194results about How to "Increase active area" patented technology

The invention discloses a lithium ion battery cathode material embedded nano metal loaded carbon nanosheet as well as a preparation method and an application thereof. By taking sugar (chitosan, cane sugar, fructose and glucose) as a carbon source, nitrate of transitional metals (Fe, Co and Ni) as a metal source and a catalyst and inert salts (sodium sulfate, sodium chloride, potassium chloride and cesium chloride) as a template and a dispersant, a two-dimensional carbon nanosheet which uniformly loads embedded nickel (or iron or cobalt) nanoparticles is prepared by a pyrolytic method in one step. The two-dimensional carbon nanosheet which uniformly loads embedded nickel (or iron or cobalt) nanoparticles prepared by the method is high in degree of graphitization, relatively high in specific surface area and high in conductivity, uniform in distribution and easy to separate, and the surface of the nanosheet is in a porous structure. The nanosheet as the lithium ion battery cathode material has relatively good circulating and rate performances.

The invention relates to a carbon-based composite electrode material and a preparation method thereof, and application of the carbon-based composite electrode material to a super capacitor. The electrode material contains a conductive polymer and a carbon-based material. The conductive polymer is attached to a surface of the carbon-based material in a manner of a nanowire array of a conductive polymer, wherein the arrangement of the nanowire array of the conductive polymer is in a good order; besides, a diameter of the nanowire of the nanowire array of the conductive polymer is 40 to 100 nm and a length of the nanowire is 100 to 1500 nm. The carbon-based composite electrode material provide in the invention has a large specific surface area, so that an active area of a conductive polymer is substantially improved and thus high capacitance can be obtained; besides, the carbon-based composite electrode material provide in the invention has a highly ordered nano structure, so that a transmission path of an electrolyte ion is reduced and an internal resistance of an electrode is also reduced; therefore, the ion in an electrode material can be diffused and transmitted conveniently, and thus high power density can be obtained.

The invention provides a flexible supercapacitor. The flexible supercapacitor comprises a housing, two electrodes facing each other and separated with each other, and electrolyte between the two electrodes. The two electrodes facing each other and the electrolyte between the two electrodes are accommodated in the housing. The supercapacitor is characterized in that the electrodes are composed of a conducting polymer and a carbon-based material, and the conducting polymer attaches to a surface of the carbon-based material in a form of a nanowire array of the conducting polymer. The invention also provides a preparation method for the flexible supercapacitor. The flexible supercapacitor prepared by the method has high capacitance, good charge-discharge cycling stability, and is low in cost and simple in preparation technology.

The invention discloses a method for modifying a positive electrode of a lithium ion battery by adding a metal oxide/carbon composite material, and belongs to the technical field of secondary lithium ion batteries. The modification method comprises: mechanically mixing a positive electrode active material of the lithium ion battery with an electrode additive, wherein the electrode additive is the composite material and consists of two parts of a conductive carbon material carrier and a metal oxide load. The electrode additive can reduce the rate of increment of impedance of the positive electrode of the lithium ion battery along with charging/discharging cycle, thereby achieving the purpose of improving the cycle performance of the lithium ion battery.

The invention discloses a polypyrrole minitype super capacitor in the range of the capacitor manufacturing technology based on MEMS technology and the preparation method thereof. The polypyrrole minitype super capacitor adopts the structure that a metal comb two-dimensional plane structure as a current collector is prepared on the surface of the silicon matrix by utilizing the micro-machining technology; a comb-shaped polypyrrole active electrode is prepared on the surface of the current collector by adopting the method of polypyrrole substance being prepared by the electric precipitation method; a layer of gel solid electrolyte is covered on the surface of the comb-shaped polypyrrole electrode and between a positive electrode and a negative electrode; and a layer of polyimide material is covered on the surface of the structure to accomplish the encapsulation of the minitype super capacitor. The MEMS-based manufacturing technology has the characteristic that the process is simple, and is suitable for mass manufacture. The minitype super capacitor has the advantages of small volume, high energy storage and stable performance, and is widely applicable to micro-robot electronic intelligence systems, chemical sensors, battlefield friend-or-foe identification devices, distributed type battlefield sensors and other fields.

The invention discloses an iron-cobalt-nickel-copper-based high-entropy alloy water electrolysis catalytic material and a preparation method thereof, and belongs to the technical field of composite material preparation. The water electrolysis catalytic material is composed of a reaction active matter and a carrier, wherein the reaction active matter is iron-cobalt-nickel-copper-tin, iron-cobalt-nickel-copper-manganese, iron-cobalt-nickel-copper-vanadium and other iron-cobalt-nickel-copper-based high-entropy alloy nanoparticles, and the carrier is a carbon nanofiber material prepared through anelectrostatic spinning method. The prepared water electrolysis catalytic material has a high specific surface area, diffusion of electrolytic solution and desorption of gas are facilitated, hydrogenand oxygen can be produced under an alkaline condition, and the hydrogen production rate under high voltage is far higher than that of a 20% Pt/C electrode; and carbon nanofibers can effectively protect the high-entropy alloy nanoparticles from being eroded by an electrolytic solution, so that the catalytic material is endowed with good stability.

The invention relates to a single-step manufacturing method of a carbon-based composite fiber electrode material and the carbon-based composite fiber electrode material manufactured by the single-step manufacturing method of the carbon-based composite fiber electrode material. The electrode material comprises a conductive polymer and a carbon-based material, and the conductive polymer is distributed in the carbon-based composite material in the mode of conductive polymer nanowires. The diameter of the conductive polymer nanowires is 40 nm to 100 nm, and the length of the conductive polymer nanowires is 1 micron to 10 microns. The manufacturing method of the carbon-based composite fiber is novel in technology, and concise in method, and greatly simplifies steps of the preparation of the electrode materials. The carbon-based composite fiber electrode material is large in specific surface area and good in suppleness, and greatly improves volume of a super capacitor and mechanical capacity of the super capacitor.

The invention relates to a metal-doped nitrogen-containing carbon-based catalyst of a fuel cell and application of the catalyst. The catalyst adopts organic surface active agents as a protection agent and a structural guide agent and adopts an aromatic compound and aldehyde as reaction monomers, metal elements are added in the reaction process to obtain a polymer-metal compound, and the polymer-metal compound is dried and then is subjected to high-temperature processing with inert gas or/and ammonia gas to finally obtain the metal-doped nitrogen-containing carbon-based catalyst. When the metal-doped nitrogen-containing carbon-based catalyst is used as a cathode catalyst of a proton exchange membrane fuel cell and a direct-methanol fuel cell, the oxide reduction activity, stability and toxicity resistance are excellent; moreover, the catalyst has an environment-friendly effect, is low in cost, controllable in aperture, high in specific surface area and rich in resource and can substitute for platinum to serve as an electric catalyst of the proton exchange membrane fuel cell.

The invention provides a porous electrode for a flow battery and a preparation method of the porous electrode, and relates to the field of flow batteries. The preparation method comprises the following steps: S1, adding polyacrylonitrile and a metal salt into N, N-dimethylformamide or N, N-dimethylacetamide, carrying out heating and mixing until polyacrylonitrile and the metal salt are dissolved,so as to obtain an electrospinning stock solution; S2, carrying out electrostatic spinning by using the electrospinning stock solution to obtain an electrospun fiber membrane; S3, dissolving an organic ligand in a solvent to obtain an organic ligand solution, soaking the electrospun fibrous membrane in the organic ligand solution for a period of time, and generating MOF particles in situ on the surface of the electrospun fibrous yarn; and S4, carrying out pre-oxidation on the fibers with the MOF particles deposited on the surfaces, and then carrying out carbonization in an inert gas atmosphereto obtain the porous electrode. The porous electrode prepared in the invention has a large specific surface area, is helpful for reducing the activation loss of the battery and improving the performance of the battery, and can be suitable for various flow batteries.

A light emitting device comprises an n-type layer, a p-type layer, and an active region sandwiched between the n-type layer and the p-type layer, wherein the active-region has a wavy structure with nano or micro fluctuations in its thickness direction. The n-type layer comprises crystal facets on its upper surface, and the active-region is conformally formed on the upper surface of the n-type layer and substantially follows the shape of the crystal facets so as to form the wavy structure. A method for fabricating the same is also provided.

The invention belongs to the technical field of preparation of electrochemical sensors, and relates to a preparation method of a molecularly imprinted sensor based on a carbon quantum dot/a hollow nickel base material composite film modified glassy carbon electrode. The preparation method comprises the following steps of firstly depositing a Ni-Cu alloy layer in a three-electrode system, and thendealloying and removing copper to obtain a nano hollow nickel sphere layer; preparing an environment-friendly carbon quantum dot solution by adopting a biomass material, and modifying a glassy carbonelectrode coated with a nano hollow nickel sphere by using a composite solution of the carbon quantum dot and chitosan; and taking 3-aminophenylboronic acid as a functional monomer, and preparing themolecular imprinted sensor which has specific recognition response to the template molecular glucose on the surface of the glassy carbon electrode modified by a composite film through an electrochemical polymerization method. The preparation method of the molecularly imprinted sensor based on the carbon quantum dot/the hollow nickel base material composite film modified glassy carbon electrode provided by the invention effectively improves the active area and the electron transport performance. Combined with the molecular imprinting technology, the molecularly imprinted sensor with specific recognition response to glucose is prepared, and the molecularly imprinted sensor has the advantages of being simple in operation, low in cost, high in selectivity and sensitivity, and is expected to bepractical.

The invention discloses an iron-doped copper sulfide nanosheet material with rich defects and a preparation method and application thereof. The method comprises the following steps of adding a coppersalt solution into a thiourea solution, and rapidly forming a white floccule solution during stirring; mixing a ferrous salt solution with the white floccule solution under stirring, conducting stirring for 15 minutes, then transferring the solution into a reaction kettle, conducting a hydrothermal reaction for 12-15 hours at 140-160 DEG C, and conducting centrifugation, washing and drying to obtain the material. The iron-doped copper sulfide nanosheet material has the advantages that the iron-doped copper sulfide nanosheet material with the rich defects coats foamed nickel and serves as a working electrode material for electrolyzing water, the high stability and a large specific surface area are achieved, a larger activity area is provided, and therefore the water can be fast and efficiently electrolyzed.

A cathode assembly, a system including the cathode assembly, and method of using the assembly and system are disclosed. The cathode assembly includes high surface area material to allow efficient recovery of metal at reduced current densities at the cathode, which allows increased rates of metal recovery to be obtained, while maintaining desired properties of the electrowon metal.