Composite carbon particles including a porous carbon material and a silicon component, the composite carbon particle having an average aspect ratio of 1.25 or less, and a ratio (I.sub.Si/I.sub.G) of a peak intensity (I.sub.Si) in the vicinity of 470 cm.sup.−1 to a peak intensity (I.sub.G) in the vicinity of 1580 cm.sup.−1 as measured by Raman spectroscopy of 0.30 or less, wherein the porous carbon material satisfies V.sub.1/V.sub.0>0.80 and V.sub.2/V.sub.0<0.10, when a total pore volume at a maximum value of a relative pressure P/P.sub.0 is defined as V.sub.0 and P.sub.0 is a saturated vapor pressure, a cumulative pore volume at a relative pressure P/P.sub.0=0.1 is defined as V.sub.1, a cumulative pore volume at a relative pressure P/P.sub.0=10.sup.−7 is defined as V.sub.2 in a nitrogen adsorption test, and has a BET specific surface area of 800 m.sup.2/g or more.

Porous carbon particles, and a positive electrode active material and a lithium secondary battery including the same. This may improve the energy density of the lithium secondary battery by applying a porous electrode containing micropores and mesopores and having a uniform size distribution and shape as a positive electrode material.

Porous carbon particles, and a positive electrode active material and a lithium secondary battery including the same. This may improve the energy density of the lithium secondary battery by applying a porous electrode containing micropores and mesopores and having a uniform size distribution and shape as a positive electrode material.

Silicon-carbon composite materials and related processes are disclosed that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Compared to other, inferior materials and processes described in the prior art, the materials and processes disclosed herein find superior utility in various applications, including energy storage devices such as lithium ion batteries.

The present invention relates to composite particles containing silicon and carbon, wherein a domain size region of vacancies of 2 nm or less is 44% by volume or more and 70% by volume or less when volume distribution information of domain sizes obtained by fitting a small-angle X-ray scattering spectrum of the composite particles with a spherical model in a carbon-vacancy binary system is accumulated in ascending order, and a true density calculated by dry density measurement by a constant volume expansion method using helium gas is 1.80 g/cm.sup.3 or more and 2.20 g/cm.sup.3 or less.

A filter medium of the present invention includes a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a volume of fine pores by a BJH method of 0.3 cm.sup.3/g or more, and a particle size of 75 μm or more, alternatively, a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a total of volumes of fine pores having a diameter of from 1×10.sup.−9 m to 5×10.sup.−7 m, obtained by a non-localized density functional theory method, of 1.0 cm.sup.3/g or more, and a particle size of 75 μm or more.

A filter medium of the present invention includes a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a volume of fine pores by a BJH method of 0.3 cm.sup.3/g or more, and a particle size of 75 μm or more, alternatively, a porous carbon material having a value of a specific surface area by a nitrogen BET method of 1×10.sup.2 m.sup.2/g or more, a total of volumes of fine pores having a diameter of from 1×10.sup.−9 m to 5×10.sup.−7 m, obtained by a non-localized density functional theory method, of 1.0 cm.sup.3/g or more, and a particle size of 75 μm or more.

A method for preparing carbon nanotubes, nanofibres or nanofilaments by decomposition of at least one carbon precursor in the presence of a catalyst, in which method continuously:—a first gas stream comprising a precursor of a catalyst is brought into contact with a porous substrate (43);—a second gas stream comprising at least one carbon precursor is brought into contact with said porous substrate (43);—said porous substrate (43) is heated to a temperature leading to the deposition of catalyst particles and to the catalytic growth of carbon nanotubes.

A method for preparing carbon nanotubes, nanofibres or nanofilaments by decomposition of at least one carbon precursor in the presence of a catalyst, in which method continuously:—a first gas stream comprising a precursor of a catalyst is brought into contact with a porous substrate (43);—a second gas stream comprising at least one carbon precursor is brought into contact with said porous substrate (43);—said porous substrate (43) is heated to a temperature leading to the deposition of catalyst particles and to the catalytic growth of carbon nanotubes.

A method for making a soft carbon includes providing a coke, and subjecting the coke to a carbonization process. The carbonization process includes a preliminary calcination treatment conducted by calcining the coke at a first temperature ranging from 800° C. to 1000° C. to obtain a pre-calcinated coke, followed by a main calcination treatment conducted by calcining the pre-calcinated coke at a second temperature ranging from 1000° C. to 1200° C., and/or a surface-modifying calcination treatment conducted by calcining the pre-calcinated coke in the presence of a carbonaceous material for modifying surfaces thereof at a third temperature ranging from 1000° C. to 1200° C. A soft carbon made by the method is also disclosed.