Classifications

• • 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
• • 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
• • 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
  • H01M10/36—Accumulators not provided for in groups H01M10/05-H01M10/34
  • H01M10/39—Accumulators not provided for in groups H01M10/05-H01M10/34 working at high temperature
• • 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
  • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• • 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
  • H01M4/1397—Processes of manufacture of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• • 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
• • 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
• • 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
  • 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
  • H01M4/381—Alkaline or alkaline earth metals elements
  • H01M4/382—Lithium
• • 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 invention relates to a process for the preparation of a cathode, characterized in that they are mixed together:
• (C) at least one saccharide selected from monosaccharides, disaccharides, oligosaccharides and polysaccharides, which is soluble or swellable in acidic aqueous medium, and the resulting mixture on a flat support (D) and then optionally dried.
• the present invention relates to electrodes containing
• Secondary batteries, accumulators, rechargeable batteries, or “rechargeable batteries” are just a few embodiments for storing and using electrical energy after production because of their significantly better power density, they have recently strayed and developed from water-based secondary batteries such batteries in which the charge transport is accomplished by lithium-ion.
• lithium-ion secondary batteries having a carbon anode and a metal oxide-based cathode are limited in their energy density. New dimensions were opened by lithium-sulfur cells. In lithium-sulfur cells, sulfur in the sulfur cathode is reduced via polysulfide ions to S 2_ ions, which are oxidized again when the cell is charged.
• Sulfur (A) is known as such and in the context of the present invention may also be referred to briefly as sulfur.
• Carbon in an electrically conductive modification (B) may also be referred to as carbon (B) in the context of the present invention.
• carbon (B) may be selected from graphite, carbon black, carbon nanotubes, graphene or mixtures of at least two of the foregoing.
• carbon (B) is carbon black.
• Carbon black may, for example, be chosen from lampblack, furnace black, flame black, thermal black, acetylene black, carbon black and furnace carbon black.
• Carbon black may contain impurities, for example hydrocarbons, in particular aromatic hydrocarbons, or oxygen-containing compounds or oxygen-containing groups, for example OH groups.
• sulfur or iron-containing impurities in carbon black are possible.
• carbon (B) is partially oxidized carbon black.
• carbon (B) is carbon nanotubes.
• Carbon nanotubes carbon nanotubes, short CNT or English carbon nanotubes
• SW CNT single-walled carbon nanotubes
• MW CNT multi-walled carbon nanotubes
• graphene is understood as meaning almost ideal or ideally two-dimensional hexagonal carbon crystals, which are constructed analogously to individual graphite layers.
• carbon (B) is selected from graphite, graphene, activated carbon and especially carbon black.
• Carbon (B) may be present, for example, in particles having a diameter in the range of 0.1 to 100 ⁇ m, preferably 2 to 20 ⁇ m.
• the particle diameter means the average diameter of the secondary particles, determined as volume average.
• carbon (B), and especially carbon black has a BET surface area in the range of 20 to 1500 m 2 / g, measured according to ISO
• BET surface area in the range of 20 to 1500 m 2 / g, measured according to ISO
• at least two, for example two or three different types of carbon (B) are mixed.
• Different types of carbon (B) may differ, for example, in terms of particle diameter or BET surface area or level of contamination.
• carbon (B) is selected from a combination of carbon black and graphite.
• An acidic aqueous medium is understood as meaning aqueous solutions which have a maximum pH of 6.9, for example a pH in the range from 1 to 6.9, preferably in the range from 3 to 6.5.
• Acetylcellulose which is soluble in a basic aqueous medium, but neither swellable nor soluble in an acidic aqueous medium, is not an example of saccharide (C). Even starch is neither swellable nor soluble in an acidic aqueous medium and in the context of the present invention is not an example of saccharide (C).
• water-soluble is understood as meaning those sugar compounds which form an aqueous solution which appears to be clear to the naked eye.
• Water-swellable in the context of the present invention means those sugar compounds which have at least 100% of their weight in water can reversibly absorb at a temperature in the range of 20 to 90 ° C.
• saccharides (C) are selected from glucose, fructose, sucrose, mannose and maltose.
• saccharides (C) are selected from monosaccharides, especially glucose and fructose. In one embodiment of the present invention, saccharides (C) are selected from disaccharides, especially sucrose.
• saccharides (C) are selected from polysaccharides, in particular amylopectin.
• saccharides (C) are selected from partially oxidized saccharides, in particular from partially oxidized mono- or disaccharides, in particular especially from caramelized sugars such as caramelized sucrose, caramelized glucose and caramelized fructose.
• the procedure is such that sulfur (A), carbon (B) and at least one saccharide (C) are first mixed with one another and the mixture obtainable is applied to a flat carrier (D) and then dried.
• the mixing can be carried out by methods known per se, for example by grinding together sulfur (A), carbon (B) and at least one saccharide (C), in particular in a ball mill, or by mixing sulfur (A), carbon ( B) and at least one saccharide (C) are stirred together in aqueous suspension with each other. Also, kneading of sulfur (A), carbon (B) and at least one saccharide (C) with addition of water to an aqueous paste is possible. Preferably, at least two mixing methods are combined with one another. Very particular preference is given to milling together sulfur (A), carbon (B) and at least one saccharide (C), for example in a ball mill, and then suspended in water or aqueous formulation.
• first sulfur (A), carbon (B) and at least one saccharide (C) are stirred together in a liquid, for example in water or in a water / alcohol mixture, and then ground, for example in a ball mill.
• the action of ultrasound is chosen as the method of mixing.
• a mixture of sulfur (A), carbon (B) and at least one saccharide (C), which may have one or more further constituents, for example water or at least one organic solvent, is obtained.
• Aqueous formulation should also be used in the context of the present invention.
• Aqueous formulation can be designed as a paste or as an ink.
• Aqueous formulation may contain, for example, 0.1 to 70% by volume, based on water, of at least one organic solvent, in particular in the range of 5 to 60% by volume.
• Suitable organic solvents are, for example, water-soluble alcohols, in particular methanol, ethanol and isopropanol.
• aqueous formulation does not contain an organic solvent.
• mixture of sulfur (A), carbon (B) and at least one saccharide (C) contains neither water nor organic solvent, but is a powdery mixture.
• ink those preferably aqueous formulations which have a solids content in the range from 1.1 to 20% by weight are referred to as ink.
• paste Such preferably aqueous formulations which have a solids content of more than 20% by weight up to 45% by weight, preferably at least 20.1% by weight, are referred to as paste.
• sulfur (A), carbon (B) and saccharide (C) ranges from 1.1 to 20.
• mixture of sulfur (A), carbon (B) and at least one saccharide (C) on flat support (D) prepared in the first step can be done for example by spraying, for example spraying or spraying, furthermore knife coating, printing, in particular by screen printing , or by pressing.
• spraying is also counted by means of the application of a spray gun, a process which is frequently also referred to as "airbrushing” or “airbrushing” for short. If it is desired to apply a mixture of sulfur (A), carbon (B) and at least one saccharide (C) prepared by spraying onto flat support (D) in the first step, it is preferable to formulate the mixture as an ink.
• the flat carrier (D) is a medium which conducts the electric current, for example a current collector.
• planar carrier (D) is chemically indifferent to the reactions which take place in an electrochemical cell during normal operation, ie during charging and discharging.
• planar support (D) has an internal BET surface area in the range from 20 to 1500 m 2 / g, which is preferably determined as the apparent BET surface area.
• flat supports (D) are selected from metal nets, for example steel nets, in particular stainless steel nets, nickel nets or tantalum nets.
• Metal nets can be coarse or fine mesh.
• planar supports (D) are selected from electrically conductive fabrics, for example mats, felts or fleeces of carbon or organic polymer containing metal filaments, for example tantalum filaments or nickel filaments.
• metal foils for example, metal foils, especially aluminum foils, are particularly well suited.
• Metal foils can, for example, have a thickness in the range from 4 ⁇ m to 200 ⁇ m, in particular from 20 to 50 ⁇ m.
• the format of flat carrier (D) can be chosen in a wide range, for example in the form of endless belts that can be processed by battery manufacturers.
• flat carriers (D) may be formed, for example, in the form of round, elliptical or square disks or cuboidal or as planar electrodes.
• flat carrier D
• a mixture of sulfur (A), carbon (B) and at least one saccharide (C) on one side to flat support (D).
• a mixture comprising sulfur (A), carbon (B) and at least one saccharide (C) is applied to only one side of the sheet.
• a mixture of sulfur (A), carbon (B) and at least one saccharide (C) is applied to flat support (D) such that the layer thickness is in the range from 30 to 200 ⁇ m, preferably 60 to 120 ⁇ per layer, determined after drying.
• the optionally carried out drying can be carried out for example at a temperature in the range of 30 to 100 ° C, preferably in the range of 40 to 50 ° C.
• the optionally carried out drying can be carried out at atmospheric pressure or preferably at reduced pressure, for example at 1 to 500 mbar.
• Suitable devices for a drying step are drying cabinets and, in particular, vacuum drying cabinets.
• the thus coated flat support (D) can be used in electrochemical cells as an electrode.
• Surface carriers (D) coated by the process according to the invention show numerous advantages as electrodes in electrochemical cells. These include, for example, a uniform distribution of sulfur, good bonding and contacting with the sheet carrier (D) and a high sulfur utilization rate.
• Another object of the present invention are electrodes containing
• Sulfur (A), carbon (B) and saccharide (C) are defined above.
• carbon (B) is selected from graphite, graphene, carbon black and activated carbon, preferably carbon black.
• the electrode according to the invention contains at least two, for example two or three different types of carbon (B). Different types of carbon (B) may differ, for example, in terms of particle diameter or BET surface area or level of contamination.
• saccharides (C) are selected from glucose, fructose, sucrose, mannose and maltose.
• saccharides (C) are selected from monosaccharides, especially glucose and fructose. In one embodiment of the present invention, saccharides (C) are selected from disaccharides, especially sucrose.
• saccharides (C) are selected from polysaccharides, in particular amylopectin.
• saccharides (C) are selected from partially oxidized saccharides, in particular from partially oxidized mono- or disaccharides, in particular from caramelized sugars such as, for example, caramelized sucrose, caramelized glucose and caramelized fructose.
• the coating of laminar support (D) with sulfur (A), carbon (B) and saccharide (C) has a thickness in the range from 30 to 200 ⁇ m, preferably 60 to 120 ⁇ m per layer After drying, with two-sided application so a total thickness of 60 to 400 ⁇ , preferably 120 to 240 ⁇ .
• Electrodes are particularly suitable as part of lithium-containing batteries.
• the present invention is the use of electrodes according to the invention as a component of or for the production of electrochemical cells.
• Another object of the present invention are electrochemical cells containing at least one electrode according to the invention.
• the electrode according to the invention is the cathode, which may also be referred to as sulfur cathode or S-cathode. In the context of the present invention, that electrode is referred to as the cathode at which the reduction reaction takes place during the discharge.
• Inventive electrodes may, for example, thicknesses in the range of 60 to 230 ⁇ , preferably 90 to 150 ⁇ have. They may be, for example, rod-shaped, in the form of round, elliptical or square columns or cuboidal or as flat electrodes.
• electrochemical cells according to the invention comprise, in addition to the electrode according to the invention, at least one electrode which contains metallic lithium or a lithium alloy, for example an alloy of lithium with tin, silicon and / or aluminum.
• electrochemical cells according to the invention comprise, in addition to electrode according to the invention and a further electrode, at least one nonaqueous solvent which may be liquid or solid at room temperature, preferably selected from polymers, cyclic or noncyclic ethers, cyclic and noncyclic Acetals, cyclic or non-cyclic organic carbonates and ionic liquids.
• a nonaqueous solvent which may be liquid or solid at room temperature, preferably selected from polymers, cyclic or noncyclic ethers, cyclic and noncyclic Acetals, cyclic or non-cyclic organic carbonates and ionic liquids.
• polymers are in particular polyalkylene glycols, preferably P0IV-C1-C4-alkylene glycols and in particular polyethylene glycols.
• Polyethylene glycols may contain up to 20 mol% of one or more C 1 -C 4 -alkylene glycols in copolymerized form.
• polyalkylene glycols are polyalkylene glycols double capped with methyl or ethyl.
• the molecular weight M w of suitable polyalkylene glycols and in particular of suitable polyethylene glycols may be at least 400 g / mol.
• the molecular weight M w of suitable polyalkylene glycols and in particular of suitable polyethylene glycols may be up to 5,000,000 g / mol, preferably up to 2,000,000 g / mol.
• non-cyclic ethers examples include, for example, diisopropyl ether, di-n-butyl ether, 1, 2-dimethoxyethane, 1, 2-diethoxyethane, preference is 1, 2-dimethoxyethane.
• suitable non-cyclic ethers are diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol diethyl ether and tetraethylene glycol diethyl ether.
• Suitable cyclic ethers are tetrahydrofuran and 1,4-dioxane.
• suitable non-cyclic acetals are, for example, dimethoxymethane, diethoxymethane, 1,1-dimethoxyethane and 1,1-diethoxyethane.
• suitable cyclic acetals are 1, 3-dioxane and in particular 1, 3-dioxolane.
• non-cyclic organic carbonates examples include dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate.
• Suitable cyclic organic carbonates are compounds of the general formulas (I) and (II)
• R 1 , R 2 and R 3 may be identical or different and selected from hydrogen and C 1 -C 4 -alkyl, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec. Butyl and tert-butyl, preferably R 2 and R 3 are not both tert-butyl.
• R 1 is methyl and R 2 and R 3 are each hydrogen or R 1 , R 2 and R 3 are each hydrogen.
• the solvent or solvents are used in the so-called anhydrous state, i. with a water content in the range of 1 ppm to 0.1 wt .-%, determined for example by Karl Fischer titration.
• electrochemical cells according to the invention comprise one or more conductive salts, preference being given to lithium salts.
• suitable lithium salts are LiPF 6, LiBF 4, LiCI0 4, LiAsF 6, L1CF3SO3, LiC (C n F 2n + IS02) 3, lithium imides such as LiN (C n F 2n + IS02) 2, where n is an integer in the range 1-20 LiN (SO 2 F) 2, Li 2 SiFe,
• LiSbF 6, LiAICU, and salts of the general formula (C n F 2n + IS02) mXLi, wherein m is defined as follows: m 1 if X is selected from oxygen and sulfur,
• Preferred conducting salts are selected from LiC (CFsSO 2) 3 and LiN (CF 2 SO 2) 2, and more preferably LiN (CF 3 SO 2 ) 2 .
• electrolytes of electrochemical cells according to the invention may contain one or more additives, for example one or more ionic liquids.
• electrochemical cells according to the invention contain one or more separators, by means of which the electrodes are mechanically separated.
• Suitable separators are polymer films, in particular porous polymer films, which are unreactive with respect to metallic lithium and to lithium sulfides and lithium polysulfides.
• Particularly suitable materials for separators are polyolefins, in particular film-shaped porous polyethylene and film-shaped porous polypropylene.
• Polyolefin separators especially polyethylene or polypropylene, may have a porosity in the range of 35 to 45%. Suitable pore diameters are for example in the range from 30 to 500 nm.
• separators made of PET particles filled with inorganic particles may have a porosity in the range of 40 to 55%. Suitable pore diameters are for example in the range of 80 to 750 nm.
• Inventive electrical cells are characterized by particularly high capacity, high performance even after repeated charging and greatly delayed cell death.
• Electric cells according to the invention are very well suited for use in automobiles, aircraft, ships or stationary energy storage devices. Such uses are a further subject of the present invention.
• Carbon black (B.1) commercially available as Ketjen®, BET surface area: 900 m 2 / g (measured according to ISO 9277), mean particle diameter: 10 ⁇ m Carbon black (B.2), commercially available as Printex®, BET surface area: 100 m 2 / g (measured according to ISO 9277), average particle diameter: 10 ⁇ m
• the one-side coated aluminum foil was carefully laminated between two rubber rollers. It was chosen a low contact pressure, so that the coating remains porous.
• Electrodes were used in addition to the invention:
• Anode Li foil, 50 ⁇ thick,
• Electrolyte 8% by weight LiN (SO 2 CF 3 ) 2 , 46% by weight 1, 3-dioxolane and 46% by weight 1, 2-dimethoxyethane.
• FIG. 1 shows the schematic structure of a disassembled electrochemical cell for testing electrodes according to the invention.
• the explanations in Figure 1 mean:
• Inventive electrochemical cell EZ.1 (based on inventive electrode Elektr.1) or electrochemical cell EZ.2 according to the invention (based on electrode 6 according to the invention) was obtained.
• the electrochemical cells of the invention showed a resting potential of 2.6 to 2.9 volts.
• the cell potential dropped to 2.2 to 2.3 volts (1st plateau) and then to 2.0 to 2.1 volts (2nd plateau).
• the cells were discharged to 1.7V and then charged.
• the cell potential increased to 2.2 volts and the cell was charged to reach 2.5 volts. Thereafter, the unloading process started again.
• the prepared electrochemical cells of the invention achieved more than 30 cycles with very little capacity loss.

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• 2012
  • 2012-01-11 JP JP2013548921A patent/JP2014505980A/ja active Pending
  • 2012-01-11 WO PCT/IB2012/050141 patent/WO2012095802A1/fr active Application Filing
  • 2012-01-11 CN CN2012800052024A patent/CN103299454A/zh active Pending
  • 2012-01-11 EP EP12734684.9A patent/EP2664018A4/fr not_active Withdrawn
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