⁇ .
• the electrode active material is a cathode active material.
• the cathode active material can be any material comprising, consisting of, or consisting essentially of lithium-containing transition metal oxides.
• the cathode active material in one non-limiting embodiment, can be selected from the group consisting of lithium iron phosphate (LiFeP0 4 ), lithium cobalt oxide (UCo0 2 ), lithium nickel oxide (LiNi0 2 ), lithium nickel cobalt aluminum oxide (LiNiCoAl0 2 ), lithium nickel manganese cobalt oxide ⁇ Li iMnCo0 2 ⁇ , lithium titanate (Li 4 Ti 5 0i 2 ), lithium manganese oxide
• redispersible powder can be present in the binder precursor composition in a range from about 0.25% to about 3.5%, or from about 0.75% to about 2.5%, or from about 1.25% to about 1.75% by dry weight basis
• the electrode active material can be present in the binder precursor composition in a range from about 94.25% to about 99.5%, or from about 95% to about 99%, or from about 96.5% to about 98.5% by dry weight basis.
• the slurry comprises, consists of, or consists essentially of the above-identified binder precursor composition(s) in water, wherein the ionizab!e water soluble polymer can be present in the slurry in a range of from about 0.25% to about 2.25%, or from about 0.5% to about 1.75%, or from about 0.75% to about
• the protective colloid is present in the slurry in a range of from about 0.05% to about 0.2%, or from about 0.1% to about 0.19%, or from about 0.165% to about 0.185% by dry weight basis;
• the anticaking agent is present in the slurry in a range of from about 0.1% to about 0.5%, or from about 0.2% to about 0.4%, or from about 0.25% to about 0.35% by dry weight basis;
• the latex polymer is present in the slurry in a range of from about 0.5% to about 4%, or from about 1% to about 3%, or from about 1.5% to about 2.5% by dry weight basis;
• the electrode active material is present in the slurry in a range of from about 94.25% to about 99.5%, or from about 95% to about 99%, or from about 96.5% to about 98.5% by dry weight basis.
• the above-described slurry has a Brookfield viscosity in a range of from about 1,000 cps to about 15,000 cps, or from about 4000 cps to about
• the presently disclosed and/or claimed inventive concept(s) encompasses an electrode comprising, consisting of, or consisting essentially of (i) a film comprising, consisting of, or consisting essentially of (1) an electrode active materia! as described above, and (2) a binder precursor composition as described above, and (ii) a current collector.
• the ionizable water soluble polymer is present in the film in a range of from about 0.25% to about 2.25%, or from about 0.5% to about
• the protective colloid is present in the slurry in a range of from about 0.05% to about 0.2%, or from about 0.1% to about
• the anticaking agent is present in the slurry in a range of from about 0.1% to about 0.5%, or from about 0.2% to about
• the latex polymer is present in the slurry in a range of from about 0.5% to about 4%, or from about 1% to about 3%, or from about 1.5% to about 2.5% by weight
• the electrode active material is present in the slurry in a range of from about 94.25% to about 99.5%, or from about 95% to about 99%, or from about 96.5% to about 98.5% by weight.
• the film has a thickness in a range of from about 30 ⁇ xm to about 150 ⁇ , or from about 40 ⁇ to about 130 ⁇ , or from about 50 ⁇ to about 100 ⁇ .
• the current collector can be any material that acts as an electrical conductor for either the anode active material or the cathode active material.
• the current collector can be selected from the group of materials comprising, consisting of, or consisting essentially of aluminum, copper, stainless steel, nickel, zinc, silver, and combinations thereof.
• the current collector for the anode is a copper foil.
• the current collector for the cathode is an aluminum foil.
• the above-described film can be bound to a surface of the above-described current collector to form a bond.
• the adhesive strength of the bond is at least about 0.3 gf/mm, or at least about 0.6 gf/mm, or at least about 1.0 gf/mm as determined by the 90 Degree Peel Adhesion Test, which will be described below.
• the presently disclosed and/or claimed invention also encompasses a method(s) for making the electrode(s) described above comprising, consisting of, or consisting essentially of: (i) combining an electrode active material as described above, an ionizable water soluble polymer as described above, a redispersible powder as described above, and water to form the slurry; (ii) applying the above-described slurry to a current collector as described above to form a coated current collector comprising a slurry layer on the current collector; and (iii) drying the slurry layer on the coated current collector to form a film on the current collector, wherein the above-described film and the current collector comprise the electrode.
• the ionizable water soluble polymer is a hydrophilically modified hydroxyalkyl cellulose as described above,
• FIG. 1 is a schematic diagram of one embodiment of a method/system 100 of making a slurry for use in the manufacture of an electrode.
• the ionizable water soluble polymer is delivered to a vessel 102 via conduit 104 and the redispersible powder is delivered to the vessel 102 via conduit 106, wherein the ionizable water soluble polymer and the redispersible powder are dry admixed to form a dry binder precursor composition.
• the dry binder precursor composition is delivered to a vessel 108 via conduit 110, the electrode active material is delivered to vessel 108 via conduit 112, and the water is delivered to vessel 108 via conduit 114, wherein the ionizable water soluble polymer, the redispersible powder, the electrode active material, and the water are mixed to form the slurry.
• Figure 2 is a schematic diagram of an alternative embodiment of a
• the ionizable water soluble polymer is delivered to a vessel 202 via conduit 204
• the redispersible powder is delivered to the vessel 202 via conduit 206
• the electrode active material is delivered to vessel 202 via conduit 208, wherein the ionizable water soluble polymer, redispersible powder, and electrode active material are dry admixed to form a dry binder precursor composition.
• the dry binder precursor composition is delivered to a vessel 210 via conduit 212 and the water is delivered to vessel 210 via conduit 214, wherein the ionizable water soluble polymer, the
• redispersible powder, the electrode active material, and the water are mixed to form the slurry.
• FIG 3 is a schematic diagram of an additional alternative embodiment of a method/system 300 of making a slurry for use in the manufacture of an electrode.
• the ionizable water soluble polymer is first delivered to a vessel 302 via conduit 304 along with water which is delivered to the vessel 302 via conduit 306 to form an aqueous solution.
• the redispersible powder is delivered to vessel 308 via conduit 310 and the electrode active material is added to vessel 308 via conduit 312, wherein the redispersible powder and electrode active material are dry admixed and thereafter added to vessel 302 via conduit 314 for mixture with the ionizable water soluble polymer and water in vessel 302 to form the slurry.
• the ionizable water soluble polymer, electrode active material, and redispersible powder can all be pre-mixed or pre-mixed in various combinations and added to water at the same time or individually.
• the use of redispersible powders in the binder materials for lithium ion batteries can reduce the mixing efforts necessary to form a slurry for the production of lithium ion batteries, and actually leads to better electrochemical performances of the lithium ion batteries.
• the above-described electrodes have a capacity retention at a C-Rate of 0.05C and 25°C for 50 cycles which is greater than about 80%, or greater than about 90%, or greater than about 96%, wherein the fiim thickness is in the range from about 30 ⁇ to about 100 ⁇ , or from about 35 ⁇ to about 95 ⁇ , or from about 65 ⁇ to about 75 ⁇ .
• the capacity retention of the above-described electrodes have a capacity retention at a C-Rate of 0.05C and 25°C for 100 cycles which is greater than about 60%, or greater than about 80% or greater than about 92%, wherein the film thickness is in the range from about 30 ⁇ to about 100 ⁇ , or from about 35 ⁇ to about 90 ⁇ , or from about 65 ⁇ to about 75 ⁇ .
• the above-described electrodes have an impedance less than about 300 ct , or less than about 250 R rt , or less than about 200 R rt , wherein the film thickness is less than about 70 ⁇ , or less than about 60 ⁇ , or less than about 35 ⁇ .
• Graphite slurries are prepared using two different formulations: a “wet” process and a “dry” process.
• the "wet" process for preparing graphite slurries comprises: 1) preparing a solution by adding either a carboxymethyl hydroxyethyl cellulose or a hydroxyethyl cellulose in water and then mixing for an amount of time using an overhead mixer; 2) dispersing graphite powder in water; 3) adding the carboxymethyl hydroxyethyl cellulose or hydroxyethyl cellulose to the graphite dispersion and then mixing for an amount of time with the overhead mixer; 4) adding either a latex emulsion (hereinafter "latex”) or a redispersible powder to the slurry comprising graphite and either carboxymethyl hydroxyethyl cellulose or hydroxyethyl cellulose, and then mixing with an overhead mixer for an amount of time.
• latex latex emulsion
• the "wet" process for preparing slurries containing a carboxymethyl cellulose comprised: 1) preparing a carboxymethyl cellulose solution in water at 25°C with an overhead mechanical mixer; 2) dispersing graphite powder in water in a 150 mL container; 3) adding the carboxymethyl cellulose solution to the graphite dispersion and then mixing for one hour with an overhead mixer; and 4 ⁇ adding either a latex emulsion or a redispersible powder to the graphite/carboxymethyl cellulose slurry and thereafter mixing with an overhead mixer for 10 minutes.
• the "dry" process for preparing graphite slurries comprises: 1) dispersing an amount of a blend of graphite powder and either a carboxymethyl hydroxyethyl cellulose powder or a hydroxyethyl cellulose powder in water and mixing for an amount of time using an overhead mixer, and 2) adding either a latex or a redispersible powder to the graphite/cellulose slurry and thereafter mixing with an overhead mixer for an amount of time.
• the "dry" process for preparing slurries containing a carboxymethyl cellulose comprised: 1) dispersing a carboxymethyl cellulose powder and graphite powder blend in water in a 150 mL container and mixing for one hour with an overhead mixer, and 2) adding either a latex emulsion (hereinafter "latex”) or a redispersible powder to the graphite/carboxymethyl cellulose slurry and thereafter mixing with an overhead mixer for 10 minutes.
• latex latex emulsion
• redispersible powder redispersible powder
• the slurries were prepared using several different formulations.
• the total amount of solids i.e., graphite, carboxymethyl cellulose, and latex or redispersible powder
• the total amount of solids was approximately 47% by weight with the remaining 53% by weight comprising water.
• the amount, ratio, and type of graphite, carboxymethyl cellulose, and latex or redispersible powder varied throughout the examples; however, for those examples comprising redispersible powder instead of a latex, the redispersible powder was comprised of 75% by weight latex particles, 20% by weight anticaking agent, and 5% by weight protective colloid, wherein the anticaking agent was calcium carbonate (CaC0 3 ) and lithium carbonate, the protective colloid (or "redispersing aid") was polyvinyl alcohol (PVOH), and the latex particles varied depending on the redispersible powder as suggested in the tables below.
• the anticaking agent was calcium carbonate (CaC0 3 ) and lithium carbonate
• the protective colloid or "redispersing aid”
• PVOH polyvinyl alcohol
• Table 1 presents a detailed description of a slurry composition prepared by the "wet” process having a total solids (i.e., graphite, carboxymethyl cellulose, and latex or redispersible powder) amount of approximately 47% by weight, wherein the normalized ratio of graphite, carboxymethyl cellulose (CMC), and redispersible powder (RDP) or latex is 100/1/1.5.
• a slurry composition prepared by the "dry” process can be calculated from a normalized ratio of graphite, CMC, and RDP or latex taking into consideration that the CMC was mixed with the graphite prior to adding water to form an aqueous solution.
• Silicon slurries are prepared using a “wet” process and a “dry” process.
• the "wet" process for preparing silicon slurries comprises: 1) preparing a solution by adding a carboxymethyl hydroxyethyl cellulose, a carboxymethyiceliulose or a hydroxyethyl cellulose in water and then mixing for an amount of time using an overhead mixer; 2) dispersing a powder of a silicon containing compound in water; 3) adding the carboxymethyl hydroxyethyl cellulose, carboxymethyiceliulose or hydroxyethyl cellulose to the dispersion of the silicon containing compound and then mixing for an amount of time with the overhead mixer; 4) adding either a latex or a redispersible powder to the slurry comprising the silicon containing compound and carboxymethyl hydroxyethyl cellulose, carboxymethyiceliulose or hydroxyethyl cellulose, and then mixing with an overhead mixer for an amount of time.
• the "dry" process for preparing silicon slurries comprises: 1) dispersing an amount of a blend of powder comprising a silicon containing compound, and a carboxymethyl hydroxyethyi cellulose powder, a carboxymethylceilulose powder or a hydroxyethyi cellulose powder in water and mixing for an amount of time using an overhead mixer, and 2 ⁇ adding either a latex or a redispersible powder to the silicon containing compound/cellulose slurry and thereafter mixing with an overhead mixer for an amount of time.
• Graphite/Silicon slurries are prepared using two different formulations: a
• the "wet" process for preparing graphite/silicon slurries comprises: 1) preparing a solution by adding either a carboxymethyl hydroxyethyi cellulose or a hydroxyethyi cellulose in water and then mixing for an amount of time using an overhead mixer; 2) dispersing graphite powder and powder of a silicon containing compound in water; 3) adding the carboxymethyl hydroxyethyi cellulose or hydroxyethyi cellulose to the graphite/silicon dispersion and then mixing for an amount of time with the overhead mixer; 4) adding either a latex emulsion (hereinafter "latex”) or a redispersible powder to the slurry comprising graphite, the silicon containing compound, and either
• latex latex emulsion
• the "wet" process for preparing graphite/silicon slurries containing a carboxymethyl cellulose comprised: 1) preparing a carboxymethyl cellulose solution in water at 25°C with an overhead mechanical mixer; 2) dispersing graphite powder and SiO x powder in water in a 150 mL container; 3) adding the carboxymethyl cellulose solution to the graphite and SiO x dispersion and then mixing for one hour with an overhead mixer; and 4) adding either a latex emulsion or a redispersible powder to the graphite/SiOx/carboxymethyl cellulose slurry and thereafter mixing with an overhead mixer for 10 minutes.
• the "dry" process for preparing graphite/siiicon slurries will comprise: 1) dispersing an amount of a blend of graphite powder, powder of a silicon containing compound, and either a carboxymethyl hydroxyethyi cellulose powder or a hydroxyethyi cellulose powder in water and mixing for an amount of time using an overhead mixer; and 2) adding either a latex or a redispersible powder to the graphite/silicon/cellulose slurry and thereafter mixing with an overhead mixer for an amount of time.
• the "dry" process for preparing slurries containing a carboxymethyl cellulose comprised: 1) dispersing a carboxymethyl cellulose powder and graphite powder/SiO x blend in water in a 150 mL container and mixing for one hour with an overhead mixer, and 2) adding either a latex emulsion (hereinafter "latex") or a redispersible powder to the graphite/SiO x /carboxymethyl cellulose slurry and thereafter mixing with an overhead mixer for 10 minutes.
• latex latex emulsion
• redispersible powder redispersible powder
• RDP-1 was prepared by the following: 1) an amount of vinyiacetate ethylene (VAE) copolymer latex having a Tg of +10°C (Ceivolit ® 1328 from Celanese Co., Houston, TX) was added to an aqueous solution comprising 20 wt% of a redispersing agent (Celvol ® 504 from Celanese Co., Houston, TX) such as to form a liquid feed stock, wherein 45 wt% of the feedstock was comprised of the VAE latex and redispersing agent; 2) Separately, Calcium carbonate (CaC0 3 ) having a small particle size (e.g.
• the redispersible powder produced by the process, RDP-1 had a bulk density between 0.4 - 0.5 g/cm 3 , a particle size between 80 - 120 ⁇ , a moisture content ⁇ 1 wt%, and ash contents between 5 - 20 wt .
• RDP-2 was prepared by the following: 1) an amount of vinyiacetate ethylene
• VAE (VAE) copolymer latex having a Tg of -10°C (Ceivolit ® 1388 from Celanese Co., Houston,
• TX was added to an aqueous solution comprising 20 wt% of a redispersing agent ⁇ Celvol ®
• Calcium carbonate (CaC0 3 ) having a small particle size ⁇ e.g. ⁇ 2 ⁇ ) was blended with a clay having a particle size ⁇ 1 ⁇ in a weight ratio of 3:1 to form an anticaking agent;
• the redispersible powder produced by the process, RDP-2 had a bulk density between 0.4 - 0.5 g/cm 3 , a particle size between 80 - 120 ⁇ , a moisture content ⁇ 1 wt%, and ash contents between 5- 20 wt .
• select silicon slurry samples are measured by placing the slurries in capped cylindrical glass bottles which are then stored at room temperature for a week. Specifically, select slurry samples are placed in approximately 50 mL glass bottles for around 7 days during which the samples are monitored for phase separation phenomena every day. it is predicted that the unstable slurry samples separate such that the water or iow viscosity solution form a top layer and the graphite or silicon solution form a bottom layer in the glass bottles. The slurries are determined to be stable if they stay in solution for around 5 or more days.
• Graphite slurry or Graphite/Silicon slurry stabilities was measured for select slurry samples by placing the slurries in capped cylindrical glass bottles which were then stored at room temperature for a week. Specifically, 30 g of the graphite slurry or the graphite/silicon slurry samples were placed in 50 mL glass bottles for 7 days during which the samples were monitored for phase separation phenomena every day. The unstable slurry samples were separated such that the water or low viscosity solution formed a top layer and the graphite or the graphite/siiicon solution formed a bottom layer in the glass bottles. The graphite or graphite/silicon slurries were determined to be stable if they stayed in solution for 5 or more days.
• Viscosities of the experimental slurry compositions were measured with a TA Rheometer from TA Instruments ® (New Castle, Delaware) as a function of shear rate at 25°C using a cone and plate geometry.
• Adhesion measurements were obtained by performing a 90 Degree Peel Test on electrodes formed by coating and drying the slurry compositions, as identified above, on copper current coilectors.
• the electrodes were formed by coating the slurry compositions on copper current coilectors having a thickness of approximately 20 pm and then used a tape caster (doctor blade) to lessen the slurry layer to a wet thickness of approximately 230 pm.
• the copper current collector coated with the slurry composition was dried at room
• the electrodes were then subjected to a 90 degree peel test using a peel test fixture from instron ® , Norwood, MA.
• the individual electrode samples were mounted on a stainless steel plate with 3M ® double sided scotch tape from 3M Corporation (St. Paul, MN) after which the film, which was also stuck to the scotch tape, was peeled off at a rate of 1 foot/min by the Instron ® instrument during which the instron ® instrument measured the force necessary to pee! the film off the current collector.
• An adhesion above 0.3 gf/mm is generally considered to be acceptable, while an adhesion value above 0.5 gf/mm is considered to be good.
• Table 2 presents the formulations for Examples 1-5 which varied in the types of latex or redispersible powder used in the slurry compositions (see Table 1 for the ratio of components) but kept constant the type of graphite and carboxymethyl cellulose used therein. Examples 1-5 were prepared by the "wet” process and the normalized ratio of graphite, carboxymethyl cellulose, and redispersible powder (or latex) was held constant at 100/1/1.5, respectively.
• JSR ® TR2001 Commercially-available styrene butadiene latex from JSR Corporation, Tokyo, Japan.
• Dehydro ® 6480 Redispersible powder from Acquos Pty Ltd. (Camp Bettefield, Australia) comprising
• Dehydro ® 7552 Redispersible powder from Acquos Pty Ltd. (Camp Bettefield, Australia) comprising styrene acrylic latex.
• Examples 1-5 were subjected to the above-described tests to determine rheology measurements and adhesion measurements. Table 3 presents the results. As is apparent from Table 3, the slurries were subjected to both the TA Rheometer at 25°C using a cone and plate geometry and the Brookfield ® viscometer at 30 rpm with spindle Table 3
• Example 3 the viscosities of the compositions containing redispersibie powders instead of just latex (Examples 2-4 ⁇ are comparable to Example 1 which contains latex. Additionally, the slurry samples containing various redispersibie powders (Examples 2-4) were stable (i.e., the graphite and binder did not separate) during the 5 days of storage. Further, Table 3 suggests that the adhesion values of the films bonded to copper foil and comprised of redispersibie powders and CMC (Examples 2-4) are equal in acceptable quality (i.e., close to or over 0.5 gf/mm) to the film
• Example 4 is a graphical representation of the viscosities of Examples 1-4 as obtained by the TA
• Table 4 presents the formulations for Examples 6-12 which vary in the types and amounts of latex or redispersibie powder used in the slurry compositions (see Table 1 for the ratio of components) but keep constant the type of graphite and carboxymethyl cellulose used therein. Examples 6-12 were prepared by the "wet” process and the normalized ratio of graphite, carboxymethyl cellulose, and redispersibie powder (or latex) ranged from 100/1/1.5 to 100/1/3 due to the increased levels of RDP or latex for some of the examples. Table 4
• FSNC-1 Graphite from Shanshan Tech Co., Shanghai, China.
• JSR ® TR2001 Commercially-available styrene butadiene latex from JSR Corporation, Tokyo, Japan.
• Rovene ® 4002 Commercially-available carboxylated styrene butadiene latex emulsion from Mallard
• Examples 6-12 were subjected to the above-described tests to determine rheology measurements, slurry stability test, and adhesion measurements. Table 5 presents the results. As is apparent from Table 5, the slurries of Examples 6-12 were also subjected to both the TA Rheometer at 25°C using a cone and plate geometry and the Brookfield ® viscometer at 30 rpm with spindle 4. Table 5
• compositions to the copper current collector especially when added to increasing amounts of redispersible powder, when compared with Table 3, which presents the adhesion data for compositions containing Aqualon ® Aqu D-5139.
• Figure 5 is a graphical representation of the viscosities of Examples 7-12 as obtained by the TA Rheometer.
• Table 6 presents Examples 13-24 which vary in the types and amounts of latex or redispersible powder and vary in the types of carboxymethyl cellulose used in the slurry compositions but keep constant the type of MAG graphite used therein.
• Examples 13-24 were prepared by the "wet" process (with 40% total solid in water) and the normalized ratio of graphite, carboxymethyl cellulose, and redispersible powder (or latex) ranged from 100/1/1.5 to 100/1/3 due to the increased levels of RDP or latex for some of the examples.
• Table 6 presents Examples 13-24 which vary in the types and amounts of latex or redispersible powder and vary in the types of carboxymethyl cellulose used in the slurry compositions but keep constant the type of MAG graphite used therein. Examples 13-24 were prepared by the "wet" process (with 40% total solid in water) and the normalized ratio of graphite, carboxymethyl cellulose, and redispersible powder (or latex) ranged from 100/1/1.5 to 100/1/3 due to the increased levels
• MAG Synthetic graphite from Hitachi Chemical Co., Tokyo, Japan. Average particle size: 22.4 microns. Tap density: 0.78 g/cm 3 . Bet surface area: 3.7 m 2 /g-
• Aquaion ® Aqu D-5139 Commercially available carboxymethyl cellulose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.82-0.95 and a Brookfieid ® viscosity of 5,700-9,000 cps for a 1% solution pm with spindle 4.
• Aquaion ® Aqu D-5283 Commercially available carboxymethyl cellulose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.65-0.9 and a Brookfield ® viscosity of 4,000-9,000 cps for a 1% solution at 30 rpm with spindle 4.
• Zeon ® BM-480B Commercially-available styrene butadiene latex from Zeon Corporation, Tokyo, Japan.
• Examples 13-24 were subjected to the above-described tests to determine rheology measurements and adhesion measurements.
• FIG. 6 presents the viscosity data for Examples 13 -18
• FIG. 7 presents the viscosity data for Examples 17-22
• F!G. 8 presents the adhesion data for Examples 13-24.
• FIGS. 6 and 7 show the viscosities versus shear rates for Examples 13-22, which indicate that the type of carboxymethyl cellulose do not greatly impact the rheology of the compositions.
• FIG. 6 and 7 show the viscosities versus shear rates for Examples 13-22, which indicate that the type of carboxymethyl cellulose do not greatly impact the rheology of the compositions.
• FIG. 8 suggests that the adhesion measurements of the films comprising redispersible powders instead of just latex (Examples 13-16 and 19-22) are equal in acceptable quality, if not better (i.e., close to or over 0.5 gf/mm), as the examples which only contain a latex (Examples 17-18 and 23-24).
• FIG. 8 suggests that compositions containing Aqualon ® Aqu D-5283 carboxymethyl cellulose (Examples 14, 16, 18, 20, 22, and 24) instead of Aqualon ® Aqu D- 5139 (Examples 13, 15, 17, 19, 21, and 23) may improve the adhesion of the binder composition to the copper current collector, especially when added in increasing amounts (See, Examples 16 and 22 compared with Examples 15 and 21).
• Table 7 presents Examples 25-32 which vary in the types of carboxymethyl cellulose and latex or redispersible powder used in the slurry compositions (40% total solids formulation) but keep constant the type of graphite used therein. Additionally, Examples 25-32 vary as to the preparation process used to make the samples, i.e., Examples 25, 27, 29, and 31 were prepared by the "dry” process and Examples 26, 28, and 30 were prepared by the "wet” process, wherein the normalized ratio of graphite, carboxymethyl cellulose, and redispersible powder (or latex) was held constant at 100/1/1.5, respectively, for the compositions prepared by both the wet or dry processes. Examples 25-32 were also subjected to the adhesion test as described above, the results of which are presented in Table 7.
• MAG Synthetic graphite from Hitachi Chemical Co., Tokyo, Japan. Average particle size: 22.4 microns. Tap density: 0.78 g/cm 3 . Bet surface area: 3.7 m 2 /g-
• Aqualon ® Aqu D-5139 Commercially available carboxymethyl cellulose from Ashland, Inc. ⁇ Wilmington, DE) with a degree of substitution from 0.82-0.95 and a Brookfield ® viscosity of 5,700-9,000 cps for a 1% solution at pm with spindle 4.
• Zeon ® BM-400 Commercially-available styrene butadiene latex from Zeon Corporation, Tokyo, Japan.
• the adhesion measurements of the films comprising redispersible powders instead of just latex are acceptable (i.e., close to or over 0.5 gf/mm) and, in fact are equal to or better than Examples 25 and 26 which contained just latex.
• Table 7 suggests that Aqualon ® Aqu D-5283 carboxymethyl cellulose (Examples 29, 30, and 32) may improve the adhesion of the binder composition to the copper current collector when compared to Aqualon ® Aqu D-5139 (25-28, and 31) and Aqualon ® Aqu D-5284 carboxymethyl celluloses (See, Examples 6-12 of Table 5).
• Table 7 suggests that both the wet and dry processes can provide very good adhesion (i.e., approximately 0.5 gf/mm or more). Examples 33-38
• Table S presents Examples 33-38 which vary in the types of graphite and latex or redispersible powder used in the slurry compositions but keep constant the type of carboxymethyl cellulose used therein.
• Examples 33-38 were prepared by the "dry” process, wherein the normalized ratio of graphite, carboxymethyl cellulose, and redispersible powder (or latex) was held constant at 100/1/1.5, respectively.
• Examples 33-38 were also subjected to the above-described adhesion test, the results of which are also presented in Table 8.
• MAG Synthetic graphite from Hitachi Chemical Co., Tokyo, Japan. Average particle size: 22.4 microns.
• Aqualon ® Aqu D-5139 Commercially available carboxymethyl cellulose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.82-0.95 and a Brookfieid ® viscosity of 5,700-9,000 cps for a 1% solution at 30 rpm with spindle 4.
• Rovene ® 4002 Commercially-available carboxylated styrene butadiene latex emulsion from Mallard Creek Polymers, Charlotte, North Carolina.
• compositions comprising MAG graphite.
• Aqua!on ® Aqu D-5284 Commercially available carboxymethyl ceilulose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.8-0.95 and a Brookfieid ® viscosity of 2,500 - 4,500 cps for a 1% solution at 30 rpm with spindle 4.
• JSR ® TR2001 Commercially-available styrene butadiene latex from JSR Corporation, Tokyo, Japan.
• Dehydro 8 6480 Redispersible powder from Acquos Pty Ltd. (Camp Bettefield, Australia) comprising vinyl acrylic iatex.
• Dehydro ® 7552 Redispersible powder from Acquos Pty Ltd. (Camp Bettefield, Australia ⁇ comprising styrene acrylic Iatex.
• Electrodes specifically anodes, were prepared by coating copper current collectors with slurry compositions containing electrode-active materials, using the methods described above, to form films of a prescribed thickness on the current collectors.
• the electrodes prepared had either a film thickness of 35 im or 70 ⁇ .
• the slurries coated on the copper current collectors were prepared using the above-described f 'wet" process.
• the process comprised: (1) adding 22.9 g of a 0.7wt carboxymethyl cellulose (CMC) solution to 15.6 g of graphite and mixing the
• the slurries were prepared using several different formulations.
• the total amount of solids i.e., graphite, carboxymethyl cellulose, and Iatex or redispersible powder
• the total amount of solids was approximately 47% by weight with the remaining 53% by weight comprising water.
• the type of carboxymethyl cellulose and Iatex or redispersible powder varied throughout the examples; however, for those examples comprising redispersible powder instead of a iatex, the redispersible powder was comprised of 75% by weight iatex particles, 20% by weight anticaking agent, and 5% by weight protective colloid, wherein the anticaking agent was calcium carbonate (CaC0 3 ), the protective colloid (or “redispersing aid") was polyvinyl alcohol (PVOH), and the latex particles varied depending on the redispersible powder as presented in the tables below.
• the anticaking agent was calcium carbonate (CaC0 3 )
• the protective colloid or "redispersing aid”
• PVOH polyvinyl alcohol
• Table 10 presents a detailed description of the different slurry compositions that were prepared.
• the ratio of the dry components i.e., only the graphite, carboxymethyl cellulose, and redispersible powder
• the latex comprised a mixture of Zeon ® BM-400 and Zeon ® BM-480B latexes in an equal ratio, such that the ratio of dry components, i.e., only the graphite, carboxymethyl cellulose, Zeon ® BM-400, and Zeon® BM-480, was
• Aqualon ® Aqu D-5139 Commerciaily availabie carboxymethyi DCluiose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.82-0.95 and a Brookfieid ® viscosity of 5,700-9,000 cps for a 1% solution at 30 rpm with spindle 4.
• Aqualon ® Aqu D-5283 Commerciaily availabie carboxymethyi DCiulose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.65-0.9 and a Brookfield ® viscosity of 4,000-9,000 cps for a 1% solution at 30 rpm with spindle 4.
• Zeon ® BM-480B Commercialiy-avaiiabie styrene butadiene latex from Zeon Corporation, Tokyo, Japan.
• Zeon ® BM-400 Commercially-available styrene butadiene latex from Zeon Corporation, Tokyo, Japan.
• Half coin cells having a 20 mm diameter and a 3.2 mm height were produced using the anodes described above in combination with lithium metal disc cathodes, a Ceigard ® po!yoiefin separator from Celgard LLC (Charlotte, North Caroiina), and an electrolyte comprising a mixture of organic solvents of ethylene carbonate (EC), ethylmethyl carbonate (EMC), propylene carbonate (PC), and
• the current industry standard is for impedance to be less than approximately 228 Rct, which is represented by Sample A.
• samples B, D, and F (corresponding to Experiment numbers 74, 76, and 78) all perform better than the industry standard, noting that lower impedance is preferred.
• Each slurry composition contained graphite (MAG)/ Si oxide(SiOx) anode (92/5), carboxymethyl cellulose (Aqu D-5283), and redispersible powder(RDP) binder,(dry ratio was 100/0.67/1.19) in water.
• the solid content in the slurry was 40-50%.
• the composition containing latex the latex comprised a mixture of Zeon ® BM-400 and Zeon ® BM-480B latexes in an equal ratio, such that the ratio of dry components, i.e., only the graphite/SiO x , carboxymethyl cellulose, Zeon ® BM-400, and Zeon ® BM-480B, was 97.5/1/0.75/0.75.
• the slurry was coated onto the copper foil to prepare the half coin cells and their electro chemistry and cycle performance was evaluated. The data is presented in Table 15 and plots in Fig. 15 & Fig. 16. Table 15
• SiO x anode was purchased from OTC, Osaka, Japan
• Aqualon ® Aqu D-5283 Commercially available carboxymethyl cellulose from Ashland, Inc. (Wilmington, DE) with a degree of substitution from 0.65-0.9 and a Brookfield ® viscosity of 4,000-9,000 cps for a 1% solution at 30 rpm with spindle 4.
• Dehydro 6880,7660 & 6150 are redispersible powder purchased from Acquos Pty Ltd, Austraiia). They are made of styrene-acrylic or vinyl acrylic emulsion latex, anticaking agent and protective colloid with spray drier.
• Zeon ® BM-480B Commerciai!y-available styrene butadiene latex from Zeon Corporation, Tokyo, Japan.
• Zeon ® BM-400 Commercially-available styrene butadiene latex from Zeon Corporation, Tokyo, Japan.
• a two-quart stirred autoclave glass bowl was charged with 64.8 g (0.4 moles) cotton linters (dry weight) and 1000 ml t-butyl alcohol (99.5+ %). The bowl was then sealed to the reactor and purged of oxygen, evacuating to 26 inches gauge vacuum followed by pressurization to 20 psig with nitrogen. This vacuum-pressurized cycle was repeated 5 times, after which a caustic solution (61.7 g 50% NaOH/73 m! H 2 0) was added, via a syringe, to the stirred cellulose slurry under vacuum. The reactor was given another five degassing cycles, as above.
• the alkali cellulose was allowed to stir for 60 minutes at 15°-20° C underlO psig nitrogen.
• a monochioroacetic acid solution (10.4 g MCA/25 ml. tert-butyl alcohol) was then introduced to the slurry, under vacuum, via a syringe. After pressurization to 10 psig N 2/ the reaction was then heated to 70° C
• compositions that were prepared. Each slurry composition containing graphite (MAG)/ Si oxide(SiOx) anode (92/5), carboxymethyl hydroxycellulose(CMHEC, prepared in Example A), and redispersible powder(RDP) binder,(dry ratio was 100/1/1.5) in water. The solid content of the slurry was 40-50%. Additionally, as the reference slurry, the composition containing latex, the latex comprised of Zeon ® BM-480B latex. The slurry was coated onto the copper foil to prepare the anode electrode. The slurry viscosity and adhesions were measured. The data is presented in Table 18. The electrode from formulation 93 has good adhesion, flexible and good coating appearance.
• CMHEC-A & CMHEC-B are carboxymethyl hydroxy cellulose, AQU D-5278, with different MW; 1% viscosity A: 3500 cps, B: 2200 cps .

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