An embodiment is directed to a separator with a ceramic-comprising separator layer. The ceramic-comprising separator layer comprises porous metal oxide fibers with diameters in the range from around 3 nm to around 2 microns, aspect ratios in the range from around 20 to around 100,000, and a total open pore volume among the porous metal oxide fibers in the range from around 0.01 cm.sup.3/g to around 1 cm.sup.3/g.

An integrated flexible self-charging power supply for energy harvesting in an agricultural environment and a preparation method thereof are provided, wherein the integrated flexible self-charging power supply for the energy harvesting in the agricultural environment includes polydimethylsiloxane (PDMS) and a graphene electrode entirely encapsulated in the PDMS, where the graphene electrode includes a power generation portion and an interdigital portion; the power generation portion and the interdigital portion are integrally encapsulated in the PDMS; the interdigital portion is covered with a solid electrolyte; two ends of the interdigital portion of the graphene electrode are led out by wires to serve as two output ends of the power supply.

An integrated flexible self-charging power supply for energy harvesting in an agricultural environment and a preparation method thereof are provided, wherein the integrated flexible self-charging power supply for the energy harvesting in the agricultural environment includes polydimethylsiloxane (PDMS) and a graphene electrode entirely encapsulated in the PDMS, where the graphene electrode includes a power generation portion and an interdigital portion; the power generation portion and the interdigital portion are integrally encapsulated in the PDMS; the interdigital portion is covered with a solid electrolyte; two ends of the interdigital portion of the graphene electrode are led out by wires to serve as two output ends of the power supply.

The present application is generally directed to composites comprising a hard carbon material and an electrochemical modifier. The composite materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed composite materials are also disclosed.

The present application is generally directed to composites comprising a hard carbon material and an electrochemical modifier. The composite materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed composite materials are also disclosed.

Solid-state supercapacitors and microsupercapacitors comprising printed graphene electrodes and related methods of preparation.

Solid-state supercapacitors and microsupercapacitors comprising printed graphene electrodes and related methods of preparation.

A logging system and method for operating a logging system are typically used in a wellbore. The logging system may include a logging instrument including a rechargeable energy storage and logging electronics, and a cable configured to trickle charge the rechargeable energy storage. The rechargeable energy storage may include an ultracapacitor. The rechargeable energy storage may be trickle charged through the cable from a remote power source.

A negative active material includes a carbon material. The carbon material satisfies the following relationship: 6<Gr/K<16, Gr is a graphitization degree of the carbon material, measured by X-ray diffraction; and K is a ratio Id/Ig of a peak intensity Id of the carbon material at a wavenumber of 1250 cm.sup.−1 to 1650 cm.sup.−1 to a peak intensity Ig of the carbon material at a wavenumber of 1500 cm.sup.−1 to 1650 cm.sup.−1, and is measured by using Raman spectroscopy, and K is 0.06 to 0.15.

A process for preparing surface-modified carbon, comprising adding carbon material to a solution of a reaction product of primary aromatic amine and excess molar amount of nitrite source, and recovering surface-modified carbon bearing redox-active sites. Surface-modified carbon material, electrodes and capacitors based thereon are also provided.