Abstract: A dye-sensitized solar cell comprising a semiconductor electrode prepared by spraying a metal oxide nanoparticle dispersion on a conductive substrate using an electric field to form a metal oxide nanoball layer which is composed of agglomerated metal oxide nanoparticles and has a high porosity and specific surface area, exhibits improved photoelectric properties even when a gel or solid electrolyte is used.

Abstract: The present invention provides a gas sensor, including: a sensor substrate provided with an electrode; and a thin layer of sensor material formed by spraying a solution in which metal oxide nanoparticles are dispersed onto the sensor substrate. The gas sensor is advantageous in that a sensor material is formed into a porous thin layer containing metal oxide nanoparticles having a large specific surface area, thus realizing high sensitivity on the ppb scale and a high reaction rate. Further, the gas sensor is advantageous in that it can be manufactured at room temperature, and the thickness of a sensor material can be easily adjusted by adjusting the spray time, so that a thin gas sensor or a thick gas sensor can be easily manufactured.

Abstract: The present invention discloses an improved electrode for a supercapacitor and a method of preparation thereof. The inventive electrode comprises a collector, a carbon substrate disposed on the collector comprising ultrafine carbon fibers having a specific surface area of at least 200 m2/g (BET) and a d002 value of 0.36 nm or less, and a metal oxide thin layer formed on the carbon substrate. The electrode of the subject invention retains a high specific capacitance during high-speed charging and discharging cycles.

Abstract: An ultrafine fiber-based composite separator comprising a fibrous porous body which comprises ultrafine metal oxide/polymer composite fibers, or ultrafine metal oxide fibers and a polymer resin coating layer formed on the surface thereof, the ultrafine fibers being continuously randomly arranged and layered, and obtained by electrospinning a metal oxide precursor sol-gel solution or a mixture of a metal oxide precursor sol-gel solution and a polymer resin solution, wherein the surface of the metal oxide/polymer composite fibers has a uniform mixing composition of the metal oxide and the polymer resin, in which the separator has a heat shrinkage rate at 150˜250° C. of 10% or less and does not break down due to melting at a temperature of 200° C. or lower, has low heat shrinkage rate, and superior heat resistance and ionic conductivity, being capable of providing improved cycle and power properties when used in manufacturing a battery.

Abstract: Disclosed is: a single crystalline silicon carbide nanofiber having improved thermal and mechanical stability as well as a large specific surface area which is applicable to a system for purifying exhaust gas, silicon carbide fiber filter, diesel particulate filter having a high temperature stability and may be used in the form of nanostructures such as nanorods and nanoparticles.

Abstract: An ultrafine continuous fibrous ceramic filter, which comprises a filtering layer of a fibrous porous body, wherein the fibrous porous body comprises continuous ultrafine fibers of metal oxide which are randomly arranged and layered, and powdery nano-alumina incorporated into the ultrafine fibers or coated thereon, the ultrafine fibers being obtained by electrospinning a spinning solution comprising a metal oxide precursor sol-gel solution, and optionally, a polymer resin, and sintering the electrospun fibers, in which the ultrafine fibers have an average diameter of 10˜500 nm, and the fibrous porous body has a pore size of maximum frequency ranging from 0.05 to 2 ?m, exhibits high filtration efficiency at a high flow rate, and can be regenerated.

Abstract: There is provided a metal oxide having a continuous nano-fiber network structure as a negative active material for a secondary battery. A method for fabricating such negative active material for a secondary battery comprises spinning a mixed solution of a metal oxide precursor and a polymer onto a collector to form composite fibers mixed with the metal oxide precursor and the polymer, thermally compressing or thermally pressurizing the composite fibers, and thermally treating the thermally compressed or thermally pressurized composite fibers to remove the polymer from the composite fiber.

Abstract: The present invention relates to a white and color photoexcitation light emitting sheet comprising a substrate, a light source formed on the substrate, and a white and color photoexcitation light emitting layer capable of converting a light emitted from the light source into a light having a different wavelength, where the white and color photoexcitation light emitting layer is fabricated by mixing a matrix polymer, white and color photoexcitation light emitting materials and a solvent, spinning the resulting mixture to prepare an ultrafine composite fiber layer of the matrix polymer/photoexcitation light emitting materials, and thermocompressing the ultrafine composite fiber layer; and a method for fabrication thereof. The white and color photoexcitation light emitting sheet according to the present invention has uniform brightness and color coordinates and exhibits high color reproducibility.

Abstract: The present invention discloses an ultrafine graphitic carbon fiber and a preparation method thereof. An ultrafine fiber having a diameter of 1 to 3000 nm is prepared by electrospinning a halogenated polymer solution containing a metal compound inducing graphitization. In carbonization, an ultrafine porous graphitic carbon fiber having a large specific surface area, micropores and macropores is prepared by the graphitization by a metal catalyst generated from the metal compound. The ultrafine carbon fiber can be used as a carbon material for storing hydrogen, an adsorbing material of biochemically noxious substances, an electrode material of a supercapacitor, a secondary cell and a fuel cell, and a catalyst carrier material.

Abstract: A complex membrane for an electrochemical device such as a lithium secondary battery, its manufacturing method, and an electrochemical device having the complex membrane are disclosed. The complex membrane includes a micro-porous polyolefin membrane, and a web-phase porous membrane united to at least one side of the micro-porous polyolefin membrane and composed of nano-fibers. Since the complex membrane is capable of absorbing an electrolyte uniformly, it greatly improves performance of a battery when being used for an electrochemical device. In addition, owing to excellent mechanical strength and good binding capacity to an electrode, it helps to increase a process rate for manufacturing the battery.

Abstract: Disclosed are a graphene composite nanofiber and a preparation method thereof. The graphene composite nanofiber is produced by dispersing graphenes to at least one of a surface and inside of a polymer nanofiber or a carbon nanofiber having a diameter of 1˜1000 nm, and the graphenes include at least one type of monolayer graphenes, and multilayer graphenes having a thickness of 10 nm or less. The graphene composite nanofiber can be applied to various industrial fields, e.g., a light emitting display, a micro resonator, a transistor, a sensor, a transparent electrode, a fuel cell, a solar cell, a secondary cell, and a composite material, owing to a unique structure and property of graphene.

Abstract: A polyolefin separator having an heat-resistant ultrafine fibrous layer and a secondary battery using the same, in which the separator has a shutdown function, low thermal contraction characteristics, thermal endurance, excellent ionic conductivity, excellent cycling characteristics at the time of battery construction, and excellent adhesion with an electrode. The present N invention adopts a very simple and easy process to form an ultrafine fibrous layer through an electrospinning process, and at the same time, to remove solvent and to form pores. Accordingly, the separator of the present invention is useful particularly for electrochemical devices used in a hybrid electric automobile, an electric automobile, and a fuel cell automobile, requiring high thermal endurance and thermal stability.

Abstract: A heat-resisting ultrafine fibrous separator of the present invention is prepared by an electrospinning process, formed of ultrafine fibers of heat-resisting polymer resin having a melting point more than 1800 C or not having the melting point, or ultrafine fibers of polymer resin capable of swelling in an electrolyte, together with the ultrafine fibers of heat-resisting polymer resin. Also, polyolefine fine particles providing a shutdown function are dispersed in the heat-resisting resin or the polymer resin capable of swelling in the electrolyte. The heat-resisting ultrafine fibrous separator of the present invention has the shutdown function, low thermal contraction, thermal endurance, excellent ionic conductivity and excellent adhesive property with an electrode, so a battery having excellent cycling characteristics, and having high-energy density and high capacity can be prepared.

Abstract: A dye-sensitized solar cell comprising a semiconductor electrode comprising electrospun ultra-fine titanium dioxide fibers and fabrication method thereof are disclosed. The dye-sensitized solar cell comprises a semiconductor electrode comprising an electrospun ultra-fine fibrous titanium dioxide layer, a counter electrode and electrolyte interposed therebetween. A non-liquid electrolyte such as polymer gel electrolyte or the like having low fluidity, as well as the liquid electrolyte, can be easily infiltrated thereinto. In addition, electrons can be effectively transferred since titanium dioxide crystals are one-dimensionally arranged.

Abstract: Disclosed are to provide a modified carbon nanotube obtained by reacting a polymer to a carbon nanotube by a radical graft method, capable of minimizing lowering of a physical property of a carbon nanotube caused when being modified, and capable of enhancing dispersibility of the carbon nanotube and an adhesion strength between carbon nanotubes, the polymer having a molecular weight controlled by a living radical polymerization and still having a living radical end group.

Abstract: A dye-sensitized solar cell comprising a semiconductor electrode prepared by spraying a metal oxide nanoparticle dispersion on a conductive substrate using an electric field to form a metal oxide nanoball layer which is composed of agglomerated metal oxide nanoparticles and has a high porosity and specific surface area, exhibits improved photoelectric properties even when a gel or solid electrolyte is used.

Abstract: A supercapacitor having a metal oxide electrode and a method for preparing the same. The method comprises preparing a substrate composed of a current collector and a titanium dioxide ultrafine fiber matrix layer formed on the current collector, and electrochemically depositing a metal oxide thin film layer onto the substrate by a constant current potentiometry or a cyclic voltammetric method. Since the metal oxide is uniformly deposited on the substrate having a wide specific surface area with the titanium dioxide ultrafine fiber, a bonding material or a conductive particle need not to be added to the capacitor electrode. Therefore, a resistance of the capacitor electrode is prevented from being increased, and thus a capacitance of the capacitor electrode is prevented from being decreased.

Abstract: Disclosed is a method for fabricating a carbon material, by which carbon fibers or carbon tubes, particularly branched carbon fibers or carbon tubes, are obtained via a so-called self-growing process without using external carbon sources. The carbon material obtained by the method has a large specific surface area and further includes a metal catalyst, and thus may be used in cell materials for a fuel cell or secondary battery, hydrogen storage devices, capacitors, solar cells, display panel or the like.

Abstract: The present invention relates to a porous conducting metal oxide electrode prepared by depositing a porous conducting metal oxide film comprising a conducting metal oxide film layer having a network structure of nanofibers, comprising nanograins or nanoparticles, on at least one surface of a current collector, and a conducting metal oxide coating layer on the network layer of the porous conducting metal oxide through the constant current method or the cyclic voltammetric method, and a high-speed charge/discharge and ultrahigh-capacity supercapacitor using the porous conducting a metal oxide electrode.

Abstract: A method for fabricating an ultra-sensitive metal oxide gas sensor is disclosed, which comprises the steps of spinning a mixture solution including a metal oxide precursor and a polymer onto a sensor electrode to form a metal oxide precursor-polymer composite fiber; thermally compressing or thermally pressurizing the composite fiber; and thermally treating the thermally compressed or thermally pressurized composite fiber to remove the polymer from the composite fiber. Since the gas sensor includes a macro pore between nanofibers and a meso pore between nano-rods and/or nano-grains, gas diffusion and surface area can be maximized. Also, the ultra-sensitive sensor having high stability in view of mechanical, thermal, and electrical aspects can be obtained through rapid increase of adhesion between the metal oxide thin layer and the sensor electrode.