34results about How to "Capacitive increase" patented technology

The invention relates to a nano-nickel oxide / graphene composite material and a preparation method thereof. The composite material is characterized in that: nickel oxide nano-particles uniformly grow on two sides of single-layer graphene to form a novel quasi-two-dimensional composite nano-material. The graphene serving as a substrate frame has good conductivity, and excellent conductivity among the nickel oxide particles is realized through the graphene substrate, so that the apparent electric conductivity of the composite material is improved. The sizes of the nickel oxide nano-particles growing on the graphane flake are between 1 and 10 nanometers; the plane size of the composite graphene nano-flake is between 0.1 and 100 microns, and the thickness of the composite graphene nano-flake is between 1 and 20 nanometers; and the weight percentage of the nickel oxide in the composite material is between 60 and 95 percent. The preparation method comprises two typical steps of: preparing a nano-nickel oxide / graphene precursor material by adopting a chemical solution method; and sintering to form a phase at high temperature in protection of an inert gas. The nano-nickel oxide / graphene composite material prepared by the method has high single electrode capacitance and good circulating performance, and is suitable for electrode materials of super capacitors.

The invention discloses a preparation method and application of a heteroatom-doped porous carbon nano-tube in the technical field of the inorganic carbon nano industry. The carbon nano-tube prepared by using a polyphosphazene nano-tube as a precursor has relatively large specific surface area, and abundant mesoporous structures are formed on the tube wall of the carbon nano-tube. According to the invention, the preparation process is simple in technology and high in yield; the prepared carbon nano-tube is regular in shape and appearance and high in heteroatom content, and has good capacitive performance when being used as an electrode material of a super-capacitor. Charge and discharge tests show that a sample subjected to carbonization at 900 DEG C has the specific capacity of 190F / g and excellent cycling stability.

The invention provides an activated graphene sheet and a preparation method thereof. The preparation method of the activated graphene sheet comprises the steps of adding sulfuric acid, nitric acid and potassium permanganate to carry out intercalation treatment on a graphene sheet serving as a raw material and then carrying out KOH activation process. The activated graphene sheet disclosed by the invention has the advantages of good conductivity, large specific surface area, high mesopore content, less impurities, low production cost, low equipment investment, simple operation, excellent electrochemical properties and good physical and chemical stabilities and can be put into industrialization easily.

The invention discloses a Ni-Co-S loaded porous carbon material based on yeast cells. The preparation method comprises the following steps: preparing carbonized yeast cell porous carbon, carrying outhydrothermal reaction on the carbonized yeast cell porous carbon, cobalt nitrate, nickel nitrate and urea, and oxidizing and vulcanizing to obtain the material, the obtained material is of a core-shell structure, and cobalt and nickel elements are uniformly loaded on the surface of the yeast cell porous carbon in the form of NiCo2S4; wherein the shell-core structure is formed by carbonizing ellipsoidal single-cell fungal yeast, and carbonized yeast cells are of a hollow carbon sphere structure. The preparation method comprises the following steps: 1) preparing yeast cell porous carbon; 2) adsorbing cobalt-nickel metal ions by yeast cell porous carbon; and 3) vulcanizing the yeast cell porous carbon adsorbing the cobalt-nickel metal ions. When the material is used as a supercapacitor, the material is charged and discharged in a range of-0.2 to 0.5, and when the discharge current density is 1 A / g, the specific capacitance is 700 to 800 F / g. The invention has the following advantages: noharm is caused to human body; and the tolerance problem of the yeast cell metal salt solution is solved.

The invention relates to a nickel cobaltate-graphene composite material and a preparation method thereof. The composite material comprises graphene and nickel cobaltate, wherein nickel cobaltate nanowires are uniformly grown on a graphene sheet, the wire length of the nickel cobaltate nanowires is 50-300nm, and the wire width is 5-30nm. The preparation method comprises the following steps of: taking a graphene oxide water solution and a cobalt salt and nickel salt water solution which are dispersed in an ultrasonic manner, mixing, further adding a precipitator, uniformly stirring and mixing, transferring into a high-temperature reaction kettle, performing hydro-thermal reaction for a certain period of time, filtering, washing and drying an obtained product, and further performing thermal treatment so as to obtain the nickel cobaltate nanowire-graphene composite material. The nickel cobaltate nanowire-graphene composite material prepared by the method disclosed by the invention has the advantages of high single-electrode capacitance and good cycle performance, and is suitable for being used as an electrode material of a super-capacitor.

The invention provides a cobalt sulfide / g-C3N4 composite electrode material with a two-dimensional hollow nano-sheet structure and a preparation method thereof. The invention provides the preparationmethod of the cobalt sulfide / g-C3N4 with the two-dimensional hollow nano-sheet structure. Specifically, g-C3N4 is added into a reaction solution containing a cobalt salt, C4H6N2 and a solvent, cobaltions react with C4H6N2 to form a two-dimensional nano-sheet precursor in situ on the g-C3N4, then a sulfur source is added, and the cobalt sulfide / g-C3N4 composite electrode material with the two-dimensional hollow nano-sheet structure is obtained through hydrothermal reaction. The preparation process of the material is simple, the cost is low, and no pollution is caused. The composite electrode material can increase the contact area between an electrolyte solution and an electrode material, shorten the ion transmission path, accelerate the ion transmission rate and increase the conductivity.As the electrode material of a supercapacitor, the material has excellent specific capacitance and cycle stability.

The invention relates to a porous grapheme / MnO2 composite film and a preparation method and application thereof. The preparation method comprises the following steps of (1), providing a ball-shaped formwork and coating the surface of the ball-shaped formwork with a polymer layer; (2) providing graphene oxide solution, evenly mixing a small formwork ball coated with the polymer layer obtained in the step (1) with the graphene oxide solution, performing vacuum filtration, and stripping the composite film from a filter membrane after drying; (3) performing high temperature annealing on the composite film obtained in the step (2) to obtain a film of a porous structure; (4) putting the film obtained in the step (3) into potassium permanganate solution to perform hydrothermal reaction to obtain the porous grapheme / MnO2 composite film. No any binder or conductive agent is needed to be added to the porous composite film prepared by the method, and the porous composite film is good mechanical property and super capacitive performance, has the advantages of being good in high-rate charge and discharge performance, long in circle life and the like, and can be applied to preparing super-capacitors and improve performance of super-capacitors greatly.

The invention relates to a method for synthesizing monolayer manganese dioxide nanosheet by one step, belonging to the technical field of controllable synthesis and appearance control of transition metal oxide nano materials. According to the method, hypermanganate is subjected to in-situ reduction through one step reaction of hypermanganate in acid alkyl sulfate surfactant water solution and utilizing corresponding alcohol generated by hydrolyzing the alkyl sulfate surfactant to produce manganese dioxide. Compared with the method in which the reducing agent alcohol is directly added, according to the method, the generation speed of manganese dioxide is effectively controlled through hydrolysis of the surfactant step by step, and the surfactant is also used as a structural induction reagent, so that the monolayer manganese dioxide nanosheet is prepared by one step. The prepared monolayer manganese dioxide nanosheet has excellent electrochemical capacitive performance, and can be widely used in the fields of batteries, sensing, catalysis and the like.

The invention discloses a preparation method and an application of an MXene derivative / metal nano composite material. The preparation method comprises the following steps: dispersing MXene Ti3C2 and H2O2 in a KOH solution, magnetically stirring, and transferring into a high-pressure kettle for a hydrothermal reaction at 140 DEG C for 12 hours; washing with deionized water, and carrying out vacuum drying to obtain a MXene derivative (AMX); mixing an AMX powder, metal salt M and polyvinylpyrrolidone k-30, dispersing in ethylene glycol, magnetically stirring, transferring into the high-pressure kettle, and carrying out hydrothermal treatment at 160 DEG C for 3 hours; and washing a product with deionized water, and carrying out vacuum drying to obtain the MXene derivative / metal nano composite material. The MXene derivative / metal composite material is synthesized in one step through a hydrothermal method and used as an electrode material of a supercapacitor, good electrochemical energy storage characteristics are achieved, and the preparation method is simple in process, low in cost, environmentally friendly, high in repeatability, capable of achieving large-scale preparation and the like.

The invention discloses a preparation method of N-doped carbon nanotube / nickel cobalt oxide / N-doped porous carbon. The method comprises the steps of (1) adding coal-based polyaniline to a nickel acetate solution to obtain paste A; (2) adding the coal-based polyaniline to a cobalt oxalate suspension to obtain paste B; (3) pyrolyzing the paste A; (4) pyrolyzing the paste B; (5) mixing products, which are collected through twice pyrolysis, on a quartz plate evenly and marking quartz plate products; (6) mixing a quartz boat product A, a quartz boat product B and the quartz plate products evenly toobtain mixed powder; (7) carrying out hydrothermal reaction to obtain a black sediment; and (8) washing, drying and burning to obtain N-doped carbon nanotube / nickel cobalt oxide / N-doped porous carboncomposite powder. The prepared N-doped carbon nanotube / nickel cobalt oxide / N-doped porous carbon composite powder has relatively low internal resistance and charge transfer resistance, relatively high specific capacitance and relatively good rate characteristics and cycling stability.

The invention relates to a preparation method and application of a graphene nickel foam electrode. The preparation method comprises the steps of cleaning and drying nickel foam as a working electrode,carrying out scanning in a graphene oxide dispersion liquid by using a cyclic voltammetry to prepare a graphene oxide nickel foam electrode; and drying and then carrying out constant-potential reduction in a glycine-hydrochloric acid buffer solution to obtain the graphene nickel foam electrode. Compared with the preparation methods of other graphene electrodes, the preparation method of the graphene nickel foam electrode has the advantages of being cheap in raw materials, free of pollution, green and environment-friendly, and mass production is facilitated. The graphene nickel foam electrodesupported through the nickel foam has good capacitive performance in a neutral electrolyte and can be applied to the field of energy storage.

The invention relates to vanadium oxide and carbon composite material with a hierarchical pore structure and a preparation method of the vanadium oxide and carbon composite material with the hierarchical pore structure. The vanadium-carbon ratio of the material is 0.4-1.5, the material is of the hierarchical pore structure and provided with macropores and mesopores, the diameters of the macropores are 0.2-1.5 micrometers, the diameters of the mesoporous are 15-50 nanometers and 2.6-5.4 nanometers, and the specific surface areas of the material are 105.0-413.8 square meter per gram. The preparation method includes the following steps: mixing hydrochloric acid, segmented copolymers, ethanol, phenolic resin and ammonium metavanadate, and obtaining the material through thermal polymerization and carbonization after volatilization induced self-assembly. The composite material can be used as supercapacitor electrode material. Researches in cyclic voltammetry and continuous current charge and discharge of a three-electrode system show that capacitive performance of a vanadium oxide and carbon composite material electrode is improved obviously compared with capacitive performance of an electrode made of mesoporous carbon. The preparation method is simple, low in requirement for devices, good in operability, and low in cost.

The invention belongs to the technical field of conducting materials and discloses an ionic liquid coated paper of a thin-walled carbon nanotube and a preparation method of the ionic liquid coated paper. An ionic liquid in the paper of carbon nanotubes is evenly coated on the outer surfaces of the carbon nanotubes to form a coaxial structure, and then the carbon nanotubes are mutually lapped to form a net structure. The paper of the carbon nanotubes is prepared by the steps that firstly 15wt% to 30wt% of ionic liquid and the thin-walled carbon nanotube are subjected to dispersion mill, and then are compacted. The ionic liquid can have functions of dispersing the thin-walled carbon nanotube, opening tube bundles of the thin-walled carbon nanotube and serving as an adhesive. Compared with resistance of papers of thin-walled carbon nanotubes, which are directly compacted without using the ionic liquid, the resistance of the prepared paper of the thin-walled carbon nanotube is reduced by 20-40%, when the paper is used as an electrode material of a supercapacitor at a voltage of 4-6.5 volts, the performances of the supercapacitor are improved by 20-100%, and when the paper is used as a strength material, the tensile strength is improved by 20-100%. Besides, the preparation method has the advantages of being low in cost and easy to repeat and amplify.

The invention discloses a method for jointly preparing carbon micro-nanotubes and N-doped porous carbon / nickel-manganese oxide, comprising: 1. preparing coal-based polyaniline; 2. placing nickel acetate and coal-based polyaniline in absolute ethanol , to obtain a paste; 3. spin-coat the nickelocene solution on the quartz sheet; 4. place the paste in the first temperature zone of the horizontal tubular atmosphere furnace, and place the quartz sheet in the second temperature zone; 5. Introduce nitrogen, heat up, collect the product carbon micronanotubes on the quartz sheet, and collect the product in the quartz boat in the first temperature zone; 6. Process the product in the quartz boat; 7. Wash after suction filtration, vacuum dry, and calcine. N-doped porous carbon / nickel-manganese oxide is obtained. In the pyrolysis of coal-based polyaniline, the present invention effectively utilizes the hydrogen-containing gaseous hydrocarbons produced by cracking to crack and deposit carbon micronanotubes on the surface of nickel; α‑MnO2 and NiMn2O4 comprehensively improve the capacitive performance of the composite.

The invention discloses a hollow carbon sphere material co-doped with nitrogen and phosphorus, and the shell layer has a hierarchical macropore-mesoporous structure and a preparation method thereof. The in-situ doping method is adopted, and silicon dioxide nanospheres are used as hard templates. Formaldehyde resin is used as the carbon precursor and nitrogen source, and hydroxyethylidene diphosphonic acid is used as the catalyst and phosphorus source. Finally, a hollow carbon microsphere material with nitrogen and phosphorus co-doped and a hierarchical macropore-mesoporous structure in the shell is synthesized. The prepared hollow carbon microsphere material has the advantages of high doping amount of nitrogen and phosphorus atoms, controllable shape, and excellent electrochemical performance. At the same time, the preparation of raw materials is low in price, low in cost, simple in preparation method, and suitable for large-scale industrial production. .

The invention relates to a fabrication method of an Ag / PPy composite nanometer material-based printed supercapacitor. Acetate is introduced to the fabrication process of an Ag / PPy composite nanometermaterial, so that the obtained Ag / PPy composite nanometer material has a legume-shaped core-shell structure, the capacitance performance of the material is favorably improved, and a flexible and solid-state supercapacitor is fabricated by selecting different flexible substrates and printing silver paste, the synthesized Ag / PPy composite nanometer material and a PVA-H3PO4 solid-state electrolyte byemploying silk-screen printing mode. The energy density of the supercapacitor manufactured by the method can reach 4.33 micro watt hour per square meter, 77.6% of unit specific capacitance is still maintained after the supercapacitor is bent for 1,000 times, 82.6 of unit specific capacitance is still maintained after the supercapacitor is bent for 10,000 times, the supercapacitor is low in cost,and substitution and supplement of a traditional high-cost energy storage device are achieved; and moreover, the supercapacitor has the advantages of simple reaction step, short reaction time and thelike, is simple and convenient to operate, can be used for industrial mass fabrication and production and can be applied to the field of flexible energy storage, and the synthesis method is clean andenvironmental-friendly and is suitable for promotion and application.

The invention provides a preparation method for a bismuth molybdate / polyaniline composite supercapacitor electrode material. The preparation method comprises the following steps of dissolving bismuth nitrate and sodium molybdate into ethylene glycol at a molar ratio at a room temperature to obtain a mixed solution A, and performing ultrasonic uniformity and adding a mixed solution of urea and absolute ethyl alcohol; stirring continuously and uniformly and then pouring the mixed solution into a polytetrafluoroethylene stainless steel hydrothermal reaction kettle, sealing and performing a solvothermal reaction; after naturally cooling, performing washing and drying to obtain bismuth molybdate; performing ultrasonic dispersion of bismuth molybdate and lignin sodium sulfonate into deionized water to obtain a mixed solution, then adding an aniline monomer and p-toluenesulfonic acid, and then changing into ice- bath stirring, after the aniline is dispersed, obtaining a mixed solution B; and slowly dropwise adding an ammonium persulfate solution to the mixed solution B, and after the ice-bath reaction is completed, performing washing and drying to obtain the bismuth molybdate / polyaniline composite material. The method is simple, and the capacitance performance of the prepared bismuth molybdate / polyaniline composite material is greatly improved.

The invention relates to a nano-nickel oxide / graphene composite material and a preparation method thereof. The composite material is characterized in that: nickel oxide nano-particles uniformly grow on two sides of single-layer graphene to form a novel quasi-two-dimensional composite nano-material. The graphene serving as a substrate frame has good conductivity, and excellent conductivity among the nickel oxide particles is realized through the graphene substrate, so that the apparent electric conductivity of the composite material is improved. The sizes of the nickel oxide nano-particles growing on the graphane flake are between 1 and 10 nanometers; the plane size of the composite graphene nano-flake is between 0.1 and 100 microns, and the thickness of the composite graphene nano-flake is between 1 and 20 nanometers; and the weight percentage of the nickel oxide in the composite material is between 60 and 95 percent. The preparation method comprises two typical steps of: preparing a nano-nickel oxide / graphene precursor material by adopting a chemical solution method; and sintering to form a phase at high temperature in protection of an inert gas. The nano-nickel oxide / graphene composite material prepared by the method has high single electrode capacitance and good circulating performance, and is suitable for electrode materials of super capacitors.

The invention discloses a nitrogen-doped porous carbon material based on polyvinylidene chloride, using polyvinylidene chloride as a carbon source, and using a basic nitrogen-containing compound ethylenediamine or diethylenetriamine as a dehalogenating agent and nitrogen source. One-step method to achieve dechlorination and nitrogen doping, and finally activated by calcination. The preparation method of nitrogen-doped porous carbon materials based on polyvinylidene chloride includes the following steps: 1) one-step dechlorination and nitrogen doping; 2) calcination activation of carbon precursors. As the application of supercapacitor electrode material, when the current density is 0.5A g ‑1 , the specific capacitance value ranges from 401‑470 F g ‑1 . The invention has the following advantages: 1. realizing recycling of PVC and PVDC; 2. realizing dehalogenation of polyvinylidene chloride at normal temperature; and having broad application prospects in the field of porous carbon materials and supercapacitors.