Global Graphene Group, Inc.

Nanotek Instruments, Inc.

Jun Yin

Bor Z Jang

Aruna Zhamu

Yu-Sheng Su

Jen-Hsien Yang

Qing Fang

A process for producing a graphene/Si nanowire hybrid material, comprising: (a) dispersing catalyst metal-coated Si particles, graphene sheets, and an optional blowing agent in a liquid medium to form a graphene/Si dispersion; (b) dispensing and depositing the dispersion onto a supporting substrate to form a wet layer and removing the liquid medium from the wet layer to form a dried layer of graphene/Si mixture material; (c) exposing the dried layer to a high temperature environment, from 300&#xb0; C. to 2,000&#xb0; C., to induce volatile gas molecules from graphene sheets or to activate the blowing agent for producing the graphene foam and to enable a catalyst metal-catalyzed growth of multiple Si nanowires emanated from Si particles as a feed material in pores of the foam to form a layer of the hybrid material; and (d) operating a mechanical breaking means to produce the Si nanowire/graphene hybrid material in a powder mass form.

Process for producing graphene/silicon nanowire hybrid material for a lithium-ion battery

An anode for a lithium battery comprises a graphene foam structure composed of multiple pores and pore walls and Si nanowires residing in the pores. The Si nanowires are formed in situ inside the pores. The pore walls comprise a 3D network of interconnected graphene planes or stacked graphene planes having an inter-plane spacing dfrom 0.3354 nm to 0.40 nm as measured by X-ray diffraction. The Si nanowires have a diameter from 2 nm to 100 nm and a length-to-diameter aspect ratio of at least 5 and the Si nanowires are in an amount from 0.5% to 99% by weight based on the total weight of the graphene foam and the Si nanowires combined.

Lithium battery anode containing silicon nanowires formed in situ in pores of graphene foam

Provided is graphene-embraced particulate for use as a lithium-ion battery anode active material, wherein the particulate comprises primary particle(s) of an anode active material and multiple sheets of a first graphene material overlapped together to embrace or encapsulate the primary particle(s) and wherein a single or a plurality of graphene-encapsulated primary particles, along with an optional conductive additive, are further embraced or encapsulated by multiple sheets of a second graphene material, wherein the first graphene and the second graphene material is each in an amount from 0.01% to 20% by weight and the optional conductive additive is in an amount from 0% to 50% by weight, all based on the total weight of the particulate. Also provided are an anode and a battery comprising multiple graphene-embraced particulates.

Multi-level graphene-protected anode active material particles for battery applications

Provided is a method of producing a mass of graphene-embraced particulates, comprising (A) peeling off graphene sheets from graphite particles and directly or indirectly transferring these graphene sheets to encapsulate primary particles of an anode active material using an energy-impact device, wherein multiple graphene sheets are overlapped together to embrace or encapsulate a primary particle; and (B) combining the resulting graphene-encapsulated primary particles with additional graphene sheets, along with an optional conductive additive, to form graphene-embraced particulates. Also provided are an anode electrode comprising multiple graphene-embraced particulates and a battery comprising such an anode electrode.

Method of producing multi-level graphene-protected anode active material particles for battery applications

Method of producing multi-level graphene-protected cathode active material particles for battery applications

A process for producing an anode layer, comprising: (a) dispersing catalyst metal-coated Si particles, graphene sheets, and an optional blowing agent in a liquid medium to form a graphene/Si dispersion; (b) dispensing and depositing the dispersion onto a supporting substrate to form a wet layer and removing the liquid medium from the wet layer to form a dried layer of graphene/Si mixture material; and (c) exposing the dried layer to a high temperature environment, from 300&#xb0; C. to 2,000&#xb0; C., to induce volatile gas molecules from graphene sheets or to activate the blowing agent for producing the graphene foam and, concurrently, to enable a catalyst metal-catalyzed growth of multiple Si nanowires emanated from Si particles as a feed material in pores of the foam to form the anode layer; wherein the Si nanowires have a diameter of 5-100 nm and a length-to-diameter aspect ratio of at least 5.

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Miamisburg, OH, United States of America

Jun Yin