The invention relates to electrocatalysts comprising a carbonitride (CN) shell featuring good electrical conductivity, coordinating suitable catalytically active sites. In a preferred aspect of the invention, the aforesaid carbonitride shell coordinates nanoparticles or aggregates of nanoparticles, on which the active sites of the electrocatalyst are located. In a preferred form of the invention, said carbonitride shell covers suitable cores with good electrical conductivity. Said electrocatalysts are obtained through a process involving the pyrolysis of suitable precursors; in one aspect of the invention, the preparation process requires certain further steps. In one preferred aspect, the steps comprise one or more of the following: chemical treatments; electrochemical treatments; further pyrolysis processes.

Provided herein are electrochemical systems and related methods of making and using electrochemical systems. Electrochemical systems of the invention implement novel cell geometries and composite carbon nanomaterials based design strategies useful for achieving enhanced electrical power source performance, particularly high specific energies, useful discharge rate capabilities and good cycle life. Electrochemical systems of the invention are versatile and include secondary lithium ion cells, useful for a range of important applications including use in portable electronic devices.

Photovoltaic cells are fabricated in which the compositions of the light-absorbing layer and the electron-accepting layer are selected such that at least one side of the junction between these two layers is substantially depleted of charge carriers, i.e., both free electrons and free holes, in the absence of solar illumination. In further aspects of the invention, the light-absorbing layer is comprised of dual-shell passivated quantum dots, each having a quantum dot core with surface anions, an inner shell containing cations to passivate the core surface anions, and an outer shell to passivate the inner shell anions and anions on the core surface.

To provide a graphene compound having an insulating property and an affinity for lithium ions. To increase the molecular weight of a substituent included in a graphene compound. To provide a graphene compound including a chain group containing an ether bond or an ester bond. To provide a graphene compound including a substituent containing one or more branches. To provide a graphene compound including a substituent including at least one of an ester bond and an amide bond.

A mesoporous, nanocrystalline, metal oxide construct particularly suited for capacitive energy storage that has an architecture with short diffusion path lengths and large surface areas and a method for production are provided. Energy density is substantially increased without compromising the capacitive charge storage kinetics and electrode demonstrates long term cycling stability. Charge storage devices with electrodes using the construct can use three different charge storage mechanisms immersed in an electrolyte: (1) cations can be stored in a thin double layer at the electrode/electrolyte interface (non-faradaic mechanism); (2) cations can interact with the bulk of an electroactive material which then undergoes a redox reaction or phase change, as in conventional batteries (faradaic mechanism); or (3) cations can electrochemically adsorb onto the surface of a material through charge transfer processes (faradaic mechanism).

Provided herein are electrochemical systems and related methods of making and using electrochemical systems. Electrochemical systems of the invention implement novel cell geometries and composite carbon nanomaterials based design strategies useful for achieving enhanced electrical power source performance, particularly high specific energies, useful discharge rate capabilities and good cycle life. Electrochemical systems of the invention are versatile and include secondary lithium ion cells, such as silicon-sulfur lithium ion batteries, useful for a range of important applications including use in portable electronic devices. Electrochemical cells of the present invention also exhibit enhanced safety and stability relative to conventional state of the art lithium ion secondary batteries by using prelithiated active materials to eliminate the use of metallic lithium and incorporating carbon nanotube and/or graphene, composite electrode structures to manage residual stress and mechanical strain arising from expansion and contraction of active materials during charge and discharge.

Provided is an internal hybrid electrochemical cell comprising: (A) a pseudocapacitance cathode comprising a cathode active material that contains a conductive carbon material and a porphyrin compound, wherein the porphyrin compound is bonded to or supported by the carbon material to form a redox pair for pseudocapacitance, wherein the carbon material is selected from activated carbon, activated carbon black, expanded graphite flakes, exfoliated graphite worms, carbon nanotube, carbon nanofiber, carbon fiber, a combination thereof; (B) a battery-like anode comprising lithium metal, lithium metal alloy, or a prelithiated anode active material (e.g. prelithiated Si, SiO, Sn, SnO.sub.2, etc.), and (C) a lithium-containing electrolyte in physical contact with the anode and the cathode; wherein the cathode active material has a specific surface area no less than 100 m.sup.2/g which is in direct physical contact with the electrolyte.

The present disclosure relates to a method for the preparation of graphene from coal as a raw material, and more particularly to a method for the preparation of microporous graphene from Chinese Zhundong coal. The process consists of the following steps: first, refining the coal block or coal particle to get fine powdered coal; second, immersing the powdered coal with activation agent solution and drying water to get molten mixture; third, carbonizing the molten mixture in an inert atmosphere and at a high temperature to obtain the carbonized product; fourth, successively acid washing, water-washing and drying the carbonized product to obtain the coal-based porous graphene with the surface area up to 3345 m.sup.2/g. The invention mainly solves the problems of the current method for the preparation of the microporous graphene with high specific surface area, including high cost of raw materials, complicated procedures and low yield. The porous graphene obtained by the invention is expected to realize excellent application values in the fields of gas adsorption separation, electrochemical energy storage and catalysis.

An object of the present invention is to provide an n-type thermoelectric conversion layer, which has a high power factor and exhibits excellent performance stability, a thermoelectric conversion element including the n-type thermoelectric conversion layer, and a composition for forming an n-type thermoelectric conversion layer used in the n-type thermoelectric conversion layer. The n-type thermoelectric conversion layer of the present invention contains carbon nanotubes and an amine compound which is represented by General Formula (1) or (2) and has a C log P value of 2.0 to 8.2. ##STR00001##

To provide a graphene compound having an insulating property and an affinity for lithium ions. To increase the molecular weight of a substituent included in a graphene compound. To provide a graphene compound including a chain group containing an ether bond or an ester bond. To provide a graphene compound including a substituent containing one or more branches. To provide a graphene compound including a substituent including at least one of an ester bond and an amide bond.