1988 results about "Carbon coated" patented technology

A process for the production of coated silicon/carbon particles comprising: providing a carbon residue forming material; providing silicon particles; coating said silicon particles with said carbon residue forming material to form coated silicon particles; providing particles of a carbonaceous material; coating said particles of carbonaceous material with said carbon residue forming material to form coated carbonaceous particles; embedding said coated silicon particles onto said coated carbonaceous particles to form silicon/carbon composite particles; coating said silicon/carbon composite particles with said carbon residue forming material to form coated silicon/carbon composite particles; and stabilizing the coated composite particles by subjecting said coated composite particles to an oxidation reaction. The coated composite particles will have a substantially smooth coating. The particles may be coated with multiple layers of carbon residue forming material/

A method for the synthesis of compounds of the formula C-LixM1-yM'y(XO4)n, where C represents carbon cross-linked with the compound LixM1-yM'y(XO4)n, in which x, y and n are numbers such as 0<=x<=2, 0<=y<=0.6, and 1<=n<=1.5, M is a transition metal or a mixture of transition metals from the first period of the periodic table, M' is an element with fixed valency selected among Mg<2+>, Ca<2+>, Al<3+>, Zn<2+> or a combination of these same elements and X is chosen among S, P and Si, by bringing into equilibrium, in the required proportions, the mixture of precursors, with a gaseous atmosphere, the synthesis taking place by reaction and bringing into equilibrium, in the required proportions, the mixture of the precursors, the procedure comprising at least one pyrolysis step of the carbon source compound in such a way as to obtain a compound in which the electronic conductivity measured on a sample of powder compressed at a pressure of 3750 Kg.cm<-2 >is greater than 10<-8 >S.cm<-1>. The materials obtained have excellent electrical conductivity, as well a very improved chemical activity.

The invention discloses a precipitation method for preparing nanometer level iron phosphate lithium coated with carbon. The method comprises the following steps: firstly, weighing iron salt, deionized water and a compound of metallic elements; after the stirring and the mixing are performed, adding a phosphorous compound and citric acid diluted with water to the mixture; after the stirring is performed again, adding a precipitation agent to the mixture and controlling to the neutrality; stirring to react in a container, and after the static placement, respectively adding the deionized water, a carbon source and lithium salt to mix uniformly after the precipitate is filtered and washed; stirring again to react, and drying the water at 30 to 160 DEG C and warming up at the heating rate under the protection of non-oxidized gas after a product is crashed; baking at a constant temperature of 450 to 850 DEG C, cooling down to a room temperature at a cooling rate or with a stove, and finally obtaining the nanometer level ferric phosphate lithium coated with the carbon after crashing is performed. The precipitation method has the advantage that the raw material cost and the processing cost are low because bivalent iron is taken as the raw material. The iron phosphate lithium prepared by using the process has the characteristics of good physical processing performance and good electrochemistry performance, and is suitable for industrialized production.

The invention relates to a catalyst for selective hydrogenation reaction of an aromatic nitrocompound and a preparation method of the catalyst. The catalyst consists of a catalyst carrier and active metal coated with carbon, wherein the catalyst carrier includes a carbon-base carrier, SiO2, TiO2 or Al2O3; the active metal is selected from Co, Fe, Ni or Cu and other poor and noble metals. The catalyst is prepared by adopting a Pechini type sol-gel process which comprises the steps of dispersing an active metal precursor to water containing a coordination compound, adding a polyhydric alcohol solution and a macromolecule auxiliary, then adding the carrier, stirring for dispersion, carrying out hydrothermal reaction, separating out solid on the lower layer, and calcining in the inert atmosphere to obtain the catalyst in which carbon coats the active metal. Compared with the prior art, the catalyst can realize the hydrogenation reaction of a substituted aromatic nitrocompound in the mild condition; substrate conversion rate and production selectivity are high; the catalyst has recyclable economy and good application prospect.

The disclosure relates a niobium oxide useful in anodes of secondary lithium ion batteries. Such niobium oxide has formula Li_xM_1−yNb_yNb₂O₇, wherein 0≦x≦3, 0≦y≦1, and M represents Ti or Zr. The niobium oxide may be in the form of particles, which may be carbon coated. The disclosure also relates to an electrode composition containing at least one or more niobium oxides of formula Li_xM_1−yNb_yNb₂O₇. The disclosure further relates to electrodes, such as anodes, and batteries containing at least one or more niobium oxides of formula Li_xM_1−yNb_yNb₂O₇. Furthermore, the disclosure relates to methods of forming the above.

A method and coating are provided for temporarily protecting a substrate or article during shipping, handling or storage by applying a removable protective coating over at least a portion of the substrate. The substrate may be flat or curved and may have zero, one or more functional coatings. A plurality of substrates with the protective coating of the invention may be arranged in a shipping container so that the protective coating reduces the possibility of damage to the substrate or optional functional coating. In one embodiment, the protective coating is the evaporation or reaction product of an aqueous coating composition containing a polyvinyl alcohol polymer which may be subsequently removed by aqueous washing, thermal decomposition or combustion. In another embodiment, the protective coating is formed by sputtering a substantially carbon coating onto the substrate. The carbon coating is subsequently removed by combustion. The protective coating may have identification materials, such as colorants or fragrance materials, such that different types of substrates and/or functional coatings can be distinguished from each other. Additionally, the temporary protective coating can improve the heating of a functionally coated glass substrate.

The invention discloses a preparation method of a silicon and carbon-coated graphene composite cathode material. The technical problem to be solved is to enhance the electronic conductivity of the silicon-based cathode material, buffer the volume effect produced in the process of deintercalation of the lithium in the silicon-based cathode material and enhance the structure stability in the circulation process of the material at the same time. The material is prepared by using a spray drying-thermally decomposing treatment process in the invention. The preparation method comprises the following steps of: evenly dispersing nano silicon and graphite micro powder in a dispersion solution of oxidized graphene, carrying out thermal treatment under an inert protection atmosphere after spray drying, subsequently cooling along a furnace to obtain the silicon and carbon-coated graphene composite cathode material. The extra binder does not need to add in the process of manufacturing balls in the invention and the outer oxidized graphene is thermally reduced in situ to graphene in the thermal treatment process of the composite precursor, so that the process is simple and easy to operate; and the practical degree is high. The prepared composite material has the advantages of great reversible capacity, designable capacity, good cycling performance and high-current discharging performance, high tap density and the like.

Highly purified single-wall carbon nanotubes (SWNTs) and production thereof. The highly purified single-wall carbon nanotubes may be produced according to one embodiment of the invention by generating a crude SWNT material having a carbon nanotube fraction and a non-nanotube carbon fraction, refluxing the crude SWNT material in an acid solution to redistribute the non-nanotube carbon fraction as a uniform carbon coating on the carbon nanotube fraction, and oxidizing the refluxed SWNT material to remove the uniform carbon coating formed thereon. Preferably, metal is also removed during reflux.

Nanocomposits of conductive, nanoparticulate polymer and electronically active material, in particular PEDOT and LiFePO₄, were found to be significantly better compared to bare and carbon coated LiFePO₄ in carbon black and graphite filled non conducting binder. The conductive polymer containing composite outperformed the other two samples. The performance of PEDOT composite was especially better in the high current regime with capacity retention of 82% after 200 cycles. Hence an electrode based on composite made of conductive, nanoparticulate polymer and electronically active material, in particular LiFePO₄ and PEDOT nanostubs, with its higher energy density and increased resistance to harsh charging regimes proved to dramatically extend the high power applicability of materials such as LiFePO₄.

Described is an anode material which is a transition metal nitride or carbide in form of nanoparticles, preferably a nitride or carbide with one nitrogen or carbon per metal, and especially a nitride or carbide having rock salt structure. A preferred anode material is vanadium nitride, in particular carbon coated vanadium nitride having a mean particle size of <500 nm. Embedded in an electrically conducting environment, such nanoparticulate material, in particular the vanadium nitride shows exceptional good charging-discharging cycle stability.

The invention relates to a process for separating a dispersed phase from a continuous phase comprising the steps of i) contacting said phases with an effective amount of nanoparticles; ii) applying a magnetic field gradient to the obtained system; iii) separating the obtained phases wherein said nanoparticles are of the core shell type, said core consists of a metal or alloy having soft magnetic properties and said shell contains a graphene layers which are optionally functionalized; to new nanoparticles and method of manufacturing such nanoparticles.

The invention discloses a preparation method of carbon-coated lithium titanate used for a lithium ion battery; the method comprises the following steps: (1) lithium salt and titanium dioxide are weighted according to proportion, a dispersing agent is added, a ball milling method is used for mixing fully and then the obtained mixture is dried in vacuum, thus obtaining a precursor; (2) the obtained precursor is roasted for 8 to 20 hours at the temperature of 750 to 1000 DEG C so as to prepare lithium titanate; (3) carbon source materials are coated on the surface of the prepared lithium titanate by a dipping and steaming method; and (4) the lithium titanate coated with the carbon source materials is placed in a tubular furnace, and is roasted for 0.5 to 5 hours at the temperature of 750 to 1000 DEG C under the protection of inert gas so as to obtain the carbon-coated lithium titanate. The preparation method of the invention forms chemically coated carbon on the surface of the lithium titanate by the pyrolytic reaction of the carbon-coated materials, and the surface contact of the coated carbon and the lithium titanate material is more firm and tight, thus improving the electron conductivity of the materials greatly and enhancing the charge and discharge performance of magnification of the materials.

Composites for destroying chemical and biological agents such as toxins and bacteria, and methods of preparing and using those composites are provided. According to the invention, the substance to be destroyed is contacted with the inventive composites which comprise finely divided metal oxide nanoparticles at least partially coated with carbon. Advantageously, the composites exclude water while not excluding the target compound or adsorbates. The desired metal oxide nanoparticles can be pressed into pellets for use when a powder is not feasible. Preferred metal oxide nanoparticles include MgO, SrO, BaO, CaO, TiO₂, ZrO₂, FeO, V₂O₃, V₂O₅, Mn₂O₃, Fe₂O₃, NiO, CuO, Al₂O₃, SiO₂, ZnO, Ag₂O, and mixtures thereof.

An electro-mechanical electrostatic air cleaner that combines a low air resistance dielectric fibrous filter material positioned between and electrically charged by two electrically resistant carbon coated screens. The screens are charged by a remotely mounted bi-polar power supply. A pair of post ionization electrodes charge particles in the air with opposite charges, causing the particles to agglomerate. A plurality of screens may be placed in an array for increased one-pass filtration.

The invention relates to a preparation method of lithium iron phosphate for the carbon cladding of a lithium ion battery. The prior lithium iron phosphate preparation technical art is complex, and has high cost. The invention has the synthetic process that: ferric oxide, phosphoric acid, simple organics and doped element compound are mixed and dried, the mol ratio of phosphate radical ion, ferric ion and doped element ion is 1:y:z, wherein, y is larger than or equal to 0.95 and smaller than or equal to 1, and y plus z is equal to 1; the mixture is added with lithium source compound, added with water to be mixed and dried, the mol ratio of lithium ion and phosphate radical ion is x:1, and x is larger than or equal to 0.95 and smaller than or equal to 1.05; the mixture which reacts for 2 to 20 hours under 500 to 800 DEG C is cooled in a furnace. The invention finally produces the precursor uniformly mixed with superfine crystal grain, and during the subsequent high temperature solid phase reaction, the end product lithium iron phosphate can be produced through shorter distance diffuseness of atoms. The end product has high purity, the crystallisation is good, the capacity is high, and the cycle stability is good.

The invention relates to a carbon-coated nano silicon/graphene/cracked carbon layer composition material, a preparation method thereof, and a lithium ion battery including the composition material. The composite material comprises spherical particles formed by uniformly dispersing carbon-coated nano silicon in graphene sheets, and a cracked carbon layer which coats the surfaces of the spherical particles. The carbon-coated nano silicon comprises nano silicon and carbon coating layer which coats the surface of the nano silicon. The method is simple, has excellent process performance and is environment-friendly. The carbon-coated nano silicon/graphene/cracked carbon layer composition material has stable structure and high compact density, has excellent performance when being used as an anode material of the lithium ion battery, has high anode capacity, excellent rate capability and cyclic performance, is more than 1500 mAh/g in first-time reversible capacity, is more than 90% in first-time coulomb efficiency and is more than 90% in 500-time cyclic capacity retention ratio and has low expansion.

The present invention provides anode materials, methods of producing them, anodes, methods of producing them, electrochemical cells, and lithium-ion batteries, where the anode material comprises a silicon monoxide nanoparticle. In certain embodiments, the silicon monoxide is porous or mesoporous. In certain embodiments, the porous or mesoporous silicon additionally comprises other materials within its pores, such as lithium.

The invention provides a preparation method for a carbon-coated silicon negative electrode material for a lithium ion battery. The negative electrode material for the lithium ion battery with excellent performance is obtained from silicon powder by two times of carbon coating; the preparation method comprises the following steps of carrying out liquid phase dispersion on the silicon powder, then carrying out dispersion on the silicon powder, the first carbon coating layer and a dispersing agent; removing the solvent, and carrying out high-temperature carbonization treatment on the obtained solid material to obtain primary carbon-coated silicon negative electrode material; preparing a dispersion solution of a second carbon-coated material, dispersing the primary carbon-coated silicon material to the dispersion solution of the second carbon-coated material, and then removing the solvent and carrying out secondary roasting to obtain the secondary carbon-coated silicon negative electrode material. According to the preparation method, the raw materials are low in cost and easily available; the ratio of silicon to carbon can be optionally regulated and controlled; and the preparation method is simple in equipment, easy to implement the technological process, and suitable for scale production.

The invention discloses a current collector carbon coated aluminum foil and its preparation method. A carbon-containing composite layer is arranged on the substrate of the current collector carbon coated aluminum foil, and is combined with the substrate through a binder, wherein the thickness of the carbon-containing composite layer is 1-100mum; the carbon-containing composite layer comprises granular conductive carbon black pre-dispersed by a dispersant, and fibrous conductive carbon; the granular conductive carbon black and the fibrous conductive carbon filled between the layers of the granular conductive carbon black form a netted node form conductive network. The composite layer is tightly combined with the substrate of the aluminum foil, so the conductivity and the corrosion resistance of the aluminum foil are improved, and the aluminum foil is protected from oxidation or chemical corrosion. The preparation method of the aluminum foil comprises the following operations: mixing the conductive carbon black with the dispersant in an organic solvent to pre-disperse, adding the fibrous conductive carbon, uniformly mixing, adding the binder to prepare a slurry, coating on the aluminum foil, and carrying out vacuum drying. The current collector carbon coated aluminum foil enables the interface impedances of the current collector and an active layer to be reduced, the internal resistance of a battery to be reduced, and the cycle life and the ratio performances of the battery to be improved when the aluminum foil is used as a lithium ion battery anode current collector. The aluminum foil has the advantages of simple technology, low cost and wide application prospect.

The invention discloses a hard carbon coated lithium ion battery anode material and a preparation method thereof. The anode material is characterized in that the coating material is formed by a heteroatom modifier, a hard carbon precursor material and a soft carbon precursor material, wherein the weight ratio of the heteroatom modifier to the hard carbon precursor to the soft carbon precursor is 1:(2-3.3):(3-9). The preparation method is mainly characterized by comprising the following steps: fully mixing graphite and the coating material, and then carrying out heat treatment on the mixture under the protection of inert atmosphere; preserving the temperature for 0.5-6 hours, and then cooling; and carrying out secondary high-temperature graphitization treatment under the protection of inert atmosphere. The heteroatom modifier can change the structure of the hard carbon in the coating material, and the hard carbon precursor has the characteristics of dissolvability and condensation polymerization with the soft carbon precursor asphalt, thus improving the uniformity and operability of the coated graphite particles; and the ratio of the heteroatom modifier to the hard carbon precursor to the soft carbon precursor has an important effect on the performance of the three. By optimizing the ratio of the heteroatom to the hard carbon precursor to the soft carbon precursor in the coated graphite material, the aims of increasing the capacity of the anode material and improving the cycle performance of the anode material are achieved.

A process for preparing carbon coated graphite microparticles used as negative electrode material of Li-ion battery features use of spray granulating method. It can elongate the service life of Li-ion battery.

The present invention provides a process for making uniform carbon-coated LiMPO₄ powders for use as a cathode material in lithium ion batteries. In one embodiment, the process comprises synthesizing a LiMPO₄ powder. The process further comprises coating a carbonaceous coating on to the LiMPO₄ powder to form a coated LiMPO₄ powder. Additionally, the process comprises carbonizing the coated LiMPO₄ powder.