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 discloses a preparation method for cicada slough based porous carbon material capable of being used for an electrochemical capacitor. Cicada slough is adopted as a carbon source, an alkaline metal hydroxide is adopted as an activating agent, and the two steps of medium-temperature pre-carbonation and high-temperature activation are carried out, so that the cicada slough based porous carbon material for a high-performance supercapacitor is prepared; the prepared carbon material has the characteristics such as higher specific capacitance value, better cycle performance and higher multiplying power in a water system electrolyte, for example, in a 6.0 M KOH electrolyte, the weight specific capacitance value of the carbon material can reach 355 Fg<-1>, 288 Fg<-1> and 283 Fg<-1> respectively under the electric current density of 1 Ag<-1>, 10 Ag<-1> and 30 Ag<-1>, and after the carbon material is charged and discharged in a circulating manner for 3000 times under the condition of 10 Ag<-1>, the capacitance retention value of the carbon material is still 90% or above of the original value. According to the invention, biomass materials are fully utilized, the cost is low, the sources are wide, the preparation technology is simple, and the prepared porous carbon material has large specific surface area and excellent electrochemical capacitor performance, and has wide application prospect in the field of electrochemical energy storage.

The invention relates to a high-density graphene material and a preparation method thereof and application of the high-density ordered graphene into supercapacitors, in particular to a high-density ordered graphene with ion spacer layers and a preparation method and application of the high-density ordered graphene and aims to solve the technical problem of low volumetric specific capacitance and low density of existing graphene. The high-density ordered graphene with the ion spacer layers has graphene lamination layers in ordered parallel arrangement, alkali metal ions are embedded among the graphene lamination layers to form the spacer layers, and the high-density ordered graphene is porous high-density graphene. The preparation method of the high-density graphene material includes: subjecting oxidized graphene aqueous dispersion to reduction in an alkaline reduction medium, and directly coating graphene aqueous dispersion onto a current collector after lavation to make a film or grind into powder after drying. The high-density ordered graphene has the advantages of high density, high volumetric specific capacitance, high rate capability and long cycle life and is applicable to electrode active materials of supercapacitors.

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 relates to a method for preparing copper-doped activated carbon by utilizing a chemical complexing process, and belongs to the technical fields of chemical industry and environmental protection. The method comprises the following steps of functionalizing nitrile groups of a polyacrylonitrile copolymer serving as a raw material by using hydroxylammonium chloride to obtain a product containing a great number of amino groups and hydroxyl groups, chemically complexing the product and a copper ion aqueous solution to obtain copper-doped polyacrylonitrile, and activating copper-doped polyacrylonitrile under different conditions by using potassium hydroxide as an activator to obtain the copper-doped activated copper. The method has the advantages that polyacrylonitrile is used as the raw material, and the nitrile groups of polyacrylonitrile can be effectively and conveniently functionalized; a chemical complexing method is adopted, so that the activated carbon can be efficiently and uniformly doped with copper; in addition, the method has the advantages of simplicity in an operation process, less environmental pollution and the like; compared with an activated carbon material, the copper-doped activated carbon has high specific capacitance, and can be used for a capacitor electrode material.

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.

A method for making activated carbon materials for organic supercapacitors from straws, characterized in that crop straws are selected as raw materials, and the activated carbon materials for organic supercapacitors are obtained through the process steps of drying and crushing, carbonization, and activation in sequence. The activated carbon prepared by the method of the present invention has a large specific surface area, and when 1.2mol / l MeEt3NBF4 / AN is used as the electrolyte, the cyclic voltammetry test is carried out, and the specific capacitance is 232F / g at 2mv / s, which is suitable as an electrode material for organic supercapacitors .

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 provides a method for synthesizing cobalt molybdate for a supercapacitor electrode material. The synthesizing method comprises steps of s1, mixing and dissolving a cobalt salt and deionized water to obtain a solution A; s2, mixing and dissolving a shape modifier, molybdate and deionized water, and then adding an acid-base modifier to adjust the mixture to be neutral to obtain a solution B; and s3, mixing the solution A and the solution B having the same volume for a precipitation reaction, and cooling the mixed solution after the precipitation reaction is completed, and washing and drying and the mixed solution to obtain the cobalt molybdate. The method for synthesizing the cobalt molybdate, by means of the characteristic that the molybdate has various oxidation statess and low-point conversion reactions, uses the cobalt molybdate obtained by combining the cobalt salt with the molybdate as a capacitor electrode material so as to achieve high reversibility and excellent cycle performance and stability. The prepared cobalt molybdate is a petal-like sheet structure and has large specific surface area, so that the specific capacitance of a capacitor can be greatly increased and good electrochemical performance can be achieved.

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 discloses a porous carbon material based on a nitrogen-rich covalent organic framework structure and a preparation method and application of the porous carbon material. A nitrogen-rich covalent organic framework material LNUs is prepared through a Friedel-Crafts coupling reaction of a carbazole-containing organic monomer and cyanuric chloride, and the nitrogen-rich covalent organic framework material LNUs is directly carbonized at a high temperature as a precursor to obtain the porous carbon material. According to the method, the raw materials are easy to obtain, the preparation process is simple and reliable, the obtained precursor LNUs framework is rich in nitrogen, the porous carbon material obtained by carbonizing the precursor LNUs framework can be directly used as an electrode material of a supercapacitor, the specific capacitance value of the porous carbon material reaches up to 402F / g, excellent electrochemical performance is shown, and the porous carbon material has a very good application prospect in the field of energy storage.

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.

High-density ordered graphene with an ion spacer layer and its preparation method and application, which relate to a high-density graphene material, its preparation method and its application in supercapacitors. The invention aims to solve the technical problems of low density and low volume specific capacitance of the existing graphene. The high-density ordered graphene with an ion spacer layer of the present invention has graphene sheets arranged in parallel in an orderly manner, and alkali metal ions are embedded between the graphene sheets to form a spacer layer, which is high-density graphene containing pores. Preparation method: reduce the graphene oxide aqueous dispersion in an alkaline reducing medium, and after washing, apply the graphene hydrogel directly on the current collector to form a thin film or grind it into a powder after drying. The material has high density, high volume specific capacitance, high rate performance and long cycle life. Electrode active materials that can be used in supercapacitors.

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 present invention is a kind of preparation method of flexible nano-porous nickel / nickel oxide composite electrode sheet, and the method comprises the following steps: the first step, prepare Ni-Ti precursor amorphous alloy strip, according to atomic percentage Ni:Ti=( 35+x): (65‑x), wherein, x=0~10, select high-purity Ni and Ti metals, and then smelt Ni‑Ti alloy ingots with electric arc melting furnaces; then Ni‑Ti alloy ingots Remove the superficial oxide skin, and use vacuum strip equipment to prepare Ni-Ti amorphous alloy thin strips to obtain Ni-Ti amorphous alloy thin strips with a thickness of 25-30 µm; in the second step, the Ni-Ti amorphous alloys obtained above are The strip is placed in an acidic corrosion solution at room temperature for free dealloying for 40-100 minutes, and then the obtained nanoporous thin strip is rinsed with deionized water to obtain a nanoporous nickel / nickel oxide composite electrode sheet. The composite electrode material prepared by the invention exhibits excellent flexibility and good electrochemical performance.

The invention relates to a nano-porous copper silver supported manganese dioxide electrode slice and a preparation method therefor. The cross section of the electrode slice comprises three layers. A middle core layer is an amorphous matrix. The other two sides are nano-porous copper silver. A hole wall and a surface of the nano-porous copper silver grow a layer of uniform thin manganese dioxide. The thickness of the electrode slice is about 25-35 mum. The thickness of an inside amorphous matrix layer is about 12-28 mum. The thickness of a single side of nano-porous copper silver or manganese dioxide composite electrode material layer is about 3-11 mum. The amorphous matrix comprises CuxZryAgz alloy components, wherein x is greater than or equal to 40 and less than or equal to 45, y is greater than or equal to 45 and less than or equal to 50, z is greater than or equal to 5 and less than or equal to 15, and x plus y plus z equals 100. The preparation method can realize independent support of the electrode slice. Compared with a conventional complicated process of flaking the electrode slice, the preparation method saves the step of adding substances such as a conductive agent, a binder and so on, thereby overcoming the defects in the prior art that active substances have poor dispersibility, are easy to fall off and have small effective specific surface area.

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.

The invention discloses a preparation method of a polyaniline / carbon nano tube / nano-copper composite material, relates to a preparation method of the polyaniline / carbon nano tube composite material, and aims at solving the problems that the existing polyaniline / carbon nano tube composite material is low in electric conductivity and low in capacitance. The method is implemented as follows: firstly, putting a carbon nano tube into mixed acid, conducting backflow processing on the carbon nano tube and then conducting vacuum drying; secondly, acidizing the carbon nano tube, adding the acidized carbon nano tube into copper sulfate solution, adding NaOH solution and hydrazine hydrate solution respectively, heating, and then conducting vacuum drying to obtain nano copper / carbon nano tube composite powder; adding the nano copper / carbon nano tube into mixed solution of aniline and hydrochloric acid, then dropping ammonium persulfate solution, heating and conducting vacuum drying to obtain the polyaniline / carbon nano tube / nano-copper composite material. According to the preparation method, the size of the nano copper particles is 5-15nm, surface active agent is not needed, the nano copper can be prevented from being oxidized, the electric conductivity of the composite electrode materials is improved, the specific capacitance value is improved, and the preparation method is applied to the field of capacitor electrode materials.

The invention relates to a method for improving carbide derived carbon super capacitor performance. The method mainly comprises steps that firstly, acid solution of nitric acid and hydrofluoric acid is prepared according to a mole proportion of MHNO3:MHF of 1:2-2:1, secondly, to-be-treated carbide derived carbon is completely dipped into the acid solution, through ultrasonic concussion, air left on the carbide derived carbon is removed, under the 25-40 DEG C environment temperature, standing dipping for 48-264 hours is carried out, and lastly, washing is carried out till neutral property is realized, drying is then carried out, treatment on the carbide derived carbon is accomplished. The method is advantaged in that the method is simple and easy, cycle utilization of the acid solution can be realized, a raw material utilization rate is high, on the condition that excellent power characteristics of the carbide derived carbon and double electric layer characteristics are kept, a specific capacitance value is substantially improved, and excellent super capacitor performance is presented.

The invention discloses a method for preparing a nitrogen-containing porous carbon / manganese dioxide nanowire composite electrode for a supercapacitor, which uses nitrogen-containing biomass carbon and manganese dioxide as raw materials to prepare the electrode. First, manganese dioxide nanowires are synthesized by hydrothermal method, and then manganese dioxide nanowires, nitrogen-containing biomass carbon and silicon dioxide are mixed, followed by high-temperature carbonization and alkali etching, and finally a composite electrode material is formed. The prepared composite electrode material has a high specific capacitance value, at 2mol / L Ca(NO 3 ) 2 In the electrolyte, the specific capacity can reach up to 357.5F / g, and it has excellent cycle stability. After 5000 cycles, the specific capacity can still maintain 97.2%. The biomass carbon used in the invention is a renewable resource, and the manganese dioxide is an environment-friendly raw material, both of which have the characteristics of abundant raw materials and low cost. The composite electrode for supercapacitor prepared by the invention has excellent performance and simple operation, and can meet the application requirements of energy storage.

The invention discloses a preparation method of porous carbon and a product thereof. The preparation process of the method comprises the following steps: uniformly mixing a biomass carbon source, a structure-directing agent and water to obtain mixed liquor; carrying out a hydrothermal reaction; cooling, washing, drying and calcining to obtain the porous carbon, wherein the mass ratio of the structure-directing agent to the biomass carbon source is 1:5000-1:50; the structural guiding agent is ionic polyelectrolyte. The invention further discloses porous carbon prepared by using the method. The particle diameter of the porous carbon is 50-100 nanometers, the BET specific surface area is 1000-2000m<2> / g, the BJH beverage aperture is 2-10 nanometers, the pore volume is 0.8-1.2cm<3> / g, and meso pores account for 50-70 percent of the total pore volume. A super capacitor manufactured by taking the porous carbon as an electrode material has the advantages of high activity, low resistance and large specific capacitance, and the maximum specific capacitance value can be up to 223F / g.

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 present invention provides a method for preparing a polyaniline / RuO2 / SnO2 composite electrode material, including: sputtering a SnO2 film onto a tantalum substrate by a magnetron sputtering method, to form a SnO2 layer; preparing porous-structured RuO2 nanoparticles with a uniform pore size distribution (10-15 nm) by a template method; and embedding polyaniline into the RuO2 nanoparticle matrix by a electrodeposition method, to finally obtain a multilayer-structured polyaniline / RuO2 / SnO2 composite electrode material with a specific capacitance value of 680-702 F·g−1 and an excellent cycling charge-discharge performance after it is assembled into an electrochemical capacitor.