To provide a manufacturing method of graphene oxide that allows mass production through a relatively simple process, at low costs, and with safety and efficiency. A hydrogen peroxide solution, sulfuric acid, and flake graphite are put in a reaction container, and the mixture is stirred to obtain expansion graphite. The synthesized expansion graphite is washed not with pure water but with a saturated aqueous solution of magnesium sulfate (MgSO.sub.4) or an organic solvent, whereby a large amount of sulfuric acid is contained between graphite layers. The expansion graphite is subjected to heat treatment or microwave irradiation to form expanded graphite, and a graphite layer is peeled by ultrasonic treatment and then oxidized to form a graphene compound.

Provided is a process for manufacturing 2D inorganic compound platelets, the process comprising (a) preparing a first stock containing a 3D layered inorganic compound material dispersed in a liquid medium, (h) injecting the first stock into a continuous reactor having a vortex flow, (c) operating the continuous reactor to form a reaction product suspension containing 2D inorganic compound platelets dispersed in the liquid medium, and (d) separating and recovering said 2D inorganic compound platelets from said product suspension. The product suspension may be directed to flow back to the continuous director for further processing for at least another pass through the reactor, prior to step (d). The continuous reactor is preferably a Couette-Taylor reactor.

Provided is a process for manufacturing 2D inorganic compound platelets, the process comprising (a) preparing a first stock containing a 3D layered inorganic compound material dispersed in a liquid medium, (h) injecting the first stock into a continuous reactor having a vortex flow, (c) operating the continuous reactor to form a reaction product suspension containing 2D inorganic compound platelets dispersed in the liquid medium, and (d) separating and recovering said 2D inorganic compound platelets from said product suspension. The product suspension may be directed to flow back to the continuous director for further processing for at least another pass through the reactor, prior to step (d). The continuous reactor is preferably a Couette-Taylor reactor.

A method for the manufacture of graphene oxide from electrode graphite scrap including the provision of electrode graphite scrap, the grinding of electrode graphite scrap to obtain ground graphite electrode and an oxidation step of the ground graphite electrode to obtain graphene oxide.

A method for the manufacture of graphene oxide from electrode graphite scrap including the provision of electrode graphite scrap, the grinding of electrode graphite scrap to obtain ground graphite electrode and an oxidation step of the ground graphite electrode to obtain graphene oxide.

A conductive powder for an internal electrode includes a metal particle; and a graphene layer or an oxidized graphene layer disposed on at least a portion of a surface of the metal particle.

A conductive powder for an internal electrode includes a metal particle; and a graphene layer or an oxidized graphene layer disposed on at least a portion of a surface of the metal particle.

Systems for the production of graphene oxide sheets are provided. The systems include electro-deposition and spray deposition techniques. The graphene oxide sheets may be used as pre-cursors for the formation of porous graphene network (PGN) anodes and lithiated porous graphene (Li-PGN) cathodes. The method of making PGN electrodes includes thermally reducing a pre-cursor sheet of graphene oxide to provide a PGN anode and exposing the sheet to lithium or a lithium-containing compound to produce a Li-PGN cathode. The Li-PGN cathode and PGN anode may be combined with an electrolyte to provide an all-carbon battery that is useful in various applications, such as automotive applications.

Systems for the production of graphene oxide sheets are provided. The systems include electro-deposition and spray deposition techniques. The graphene oxide sheets may be used as pre-cursors for the formation of porous graphene network (PGN) anodes and lithiated porous graphene (Li-PGN) cathodes. The method of making PGN electrodes includes thermally reducing a pre-cursor sheet of graphene oxide to provide a PGN anode and exposing the sheet to lithium or a lithium-containing compound to produce a Li-PGN cathode. The Li-PGN cathode and PGN anode may be combined with an electrolyte to provide an all-carbon battery that is useful in various applications, such as automotive applications.

A power storage device with high output is provided, in which the specific surface area is increased while keeping the easy-to-handle particle size of its active material. The power storage device includes a positive electrode including a positive electrode current collector and a positive electrode active material layer, a negative electrode including a negative electrode current collector and a negative electrode active material layer, and an electrolyte. The negative electrode active material layer includes a negative electrode active material which is a particle in which a plurality of slices of graphite is overlapped with each other with a gap therebetween. It is preferable that the grain diameter of the particle be 1 m to 50 m. Further, it is preferable that the electrolyte be in contact with the gap between the slices of graphite.