54results about How to "High nitrogen doping" patented technology

The invention discloses a nitrogen-doped porous carbon, a preparation method and its application as a supercapacitor electrode, belonging to the technical field of energy materials and applications. The invention uses the natural waste product peanut shells as raw materials, and prepares nitrogen-doped porous carbon after ball milling, sieving, high-temperature activation and washing. The nitrogen-doped porous carbon prepared by this method has hierarchical pores of micropores and mesopores, the pore diameter is mainly distributed in the range of 2 to 5 nanometers, the specific surface area is 1000 to 1200 square meters per gram, and the mass ratio of nitrogen content is 8 to 10%. The specific capacitance is 290-310 Faradays / g, and the mass energy density of the prepared nitrogen-doped porous carbon-based supercapacitor is 40-43 Wh / kg, and has excellent cycle stability, so it can be better used in supercapacitors. Capacitor electrode field.

The invention discloses a preparation method of a composite positive pole material of a lithium sulphur battery. The preparation method comprises the following steps of: (1) utilizing activation and nitrogen doping to simultaneously carry out modification on a carbon aerogel to obtain a modified carbon aerogel material; and (2) slowly adding the modified carbon aerogel in an organic sulfur solution, taking a supercritical fluid as an extraction agent to ultrasonically extract in an extraction kettle under room temperature, carrying out pressure reduction and separation, leaching by an ethanol eluting agent, and drying to obtain the modified carbon aerogel-sulfur composite positive pole material. The material prepared by the preparation method provided by the invention has the advantages that the sulfur content is high, the sulfur particles are small, the granularity is uniformly controllable, and the material simultaneously has higher conductibility, specific surface area and porosity. The recovery of the used organic solvent is simple in the preparation process, the extraction agent is circularly used through compression, the extraction efficiency is high, the operation is simple, and the pollution is not generated.

The invention discloses a nitrogen-doped three-dimensional bicontinuous porous structure ultrathin carbon layer and a preparation method and application thereof. The preparation method comprises the steps that shrimp shell pretreatment is conducted, by taking urea or melamine or pyrrole as a nitrogen source and taking shrimp shells subjected to treatment as a raw material, under inert gas flow, low-temperature pre-carbonization is conducted, then, high-temperature pyrolysis is conducted with alkaline matter, acid treatment is conducted at last, and the nitrogen-doped three-dimensional bicontinuous porous structure ultrathin carbon layer is obtained. The nitrogen-doped three-dimensional bicontinuous porous structure ultrathin carbon layer prepared through the method has a unique nano ultrathin carbon layer structure, a high specific surface area and a total pore volume, is simple in technology, low in cost, friendly to environment, and has good physical and chemical properties. The nitrogen-doped three-dimensional bicontinuous porous structure ultrathin carbon layer can be applied to a supercapacitor, a secondary battery and gas absorption, and a new way for developing new energy biomass materials is opened up.

The invention discloses a composite material as well as a preparation method and an application thereof. The composite material has a core-shell structure which takes cobalt metal as an inner core and carbon nanomaterial doped with nitrogen atoms as a shell, wherein the surface of the cobalt metal inner core is evenly wrapped with cobalt oxide, the doping content of the nitrogen atoms is within the range of 2-9.6%, and the mass fraction of cobalt element is within the range of 5-20%. The preparation method comprises the following steps: (1) mixing melamine, concentrated acid and water in proportion, and heating until the mixture is transparent; (2) feeding the carbon nanomaterial and cobalt salt, evenly mixing and cooling; (3) drying; (4) heating up to 500-800 DEG C under the condition of insulating oxygen, and calcining for 2-10 hours. The carbon-cobalt composite nanomaterial is higher in nitrogen doping amount, has better oxygen reduction catalytic activity and stability, and is simple in preparation technology and low in cost, thus being suitable for large-scale production.

The invention belongs to the field of battery materials, and particularly discloses a nitrogen-doped expanded graphite paper current collector, which comprises expanded graphite paper and a nitrogen-doped amorphous carbon material compounded on the surface of the expanded graphite paper in situ. The invention further discloses a preparation method for the current collector. The graphite paper is infiltrated with ionic liquid, the graphite paper infiltrated with the ionic liquid is subjected to heat preservation for 5 min to 8 h at the temperature of 400 DEG C to 1000 DEG C in the air atmosphere, and the current collector is obtained. The invention also discloses the application of the current collector in preparation of a positive electrode, a battery, especially a lithium-sulfur battery.According to the preparation method for the carbon-based current collector provided by the invention, one-step treatment of nitrogen doping and expansion of the graphite paper is realized, the nitrogen doping improves the conductivity of the graphite paper, the expansion realizes the infiltration of the graphite paper by the electrolyte, buffer space is provided for the volume change of the activematerial in the charging and discharging process, and meanwhile, the active material is restrained between the layers of the expanded graphite paper, so that the active material can be prevented fromfalling off from the current collector, and the stability of the electrode is improved.

The invention discloses a method for preparing a nitrogen-doped carbon material containing pure pyridine nitrogen on the basis of chemical vapor deposition. The method comprises the following steps: generating carbon nanofibers on the surface of a substrate by virtue of a chemical vapor deposition method, performing corrosion treatment on the carbon nanofibers by adopting a hydrofluoric acid, and performing nitrogen doping on the carbon nanofibers subjected to the corrosion treatment to obtain the nitrogen-doped carbon material. The preparation method is easy to operate, low in cost and suitable for large-scale production; the prepared nitrogen-doped carbon material has the characteristics of large nitrogen doping amount and doping amount controllability, and the application requirement of a fuel cell is met by a pure pyridine nitrogen-containing structure.