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AssigneeNone recorded
InventorJeremy Barker
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In a method for synthesizing reduced metal compounds using electromagnetic radiation, starting materials comprising at least one particulate metal compound and at least one source of carbon are combined to form a mixture. The mixture is exposed to electromagnetic radiation to form a reaction product. Preferably, the carbon is a reducing carbon, and at least one metal of the starting materials is reduced in oxidation state during radiation exposure. Reducing carbon may be supplied by elemental carbon, by an organic material, or by mixtures. Preferably, the solid state reactants also include an alkali metal compound. The products of the method are preferably useful as cathode active materials in lithium ion batteries. The electromagnetic radiation is selected from among microwave, infrared, and radio frequencies of about 1 MHz to 3000 GHz.
A solid state method for synthesizing a reduced metal compound, comprising the steps of:
A solid state method for synthesizing a metal compound product, comprising the steps of:
A method for synthesizing an alkali metal compound product comprising:
A method for synthesizing an alkali metal compound product comprising:
A method of preparing a finely dispersed mixture of electrochemically active material and a conductive carbon, comprising the steps of:
Dependencies are inferred from the claim text.
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Of inorganic oxides or hydroxides: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor: employing electromagnetic waves
Phosphates: containing plural metal, or metal and ammonium
Methods of preparing compounds of metals not covered by subclasses C01B, C01C, C01D, or C01F, in general: oxides
Term end not estimated
This invention relates to methods for producing electrode active materials which can be used to formulate electrodes for use in electrochemical cells in batteries using electromagnetic radiation.
In general, batteries are devices that convert chemical energy into electrical energy, by means of an electrochemical oxidation-reduction reaction. Batteries are used in a wide variety of applications, particularly as a power source for devices that cannot practicably be powered by centralized power generation sources (e.g., by commercial power plants using utility transition lines).
Batteries can generally be described as comprising three components: an anode that contains a material that is oxidized (yields electrons) during discharge of the battery (i.e., while it is providing power); a cathode that contains a material that is reduced (accepts electrons) during discharge of the battery; and an electrolyte that provides for transfer of ions between the cathode and anode. During discharge, the anode is the negative pole of the battery, and the cathode is the positive pole. Batteries can be more specifically characterized by the specific materials that make up each of these three components. Selection of these components can yield batteries having specific voltage and discharge characteristics that can be optimized for particular applications.
The active material γ-LiV2O5 is produced according to the following general reaction scheme.
V2O5+0.5 Li2CO3+0.25 C→LiV2O5+0.75 CO2
1.82 g V2O5 (Alfa Aesar), 0.379 g Li2CO3 (Pacific Lithium Company), and 0.038 g Shawinighan black (Chevron, 25% excess) are pre-mixed and pelletized. The pellet is mounted onto a ceramic disc, sealed inside an argon-filled glass chamber using a Parafilm® covering, and placed in a Panasonic Model NN-L939 microwave oven. This oven operates at a microwave frequency of 2.45 GHz with a maximum output power of 1.2 kW. The pellet is exposed for 3 minutes at the 40% power setting, followed by exposure for an additional 2 minutes at 60% power. Gas is released during the course of the reaction. Colored flashes of light are also observed originating from the sample. Following irradiation, the sample is cooled to room temperature, and powderized. The product is black and appears uniform. X-ray diffraction shows the peaks expected for LiV2O5. Electrochemical testing indicates good reversibility for a cell including the active material.