10results about How to "Increase intrinsic conductivity" patented technology

The invention belongs to the technical field of graphene preparation, and discloses a preparation method of a modified graphene electrode material of a lithium ion battery and a related product, the method comprises the following steps: pre-mixing graphite powder and concentrated sulfuric acid, then adding an oxidant in batches, carrying out suction filtration after oxidation is completed, and washing to be neutral by using diluted hydrochloric acid and deionized water; deionized water is added into the washed graphite oxide, and after multi-stage ultrasonic treatment, a graphene oxide dispersion liquid is obtained through centrifugal separation; mixing the graphene oxide dispersion liquid with a predetermined amount of urea, carrying out a multi-step hydrothermal reaction, and then carrying out centrifugal cleaning and freeze drying to obtain nitrogen-doped modified graphene powder; the nitrogen-doped modified graphene powder and absolute ethyl alcohol are ground and mixed, the surface of a pretreated foamed nickel current collector is coated with the mixture through dip coating, compaction treatment is conducted, and the modified electrode material is obtained. According to the scheme, the conductivity and the cycling stability of the graphene electrode in the lithium ion battery can be improved.

The invention provides a preparation method of an iron atom substituted-zinc sulfide negative electrode material for a potassium ion battery. The preparation method comprises the following steps: uniformly mixing ammonium lemon ferrite, L-cysteine and deionized water to form a solution A; uniformly mixing zinc nitrate hexahydrate and deionized water to form a solution B; uniformly mixing dimethylimidazole and deionized water to form a solution C; uniformly mixing the solution A, the solution B and the solution C according to a weight ratio of 1: 2: 2-1.5: 2: 2 to obtain a precursor solution, centrifuging the precursor solution, and collecting precursor powder; the precursor powder is annealed in an inert atmosphere to obtain the iron atom substituted-zinc sulfide negative electrode material, and when the iron atom substituted-zinc sulfide negative electrode material is applied to the negative electrode material of the potassium ion battery, the specific capacity can still be kept at 583.9 mAh g <-1 > after 240 cycles under the current density of 100 mAg <-1 >. The invention also provides an iron atom substituted-zinc sulfide negative electrode material and a potassium ion battery.

This invention discloses a wide-interlayer-spacing molybdenum disulfide catalyst, its preparation method, and its application, belonging to the field of water electrolysis for hydrogen production energy conversion technology. The preparation method includes the following steps: preparing a molybdenum disulfide precursor solution using a molybdenum source and a sulfur source; then subjecting the molybdenum disulfide precursor solution to a hydrothermal reaction with a carbon-containing interlayer-spacing regulator; and obtaining the wide-interlayer-spacing molybdenum disulfide catalyst after centrifugation and washing. The carbon-containing interlayer-spacing regulator is used to insert into the interlayer of molybdenum disulfide during the hydrothermal reaction, increasing the interlayer spacing of the (002) crystal planes of the obtained molybdenum disulfide catalyst. The wide-interlayer-spacing molybdenum disulfide catalyst of this invention facilitates electrolyte penetration and hydrogen bubble release, effectively avoids active site blockage, enhances the intrinsic conductivity of the catalyst, accelerates internal charge transport, increases active sites for hydrogen evolution reaction, and improves the intrinsic hydrogen evolution catalytic activity of the catalyst.

The invention belongs to the research and development of a sodium ion battery positive electrode material, and discloses a preparation method of a molybdenum-doped vanadium manganese phosphate sodium-based positive electrode material, the structural general formula is Na < 4-2x > Mn < 1-2x > MoxV (PO4) 3 / C (0 < = x < = 0.2), and a manganese site is doped with a proper amount of molybdenum so as to jointly improve the energy density and the cycling stability. A target product can be rapidly synthesized through a sol-gel and high-temperature calcination combined method, particles are uniform, the surfaces of the particles are coated with a layer of carbon of 2-5 nm, electrochemical performance is facilitated, and industrialization is easy to achieve. Molybdenum has a high valence state, a small ion radius and a strong Mo-O bond, so that the intrinsic conductivity and the sodion deintercalation rate of the body material can be improved by doping molybdenum into a manganese site of the vanadium manganese sodium phosphate, and volume expansion and ginger-Taylor distortion during a circulation period are inhibited, so that the electrochemical performance of the vanadium manganese sodium phosphate is effectively improved; particularly, the sodium storage performance and the cycling stability in an excellent wide temperature range (-30 DEG C to 60 DEG C) are shown, and the performance is optimal when the molybdenum doping content is 7.5%.

The invention relates to the technical field of nano materials, in particular to a defect-rich MoS2 three-dimensional flower-shaped nano material and a preparation method thereof.According to the defect-rich MoS2 three-dimensional flower-shaped nano material and the preparation method thereof, a 1T / 2H coexisting MoS2 nano flower formed by assembling nanosheets is synthesized through an ultrasonic cooperation template-free hydrothermal method, and the MoS2 nano flower is reduced through NaBH4 at the room temperature to synthesize a defect-rich MoS2-x nano sheet flower-shaped structure. On one hand, due to the flower-shaped 1T / 2H nanostructure, the MoS2 nanosheet has relatively high conductivity in a 1T phase and has good stability in a 2H phase; on the other hand, the defect engineering strategy can effectively construct charge redistribution on the MoS2-x nanosheet rich in sulfur defects, the intrinsic conductivity is further improved, electrochemical active sites are increased, the diffusion rate of Zn < 2 + > is increased, and the electrochemical performance is optimized. Research results show that the defect-rich MoS2-x nanosheet obtains the specific discharge capacity of 258.3 mAh.g <-1 > at 0.1 A.g <-1 >, good rate capability and excellent cycling stability (the capacity is kept at 91.3% after 1500 times of cycling).

The application belongs to the technical field of sodium-ion battery cathode materials, and discloses a pyrophosphoric acid sodium iron phosphate composite material and a preparation method and application thereof. By regulating the microenvironment of chelation reaction, the chelation state of iron ions is optimized, iron ion precipitation is avoided, and the formation of electrochemically inert impurities is inhibited. Meanwhile, graphene oxide constructs a three-dimensional conductive network to improve the electronic transmission capacity of the material. The pyrophosphoric acid sodium iron phosphate composite material prepared by the application has small particle size, uniform dispersion, no inert impurities and is tightly coated by the conductive network. The material has a discharge specific capacity of 120.9 mAh·g ‑1 at 0.5 C, still maintains a reversible capacity of 78.1 mAh·g ‑1 at 20 C high rate, and has a capacity retention rate of 84.9% after 1000 cycles, and the full battery assembled with the hard carbon negative electrode also exhibits excellent rate and cycle performance.

The application provides a preparation method of a lithium iron phosphate positive electrode material modified by phosphoric acid pretreatment and ion doping. Lithium source, iron source, phosphorus source, carbon source, titanium source and vanadium source are mixed with water as a solvent and then sand milling is performed; the slurry is taken out after sand milling; the slurry is subjected to spray drying to obtain yellow material; the yellow material is subjected to primary calcination under an inert atmosphere to obtain a lithium iron phosphate precursor; the lithium iron phosphate precursor is aged in a phosphoric acid solution and then subjected to suction filtration and drying to obtain black powder; and the black powder is subjected to secondary calcination under an inert atmosphere to obtain the lithium iron phosphate positive electrode material. By dispersing the lithium iron phosphate precursor in a phosphoric acid solution with a certain concentration, defects are generated on the surface of the precursor after acidification, which is beneficial to the growth of particles after secondary calcination, improves the compaction density, and the residual phosphate groups are attached to the surface of the precursor and penetrate into the surface layer, which can promote the diffusion of lithium ions between particles and the transmission of lithium ions and electrons between particles.

This invention discloses a bifunctional three-dimensional porous composite material and its preparation method and application. The method includes the following steps: (1) adding a carbon source to deionized water and stirring to obtain a uniformly dispersed solution; (2) dissolving a rare earth metal source, a transition metal source, and a sulfur source in deionized water and stirring to obtain a precursor solution; (3) mixing the solution obtained in step (1) and the precursor solution to obtain a mixed solution and performing a hydrothermal reaction; (4) repeatedly washing the product obtained in step (3), drying it, and then performing heat treatment to prepare the bifunctional three-dimensional porous composite material. The bifunctional three-dimensional porous composite material can effectively buffer the volume expansion effect of the sulfur cathode during charging and discharging and promote the full wetting of the electrolyte. On the other hand, it also improves the conductivity and catalytic activity of the composite material through the doping of rare earth elements, effectively improving the electrochemical performance of lithium-sulfur batteries.

The present application provides a method for preparing an iron-atom-substituted zinc sulfide negative electrode material for a potassium ion battery, comprising: uniformly mixing ammonium ferric citrate, L-cysteine ​​and deionized water to form a solution A; uniformly mixing zinc nitrate hexahydrate and deionized water to form a solution B; uniformly mixing dimethyl imidazole and deionized water to form a solution C; uniformly mixing solution A, solution B and solution C in a weight ratio of 1:2:2-1.5:2:2 to obtain a precursor solution, centrifuging the precursor solution to collect a precursor powder; annealing the precursor powder under an inert atmosphere to obtain an iron-atom-substituted zinc sulfide negative electrode material, which, when applied to a potassium ion battery negative electrode material, can be used at 100 mAg ‑1 At this current density, the specific capacity can still be maintained at 583.9 mAh g after 240 cycles. ‑1 The present application also provides an iron atom-substituted zinc sulfide negative electrode material and a potassium ion battery.

The invention discloses a preparation method and application of a selenium nickel molybdenum sulfide catalyst, and belongs to the technical field of energy materials, the preparation method comprises the following steps: adding selenium powder into a hydrazine hydrate solution to form a solution A; dissolving sodium molybdate dihydrate and thiourea in the reduced graphene oxide suspension to form a mixed solution B; mixing the solution A and the solution B together, stirring to obtain a solution C, transferring the solution C into a high-pressure kettle, and carrying out hydrothermal reaction to obtain a solution D; adding nickel acetate into the solution D, mixing and stirring, carrying out hydrothermal reaction again, washing with deionized water, and freeze-drying to obtain a black product A; and carrying out annealing treatment on the product A by using a tubular furnace under the protection of argon to obtain the selenium nickel molybdenum sulfide catalyst. According to the preparation method and application of the selenium nickel sulfide molybdenum catalyst, the conversion rate is remarkably increased, the interlayer spacing is enlarged, rapid movement of lithium ions is promoted, and the selenium nickel sulfide molybdenum catalyst has huge application potential in the field of rapid charging.