83results about How to "High pseudocapacitance" patented technology

Provided is an internal hybrid electrochemical cell comprising: (A) a pseudocapacitance cathode comprising a cathode active material that contains a conductive carbon material and a porphyrin compound, wherein the porphyrin compound is bonded to or supported by the carbon material to form a redox pair for pseudocapacitance, wherein the carbon material is selected from activated carbon, activated carbon black, expanded graphite flakes, exfoliated graphite worms, carbon nanotube, carbon nanofiber, carbon fiber, a combination thereof; (B) a battery-like anode comprising lithium metal, lithium metal alloy, or a prelithiated anode active material (e.g. prelithiated Si, SiO, Sn, SnO₂, etc.), and (C) a lithium-containing electrolyte in physical contact with the anode and the cathode; wherein the cathode active material has a specific surface area no less than 100 m²/g which is in direct physical contact with the electrolyte.

The invention discloses a manufacturing method for a redox activity electrolyte based nitrogen-doped graphene supercapacitor, and specifically discloses manufacturing methods for a pseudocapacitance active water system electrolyte, nitrogen-doped porous graphene and a pseudocapacitance active electrolyte system supercapacitor. The capacitive performance of the supercapacitor is greatly improved mainly through the dual-capacitive contribution of electrode materials and the electrolyte. The specific capacity of the supercapacitor is improved by about three times through the pseudocapacitance contribution of the redox activity ingredients in the electrolyte, so that the great improvement potential exists in supercapacitor specific capacity and the energy density.

The invention relates to a graphene/carbon nano-tube composite material and a preparation method thereof. The preparation method comprises the following steps of a) preparing a suspension of graphene oxide, b) preparing a suspension of carbon nano-tube, and c) preparing a composite of graphene oxide/ carbon nano-tube. The invention also relates to application of the graphene/carbon nano-tube composite material which is used as an electrode material in an electrochemical capacitor. The graphene/carbon nano-tube composite material prepared by the method of the invention solves the problem that the capacitance of a graphene electrode material is relatively low, the composite carbon nano-tube prevents graphene from agglomeration to improve the double-electric-layer capacitance, and a carbonyl is added into the graphene to increase the fake capacitance and further to improve the capacitance of the electrode material.

The present invention relates to the field of material science, and aims to provide a preparation method for a grapheme-molybdenum disulfide-polyaniline ternary composite electrode material. The method comprises the steps of dispersing graphene in deionized water, then dispersing molybdenum trioxide and potassium thiocyanate in deionized water, uniformly mixing up the above material, subjecting an obtained mixture to hydrothermal reaction, washing and drying an obtained precipitate to obtain substrate powders, placing substrate powders in dilute acid for ultrasonic dispersion, adding aniline monomer and an oxidizing agent, stirring uniformly, reacting at the room temperature, filtering, washing, and drying to obtain the ternary composite electrode material. The preparation method is simple in process and strong in operability. The temperature of the synthesis condition is wider in range, and the requirement on the substrate material is lower. Therefore, the preparation method is more suitable for industrial production. In the preparation field of super capacitor electrode materials, the preparation method has a wider application prospect. Based on the preparation method, electrode materials of uniform morphology and good electrochemical performance can be prepared. Meanwhile, a high electrical double-layer capacitor and a pseudo capacitor can be obtained simultaneously. As a result, the cycle performance is more excellent.

The invention relates to a manufacturing method of a foldable paper-based micro supercapacitor and belongs to the technical field of a micro energy storage device. The method comprises steps that a graphene or graphene composite electrode is imprinted onto a paper substrate through utilizing the template imprinting technology, the solid electrolyte is coated to the electrode, and the micro supercapacitor is manufactured on the paper substrate. The sheet-like graphene or graphene composite is imprinted through the template on the paper substrate to make the outline of the electrode clear and connectivity good, porosity and the water absorption property of the paper are utilized to ensure stability of the graphene or graphene composite electrode on the paper, foldability and flexibility of the paper are utilized to make the manufactured micro supercapacitor have good flexibility and foldability, wind energy collection and utilization and output of different voltages and currents can be realized, moreover, the manufacturing process is simple, operability is high, cost is low, and large scale manufacturing is realized.

The invention belongs to the field of modified carbon nanomaterials and discloses a preparation method of a two-dimensional porous boron-nitrogen double-doping carbon nanomaterial and application thereof. The preparation method disclosed by the invention comprises the following steps: taking urea as a structure template, taking 1-butyl-3-methylimidazolium tetrafluoroborate as a pore forming substance and a doping agent, taking glucose as a carbon source, calcining and performing hydrothermal treatment, thereby obtaining the product. The method disclosed by the invention is simple in operation,short in synthesis period, excellent in repeatability, low in cost and convenient for industrial implementation. The porous boron-nitrogen double-doping carbon nanosheets prepared by the method disclosed by the invention have a uniform and porous thin-layer structure and large specific surface area. Meanwhile, due to introduction of boron atoms, the conductivity is enhanced, the redox activity can be enhanced by virtue of doping of the nitrogen, and ay capacitance is improved. When serving as an electrode material of a supercapacitor, the carbon nanomaterial has high electrochemical energy storage activities including high specific capacitance and excellent cycling stability. When charging/discharging current density is 0.1A/g, the highest specific capacitance can reach 550F/g, and the specific capacitance is much higher than that of most of the carbon-based materials.

A preparation method for high-specific capacitance activated carbon on the basis of HNO3 hydrothermal oxidizing modification includes the steps of: uniformly mixing and stirring a carbon material, nitric acid and ethanol according to the ratio of m<carbon> : V<acid> : V<ethanol> being 1 g : 5-20 ml : 40-60 ml to prepare a mixture material; according to the ratio of mass of carbon material to volume of a hydrothermal reaction kettle being 1-3 g : 200-400 ml, adding the mixture material to the hydrothermal reaction kettle, and performing a reaction at 100-180 DEG C for 3-6 h, rotation speed being 50-250 r/min; allowing the reaction product to stand, and filtering, washing and drying the reaction product to prepare the activated carbon. The activated carbon has high specific capacitance and is low in environment pollution.

The invention discloses a method for preparing a carbon-based super-capacitor electrode material from wood powder. The method includes mixing wood powder with alkali, nitrogen source and water according to the weigh ratio of 1 to (1-6) to (2-12) to (5-30) while stirring for 5 to 20 hours to obtain a mixture; freezing the mixture at the temperature of -20 to -60 DEG C for 12 to 24 hours and then drying the same at the temperature of -60 to -100 DEG C for 1 to 6 days to obtain another mixture; treating the mixture while raising the temperature from room temperature to the temperature of 700-1000DEG C by the speed of 1-5 DEG C/min under protection of nitrogen gas for 1 to 4 days, then cooling to the room temperature to obtain a black product; mixing the black product with deionized water according to the weigh ratio of 1 to 20-70 while stirring for 10 to 30 minutes, standing for 2 to 4 hours, filtering and washing the product until the product is neutral, and then drying the product for12 to 24 hours to obtain the finished product carbon powder. With treatment of activation and pre-doping, carbonization, activation and element doping are achieved synchronously by one high-temperature processing only, preparation is simplified and production cost is lowered.

The invention provides a preparation method of a manganese dioxide/polypyrrole composite electrode free of a binder. The method specifically comprises the steps of: employing a nickel foam current collector as a substrate, firstly, carrying out hydrothermal decomposition on potassium permanganate at a high temperature and making a manganese dioxide nanosheet array grow on a nickel foam skeleton; and immersing the nickel foam containing manganese oxide into an electrolyte containing pyrrole, carrying out constant potential electrochemical deposition and making polypyrrole evenly grow on the surface of a manganese dioxide sheet layer to obtain the nickel foam-loaded manganese dioxide/polypyrrole compound. Manganese dioxide directly grows on the nickel foam, so that use of the binder in the electrode preparation process can be effectively avoided; and internal resistance of the system is reduced. The wettability of the manganese dioxide electrode and the electrolyte can be improved by a polypyrrole film; and meanwhile, additional psedocapacitance is increased under the condition of not blocking an ion diffusion channel. The composite electrode material has good electrochemical property and is expected to have a good application prospect in the field of a super-capacitor material.

The invention discloses a preparation method of a hierarchical pore nitrogen-oxygen-doped carbon super capacitor electrode material. The method comprises steps of: fully mixing biomass carbon source egg yolk and trithiocyanuric acid trisodium salt in a reaction vessel to obtain a material A; keeping the material A at 300 DEG C for 60 minutes, and rising the temperature to 600-800 DEG C for carrying out carbonization treatment for 2 hours, and performing cooling to room temperature to obtain a material B; mixing the material B and a KOH solid in the reaction vessel, adding deionized water and performing full stirring and uniform mixing, performing standing at room temperature for 12 hours, and performing drying to obtain a material C; heating the material C to 600-800 DEG C for activating treatment for 2 hours, and performing cooling to room temperature to obtain a material D; transferring the material D to the reaction vessel, adding an acidic solution for immersion for 12 hours, performing washing with high-purity water until the pH of a filtrate is neutral, performing drying at 40-90 DEG C for 24 hours to obtain the hierarchical pore nitrogen-oxygen-doped carbon super capacitor electrode material. The hierarchical pore nitrogen-oxygen-doped carbon super capacitor electrode material prepared by the invention has a specific surface area of 3519.5 m2/g and a total pore volumeof 2.7 cm3/g, and contains a large number of micropores, mesopores and macropores.

Te invention discloses a three-dimensional nano bead curtain shaped composite metal nitride/oxide, which is prepared by adopting a method of growing a composite metal oxide precursor at the surface bytaking a conductive support material as an electrode and a support and then forming a composite metal nitride/oxide loaded on the conductive support material through heat treatment and nitridation. The composite metal nitride/oxide is that composite metal nitride nanoparticles connected by composite metal oxide nanosheets form a three-dimensional nano bead curtain shape on the conductive supportmaterial, wherein the size of the composite metal oxide nanosheets is 100-500nm, the diameter of the composite metal nitride nanoparticles is 5-50nm, and the loading capacity of the composite metal nitride/oxide on the conductive support is 0.1-0.5mg/cm<2>. The operation process is simple, the low cost and the high capacitive performance enable the combination of the composite metal nitride/oxideto have wide application prospects in the aspect of energy storage.

The invention belongs to the technical field of material compounding, and particularly relates to a novel compounding method of a carbon material and a transition metal compound, a composite material and application. The novel compounding method of the carbon material and the transition metal compound comprises the following steps: firstly, synthesizing an iron-cobalt MOF precursor through a hydrothermal method; then carrying out high-temperature carbonization treatment on the iron-cobalt MOF precursor to form an iron-cobalt alloy carbon nanotube doped composite material; and finally, carrying out high-temperature selenylation treatment on the obtained iron-cobalt alloy carbon nanotube doped composite material to obtain the FeSe2/CoSe2@CNT composite material. The novel compounding method is simple and convenient in process and relatively high in dispersity, and the obtained FeSe2/CoSe2-@CNT composite material has relatively high specific capacitance, stable rate capability and relatively large pseudocapacitance contribution when being applied to a sodium-ion battery.

The invention relates to a preparation method of a biomass carbon-based electrode for an asymmetric capacitance desalting device, which comprises the following steps: cleaning shrimp and crab shells,carrying out ultrasonic treatment, drying, pulverizing into powder, carbonizing in an inert atmosphere, adding an activator into a carbonized product, heating to 800-1200 DEG C under the protection ofinert gas, keeping the temperature for 2-4 hours, cooling, pickling, washing with water, filtering, and drying to obtain nitrogen-doped porous carbon; respectively carrying out sulfide modification and positive charge modification on the nitrogen-doped porous carbon, dispersing the modified nitrogen-doped porous carbon, acetylene black and polytetrafluoroethylene in absolute ethyl alcohol, evaporating to a paste, coating conductive substrate graphite paper with the paste, drying, and assembling to form an asymmetric electrode, wherein the positive electrode is positive charge modified nitrogen-doped porous carbon, and the negative electrode is sulfide-modified nitrogen-doped porous carbon. According to the method, the shrimp and crab shells are used as precursors, a nitrogen source does not need to be additionally added, raw materials are easy to obtain, cost is low, large-scale production can be achieved, and the prepared electrode is large in adsorption capacity and high in efficiency.

The invention relates to the technical field of supercapacitors, and discloses a polyaniline-bimetallic hydroxide supercapacitor material and a preparation method thereof. The polyaniline-bimetallic hydroxide supercapacitor material comprises the following formula raw materials: lanthanum doped Co-Ag bimetallic hydroxide, 2, 6-dinitroaniline and initiator. According to the polyaniline-bimetallic hydroxide supercapacitor material and the preparation method thereof, the Co-Ag bimetallic hydroxide lanthanum doped Co-Ag bimetallic hydroxide forms a layered structure and has a large specific surface area and pore size so as to make the charges move uniformly between the electrolyte and the electrode material, and Ag has a high conductivity so as to improve the conductivity of the electrode material and promote the transfer and transmission efficiency of the charges. The Polyaniline coated bimetallic hydroxide and the nitro group in the 2, 6-dinitroaniline have high electron adsorbing property so as to reduce the electron cloud density of C atom, improve the polarity of polyaniline and enhance the acid and alkali resistance and the chemical stability of polyaniline in the electrolyte.

The invention discloses an activation method of conductive carbon cloth and supercapacitor application of the conductive carbon cloth. A 1M KOH solution is used as an electrolyte solution, a two-electrode system is adopted, cyclic voltammetry treatment is carried out under a certain condition, and the activated conductive carbon cloth can be obtained. In the 1M KOH electrolyte solution, electrochemical performance evaluation is carried out on the conductive carbon cloth in a -1 to 0V electric potential window range, performance comparison is carried out on the conductive carbon cloth and original carbon cloth which does not perform activating treatment, the capacity of the original carbon cloth is 1.40 F/cm<2>, the maximum capacity of the carbon cloth after activating treatment can reach 1.84 F/cm<2>, and it is explained that the activation treatment method can obviously improve the specific capacitance of the carbon cloth.

The invention relates to a nitrogen-doped carbon nanocomposite, which is provided with a conductive network structure and is formed by making a nitrogen element participate in a conductive network skeleton, wherein the conductive network structure is obtained after in situ polymerization of an aromatic nitrile compound monomer and a carbon nanomaterial or after polymerization of a prepolymer of the aromatic nitrile compound monomer and the carbon nanomaterial. A composite structure of an aromatic nitrile polymer/carbon nanomaterial is obtained through polymerization of the aromatic nitrile compound monomer and the carbon nanomaterial, the carbon nanomaterial is taken as a basic skeleton to provide abundant conductive networks and good mechanical toughness, and the aromatic nitrile polymer has the characteristics of high nitrogen content doping and uniform nitrogen element distribution and is of a pore structure with high specific surface area and uniform distribution; and the nitrogen-doped carbon nanocomposite provided by the invention shows high specific capacitance and cycling stability in a supercapacitor.

The invention belongs to the technical field of supercapacitors, and particularly relates to a preparation method of a flexible fabric supercapacitor electrode material taking graphene/polypyrrole asan active substance. The preparation method comprises the following steps: firstly, carrying out swelling crosslinking on carboxymethyl chitosan/viscose blended non-woven fabric; preparing a graphene/non-woven fabric conductive material by adopting an impregnation-drying method, and polymerizing a pyrrole monomer onto the graphene/non-woven fabric conductive material by adopting an in-situ chemical oxidation polymerization method to obtain the flexible fabric supercapacitor electrode material taking graphene/polypyrrole as an active substance. A flexible substrate material adopted by the invention is carboxymethyl chitosan/viscose blended non-woven fabric; wherein carboxymethyl chitosan is a water-soluble polymer material, swelling of carboxymethyl chitosan in a cross-linking agent aqueous solution promotes increase of the specific surface area of the fabric, pores in the fabric can be filled with carboxymethyl chitosan, the space utilization rate of the fabric can be greatly increased, loading of a large number of electroactive substances is facilitated, and carboxymethyl chitosan is an ideal supporting material for the flexible electrode.

The invention discloses a CC-NiO-CuCoS composite material. The CC-NiO-CuCoS composite material is composed of CC, NiO and CuCo2S4, wherein CC is a base material, the microstructure of CC is of a fibrous structure, and CC is used for providing a substrate, so NiO nanosheets cannot be stacked, and the conductive substrate is beneficial to ultra-high-speed transportation of electrons; the microstructure of NiO is a nanosheet structure, and NiO is loaded on the surface of CC and is used for providing extra pseudocapacitance; and the microstructure of CuCo2S4 is a nano-particle structure, and CuCo2S4 is attached to the surfaces of the CC and NiO nanosheets, and is used for stabilizing the sheet structure of NiO and covering a part of exposed CC. According to the invention, the CC-NiO-CuCoS composite material is prepared from CC, nickel nitrate hexahydrate, ammonium fluoride, urea, cupric acetate monohydrate, cobalt acetate tetrahydrate and thiourea are used as initial raw materials throughtwo-step hydrothermal preparation. The preparation method comprises the following steps of (1) cleaning and activation of CC; (2) preparation of a CC-NiO composite material; and (3) preparation of theCC-NiO-CuCo2S4 composite material. When the composite material is used as a supercapacitor electrode material, specific capacitance is 840 F g<-1>, and cycling stability after 3000 cycles is 100%.

The invention relates to the field of lithium ion batteries, in particular to a lithium ion supercapacitor with a positive electrode pre-embedded with lithium. Lithium iron phosphate with an orthorhombic system olivine-type structure is one of positive electrode materials of lithium ion batteries and capacitors which are most widely applied in the current market, and the application of the lithium iron phosphate is greatly limited due to the problems of low electronic conductivity and poor ion diffusion rate. Based on the problem, the invention provides a lithium ion supercapacitor with a positive electrode pre-embedded with lithium, wherein the positive electrode material is a composite material obtained by compounding a spherical lithium iron phosphate material and heteroatom-doped graphene, and the outer side of the composite material is wrapped by a network carbon structure formed by carbonizing melamino-formaldehyde resin, so that the cycling stability and the rate capability of the lithium ion battery are effectively improved, and a relatively good application prospect is achieved.

The invention relates to a nitrogen-sulfur-doped nano porous carbon material with sodium alginate as a raw material and preparation thereof. The preparation method comprises the following steps of: 1, dissolving sodium alginate in a thiourea aqueous solution, and performing stirring and heating to obtain a sodium alginate thiourea solution; 2) dropwise adding a calcium salt aqueous solution into the sodium alginate thiourea solution, and stirring to obtain gel; and 3) freeze-drying the gel in the step 2), crushing, performing high-temperature carbonization activation, washing, and drying to obtain the nitrogen-sulfur doped nano porous carbon material. The nitrogen and sulfur doped nano porous carbon material is used in a supercapacitor. Compared with the prior art, the nitrogen-sulfur-doped nano-porous carbon material is prepared by taking sodium alginate which is rich in natural content as a carbon precursor and adopting a freeze-drying auxiliary carbonization template method, so that the cost is saved, the environment is protected, the process is simple, the pseudocapacitance, the conductivity, the power density and the cycling stability are enhanced, and the nitrogen-sulfur-doped nano-porous carbon material has excellent electrochemical performance, and the application prospect is wide.

The invention provides a method for preparing conducting polymer-based nanometer carbon fibers, which comprises the following steps of: processing a conducting polymer nanometer fiber precursor in the oxidizing atmosphere to obtain a preoxidation product; and carbonizing at the temperature of between 600 and 900 DEG C in the nitrogen atmosphere to obtain the conducting polymer nanometer carbon fibers, wherein in the electrode material, the stable specific electric capacity is up to 158F/g under the condition of current density of 0.1A/g; and when the current density is gradually increased from 0.1A/g to 1A/g, the retention rate of the capacity is 75 percent. The conducting polymer-based nanometer carbon fibers have high discharge specific capacity and cyclical stability.

The invention discloses a preparation method of manganese dioxide composite nitrogen-sulfur double-doped porous carbon. The preparation method comprises the following steps of dissolving thiourea in a dilute acid solution firstly to prepare an acidified thiourea solution, dropwise adding the acidified thiourea solution into a mixed solution in which sodium alginate, potassium nitrate and potassium permanganate are dissolved, and cross-linking to obtain blocky gel; after washing and freeze-drying, carrying out one-step carbonization operation at a certain temperature and under the protection of nitrogen to obtain the manganese dioxide composite nitrogen-sulfur double-doped porous carbon. According to the method, the acidified thiourea and the sodium alginate molecular chains are cross-linked to obtain the gel, wherein the thiourea can serve as a nitrogen source and a sulfur source at the same time, and the potassium permanganate serves as a manganese source, and therefore the manganese dioxide composite nitrogen-sulfur double-doped porous carbon can be prepared through one-step carbonization. By changing the concentration of potassium permanganate, the pore structure of the porous carbon and the content of manganese dioxide can be regulated and controlled, and a supercapacitor taking the obtained porous carbon composite material as an electrode material shows good electrochemical performance.