35results about How to "Higher than capacitance" patented technology

The invention relates to a preparation method for a super capacitor, comprising the following steps: (1) placing a foam nickel substrate in a chemical gas phase deposition reacting furnace, introducing argon for 10-60 minutes, exhausting air in the furnace, then heating the furnace to 450-750 DEG C, introducing hydrocarbon gases in an argon atmosphere at a flow rate between 25ml/min and 40ml/min,reacting the mixture for 30 seconds to 50 minutes at a temperature of 450-750 DEG C, and obtaining foam nickel on which carbon nano tubes grow after finishing the reaction; (2) removing surface loosing layer products, directly using the foam nickel substrate on which the carbon nano tubes grow as electrodes of the super capacitor; and (3) drying the electrodes with same thickness and size, which are obtained from the step (2), fully soaking the electrode with electrolyte for 1-36 hours, separating a diaphragm soaked with the electrolyte and assembling the components to obtain the super capacitor; and the hydrocarbon gases are acetylene, methane, ethylene or propylene. The carbon nano tubes directly grow on the foam substrate without a binding agent; and the foam nickel is used as the substrate, the volume density of electrode substances is higher and holes are reasonably distributed.

The invention discloses graphene-based hydrogel and a preparation method thereof as well as a preparation method and an application of a supercapacitor electrode taking the graphene-based hydrogel as an active material, and relates to a graphene material and a preparation method thereof as well as a preparation method of a supercapacitor electrode. The invention aims at solving the technical problems that a conventional preparation method of the graphene-based hydrogel utilizes a toxic reducing agent and is complex in operation. The graphene-based hydrogel disclosed by the invention is hydrogel formed by graphene or graphene and an ungraphitised carbon material. The preparation method comprises the following steps of: after oxidizing graphite into graphite oxide, dispersing the graphite oxide separately or with the ungraphitised carbon material in water to obtain graphene-based colloidal dispersion through reduction; after rotary evaporation or rotary centrifugal treatment at reduced pressure, obtaining the graphene-based hydrogel through leaching or washing; and after coating the graphene-based hydrogel on an electrode current collector, immersing the electrode current collector in electrolyte for dipping to obtain the supercapacitor electrode which can be used as the anode and/or cathode of a supercapacitor.

The invention relates to a graphene for an electrical double-layer capacitor and a preparation method of the graphene. The preparation method of the graphene includes the steps that (1) graphite, potassium nitrate and potassium permanganate are weighted, mixed evenly and put into a reaction kettle, and concentrated sulfuric acid is weighed and added to the reaction kettle; (2) the reaction kettle in the step (1) is placed in a thermostat and is subjected to low temperature constant temperature oxidizing reaction, medium temperature constant temperature oxidizing reaction and high temperature constant temperature oxidizing reaction; (3) oxidizing agents are added to products obtained after reaction in the step (2) is finished, oxidizing reaction is conducted, and then products are subjected to acid pickling, washing and drying; (4) the products obtained in the step (3) are subjected to puffing and reduction in the air atmosphere, or are subjected to puffing and reduction in the high temperature inert atmosphere, and end products are obtained. The graphene can be used as electrode materials of the electrical double-layer capacitor or conductive additives of a lithium ion battery, the amount of layers of the graphene is less, the crystal structure is complete, the size is large, bend and drape exist in the microstructure, the agglomerated degree is small, the specific capacitance value is high, the process is simple, and the graphene is suitable for large scale production.

The invention discloses a preparation method of a flexible nano porous nickel/nickel oxide composite electrode plate. The method comprises the following steps: (1) preparing a Ni-Ti precursor amorphous alloy ribbon, selecting high-purity Ni and Ti metals according to the atomic percentage ratio of Ni to Ti being (35+x):(65-x), wherein x is 0 to 10, carrying out melting by an arc-melting furnace to prepare a Ni-Ti alloy ingot, removing a surface scale cinder of the Ni-Ti alloy ingot, and preparing the Ni-Ti amorphous alloy ribbon by vacuum melt-spinning equipment, so as to prepare the Ni-Ti amorphous alloy ribbon with the thickness of 25-30 microns; and (2) carrying out a free dealloying treatment on the Ni-Ti amorphous alloy ribbon obtained in the previous step in an acid etching solution at a room temperature for 40-100 minutes, and washing the obtained nano porous ribbon with deionized water, so as to obtain the nano porous nickel/nickel oxide composite electrode plate. The composite electrode material prepared by the method shows excellent flexibility and simultaneously has good electrochemical properties.

The invention provides an electrode material as well as a preparation method and the application thereof. The electrode material takes coal pitch as a carbon source, takes nano calcium oxide as a template agent and takes potassium hydroxide as an activating agent. The preparation method comprises the following steps: S1, weighing the raw materials in parts by mass; S2, grinding the raw materials into powder and mixing; S3, putting the mixed sample into a tubular furnace, and introducing inert gas; S4, heating and carbonizing; S5, performing acid pickling to remove nano calcium oxide; s6, washing with distilled water; S7, drying the electrode material. The electrode material prepared by the method has the characteristics of large specific surface area, proper pore size distribution range and high oxygen element content, so that the electrode material is high in specific surface area utilization rate, high in specific capacitance, high in energy density and good in cycle performance. Thematerial can be used as an electrode material for a supercapacitor.

The invention employs a hydrothermal and calcination combined method to prepare a dual-oxide/graphene nanometer composite electrode material. The material has excellent electrochemical and energy-storage performance, and belongs to the technical field of material preparation and energy storage. The method is characterized by comprising the steps of respectively weighing a certain amount of cobalt source precursor and an aluminum source precursor and weighing a certain volume of distilled water in a small beaker, continuously adding a certain volume of graphene aqueous dispersion liquid, performing ultrasound for 30 minutes, dropwise adding a certain volume of ammonia water during stirring on a magnetic agitator, taking out a magnet, transferring a mixed solution to a stainless steel high-pressure reaction kettle containing a polytetrafluoroethylene liner, sealing the high-pressure reaction kettle, placing the high-pressure reaction kettle in a baking oven with a certain temperature, taking out the high-pressure reaction kettle after 12 hours, naturally cooling to a room temperature, performing centrifugation to obtain a precipitant, respectively washing the precipitant with the distilled water and alcohol for three times, and performing calcination on the precipitant for 3 hours under 300 DEG C to finally obtain the product. By the method, a surfactant is not needed to be used, the material is synthesized by one step, is high in yield and simple in preparation process and is suitable for industrial production, the specific capacitance value of the composite material is 968F/g when scanning current density is 1 A/g, and the retention rate still reaches 85% or above after circulation for 1,000 times.

The invention provides a synthesis method of a cobalt-molybdenum bimetallic sulfide for a supercapacitor electrode material. The synthesis method comprises the following steps: mixing and dissolving acobalt salt and deionized water to obtain a solution A, mixing and dissolving a morphology regulator, tetrathiomolybdate and deionized water to obtain a solution B, mixing the solution A and solutionB in the same volume and performing a hydrothermal reaction, cooling after the reaction is completed, and washing and drying to obtain the cobalt-molybdenum bimetallic sulfide. According to the synthesis method of the cobalt-molybdenum bimetallic sulfide in the invention, the cobalt-molybdenum bimetallic sulfide prepared by combining the cobalt salt and the tetrathiomolybdate is used as an electrode material for a supercapacitor, and has high reversibility and excellent cycle stability. Meanwhile, the prepared cobalt-molybdenum bimetallic sulfide is a loose porous structure formed by the accumulation of nanoparticles, and the loose porous structure is conducive to the diffusion of electrolyte ions, can greatly increase the specific capacitance of the capacitor and has good electrochemicalperformance.

The invention discloses a preparation method for a polyaniline-coated graphene loaded copper-nickel solid solution composite material, and belongs to the technical field of electrode materials of supercapacitors. The invention solves the technical problem that the graphite oxide is not suitable for being used as the electrode material of the supercapacitor due to the defects of low specific capacitance value and the like. Firstly, a graphene/copper-nickel solid solution composite material is prepared by adopting a microwave method, and a polyaniline/graphene/copper-nickel solid solution core-shell type composite material is prepared by adopting an in-situ polymerization method. The graphene, the copper-nickel solid solution and the polyaniline in the polyaniline/graphene/copper-nickel solid solution composite electrode material prepared by adopting the in-situ polymerization method have a synergistic effect; when the doping amount of the graphene/copper-nickel solid solution is 20 wt%of polyaniline, the specific capacitance value is up to 674.7 F/g at the current density of 1 A/g.

The invention provides a preparation method of a sulfur-doped graphene-based super capacitor electrode material, and relates to a preparation method of an electrode material. The preparation method aims to solve the problem of an existing graphene surface modification technology or an existing limited improvement effect, or the problem that covalent binding can be easily formed because electronegativity of an existing doping element is quite different from electronegativity of a carbon atom. The method comprises adopting methane, an argon gas and a hydrogen gas to prepare a graphene material, coating a graphene surface by using a diebnzyl disulfide solution, placing the coated graphene material into a quartz tube, and performing annealing processing in argon atmosphere. The preparation method is used in preparation of the sulfur-doped graphene-based super capacitor electrode material.

The invention relates to the technical field of electrode material preparation, and particularly discloses a tobacco stem activated carbon-NiCo2S4 composite electrode material and a preparation method thereof. The method comprises the following steps: firstly, preparing a tobacco stem-based activated carbon electrode material from tobacco straws, adding the tobacco stem-based activated carbon electrode material into an aqueous solution containing Co(NO3)2.6H2O, Ni(NO3)2.6H2O, hexamethylenetetramine and urea, uniformly stirring, reacting at 160-200 DEG C for 18-30 hours, separating solids to obtain grey blue powder, putting the grey blue powder into a Na2S solution, and reacting for 12-48 hours at a temperature of 100-300 DEG C to obtain the tobacco stem activated carbon-NiCo2S4 composite electrode material. The tobacco stem activated carbon-NiCo2S4 composite electrode material prepared by the method provided by the invention has excellent specific capacitance value and specific capacitance retention rate.

The invention discloses an amination-acidification modified activated carbon material. The amination-acidification modified activated carbon material is obtained by virtue of an amination process and an acidification process, namely a polymerization reaction is carried out on phenylamine on the surface of activated carbon, so as to generate polyaniline, then functional groups rich in N are formed on the surface of carbon through high temperature treatment, and finally an acidification reaction is carried out with nitric acid and then the functional groups rich in O are formed on the surface of the activated carbon. The obtained modified activated carbon material has the advantages that rich nitrogenous and oxygenous functional groups are formed on the surface, so that faradaic pseudocapacitance of the modified activated carbon material is increased, specific capacitance of the modified activated carbon material is greatly increased, ash composition in the original activated carbon is effectively removed, self discharge of the activated carbon is reduced, and electrochemical performance of the activated carbon is improved.

The invention discloses a preparation method of a biomass-based electrode material. The method specifically comprises the following steps: grinding and sieving dry locusts and potassium hydroxide, uniformly mixing, putting the mixed sample into a tubular furnace, and heating and carbonizing under the protection of inert gas; and crushing the carbon material, carrying out acid washing and water washing to be neutral, and drying to obtain the biomass-based electrode material, wherein the electrode material can be applied to supercapacitors. The electrode material prepared by the method has the characteristics of large specific surface area, reasonable pore size distribution and high heteroatom content, has good water wettability, is easy to infiltrate by electrolyte, further has high specific capacitance, high energy density and good cycle performance, and has a wide application prospect in the field of supercapacitor electrode materials.

The invention discloses a preparing method for a graphite composite film. The preparing method includes the steps that a zeolite suspension is prepared and includes nano zeolite particles with the concentration being 250 ppm to 300 ppm and the particle size being 90 nm to 180 nm; a graphite suspension is prepared and includes graphite oxide with the concentration being 150 ppm to 300 ppm; an alkaline reagent is added into the graphite suspension, and then the graphite suspension containing the alkaline reagent is oscillated under the temperature ranging from 150 DEG C to 190 DEG C; the reducedgraphite suspension and the reduced zeolite suspension are mixed according to the volume ratio being 1:1 to 2:1, and a surface active agent is added to form a mixed solution; the mixed solution is reduced; the reduced mixed solution is atomized, and multiple atomized liquid drops re formed; an electrode is used for treating the multiple atomized liquid drops so that the multiple atomized liquid drops can carry charges; and the atomized liquid drops with the charges are deposited on a base plate, and the temperature of the base plate ranges from 400 DEG C to 650 DEG C.