31results about How to "High capacitance retention" patented technology

The invention discloses an isoindole nitrogen oxide free radical modified polypyrrole and a preparation method and an application thereof. 3- and 4-site side groups in pyrrole repeating structural units of a polypyrrole high molecular material are chemically modified by an isoindole nitrogen oxide free radical derivative to obtain the product. Or 3- and 4-site side groups of pyrrole monomers are chemically modified by the isoindole nitrogen oxide free radical derivative, and then a polymerization reaction is carried out to obtain the product. Compared with polypyrrole, the modified polypyrrole has better electrical conductivity, higher charge storage density, better capacitance retention rate, fast electrode reaction dynamics performance, and oxidation-reduction ability and characteristic three-line electron paramagnetic resonance spectra similar to isoindole free radicals; the polymer has good rate capability and cycle stability in the processes of charging and discharging; and after 500-cycle charging and discharging circulation, the coulomb efficiency can be still kept at 95% or more, and the modified polypyrrole is expected to become a novel high-capacity and high-power battery material.

The invention discloses agarose/polyaniline compound gel, a method for preparing the same and application of the agarose/polyaniline compound gel. The agarose/polyaniline compound gel is of a sandwich polyaniline/agarose electrolyte/polyaniline integrated structure. The method includes steps of (1), adding agarose into electrolyte solution with certain concentration, uniformly mixing the agarose and the electrolyte solution with each other and then pouring the agarose and the electrolyte solution into molds to obtain agarose gel; (2), arranging the agarose gel in aniline solution, attaching aniline to the surfaces of the agarose gel and then immersing the agarose gel in oxidizing agent solution to obtain the agarose/polyaniline compound gel by means of oxidative polymerization. Current collectors can be arranged on the surfaces of the agarose/polyaniline compound gel, so that flexible supercapacitors on the basis of the agarose/polyaniline compound gel can be assembled. The agarose/polyaniline compound gel, the method and the application have the advantages that procedures for preparing the agarose/polyaniline compound gel are simple, electrodes and electrolyte layers are integrated on the agarose/polyaniline compound gel, the agarose/polyaniline compound gel is good in mechanical property and flexible bending property, and the supercapacitors made of the agarose/polyaniline compound gel are excellent in flexibility, capacitive character and cycling stability.

The invention belongs to the technical fields of metal thermal reduction reactions and graphene materials, and particularly discloses a method for reducing carbon dioxide into a porous carbon material, and the porous carbon material and application thereof. The method comprises the following specific steps: carrying out heat treatment on magnesium-containing metal in a CO2-containing atmosphere; after a reaction is finished, stirring an obtained product in an HCl solution; and purifying the obtained mixture, and carrying out drying overnight at room temperature to obtain the porous carbon material. The specific surface area of the porous carbon material prepared from the magnesium-zinc mixture can reach 1800-2000 m<2>/g; the conductivity of the material is as high as 1000 to 1100 S/m; thecapacitance retention rate is high; the tap density of the material is almost the same as the tap density of activated carbon and is 0.60-0.65 g/cm<3>; so the porous carbon material is an ideal material for preparing a high-power electrochemical capacitor electrode. The porous carbon material prepared from the magnesium-copper mixture has the advantages of favorable specific surface area and goodcrystallinity, and is an ideal material for preparing electrodes of microbial fuel cells.

The invention relates to a method for preparing nanometer porous carbon with xanthoceras sorbifolia bunge seed coats, nanometer porous carbon, a super-capacitor electrode slice and a preparation method of the super-capacitor electrode slice. Through regulation and control of the activation temperature and the dosage of an activator; for xanthoceras sorbifolia bunge seed coat porous carbon, the specific surface area is 2148m2/g, a porous structure is formed by a great amount of micropores which are regularly and closely arranged, and the pore diameter distribution is 2nm or below. For an electrode prepared with the porous carbon, the specific capacitance at the current density of 0.5A/g reaches up to 429F/g, the electrode still has very good specific capacitance (128F/g) when the current density rises to 20A/g, and the capacitance retention still reaches up to 98.7 percent after the electrode is charged or discharged for 1000 times under the condition with the current density being 10A/g. The porous carbon prepared with the xanthoceras sorbifolia bunge seed coats as a raw material has good electrochemical performance, can be used as an electrode material for a super-capacitor and provides a new thought and way of comprehensive development and utilization of xanthoceras sorbifolia bunge resources.

The invention discloses a carbon hollow sphere coated metal selenide composite material as well as a preparation method and application thereof, and relates to the technical field of green energy materials. The composite material is of a double-layer structure, the inner layer of the composite material is NiSex nanoparticles, the outer layer of the composite material is carbon hollow spheres, and the NiSex nanoparticles of the inner layer of the composite material are uniformly dispersed in the carbon hollow spheres. The invention further discloses a preparation method and application of the NiSex-coated CBs composite material. According to the invention, Ni-soc-MOF is taken as a template, an in-situ selenylation method is adopted to successfully prepare a composite material in which a nickel-selenium compound is embedded into a carbon hollow sphere, the specific capacitance of NiSe (at) CBs reaches up to 1720F g <-1 > when the current density is 1A g <-1 >, and the NiSe (at) CBs//AC asymmetric supercapacitor has high energy density of 45.2 W h kg <-1 > under the power density of 800kW kg <-1 >, shows excellent energy storage performance, and can be applied to the field of supercapacitor devices. The capacitance retention rate of the NiSexCBs//AC asymmetric supercapacitor after 5000 cycles still reaches up to 89%, and the NiSexCBs//AC asymmetric supercapacitor shows high cycle stability.

The invention belongs to the field of preparation of ZnNCN materials, in particular to a low-cost ZnNCN material preparation method. The method comprises the following step of synthesizing truncated rhombic dodecahedral zeolite imidazole ester skeleton-8 (TRD-ZIF-8) nanoparticles, concretely, adding 10ml of an aqueous solution in which Zn (CH3COO) 2.2 H2O (600mg) is dissolved into 10ml of an aqueous solution in which 2-methylimidazole (0.54 mM) and CTAB (2.58 mM) are dissolved, slowly stirring the solution for several seconds, after 10 minutes, changing the original transparent solution into awhite solution, standing the solution at room temperature for 3 hours, carrying out centrifuging at 9000r.p.m, enriching the solution in a 50mL centrifuge tube, and then washing the obtained TRD-ZIF-8 nanoparticles with deionized water for three times. The ZnNCN material disclosed by the invention is relatively high in yield, and the nanoparticles are relatively small in particle size, relativelylarge in specific surface area and stable in electrochemical performance.

The invention relates to a one-step preparation method of polyaniline-titanium dioxide nanotube array composite electrode. The method comprises the following steps of: adding ammonium fluoride, aniline and concentrated sulfuric acid into a mixed solvent, stirring and dissolving to obtain a mixed solution; Using this mixed solution as electrolyte, metal titanium plate as anode and platinum plate ascathode,anoding at 0-10 DEG C, 20-50V for 1-5 hour. The oxidized anode plate is washed with deionized water and dried to obtain polyaniline. TiO2 nanotube array composite electrode. The invention greatly simplifies the process steps, shortens the process flow and obtains excellent electrode performance.