In a first implementation, a method for exfoliation of graphene flakes from a graphite sample includes compressing a graphite sample in an electrochemical reactor and applying a voltage between the graphite sample and an electrode in the electrochemical cell.

Provided herein are high throughput continuous or semi-continuous reactors and processes for manufacturing expanded graphite materials. Such processes are suitable for manufacturing expanded graphite materials with little batch-to-batch variation.

Provided herein are high throughput continuous or semi-continuous reactors and processes for manufacturing expanded graphite materials. Such processes are suitable for manufacturing expanded graphite materials with little batch-to-batch variation.

A method for preparing a graphene nanosheet, wherein the method includes preparing an electrode assembly comprising a negative electrode, wherein the negative electrode comprises artificial graphite, a lithium metal counter electrode opposing the negative electrode, and a separator interposed between the negative electrode and the lithium metal counter electrode, and immersing the electrode assembly in an electrolyte, electrochemically charging the immersed electrode assembly to form a charged electrode assembly, separating the artificial graphite from the charged electrode assembly to form separated artificial graphite, and de-laminating a graphene nanosheet from the separated artificial graphite, wherein the initial discharge capacity of the negative electrode is 350 mAh/g or greater, and the electrolyte comprises an organic solvent comprising a cyclic carbonate and a linear carbonate, and a lithium salt.

A method for preparing a graphene nanosheet, wherein the method includes preparing an electrode assembly comprising a negative electrode, wherein the negative electrode comprises artificial graphite, a lithium metal counter electrode opposing the negative electrode, and a separator interposed between the negative electrode and the lithium metal counter electrode, and immersing the electrode assembly in an electrolyte, electrochemically charging the immersed electrode assembly to form a charged electrode assembly, separating the artificial graphite from the charged electrode assembly to form separated artificial graphite, and de-laminating a graphene nanosheet from the separated artificial graphite, wherein the initial discharge capacity of the negative electrode is 350 mAh/g or greater, and the electrolyte comprises an organic solvent comprising a cyclic carbonate and a linear carbonate, and a lithium salt.

A composite sheet for shielding electromagnetic and radiating heat includes: a first layer formed of metal; and a second layer that is a graphene layer formed on one surface of the first layer and including charged chemically modified graphene such that thermal conductivity and electromagnetic shielding ability are improved while securing economic efficiency by using the second layer including the charged chemically modified graphene and the graphene flakes.

A composite sheet for shielding electromagnetic and radiating heat includes: a first layer formed of metal; and a second layer that is a graphene layer formed on one surface of the first layer and including charged chemically modified graphene such that thermal conductivity and electromagnetic shielding ability are improved while securing economic efficiency by using the second layer including the charged chemically modified graphene and the graphene flakes.

A water-based graphene dispersion is made by shear stabilization. The method of preparing the water-based graphene dispersion using shear stabilization includes adding a composition containing a graphene powder, a super wetter surfactant and a water dispersible rheology agent into water to form an aqueous mixture; and shearing the aqueous mixture under high pressures to break down the thick layers of the graphene powder to thin layers of graphene platelet particles and to form the water-based graphene dispersion with the graphene platelet particles dispersed in the water-based graphene dispersion. The water-based graphene dispersion is stable without visible phase separation after storage at room temperature for at least one year or even more than one year.

A water-based graphene dispersion is made by shear stabilization. The method of preparing the water-based graphene dispersion using shear stabilization includes adding a composition containing a graphene powder, a super wetter surfactant and a water dispersible rheology agent into water to form an aqueous mixture; and shearing the aqueous mixture under high pressures to break down the thick layers of the graphene powder to thin layers of graphene platelet particles and to form the water-based graphene dispersion with the graphene platelet particles dispersed in the water-based graphene dispersion. The water-based graphene dispersion is stable without visible phase separation after storage at room temperature for at least one year or even more than one year.

Carbon-based materials, and associated methods and articles, are generally provided. In some embodiments, a carbon-based material comprises a carbon-based portion and a functional group bonded to the carbon-based portion. The functional group may be capable of forming a reversible covalent bond with a species. Carbon may make up greater than or equal to 30 wt % of the carbon-based portion. The carbon-based portion may comprise graphene, and a ratio of a total number of functional groups in a plurality of functional groups bonded to the graphene to a total number of carbon atoms in the plurality of carbon atoms of the graphene may be greater than or equal to 1:50. The carbon-based portion may comprise graphene, and greater than or equal to 70% of the graphene sheets may be spaced apart from their nearest neighbors by a distance of greater than or equal to 10 Å. A method may comprise applying a voltage to a carbon-based material. The voltage may be applied in the presence of a combination of solvents comprising a dissolved species. The combination of solvents may comprise a solvent stable at voltages of greater than or equal to −3.15 V and less than or equal to −2.2 V and/or may comprise a solvent with a surface tension within 25% of a surface tension of the carbon-based material. The voltage may be a decreasing voltage that decreases at a rate of greater than or equal to 2 μV/s and less than or equal to 40 μV/s and has a value of greater than or equal to −2.2 V and less than or equal to −3.15 V at at least one point in time.