Abstract:
A method for carrying out solid state reactions under reducing conditions is provided. Solid state reactants include at least one inorganic metal compound and a source of reducing carbon. The reaction may be carried out in a reducing atmosphere in the presence of reducing carbon. Reducing carbon may be supplied by elemental carbon, by an organic material, or by mixtures. The organic material is one that can form decomposition products containing carbon in a form capable of acting as a reductant. The reaction proceeds without significant covalent incorporation of organic material into the reaction product. In a preferred embodiment, the solid state reactants also include an alkali metal compound. The products of the method find use in lithium ion batteries as cathode active materials. Preferred active materials include lithium-transition metal phosphates and lithium-transition metal oxides. In a preferred embodiment, the reaction product contains carbon particles intimately mixed among crystals of the active materials.
Abstract:
The invention provides novel lithium-mixed metal materials which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-mixed metal materials. Methods for making the novel lithium-mixed metal materials and methods for using such lithium-mixed metal materials in electrochemical cells are also provided. The lithium-mixed metal materials comprise lithium and at least one other metal besides lithium. Preferred materials are lithium-mixed metal phosphates which contain lithium and two other metals besides lithium.
Abstract:
The invention provides novel lithium-mixed metal materials which, upon electrochemical interaction, release lithium ions, and are capable of reversibly cycling lithium ions. The invention provides a rechargeable lithium battery which comprises an electrode formed from the novel lithium-mixed metal materials. Methods for making the novel lithium-mixed metal materials and methods for using such lithium-mixed metal materials in electrochemical cells are also provided. The lithium-mixed metal materials comprise lithium and at least one other metal besides lithium. Preferred materials are lithium-mixed metal phosphates which contain lithium and two other metals besides lithium.
Abstract:
In one embodiment, the invention provides a novel composition which is stabilized against decomposition when used as an active material for an electrochemical cell. The active material of the present invention comprises particles of spinel lithium manganese oxide (LMO) enriched with lithium by a decomposition product of lithium hydroxide forming a part of each of the LMO particles. The spinel LMO product formed by the decomposition of lithium hydroxide in the presence of the LMO is characterized by a reduced surface area and increased capacity retention (reduced capacity fading) as compared to the initial, non-treated, non-enriched spinel. In another aspect, the treated spinel LMO product is combined with lithium carbonate in a cathode mixture.
Abstract:
The invention provides a new family of compounds and a method of making the compounds. The new compounds are useful as ion conductive salts, and particularly useful as salts for batteries. The compounds of the invention are prepared from three principal reagents, bis (trifluoromethanesufonyl) methane (CF.sub.3 SO.sub.2).sub.2 CH.sub.2 ; benzoyl chloride; and pyridine which facilitates reaction and then is removed. A precursor sodium salt (CF.sub.3 SO.sub.2).sub.2 CHNa is first prepared. Then, equimolar amounts of the precursor sodium salt and pyridine are dissolved in anhydrous acetonitrile. A stoichiometric amount of the selected substitute benzoyl chloride is then added drop by drop. After addition of Li.sub.3 PO.sub.4, there is pyridine release and formation of the product of the aforesaid two reagents. In the benzene ring, R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each identical or different and are each independently selected from hydrogen and an electron withdrawing substituent.
Abstract:
An electrochemical cell comprising a first electrode; a counter-electrode which forms an electrochemical couple with the first electrode; and an electrolyte comprising a solvent and a solute. The solvent comprises a dialkyl carbonate of the formula R'OCOOR" where each of R' and R' represents an alkyl, and having at least one of R' and R" selected from the group consisting of non-linear, branched alkyls where R' and R" are preferably different from one another.
Abstract:
Non-aqueous solid electrochemical cells with improved performance can be fabricated by employing intercalation based carbon anodes comprising graphite, coke, or mixtures thereof, and an electrolyte having an electrolyte solvent formed of propylene carbonate and 4,5-dichloroethylene carbonate. The cells are particularly suited for low temperature applications.
Abstract:
A method for removing plasticizers such dibutyl phthalate from the anode, cathode, and polymeric matrix components of an electrochemical cell precursor using an extraction solvent and ultrasound waves is provided.
Abstract:
Improved electrolytic deposition of semiconductors is obtained by separating the anode from the cathode by an ion-exchange membrane. The process is useful in the deposition of IIB/VIB semiconductors in the fabrication of photovoltaic cells.