68results about How to "Increase intrinsic conductivity" patented technology

The invention relates to a secondary lithium battery anode composite material, in particular to an oxygen-vacancy-containing lithium ferrous silicate and carbon composite material. The chemical formula of the composite material is Li2FeSiO4-xNy/C, wherein x is more than 0 and less than or equal to 1, y is more than 0 and less than or equal to 0.5, the condition that x is more than or equal to 3y/2 is met, and carbon content is 5-20wt%. The intrinsic conductivity and the lithium ion conductivity inside granules of the composite material are high, and the composite material has excellent performances such as high capacity and high multiplying power. The preparation method of the composite material comprises the steps of: preparing sol from lithium salt, ferrous salt, a silicon source and a carbon source and then carrying out high temperature calcination on the sol twice to obtain granular and oxygen-vacancy-containing lithium ferrous silicate and carbon composite material.

Disclosed are high-rate performance vanadium-doped lithium iron silicate anode material Li2Fel-xVxSiO4/C and a preparation method thereof. The preparation method includes: dissolving V2O5 or NH4VO3 in oxalic acid alcohol solution, mixing lithium salt, ferric salt and silica source in alcohol solution and adding to the oxalic acid alcohol solution, transferring the mixed solution into a reflux system for reflux, obtaining powder and carbon source after alcohol is vaporized, ball milling the powder and the carbon source in acetone medium and drying to obtain precursor powder, sintering, cooling and sieving to obtain the vanadium-doped lithium iron silicate anode material. By solid-phase sintering, a layer of amorphous carbon is coated on particle surface of the material while vanadium is doped, so that resistance among particles is reduced, intrinsic conductivity and lithium ion diffusion coefficient of the material are improved, charge generation in high-rate circulation of the material can be transmitted to other lithium iron silicate crystals or current collectors timely, and voltage lagging due to blocking of transmission of the charge can be restrained.

The invention discloses a low-impedance interface processing method of a solid-state lithium battery positive electrode and a positive electrode structure. By the method, impedance of two interfaces between active material particle in a positive electrode plate and solid-state electrolyte particle and between the positive electrode plate and an electrolyte piece can be effectively reduced, so thatthe capacity of active positive electrode particle in the solid-state lithium battery can be effectively developed. The dual-layer structure ceramic piece comprising a solid-state electrolyte layer and a positive electrode layer and fabricated by the method is excellent in performance and has favorable application prospect in the field of solid-state lithium batteries.

The invention provides a LiFePO4 positive electrode material modified jointly by doping and coating, and the LiFePO4 positive electrode material is modified jointly by iron doping and oxide coating. The raw materials comprise a lithium source Li2CO3, an iron source Fe2O3, a vanadium source NH4VO3, a phosphorus source NH4H2PO4, a carbon source glucose and oxide-coated acetates or esters. The acetates comprise cobalt acetate, zinc acetate or nickel acetate, and the esters comprise tetraethyl orthosilicate or zirconic acid diethyl ester. The specific method comprises the following steps: carrying out ball milling on the lithium source, the vanadium source, the iron source and the phosphorus source and then pre-roasting, carrying out carbon source ball milling and sintering, re-sintering the product after the sintered product is dissolved with the acetates or esters, and stirring the sintered sample, and then smearing the stirred sample on an aluminum foil, thus obtaining the modified LiFePO4 positive electrode material. The intrinsic conductivity of Li3V2(PO4)3 is improved by doping iron ions; the electron conductivity of Li3V2 (PO4) 3 is improved by oxide coating, the cost is low, and no pollution occurs; less harmful gas is emitted in the synthesis process; the electrochemical performance of the material is excellent.

The invention belongs to the technical field of lithium ion capacitors, and discloses a molybdenum disulfide-based composite material for a negative electrode of a lithium ion capacitor and a preparation method thereof. The method includes: (1) Ammonium molybdate tetrahydrate or ammonium molybdate, aniline, phosphorus and graphene oxide were mixed uniformly in water; the pH value of the reaction system is adjusted to 4-5, the reaction temperature is kept to obtain the precursor; (2) the precursor reacts under acidic condition and initiator to obtain intermediate product; Acidic condition refers to pH 1.7 - 2.3 of the reaction solution; 3) dispering that intermediate product and thiourea in water, and place the intermediate product and thiourea in a hydrothermal reaction device for hydrothermal reaction to obtain molybdenum disulfide matrix composite material. The method of the invention is simple and efficient. As that composite material obtain has excellent electrochemical propertiesand cycle stability, the composite material has excellent lithium storage performance in a lithium ion capacitor negative electrode material, and has wide application prospect in a lithium ion capacitor.

The invention discloses a modified positive electrode material for a lithium iron phosphate battery and a preparation method of the modified positive electrode material. The preparation method comprises the following steps of (1) carrying out mixed reaction and drying on a compound A and a compound B to obtain a zirconium-doped carbon material precursor; (2) sintering the zirconium-doped carbon material precursor obtained in the step (1) to obtain a zirconium-doped carbon material; and (3) carrying out mixed reaction and drying on lithium iron phosphate and the zirconium-doped carbon material obtained in the step (2) to obtain the modified positive electrode material for the lithium iron phosphate battery, wherein the compound A is the compound capable of providing a carbon source and a nitrogen source and the compound B is the compound capable of providing a zirconium source. Compared with the prior art, the modified positive electrode material for the lithium iron phosphate battery has the advantages that the lithium iron phosphate is modified through the zirconium-doped amorphous carbon material, the resistance of lithium ion migration is reduced, volume expansion of the material in the charge-discharge process is improved, the carbon material is prevented from falling off and the modified positive electrode material has a good application prospect. The invention further discloses a lithium-ion battery.

The invention belongs to the technical field of composite functional materials, and particularly relates to a bimetal covalent organic framework material and a preparation method thereof and an aptamer sensor. The bimetal covalent organic framework material is a metal-covalent composite organic framework material, and comprises a covalent organic framework main body formed by carrying out a Schiffbase condensation reaction on tetraamino metal phthalocyanine and PTD, and metal ions compounded with a PTD unit on the covalent organic framework main body in a metal-organic coordination form, wherein the metal in the tetraamino metal phthalocyanine is selected from cobalt or nickel. The metal ions are introduced into porous COFs in a targeted manner to form metal covalent organic frameworks (MCOFs). The MCOFs can build a bridge between the MOFs and the COFs, so that the porosity, the stability, the crystallinity and the adjustability of the MOFs and the COFs can be balanced, and complementary characteristics are formed between the MOFs and the COFs.

The invention relates to the technical field of a lithium ion battery electrode material, in particular to a preparation method of a lithium iron phosphate-based modified positive electrode material.The method comprises the following steps of putting a zirconium source compound into distilled water; performing crushing treatment through a ball milling machine until the particle diameter is 2 to 12 mu m; therefore firstly performing modification treatment on graphene and carbon nanometer tubes; then, bonding zirconium in the zirconium source compound with the carbon; after the heat treatment,introducing the zirconium onto the surface of the graphene to obtain zirconium doped carbon materials; then, modifying the lithium iron phosphate by the zirconium doped carbon materials to make the partial zirconium dope into the lithium iron phosphate. The conductivity between the lithium iron phosphate particles is enhanced; the compatibility of the material surface and electrolyte is improved;the resistance received during the lithium ion migration is reduced; the electrochemical performance of the battery in low-temperature environment can be further improved.

The invention discloses a preparation method of graphene/nano-carbon-black modified viscose fibers. Nano-carbon-black with a specific DBP value is compounded with single-layer graphene oxide accordingto a specific proportion, the graphene oxide is reduced in a heating alkaline environment to form a stable compound structure, the graphene oxide can be directly mixed with viscose spinning liquid after washing, good dispersion is kept, spinning is performed to obtain the novel viscose fibers with anti-static, anti-ultraviolet and anti-bacterial functions, product functions are stable and cannotbe attenuated along with washing, the fibers can be directly prepared on a viscose fiber production line, an original process is minimally changed, and the prepared fibers can be applied to underwear,coats, pants, socks and shoe materials.

The invention relates to a method for preparing a boron-doped nano-metal/porous silicon-carbon composite negative electrode based on cut silicon wastes. The method comprises the following steps: removing impurities from cut silicon wastes, and carrying out metal-assisted etching treatment to obtain a nano-metal/porous silicon composite material; mixing the nano-metal/porous silicon composite material with a boron source, and carrying out high-temperature treatment to form substitution doping of silicon by boron; compounding with a carbon material to obtain the boron-doped nano-metal/porous silicon-carbon composite negative electrode. By adding the porous structure of silicon and the carbon material, the volume expansion of silicon can be relieved and cycling stability is increased; the metal particles are physically compounded with silicon on the surface of the silicon substrate, and the boron has the chemical doping synergistic effect of silicon on the atomic scale, so that the intrinsic conductivity of the silicon-based composite material and the electrochemical activity are finally improved, and the boron-doped nano-metal/silicon-carbon composite negative electrode material withhigh charge-discharge specific capacity and long cycle life is prepared.

The invention relates to a sulfur-doped lithium titanate/graphene oxide composite material, a preparation method and application of the sulfur-doped lithium titanate/graphene oxide composite material.The preparation method comprises the following steps that: (a) a titanium source is dissolved in a solution, and stirring is performed, so that a titanium source solution is obtained; (b) a lithium source is dissolved in deionized water, stirring is performed, so that a lithium salt solution is obtained; (c) the lithium salt solution is added into the titanium source solution, stirring is performed, so that a mixed solution is obtained; (d) PVP and graphene oxide are added into the mixed solution, ultrasonic dispersion is carried out, then a hydrothermal reaction is carried out, centrifugingand drying are performed, so that a lithium titanate/graphene oxide precursor can be obtained; (e) the lithium titanate/graphene oxide precursor is sintered in a reducing atmosphere, so that a lithiumtitanate/graphene oxide composite material can be obtained; and (f) the lithium titanate/graphene oxide composite material is mixed with a sulfur source, an obtained mixture is sintered in a reducingatmosphere, so that the sulfur-doped lithium titanate/graphene oxide composite material can be obtained. A sodium ion battery applying the composite material prepared by the above preparation methodhas the advantages of high capacity and the like. The sulfur-doped lithium titanate/graphene oxide composite material can be used as the active material of the negative electrode of the sodium ion battery.

The embodiment of the invention relates to a soft carbon-coated boron-doped silicon-based negative electrode material and a preparation method and application thereof. The silicon-based negative electrode material is a powder material, and the powder conductivity is 2.0 S/cm to 6.0 S/cm; the soft carbon-coated boron-doped silicon-based negative electrode material comprises the following components in percentage by weight: 90wt%-99.49 wt% of a silicon-based powder material, 0.01 wt%-3wt% of a doping material doped in the silicon-based powder material and 0.5 wt%-7wt% of a soft carbon material; the silicon-based powder material is specifically a powder material containing electrochemical activity and comprises one or more of a nano silicon-carbon composite material, silicon monoxide, modified silicon monoxide, doped silicon monoxide and amorphous silicon alloy; the doping material comprises one or more of titanium boride, boron nitride, boron trichloride, boric acid, diboron trioxide, sodium tetraphenylborate, sodium borohydride and sodium borate; and the soft carbon material is coated on the outer surface of the silicon-based powder material to form a coating carbon layer of the boron-doped silicon-based negative electrode material.

The invention discloses a flame-retarding anti-static polyester and a preparation method thereof. The preparation method comprises the following steps: through selecting carbon black with a specific DBP value, in a specific proportion, compounding with carbon nano tubes and graphene, forming a nano composite structure with good electrical conductivity; and after enabling the nano composite structure to perform in-situ copolymerization and melt spinning with terephthalic acid and ethylene glycol, preparing composite polyester fibers with both flame retardance and anti-static property. The preparation method is capable of, in the case of only adding trace carbon nano tubes (0.12%), trace graphene (0.2%) and little carbon black (1.2%), remarkably improving electrical conductivity and flame retardance of a traditional polyester, in addition, a product is good in spinnability, stable in performance, low in cost, and small in industrialization difficulty, and has a remarkable practical value.

The invention relates to a super-smooth carbon nanotube epoxy resin composite material and a preparation method and application thereof. The super-smooth carbon nanotube epoxy resin composite materialcomprises a master batch and a curing agent, wherein the master batch comprises epoxy resin and super-aligned carbon nanotubes dispersed in the epoxy resin. According to the invention, the super-smooth carbon nanotubes with higher length-diameter ratio and fewer defects are added into the epoxy resin for the first time to form the composite material, and the conductive material with high conductivity and extremely low threshold value can be obtained by only needing a very small addition amount. Furthermore, a non-covalent functionalized surface treatment technology is used for modifying the superparaxial carbon nanotubes so that the dispersion of the superparaxial carbon nanotubes in the epoxy resin and the binding capacity of the superparaxial carbon nanotubes with the epoxy resin are improved, and no defects are introduced to the surfaces of the carbon tubes, thereby improving the intrinsic conductivity of the carbon tubes. Meanwhile, through the combination of different mechanicaldispersion methods, the dispersion capability of the super-smooth carbon nanotubes in the epoxy resin is further improved.