2300 results about "Carbon nanofiber" patented technology

Composite electrodes including carbon nanofibers (fibrils) and an electrochemically active material are provided for use in electrochemical capacitors. The fibril composite electrodes exhibit high conductivity, improved efficiency of active materials, high stability, easy processing, and increase the performance of the capacitor. A method for producing the composite electrodes for use in electrochemical capacitors is also provided.

A method of modifying the surface of carbon materials such as vapor grown carbon nanofibers is provided in which silicon is deposited on vapor grown carbon nanofibers using a chemical vapor deposition process. The resulting silicon-carbon alloy may be used as an anode in a rechargeable lithium ion battery.

Disclosed is a hybrid fiber tow that comprises multiple continuous filaments and nanoscale fillers embedded in the interstitial spaces between continuous filaments. Nanoscale fillers may be selected from a nanoscale graphene plate, non-graphite platelet, carbon nano-tube, nano-rod, carbon nano-fiber, non-carbon nano-fiber, or a combination thereof. Also disclosed are a hybrid fiber tow impregnated with a matrix material and a composite structure fabricated from a hybrid fiber tow. The composite exhibits improved physical properties (e.g., thermal conductivity) in a direction transverse to the continuous fiber axis. A roll-to-roll process for producing a continuous fiber tow or matrix-impregnated fiber tow and an automated process for producing composite structures containing both continuous filaments and nanoscale fillers are also provided.

A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m²/g to about 200 m²/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cm² to about 3.5 mg/cm². In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.

Disclosed are a graphene composite nanofiber and a preparation method thereof. The graphene composite nanofiber is produced by dispersing graphenes to at least one of a surface and inside of a polymer nanofiber or a carbon nanofiber having a diameter of 1˜1000 nm, and the graphenes include at least one type of monolayer graphenes, and multilayer graphenes having a thickness of 10 nm or less. The graphene composite nanofiber can be applied to various industrial fields, e.g., a light emitting display, a micro resonator, a transistor, a sensor, a transparent electrode, a fuel cell, a solar cell, a secondary cell, and a composite material, owing to a unique structure and property of graphene.

A high capacity electrode includes a conducting substrate on which a plurality of support filaments are disposed. Each of the support filaments have a length substantially greater than their width and may include, for example, a carbon nano-tube (CNT), a carbon nano-fiber (CNF), and/or a nano-wire (NW). The support filaments are coated with a material, such as silicon, having a greater ion absorbing capacity greater than the neat support filaments. A trunk region of the support filaments proximate to the substrate is optionally kept free of ion absorbing material. This trunk region allows for the expansion of the ion absorbing material without detaching the support filaments form the substrate.

Surface films, paints, or primers can be used in preparing aircraft structural composites that may be exposed to lightning strikes. Methods for making and using these films, paints or primers are also disclosed. The surface film can include a thermoset resin or polymer, e.g., an epoxy resin and/or a thermoplastic polymer, which can be cured, bonded, or painted on the composite structure. Low-density electrically conductive materials are disclosed, such as carbon nanofiber, copper powder, metal coated microspheres, metal-coated carbon nanotubes, single wall carbon nanotubes, graphite nanoplatelets and the like, that can be uniformly dispersed throughout or on the film. Low density conductive materials can include metal screens, optionally in combination with carbon nanofibers.

Disclosed herein is an acoustic diaphragm for converting electrical signals into mechanical signals to produce sounds. The acoustic diaphragm comprises carbon nanotubes or graphite nanofibers as major materials. Preferably, the carbon nanotubes or graphite nanofibers are included or dispersed in the acoustic diaphragm. Since the acoustic diaphragm has excellent physical properties in terms of elastic modulus, internal loss and strength, it can effectively achieve superior sound quality and high output in a particular frequency band as well as in a broad frequency band.

A method of depositing silicon on carbon nanomaterials such as vapor grown carbon nanofibers, nanomats, or nanofiber powder is provided. The method includes flowing a silicon-containing precursor gas in contact with the carbon nanomaterial such that silicon is deposited on the exterior surface and within the hollow core of the carbon nanomaterials. A protective carbon coating may be deposited on the silicon-coated nanomaterials. The resulting nanocomposite materials may be used as anodes in lithium ion batteries.

Disclosed herein is an acoustic diaphragm for converting electrical signals into mechanical signals to produce sounds. The acoustic diaphragm comprises carbon nanotubes or graphite nanofibers as reinforcing agents. Preferably, the carbon nanotubes or graphite nanofibers are included or dispersed in the acoustic diaphragm or coated on the surface of the acoustic diaphragm. Since the acoustic diaphragm has excellent physical properties in terms of elastic modulus, internal loss, strength and density, it can effectively achieve superior sound quality and a high output in a particular frequency band as well as in a broad frequency band.

Disclosed are supercapacitors having organosilicon electrolytes, high surface area/porous electrodes, and optionally organosilicon separators. Electrodes are formed from high surface area material (such as porous carbon nanotubes or carbon nanofibers), which has been impregnated with the electrolyte. These type devices appear particularly suitable for use in electric and hybrid electric vehicles.

An electrode composite and to its manufacturing process. The composite includes an active element, i.e. one exhibiting electrochemical activity, a conductive additive and a binder. The conductive additive is a mixture of conductive additives containing at least carbon nanofibres (CNFs) and at least carbon nanotubes (CNTs). Also, the negative electrodes for electrochemical devices of the lithium battery type including said composite and to the secondary (Li-ion) batteries provided with such a negative electrode.

A negative electrode for non-aqueous electrolyte secondary batteries has a mixture layer disposed on a current collector. The mixture layer includes a composite negative electrode active material, a first binder containing an acryl-group-containing polymer, and a second binder containing adhesive rubber particles. The composite negative electrode active material contains carbon nanofibers, a catalyst element, and silicon-containing particles capable of charging and discharging at least lithium ions. The first binder binds the silicon-containing particles to the current collector, and the second binder binds the carbon nanofibers together.

This invention provides a continuous process for the growth of vapor grown carbon fiber (VGCNT) reinforced continuous fiber preforms for the manufacture of articles with useful mechanical, electrical, and thermal characteristics. Continuous fiber preforms are treated with a catalyst or catalyst precursor and processed to yield VGCNT produced in situ resulting in a highly entangled mass of VGCNT infused with the continuous fiber preform. The continuous process disclosed herein provides denser and more uniform carbon nanotubes and provides the opportunity to fine-tune the variables both within an individual preform and between different preforms depending on the characteristics of the carbon nanotubes desired. The resulting continuous fiber preforms are essentially endless and are high in volume fraction of VGCNT and exhibit high surface area useful for many applications. The invention also provides for composites made from the preforms.

A process for producing-vapor grown carbon fiber (VGCF) reinforced continuous fiber performs for the manufacture of articles with useful mechanical, electrical, and thermal characteristics is disclosed. Continuous fiber preforms are treated with a catalyst or catalyst precursor and processed to yield VGCF produced in situ resulting in a highly entangled mass of VGCF infused with the continuous fiber preform. The resulting continuous fiber preforms are high in volume fraction of VGCF and exhibit high surface area useful for many applications. Furthermore, this invention provides for a continuous fiber preform infused with VGCF so that the carbon nanofibers are always contained within the fiber preform. This eliminates the processing steps for isolated carbon nanofibers reported in other carbon nanofiber composite approaches and therefore greatly reduces risk of environmental release and exposure to carbon nanofibers.

A monolith comprises a zeolite, a thermally conductive carbon, and a binder. The zeolite is included in the form of beads, pellets, powders and mixtures thereof. The thermally conductive carbon can be carbon nano-fibers, diamond or graphite which provide thermal conductivities in excess of about 100 W/m·K to more than 1,000 W/m·K. A method of preparing a zeolite monolith includes the steps of mixing a zeolite dispersion in an aqueous colloidal silica binder with a dispersion of carbon nano-fibers in water followed by dehydration and curing of the binder is given.

The present invention is to provide anode active material hybridized with carbon nano fibers for lithium secondary battery prepared by following steps comprising, i) dispersing the nano size metal catalyst to the surface of anode material selected from graphite, amorphous silicon or the complex of graphite and amorphous silicon; and ii) growing the carbon nano fiber by chemical vapor deposition method, wherein carbon nano fibers are grown in a vine form and surround the surface of anode active material.

A medical electrical lead having a conductor assembly covered by an insulating layer, and a shield covering positioned adjacent or proximate to at least a portion of the insulating layer in order to shield the conductor assembly from one or more electromagnetic fields. The shield covering is formed of a material that is electrically conductive, where the material is in a wrapped or woven form. The material is selected so as to have an effective combination of small size and high conductive surface area, e.g., as opposed to metal wire or coatings thinner than metal wire. As such, the shield covering exhibits sufficient conductivity in the presence of one or more high frequency electromagnetic fields so that interference to the operation of the conductor assembly is minimized. The material can have a coating formed of one or more metals. The material can include carbon. In turn, the carbon can be formed of one or more of carbon fiber, carbon nanofiber, and single or multi-walled carbon nanotube.

A medical electrical lead having a conductor assembly covered by an insulating layer, and a shield covering positioned adjacent or proximate to at least a portion of the insulating layer in order to shield the conductor assembly from one or more electromagnetic fields. The shield covering is formed of a polymer-matrix composite. The polymer-matrix composite includes a polymeric resin having discontinuous conductive fillers provided therein. The discontinuous conductive fillers include one or more of nano-sized metal structures and nano-sized non-metallic conductive structures. The nano-sized non-metallic conductive structures can have a coating formed of one or more metals. The nano-sized non-metallic conductive structures can be formed of carbon. In turn, the nano-sized non-metallic conductive structures can include one or more of carbon nanofibers, carbon filaments, carbon nanotubes, and carbon nanoflakes.

The present invention provides a composite silicon anode material hybridizing carbon nanofiber for lithium secondary battery prepared by the steps comprising: i) preparing a support made by amorphous silicon alloy after processing amorphous silicon and metal; ii) dispersing the catalyst selected from Fe, Co, Ni, Cu, Mg, Mn, Ti, Sn, Si, Zr, Zn, Ge, Pb or In on the surface of said support made by amorphous silicon alloy; and iii) growing the carbon nanofiber using a carbon source selected from carbon monoxide, methane, acetylene or ethylene on said support by a chemical vapor deposition method, wherein the amount of grown carbon nanofiber is 1˜110 wt % of the amount of said support.