A method for manufacturing carbon fiber, the method includes: placing a carbon fiber as an anode in an electrolyte, wherein the electrolyte is nitric acid, sulfuric acid, phosphoric acid, acetic acid, ammonium bicarbonate, sodium hydroxide, or potassium nitrate; and performing a surface treatment, wherein a surface of the carbon fiber is oxidized by active oxygen generated by anodic electrolysis, and thereby oxygen-containing functional groups are introduced to the surface. The disclosure also provides a carbon fiber composite bottle, which includes a bottle body and a carbon fiber. The bottle body is a type III bottle or a type IV bottle. The carbon fiber surrounds the bottle body, the surface oxygen concentration of the carbon fiber is 5-35%, and the surface roughness of the carbon fiber is 5-25 nm.

The purpose of the present invention is to provide an electrode active material layer exhibiting excellent mechanical strength. This electrode material for a non-aqueous electrolyte secondary battery includes at least an electrode active material, a carbon-based conductive auxiliary agent, and a binder. The carbon-based conductive auxiliary agent has a linear structure, and includes ultra-fine fibrous carbon having an average fibre diameter of more than 200 nm but not more than 900 nm. The electrode material configures an electrode active material layer in which the maximum tensile strength (σ.sub.M) in a planar direction and the tensile strength (σ.sub.T) in an in-plane direction orthogonal to the maximum tensile strength (σ.sub.M) satisfy relational expression (a), namely σ.sub.M/σ.sub.T≤1.6.

The present disclosure relates to a process for preparing carbon fibers. The process involves blending a carbon nano-material with a carbon material to obtain a homogenous blend, heating the homogenous blend to obtain mesophase pitch having particles with reduced mesophase sphere size followed by spinning the mesophase pitch to obtain the pitch fibers. The pitch fibers are then carbonized to obtain the carbon fibers. The carbon fibers prepared by the process of the present disclosure have improved tensile properties as compared to the conventional pitch based carbon fibers.

The present disclosure relates to a process for preparing carbon fibers. The process involves blending a carbon nano-material with a carbon material to obtain a homogenous blend, heating the homogenous blend to obtain mesophase pitch having particles with reduced mesophase sphere size followed by spinning the mesophase pitch to obtain the pitch fibers. The pitch fibers are then carbonized to obtain the carbon fibers. The carbon fibers prepared by the process of the present disclosure have improved tensile properties as compared to the conventional pitch based carbon fibers.

The present invention provides pitch-based ultrafine carbon fibers containing nitrogen atoms, wherein the average fiber diameter is more than 100 nm but not more than 900 nm; the content of the nitrogen atoms as determined by X-ray photoelectron spectroscopy (XPS) is 1.00% by atom or less; and the true density is from 1.95 to 2.20 g/cm.sup.3.

The present invention provides pitch-based ultrafine carbon fibers containing nitrogen atoms, wherein the average fiber diameter is more than 100 nm but not more than 900 nm; the content of the nitrogen atoms as determined by X-ray photoelectron spectroscopy (XPS) is 1.00% by atom or less; and the true density is from 1.95 to 2.20 g/cm.sup.3.

SiC matrix composite material, where heat-resistant long fiber such as carbon fiber is employed as a material for reinforcement and SiC is employed for the matrix, which significantly improves mechanical properties such as strength and toughness. The SiC matrix composite material, includes a SiC matrix and heat-resistant long fiber, wherein the SiC matrix includes both of alpha-type SiC and beta-type SiC, and the alpha-type SiC and the beta-type SiC are detected by micro-region X-ray diffraction with an X-ray beam diameter of no greater than 300 micrometers substantially at every region of every cross-section of the SiC matrix, the beta-type SiC has an average crystallite size that is no greater than 500 nm and greater than an average crystallite size of the alpha-type SiC, and the SiC matrix composite material has a porosity of no greater than 20% by volume.

SiC matrix composite material, where heat-resistant long fiber such as carbon fiber is employed as a material for reinforcement and SiC is employed for the matrix, which significantly improves mechanical properties such as strength and toughness. The SiC matrix composite material, includes a SiC matrix and heat-resistant long fiber, wherein the SiC matrix includes both of alpha-type SiC and beta-type SiC, and the alpha-type SiC and the beta-type SiC are detected by micro-region X-ray diffraction with an X-ray beam diameter of no greater than 300 micrometers substantially at every region of every cross-section of the SiC matrix, the beta-type SiC has an average crystallite size that is no greater than 500 nm and greater than an average crystallite size of the alpha-type SiC, and the SiC matrix composite material has a porosity of no greater than 20% by volume.

Methods and systems for producing mesophasic (between liquid and solid phases) carbon materials from plastic waste. The method and system includes a 2-stage pyrolysis reactor, including first and second pyrolysis stages where a carbon feedstock material is subjected to pyrolysis. The first pyrolysis stage may subject the carbon feedstock material to pyrolysis at a first temperature in a range of 500° C. to 700° C., and the second pyrolysis stage may operate at a second temperature in a range of 800° C. to 1000° C., providing secondary gas phase reactions (SGR). A residence time of the carbon feedstock material in the reactor may be no more than 10 seconds. After pyrolysis and SGR, a sparging and thermal treatment stage may convert pyrolysis tar products to an anisotropic pitch product suitable for use in production of carbon fiber or bulk graphite for use in fabrication of graphite electrodes.

A method for producing a carbon fiber, the method comprising: (i) subjecting a continuous carbon fiber precursor having a polymeric matrix in which strength-enhancing particles are incorporated to a stabilization process during which the carbon fiber precursor is heated to within a temperature range ranging from the glass transition temperature to no less than 20° C. below the glass transition temperature of the polymeric matrix, wherein the maximum temperature employed in the stabilization process is below 400° C., for a processing time within said temperature range of at least 1 hour in the presence of oxygen and in the presence of a magnetic field of at least 1 Tesla, while said carbon fiber precursor is held under an applied axial tension; and (ii) subjecting the stabilized carbon fiber precursor, following step (i), to a carbonization process. The stabilized carbon fiber precursor, resulting carbon fiber, and articles made thereof are also described.