A lithium-ion rechargeable battery negative electrode active material and a preparation method thereof, a lithium-ion rechargeable battery negative electrode plate, and a lithium-ion rechargeable battery are provided. The negative electrode active material includes a carbon core and a coating layer formed on a surface of the carbon core, a material of the coating layer includes amorphous carbon and a doping element, and the doping element includes element nitrogen. The lithium-ion rechargeable battery negative electrode active material has the carbon core, and the coating layer that includes the doping element and the amorphous carbon is provided on the surface of the carbon core.

A lithium-ion rechargeable battery negative electrode active material and a preparation method thereof, a lithium-ion rechargeable battery negative electrode plate, and a lithium-ion rechargeable battery are provided. The negative electrode active material includes a carbon core and a coating layer formed on a surface of the carbon core, a material of the coating layer includes amorphous carbon and a doping element, and the doping element includes element nitrogen. The lithium-ion rechargeable battery negative electrode active material has the carbon core, and the coating layer that includes the doping element and the amorphous carbon is provided on the surface of the carbon core.

A method of forming a liquid dispersion of 2D material/graphitic nanoplatelets in an aqueous solution is disclosed. The method comprises the steps of (1) creating a dispersing medium; (2) mixing the 2D material/graphitic nanoplatelets into the dispersing medium; and (3) subjecting the 2D material/graphitic nanoplatelets to sufficient shear forces and or crushing forces to reduce the particle size of the 2D material/graphitic nanoplatelets using a mechanical means. The liquid dispersion comprises the 2D material/graphitic nanoplatelets, at least one grinding media, water, and at least one wetting agent, and that the at least one grinding media is water soluble or functionalised to be water soluble.

A method of forming a liquid dispersion of 2D material/graphitic nanoplatelets in an aqueous solution is disclosed. The method comprises the steps of (1) creating a dispersing medium; (2) mixing the 2D material/graphitic nanoplatelets into the dispersing medium; and (3) subjecting the 2D material/graphitic nanoplatelets to sufficient shear forces and or crushing forces to reduce the particle size of the 2D material/graphitic nanoplatelets using a mechanical means. The liquid dispersion comprises the 2D material/graphitic nanoplatelets, at least one grinding media, water, and at least one wetting agent, and that the at least one grinding media is water soluble or functionalised to be water soluble.

An anode material having 0.8≤0.06×(Dv50).sup.2−2.5×Dv50+Dv99≤12 (1); and 1.2≤0.2×Dv50−0.006×(Dv50).sup.2+BET≤5 (2), where Dv50 represents a value in the volume-based particle size distribution of the anode material that is greater than the particle size of 50% of the particles, Dv99 represents a value in the volume-based particle size distribution of the anode material that is greater than the particle size of 99% of the particles, and BET is a specific surface area of the anode material, wherein Dv50 and Dv99 are expressed in μm and BET is expressed in m.sup.2/g. The anode material is capable of significantly improving the rate performance of electrochemical devices.

An object of the present invention is to provide composite particles capable of suppressing oxidation over time of a Si—C composite material. Composite particles (B) of the present invention contains composite particles (A) containing carbon and silicon; and amorphous layers coating surfaces thereof, where the composite particles (B) have I.sub.Si/I.sub.G of 0.10 or more and 0.65 or less, and have R value (I.sub.D/I.sub.G) of 1.00 or more and 1.30 or less, when a peak due to silicon is present at 450 to 495 cm.sup.−1, an intensity of the peak is defined as I.sub.Si, an intensity of a G band (peak intensity in the vicinity of 1600 cm.sup.−1) is defined as I.sub.G, and an intensity of a D band (peak intensity in the vicinity of 1360 cm.sup.−1) is defined as I.sub.D in a Raman spectrum, and where the composite particles (B) have a full width at half maximum of a peak of a 111 plane of Si of 3.0 deg. or more using a Cu-Kα ray in an XRD pattern.

This specification presents sheets including graphitic materials, including sandwich structures, thermoformed or wet-formed single layer or multilayer structures of graphitic materials, and methods of forming a layer of graphitic material. In accordance with one aspect, the specification presents a multi-layer structure comprising a core layer having a core density between 0.01 and 1 g/cm.sup.3; and a skin layer covering the core layer, the skin layer having at least 10% by weight of a graphitic material, the graphitic material having one or more of graphene oxide, reduced graphene oxide, graphene, graphite oxide, reduced graphite oxide and graphite, the skin layer having a skin density of between 0.5 and 2 g/cm.sup.3 , a thickness ratio of the skin layer to the core layer being of between 1:1000 and 1:1.

A method for producing an artificial graphite material for a lithium ion secondary battery negative electrode, including at least a step of performing a coking treatment on a raw material oil composition by performing a delayed coking process to generate a raw coke composition, a step of performing a heat treatment on the raw coke composition to obtain a heat-treated raw coke composition, a step of crushing the heat-treated raw coke composition to obtain heat-treated raw coke powder, a step of graphitizing the heat-treated raw coke powder to obtain graphite powder, and a step of crushing the graphite powder, in which a volatile content of the heat-treated raw coke powder is less than 3.71%, and a true density of the heat-treated raw coke powder is greater than 1.22 g/cm.sup.3 and less than 1.73 g/cm.sup.3.

A method for producing an artificial graphite material for a lithium ion secondary battery negative electrode, including at least a step of performing a coking treatment on a raw material oil composition by performing a delayed coking process to generate a raw coke composition, a step of performing a heat treatment on the raw coke composition to obtain a heat-treated raw coke composition, a step of crushing the heat-treated raw coke composition to obtain heat-treated raw coke powder, a step of graphitizing the heat-treated raw coke powder to obtain graphite powder, and a step of crushing the graphite powder, in which a volatile content of the heat-treated raw coke powder is less than 3.71%, and a true density of the heat-treated raw coke powder is greater than 1.22 g/cm.sup.3 and less than 1.73 g/cm.sup.3.

The present invention provides a carbon material dispersion in which a carbon material is contained at a high concentration in a liquid medium containing an organic solvent but is unlikely to reaggregate and is stably dispersed, and from which various products, such as an ink capable of forming a coating film having excellent electric conductivity, can be formed. This carbon material dispersion contains a carbon material, an organic solvent, and a polymeric dispersant, wherein the polymeric dispersant is a polymer having 3 to 55% by mass of a constituent unit (1) represented by the following formula (1), wherein R represents a hydrogen atom or the like, A represents O or NH, B represents an ethylene group or the like, R.sub.1 and R.sub.2 each independently represent a methyl group or the like, Ar represents a phenyl group or the like, X represents a chlorine atom or the like, and p represents an arbitrary number of repeating units, and the polymeric dispersant has an amine value of 100 mgKOH/g or less and a number average molecular weight of 5,000 to 20,000.

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