The present application is directed to methods for preparation of carbon materials. The carbon materials comprise enhanced electrochemical properties and find utility in any number of electrical devices, for example, as electrode material in ultracapacitors or batteries.

Provided is a power storage device having excellent withstand voltage performance and enabling high-voltage driving. This power storage device includes: an electrode formed of an electrode material containing a carbon material and essentially free of a binder; and an electrolytic solution including an ionic liquid including, as components, a cation and an anion.

An embodiment is directed to an electrode composition for use in an energy storage device cell. The electrode comprises composite particles, each comprising carbon that is biomass-derived and active material. The active material exhibits partial vapor pressure below around 10.sup.−13 torr at around 400 K, and an areal capacity loading of the electrode composition ranges from around 2 mAh/cm.sup.2 to around 16 mAh/cm.sup.2.

An embodiment is directed to an electrode composition for use in an energy storage device cell. The electrode comprises composite particles, each comprising carbon that is biomass-derived and active material. The active material exhibits partial vapor pressure below around 10.sup.−13 torr at around 400 K, and an areal capacity loading of the electrode composition ranges from around 2 mAh/cm.sup.2 to around 16 mAh/cm.sup.2.

Provided is a carbon material-resin composite material that can enhance the capacitor capacitance or the battery capacity when used as an electrode material for an electricity storage device. A carbon material-resin composite material including a carbon material and a resin that is at least partially grafted onto the carbon material, the carbon material-resin composite material having an ionic equivalent of 0.1 mmol/g or more.

Provided herein are highly porous electrode structures made from natural materials and retaining natural architecture, which are highly permeable and find use in capacitive deionization desalination systems and methods. Also provided herein are methods of making the electrodes and desalination systems, as well as methods of desalinating water.

The present invention relates to a carbonaceous material for an electrochemical device, having an average particle size D.sub.50 of 30 μm or larger as measured by a laser scattering method, and a basic flowability energy BFE of 270 mJ to 1,100 mJ as measured using a powder flowability analyzer equipped with a measuring vessel of 50 mm in diameter and 160 mL in volume under the conditions of a blade tip speed of 100 mm/sec and a powder sample filling capacity of 120 mL and calculated by the following formula: BFE=T/(R tan α)+F (wherein, R=48 mm, α=5°, T represents a numerical value of the rotational torque measured by the analyzer, and F represents a numerical value of the normal stress measured by the analyzer).

Methods and compositions suitable for forming electrodes and other components of energy storage devices are disclosed.

The present invention belongs to the technical field of biomass carbon materials, and relates to a lignin porous carbon nanosheet, a preparation method therefor, and an application thereof in supercapacitor electrode materials. The method of the present invention performs layer-by-layer self-assembly of sulfonated lignin and oxalate in a selective solvent to prepare a layer-by-layer self-assembled lignin/oxalate composite, which is then carbonized and pickled to obtain the lignin porous carbon nanosheets. The lignin porous carbon nanosheets prepared by the above method of the present invention have a specific surface area of 200-1500 m.sup.2/g, a micropore specific surface area of 100-500 m.sup.2/g, a mesoporous specific surface area of 100-1000 m.sup.2/g, a pore diameter of 0.5-30 nm, and a pore volume of 0.5-1.5 cm.sup.3/g; they can be applied to supercapacitor electrode materials, showing higher specific capacitance and excellent rate performance (with a specific capacitance retention rate of 76.6%), having good potential application value.

Provided is a process for producing a graphene-based supercapacitor electrode from a supply of coke or coal powder, comprising: (a) exposing this powder to a supercritical fluid for a period of time in a pressure vessel to enable penetration of the supercritical fluid into internal structure of the coke or coal; wherein the powder is selected from petroleum coke, coal-derived coke, meso-phase coke, synthetic coke, leonardite, anthracite, lignite coal, bituminous coal, or natural coal mineral powder, or a combination thereof; (b) rapidly depressurizing the supercritical fluid at a fluid release rate sufficient for effecting exfoliation and separation of the coke or coal powder to produce isolated graphene sheets, which are dispersed in a liquid medium to produce a graphene suspension; and (c) shaping and drying the graphene suspension to form the supercapacitor electrode having a specific surface area greater than 200 m.sup.2/g.