摘要:
Combinatorial synthesis methods obtain a plurality of compositions having materially different characteristics using an apparatus having a plurality of collectors. A first quantity of fluid reactants are reacted to form a first quantity of product composition. Following completion of the collection of the first quantity of product composition, a second quantity of fluid reactants are reacted to form a second quantity of product composition, the second quantity of product composition being material different from the first quantity of product composition. An apparatus includes a nozzle connected to a reactant source and a plurality of collectors. The nozzle and plurality of collectors move relative to each other such that a collector can be selectively placed to receive a fluid stream emanating from the nozzle. The plurality of product compositions can be evaluated to determine their suitability for various applications.
摘要:
A collection of silicon oxide nanoparticles have an average diameter from about 5 nm to about 100 nm. The collection of silicon oxide nanoparticles effectively include no particles with a diameter greater than about four times the average diameter. The particles generally have a spherical morphology. Methods for producing the nanoparticles involve laser pyrolysis. The silicon oxide nanoparticles are effective for the production of improved polishing compositions including compositions useful for chemical-mechanical polishing.
摘要:
Lithium manganese oxide particles have been produced with an average diameter less than about 250 nm. The particles have a high degree of uniformity. The particles can be formed by the heat treatment of nanoparticles of manganese oxide. Alternatively, crystalline lithium manganese oxide particles can be formed directly by laser pyrolysis. The lithium manganese oxide particles are useful as active materials in the positive electrodes of lithium based batteries. Improved batteries result from the use of uniform nanoscale lithium manganese oxide particles.
摘要:
Metal vanadium oxide particles have been produced with an average diameter less than about 500 nm. The particles are produced from nanocrystalline vanadium oxide particles. Silver vanadium oxide particles, for example, can be formed by the heat treatment of a mixture of nanoscale vanadium oxide and a silver compound. Other metal vanadium oxide particles can be produced by similar processes. The metal vanadium oxide particles have very uniform properties.
摘要:
An aerosol delivery apparatus is used to deliver an aerosol into a reaction chamber for chemical reaction to produce reaction products such as nanoparticles. A variety of improved aerosol delivery approaches provide for the production of more uniform reaction products. In preferred embodiments, a reaction chamber is used that has a cross section perpendicular to the flow of reactant having a dimension along a major axis greater than a dimension along a minor axis. The aerosol preferably is elongated along the major axis of the reaction chamber.
摘要:
Vanadium oxide nanoparticles were produced with vanadium in a variety of oxidation states and with different crystalline lattice structures. These particles preferably have an average diameter of 150 nm or less with a narrow distribution of diameters. The particles manifest unique properties that result from the small particle size and correspondingly large surface area. A variety of the vanadium oxide nanoparticles can be produced by a versatile laser pyrolysis arrangement. These nanoparticles can be further processed to change the properties of the particles without destroying the nanoscale size of the particles.
摘要:
High capacity silicon based anode active materials are described for lithium ion batteries. These materials are shown to be effective in combination with high capacity lithium rich cathode active materials. Supplemental lithium is shown to improve the cycling performance and reduce irreversible capacity loss for at least certain silicon based active materials. In particular silicon based active materials can be formed in composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and composites can also be formed with other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles. Additional alloys with silicon are explored.
摘要:
Lithium rich metal oxyfluorides are described with high specific capacity and, good cycling properties. The materials have particularly good high rate capabilities. The fluorine dopant can be introduced in a low temperature process to yield the materials with desirable cycling properties. In some embodiments, the positive electrode active materials have a composition represented approximately by the formula Li1+xNiαMnβCoγAδO2−zFz where: x is from about 0.02 to about 0.19, α is from about 0.1 to about 0.4, β is from about 0.35 to about 0.869, γ is from about 0.01 to about 0.2, δ is from 0.0 to about 0.1 and z is from about 0.01 to about 0.2, where A is Mg, Zn, Al, Ga, B, Zr, Ti, Ca, Ce, Y, Nb or combinations thereof.
摘要:
Improved cycling of high voltage lithium ion batteries is accomplished through the use of a formation step that seems to form a more stable structure for subsequent cycling and through the improved management of the charge-discharge cycling. In particular, the formation charge for the battery can be performed at a lower voltage prior to full activation of the battery through a charge to the specified operational voltage of the battery. With respect to management of the charging and discharging of the battery, it has been discovered that for the lithium rich high voltage compositions of interest that a deeper discharge can preserve the cycling capacity at a greater number of cycles. Battery management can be designed to exploit the improved cycling capacity obtained with deeper discharges of the battery.
摘要:
Combinations of materials are described in which high energy density active materials for negative electrodes of lithium ion batteries. In general, metal alloy/intermetallic compositions can provide the high energy density. These materials can have moderate volume changes upon cycling in a lithium ion battery. The volume changes can be accommodated with less degradation upon cycling through the combination with highly porous electrically conductive materials, such as highly porous carbon and/or foamed current collectors. Whether or not combined with a highly porous electrically conductive material, metal alloy/intermetallic compositions with an average particle size of no more than a micron can be advantageously used in the negative electrodes to improve cycling properties.