Materials and methods for preparing electrode film mixtures and electrode films including reduced damage bulk active materials are provided. In a first aspect, a method for preparing an electrode film mixture for an energy storage device is provided, comprising providing an initial binder mixture comprising a first binder and a first active material, processing the initial binder mixture under high shear to form a secondary binder mixture, and nondestructively mixing the secondary binder mixture with a second portion of active materials to form an electrode film mixture.

Materials and methods for preparing electrode film mixtures and electrode films including reduced damage bulk active materials are provided. In a first aspect, a method for preparing an electrode film mixture for an energy storage device is provided, comprising providing an initial binder mixture comprising a first binder and a first active material, processing the initial binder mixture under high shear to form a secondary binder mixture, and nondestructively mixing the secondary binder mixture with a second portion of active materials to form an electrode film mixture.

A porous silicon-containing composite includes: a porous core including a porous silicon composite secondary particle; and a shell on at least one surface of the porous core, the shell including a first graphene, wherein the porous silicon composite secondary particle includes an aggregate of a first primary particle including silicon, a second primary particle including a structure and second graphene on at least one surface of the first primary particle and the second primary particle, and wherein at least one of a shape and a degree of oxidation of the first primary particle and the second primary particle are different. Also an electrode including the porous silicon-containing composite, a lithium battery including the electrode, and a device including the porous silicon-containing composite or the carbon composite.

A composite with high energy storage capacity for use in energy storage devices includes graphene and mesoporous graphitic carbon nitride (mc@g-C.sub.3N.sub.4). The graphitic carbon nitride is coated on mesoporous carbon (mc@g-C3N4) at a concentration ranging from 3% to 33%. The graphitic carbon nitride is obtained from condensation of mesoporous carbon and urea or a precursor thereof. Electrodes may be prepared from the composite. High energy high power storage devices such as the Electric Double Layer Capacitor (EDLC) may be fabricated with these electrodes.

A composite with high energy storage capacity for use in energy storage devices includes graphene and mesoporous graphitic carbon nitride (mc@g-C.sub.3N.sub.4). The graphitic carbon nitride is coated on mesoporous carbon (mc@g-C3N4) at a concentration ranging from 3% to 33%. The graphitic carbon nitride is obtained from condensation of mesoporous carbon and urea or a precursor thereof. Electrodes may be prepared from the composite. High energy high power storage devices such as the Electric Double Layer Capacitor (EDLC) may be fabricated with these electrodes.

Provided is a polyvinylidene fluoride comprising: vinylidene fluoride unit; and a pentenoic acid unit represented by formula (1): CH.sub.2═CH— (CH).sub.2—COOY wherein Y represents at least one selected from the group consisting of an inorganic cation and an organic cation, a content of vinylidene fluoride unit is 95.0 to 99.99 mol % based on all monomer units of the polyvinylidene fluoride, and a content of the pentenoic acid unit is 0.01 to 5.0 mol % based on all monomer units of the polyvinylidene fluoride.

A metal ion capacitor with outstanding power capabilities having a negative electrode based on hard carbon (HC) and a positive electrode based on a combination of activated carbon (AC) and a sacrificial salt selected from the group consisting of squarate, oxalate, ketomalonate and di-ketosuccinate or a combination thereof. The sacrificial salt is added to AC in the positive electrode as a source of metal ions for pre-doping the HC and to efficiently compensate its high irreversible capacity by providing the metal ions necessary for the formation of solid electrolyte interphase (SEI) on the hard carbon, allowing for a 1:1 and superior mass balances between anode and cathode. Advantageously, the extraordinary performance of this approach has been successfully demonstrated not only in lithium ion capacitors (LICs) but also in other metal ion capacitors such as sodium and potassium ion capacitors.

An energy storage device according to one aspect of the present invention is an energy storage device including a negative electrode having a negative electrode substrate and a negative active material layer stacked on the negative electrode substrate directly or via another layer, and a nonaqueous electrolyte solution, in which the negative active material layer contains graphite and a solvent-based binder, and the negative active material layer is not subjected to pressing.

Provided is a composition including a polyvinylidene fluoride (A); and a vinylidene fluoride polymer (B) excluding the polyvinylidene fluoride (A), wherein the polyvinylidene fluoride (A) comprises vinylidene fluoride unit and a pentenoic acid unit represented by formula (1): CH.sub.2═CH—(CH).sub.2—COOY wherein Y represents at least one selected from the group consisting of an inorganic cation and an organic cation, a content of vinylidene fluoride unit of the polyvinylidene fluoride (A) is 95.0 to 99.99 mol % based on all monomer units of the polyvinylidene fluoride (A), and a content of the pentenoic acid unit of the polyvinylidene fluoride (A) is 0.01 to 5.0 mol % based on all monomer units of the polyvinylidene fluoride (A).

A sensor-on-clamp device for use in a drilling system, the clamp being a tool joint clamp and houses one or more sensors mounted to the tool joint clamp, a power source and sensor data transmitting means. One or more sensors for use in a drilling system, said sensors being powerable by a single commercially available, replaceable battery.