577 results about "Carbon matrix" patented technology

A rechargeable alkali metal battery comprising: (a) an anode comprising an alkali metal layer and a dendrite penetration-resistant layer comprising an amorphous carbon or polymeric carbon matrix, an optional carbon or graphite reinforcement phase dispersed in this matrix, and a lithium- or sodium-containing species that are chemically bonded to the matrix and/or the optional carbon or graphite reinforcement to form an integral layer that prevents dendrite penetration, wherein the lithium- or sodium-containing species is selected from Li₂CO₃, Li₂O, Li₂C₂O₄, LiOH, LiX, ROCO₂Li, HCOLi, ROLi, (ROCO₂Li)₂, (CH₂OCO₂Li)₂, Li₂S, Li_xSO_y, Na₂CO₃, Na₂O, Na₂C₂O₄, NaOH, NaiX, ROCO₂Na, HCONa, RONa, (ROCO₂Na)₂, (CH₂OCO₂Na)₂, Na₂S, Na_xSO_y, or a combination thereof, wherein X═F, Cl, I, or Br, R=a hydrocarbon group, x=0-1, y=1-4; (b) a cathode; and (c) a separator and electrolyte component; wherein the dendrite penetration-resistant layer is disposed between the alkali metal layer and the separator.

A carbon/carbon (C/C) composite includes a carbon matrix and a non-woven, carbon nanotube (CNT)-infused carbon fiber material. Where woven materials are employed, CNTs are infused on a parent carbon fiber material in a non-woven state. A C/C composite includes a barrier coating on the CNT-infused fiber material. An article is constructed from these (C/C) composites. A method of making a C/C composite includes winding a continuous CNT-infused carbon fiber about a template structure and forming a carbon matrix to provide an initial C/C composite or by dispersing chopped CNT-infused carbon fibers in a carbon matrix precursor to provide a mixture, placing the mixture in a mold, and forming a carbon matrix to provide an initial C/C composite.

Fiber spinning of two polymer compositions wherein one of the compositions contains carbon nanotubes produces structures such as fibers, ribbons, yarns and films of carbon nanotubes. The polymers are removed and stabilization of the carbon nanotube material is achieved by post-spinning processes. The advances disclosed herein enable the carbon nanotube composites to be used in actuators, supercapacitors, friction materials and in devices for electrical energy harvesting.

Silicon based anode active materials are described for use in lithium ion batteries. The silicon based materials are generally composites of nanoscale elemental silicon with stabilizing components that can comprise, for example, silicon oxide-carbon matrix material, inert metal coatings or combinations thereof. High surface area morphology can further contribute to the material stability when cycled in a lithium based battery. In general, the material synthesis involves a significant solution based processing step that can be designed to yield desired material properties as well as providing convenient and scalable processing.

The invention discloses a composite hard carbon cathode material of a lithium ion battery and a preparation method thereof, aiming at improving the first coulombic efficiency. In the composite hard carbon cathode material, a coating object is coated outside a hard carbon matrix, a precursor of the hard carbon matrix comprises a thermoplastic resin which forms the hard carbon matrix by pyrolysis, and a precursor of the coating object is an organic matter. The preparation method comprises the steps of curing, pyrolyzing, pulverizing and coating. Compared with the prior art, a curing agent and adopant are added to the resin for curing, the cured mixture is taken as a carbon source, and then the carbon source is pyrolyzed and coated to finally obtain the composite hard carbon cathode material; and the first reversible capacity of the obtained composite hard carbon cathode material is more than 455.2mAh/g and the first coulombic efficiency thereof is more than 79.4% in the case of 0.2C, thus the obtained composite hard carbon cathode material has high capacity and high first coulombic efficiency, meets the requirement of the lithium ion battery with high capacity, high multiplying power and excellent high and low temperature cycle performance on the charge-discharge performances of the cathode material, has low production cost and is suitable for industrial production.

The invention discloses a hard carbon material for a power and energy-storage battery and a preparation method thereof, and aims to solve the technical problem of improving high-rate charge-discharge performance of lithium-ion batteries. The material is provided with a hard carbon matrix, and a coating is coated outside the hard carbon matrix; and the surface of the hard carbon matrix has a honeycomb opening structure. The preparation method comprises the following steps of: dipping, washing, dewatering and drying, presintering at low temperature, crushing, pyrolyzing, crushing and coating. Compared with the prior art, the hard carbon material has the reversible specific capacity of more than 450mAh/g, the first cycle columbic efficiency of over 81 percent, 0.2C 300-cycles capacity-retaining rate of over 97 percent at the temperature of 60 DEG C, and the 0.2C 300-cycles capacity-retaining rate of over 88 percent at the temperature of -30 DEG C, has the advantages of excellent lithium intercalation and deintercalation capability and cycling stability, and simple preparation process, and is applicable to the lithium ion battery cathode materials for lithium ion power batteries, various portable devices and electric tools.

A composite Si-carbon fiber comprising a carbon matrix material with 1-90 wt % silicon embedded therein. The composite carbon fibers are incorporated into electrodes for batteries. The battery can be a lithium ion battery. A method of making an electrode incorporating composite Si-carbon fibers is also disclosed.

The present invention provides a process for the manufacture of an efficient and robust catalyst for the oxidative dehydrogenation of paraffins to olefins, preferably lower C_2-4 paraffins. The present invention provides a process for the preparation of an oxidative dehydrogenation catalyst of C_2-4 paraffins to olefins comprising comminuting: from 10 to 99 weight % of a mixed oxide catalyst of the formula V_xMo_yNb_zTe_mMe_nO_p, wherein Me is a metal selected from the group consisting of Ta, Ti, W, Hf, Zr, Sb and mixtures thereof; with from 90 to 1 weight % of an inert matrix selected from oxides of titanium, zirconia, aluminum, magnesium, yttria, lantana, silica and their mixed compositions or a carbon matrix to produce particles having a size from 1 to 100 microns and forming the resulting particles into pellets having a size from 0.1 to 2 mm.

A reinforced carbon-carbon (RCC) composite material has improved impact resistance. The RCC composite material is formed from a fiber reinforcement of layers or plies of thin ply carbon fiber fabric impregnated with a carbon matrix. Carbon nanotube reinforcement in the matrix further improves impact resistance. The stacking arrangement of the plies of the thin ply fabric also further improves impact resistance.

A dendrite penetration-resistant layer for a rechargeable alkali metal battery, comprising an amorphous carbon or polymeric carbon matrix, an optional carbon or graphite reinforcement phase dispersed in this matrix, and a lithium- or sodium-containing species that are chemically bonded to the matrix and/or the optional carbon or graphite reinforcement phase to form an integral layer that prevents dendrite penetration through this integral layer in the alkali metal battery, wherein the lithium- or sodium-containing species is selected from Li₂CO₃, Li₂O, Li₂C₂O₄, LiOH, LiX, ROCO₂Li, HCOLi, ROLi, (ROCO₂Li)₂, (CH₂OCO₂Li)₂, Li₂S, Li_xSO_y, Na₂CO₃, Na₂O, Na₂C₂O₄, NaOH, NaiX, ROCO₂Na, HCONa, RONa, (ROCO₂Na)₂, (CH₂OCO₂Na)₂, Na₂S, Na_xSO_y, or a combination thereof, wherein X=F, Cl, I, or Br, R=a hydrocarbon group, x=0-1, y=1-4; and wherein the lithium- or sodium-containing species is derived from an electrochemical decomposition reaction.

A brake pad assembly is provided, including a friction lining providing a wear surface for contacting a brake rotor and a back plate coupled to the friction lining. The back plate is made of a carbon fiber reinforced carbon matrix composite. In one example, a majority of the carbon fibers of the back plate are oriented in a x-y in-plane direction resulting in a structure where the thermal conductivity is at least 2 times greater in the x-y in-plane direction versus a z through-plane direction. In another example, the back plate is provided as at least one sheet of a carbon fiber reinforced carbon matrix composite. A method of manufacturing the brake pad assembly is also provided.

Hybrid materials and nanocomposite materials, methods of making and using such materials. The nanoparticles of the nanocomposite are formed in situ during pyrolysis of a hybrid material comprising metal precursor compounds. The nanoparticles are uniformly distributed in the carbon matrix of the nanocomposite. The nanocomposite materials can be used in devices such as, for example, electrodes and on-chip inductors.

The invention discloses a preparation method of a metal-loaded nitrogen-doped bulk porous carbon material. The preparation method comprises: mixing a natural polysaccharide polymer solution or suspension, an inorganic ammonium salt and a metal salt and carrying out freeze-drying to obtain a natural polysaccharide polymer porous material and carrying out high temperature carbonization on the natural polysaccharide polymer porous material to obtain the metal-loaded nitrogen-doped bulk porous carbon material. The inorganic ammonium salt is used as a pore-foaming agent and a nitrogen source and isheated to decompose and form pores on the surface of a base and the ammonia gas generated by the decomposition reacts with a carbon matrix at a high temperature so that the metal-loaded nitrogen-doped bulk porous carbon material is formed. The metal-loaded nitrogen-doped bulk porous carbon material has the advantages of high specific surface area, high porosity and low density, and has wide application prospects in the fields of energy, catalytic synthesis, gas adsorption, oil-water separation and the like.

A method for preparing a platinum-free chelate catalyst material as an intermediate product for selective electrocatalytic reduction of oxygen includes performing a low-temperature plasma treatment on a powdery form of the transition-metal chelate in a plasma reactor chamber having an inert plasma gas disposed therein. A plasma power, a plasma gas pressure, a plasma initialization and a treatment time of the low-temperature plasma treatment are selected so that molecules of the transition metal chelate are fragmented in the plasma and cross-link in a subsequent chemical reaction so as to form a carbon matrix and retain a basic chelate structure in a surrounding of the transition metal.

The invention discloses a high temperature furnace-grade curing carbon fiber thermal insulating material having simple technology and small coefficient of heat conductivity, and a production technology thereof, characterized in that the material is made of the carbon fiber by the steps of the preparation of a preform, densification, hot-vibration purification and machine processing; the invention is free from the processes of bonding, immersion, curing and charring in the preparation of the preform and has simple technology, great energy-saving property and environmental protection ability, the carbon fibers inside the preform are distributed in a crisscross pattern, strong in cohesive force, stable in structure and free from delamination, the coefficient of heat conductivity is not larger than 0.8 W/mK and the thermal insulating property is excellent; the product consists of the high-strength carbon fiber and carbon matrix and has outstanding performances such as high specific strength, good high temperature resistance, corrosion resistance and thermal insulating property, in addition, the product integrates the fire resistance and the thermal insulating property, can bear certain loads, and is an ideal upgraded product in taking the place of related high temperature furnace-grade graphite products and soft carbon felt.

The invention relates to the field of foamed metal materials, specifically metal/carbon-based composite foamed material and the preparation method thereof. The preparation method comprises processing a foamed carbon blank from foamed plastic as matrix, and forming a metal coating on the foamed carbon by direct electroplating method after the foamed carbon is molded to obtain a metal/carbon-based composite foamed material. The composite foamed material is constituted by foamed carbon and metal coating thereon. The ratio of carbon to metal, by weight percentage, is (20-90):(80-10). In this invention, the metal coating is formed uniformly and continuously on the surface of the foamed carbon matrix by electroplating method, so as to obtain a novel metal/carbon-based composite foamed material; and the toughness and heat conduction capacity of material are improved greatly without changing the appearance of foamed carbon. The inventive metal/carbon-based composite foamed material can not only used as an electronic element in radiator but also a heat exchanger for industrial and domestic uses, additionally can be used as electrode, electronic shield, catalyst and catalyst carrier in automobile, chemical and aerospace industries.

A net-shape molded heat sink is provided which includes a thermally conductive main body and a number of thermally conductive fins integrally connected to and emanating from the main body. The heat sink is formed by overmolding a carbon-carbon matrix core plate with a thermally conductive polymer composition that is filled with thermally conductive filler material. The molded heat sink is freely connecting through the part which makes it more efficient and has an optimal thermal configuration.

A three-dimensional, porous anode material suitable for use in a lithium-ion cell. The three-dimensional, porous anode material includes active anode particles embedded within a carbon matrix. The porous structure of this novel anode material allows for the expansion and contraction of the anode without the anode delaminating or breaking apart, thus improving the life-cycle of the lithium-ion cell. An example of this three-dimensional porous anode material is a porous silicon-carbon composite formed using a bi-continuous micro-emulsion (BME) template.

The invention discloses a preparation method and application of hollow tubular biochar. The preparation method includes: dispersing kapok fiber in a sulfuric acid solution for hydrothermal reaction to obtain carbonized kapok fiber; calcining the carbonized kapok fiber under protection of inert gas, cooling, washing, collecting and drying the calcined kapok fiber to obtain the hollow tubular biochar. The preparation method is simple and easy to control, carbonization and activation of the kapok fiber can be well realized on the premise that original structure of the kapok fiber is maintained, and distribution of balls in the inner surface and the outer surface of a hollow tube can be realized by controlling hydrothermal temperature and calcining temperature. In addition, the biochar prepared by the method can be applied in lithium/sodium ion batteries and supercapacitors and can be used as a carbon matrix in adsorbents, template agents and composite materials. Especially, the hollow tubular biochar presents excellent electrochemical performance when being applied in the lithium/sodium ion batteries.

The present invention relates to a process for preparing an alloy composite negative electrode material having a spherical carbon matrix structure for lithium ion batteries by spray-drying carbothermal reduction. The invention covers a process for preparing a negative electrode material for a lithium ion battery with a general formula A-M/Carbon, wherein A is a metal selected from the group consisting of Si, Sn, Sb, Ge and Al; and wherein M is different from A and is at least one element selected from the group consisting of B, Cr, Nb, Cu, Zr, Ag, Ni, Zn, Fe, Co, Mn, Sb, Zn, Ca, Mg, V, Ti, In, Al, Ge; and comprising the steps of: - providing a solution comprising an organic polymer and either chemically reducible nanometric A- and M-precursor compounds, or nanometric Si and a chemically reducible M-precursor compound, when said metal A is Si; - spray-drying said solution whereby a A- and M-precursor bearing polymer powder is obtained, and - calcining said powder in a neutral atmosphere at a temperature between 500 and 1000 DEG C for 3 to 10 hours whereby, in this carbothermal reduction, a carbon matrix is obtained bearing homogeneously distributed A-M alloy particles.

The invention discloses a simple-process environment-friendly carbon/carbon composite heating element and a production process thereof, which is characterized in that the heating element is prepared by making blank from carbon fibers, densifying, purifying, machining and purifying; the heating element is simple in process; as a net body formed by fluffy needle-like carbon fibers is adopted in the process of making the blank, a quasi-3D prefabricated part is easier to obtain in a needling process; the carbon fibers inside the prefabricated part are crisscrossed, strong in cohesive force, free from delamination and stable in structure; meanwhile, the prefabricated part is small in pore, which facilitates the acceleration of the subsequent densifying process; the heating element blank prepared through chemical vapor deposition densification consists of the carbon fibers and a carbon matrix, wherein the carbon matrix is formed by pyrolytic carbon obtained through a high temperature pyrolysis mode, which is high in purity; and a carbon/carbon composite product with the ash content less than 180 ppm can be obtained only through high-temperature purification in a vacuum or protective atmosphere, thereby saving energy and protecting environment.