US Patent 11772975 Chemical-free production of graphene materials

A method of producing isolated graphene sheets directly from a graphitic material, comprising: a) mixing multiple particles of a graphitic material and multiple particles of a solid carrier material to form a mixture in an impacting chamber of an energy impacting apparatus; b) operating the impacting apparatus for peeling off graphene sheets from the graphitic material and transferring these graphene sheets to surfaces of solid carrier material particles to produce graphene-coated solid particles inside the impacting chamber; c) separating the graphene sheets from the solid carrier material particle surfaces to recover isolated graphene sheets. The method enables production of graphene sheets directly from a graphitic material without going through a chemical intercalation or oxidation procedure. The process is fast (hours as opposed to days of conventional processes), has low or no water usage, environmentally benign, cost effective, and highly scalable.