A carbon-sulfur composite including a carbonized metal-organic framework (MOF); and a sulfur compound introduced to at least a part of an outside surface and an inside of the carbonized metal-organic framework, wherein the carbonized metal-organic framework has a specific surface area of 2500 m.sup.2/g to 4000 m.sup.2/g, and the carbonized metal-organic framework has a pore volume of 0.1 cc/g to 10 cc/g, and a method for preparing the same.

A sheet-shaped member is provided and includes a porous carbon material including a material obtained from carbonization of a raw material including rice husk, the raw material having a silicon content of at least 5 wt %, the raw material is heat treated before carbonization, and the raw material is treated by an alkali treatment after carbonization to reduce the silicon content, the porous carbon material having a specific surface area of at least 10 m2/g as measured by the nitrogen BET method, a pore volume of at least 0.1 cm3/g as measured by the BJH method and MP method, and an R value of 1.5 or greater, wherein the porous carbon material includes mesopores having pore sizes from 2 nm to 50 nm and obtained from the alkali treatment of the raw material after carbonization, the porous carbon material further includes macropores and micropores, the R value is expressed as R=B/A, the A referring to an intensity at an intersection between the baseline of a diffraction peak of the (002) plane as obtained based on powdery X-ray diffractometry of the porous carbon material and a perpendicular line downwardly drawn from the diffraction peak of the (002) plane, and the B referring to the intensity of the diffraction peak of the (002) plane.

A sheet-shaped member is provided and includes a porous carbon material including a material obtained from carbonization of a raw material including rice husk, the raw material having a silicon content of at least 5 wt %, the raw material is heat treated before carbonization, and the raw material is treated by an alkali treatment after carbonization to reduce the silicon content, the porous carbon material having a specific surface area of at least 10 m2/g as measured by the nitrogen BET method, a pore volume of at least 0.1 cm3/g as measured by the BJH method and MP method, and an R value of 1.5 or greater, wherein the porous carbon material includes mesopores having pore sizes from 2 nm to 50 nm and obtained from the alkali treatment of the raw material after carbonization, the porous carbon material further includes macropores and micropores, the R value is expressed as R=B/A, the A referring to an intensity at an intersection between the baseline of a diffraction peak of the (002) plane as obtained based on powdery X-ray diffractometry of the porous carbon material and a perpendicular line downwardly drawn from the diffraction peak of the (002) plane, and the B referring to the intensity of the diffraction peak of the (002) plane.

An amorphous silicon-carbon composite, a method for preparing the amorphous silicon-carbon composite using a pyrolysis method, a negative electrode for a lithium secondary battery, and a lithium secondary battery including the same.

The present invention discloses a nitrogen-sulfur co-doped Ti.sub.3C.sub.2-MXene nanosheet and a preparation method and application thereof. Ti.sub.3C.sub.2-MXene is obtained by etching ternary layered carbides of MAX phase through hydrofluoric acid; and then, the nitrogen-sulfur co-doped Ti.sub.3C.sub.2-MXene nanosheet is synthesized by a simple one-step method by taking thiourea as a heteroatom source. The nitrogen-sulfur co-doped Ti.sub.3C.sub.2-MXene nanosheet has a unique two-dimensional layered structure, large specific surface area and abundant heteroatomic catalytic activity sites so that the material presents excellent peroxidase-like activity. The method of the present invention can successfully dope two elements of nitrogen and sulfur in one step on Ti.sub.3C.sub.2-MXene, and can effectively overcome the tedious problem of a step-by-step doping step and the secondary pollution problem of different doping sources to endow peroxidase-like activity for Ti.sub.3C.sub.2-MXene.

Provided is a composite anode active material including: a carbonaceous material; a metal alloyable with lithium, located on a surface of the carbonaceous material; and a silicon coating layer located on a surface of the carbonaceous material, on a surface of the metal alloyable with lithium, or a combination thereof.

Powder comprising particles comprising a matrix material and silicon-based domains dispersed in this matrix material, whereby either part of the silicon-based domains are present in the form of agglomerates of silicon-based domains whereby at least 98% of these agglomerates have a maximum size of 3 μm or less, or the silicon-based domains are not at all agglomerated into agglomerates.

Powder comprising particles comprising a matrix material and silicon-based domains dispersed in this matrix material, whereby either part of the silicon-based domains are present in the form of agglomerates of silicon-based domains whereby at least 98% of these agglomerates have a maximum size of 3 μm or less, or the silicon-based domains are not at all agglomerated into agglomerates.

The invention provides a method and a system for separating lignin from a lignin containing liquid medium, such as pulp mill black liquor, and treating the separated lignin. The method comprises at least the following steps: a) a precipitation stage (1), wherein a pH lowering agent (A) is added to the lignin containing slurry for precipitating lignin, b) followed by a first separation stage (2), wherein the precipitated lignin is separated as a lignin cake from the remaining liquid phase of the lignin containing slurry, c) a suspending stage (3), wherein the lignin cake is suspended for obtaining a lignin suspension, d) a hydrothermal carbonization stage (4), wherein the lignin suspension is treated for obtaining a slurry of carbon containing material, and e) a second separation stage (5), wherein the carbon containing material is separated from the slurry.

The invention provides a method and a system for separating lignin from a lignin containing liquid medium, such as pulp mill black liquor, and treating the separated lignin. The method comprises at least the following steps: a) a precipitation stage (1), wherein a pH lowering agent (A) is added to the lignin containing slurry for precipitating lignin, b) followed by a first separation stage (2), wherein the precipitated lignin is separated as a lignin cake from the remaining liquid phase of the lignin containing slurry, c) a suspending stage (3), wherein the lignin cake is suspended for obtaining a lignin suspension, d) a hydrothermal carbonization stage (4), wherein the lignin suspension is treated for obtaining a slurry of carbon containing material, and e) a second separation stage (5), wherein the carbon containing material is separated from the slurry.