166 results about "Silicon nanoparticle" patented technology

The invention provides a sphere-like silicon-carbon negative electrode material and a preparation method and application thereof, and particularly relates to the technical field of negative electrode materials, the negative electrode material comprises a sphere-like porous carbon skeleton, silicon nanoparticles distributed in the sphere-like porous carbon skeleton, and an amorphous carbon layer coating the surface of the sphere-like porous carbon skeleton, the particle appearance of the sphere-like porous carbon skeleton is of a round irregular or asymmetric polyhedral structure and comprises one or more of a potato shape, an ellipse shape, an olive shape, a long strip shape and a pomegranate shape, the particle of the sphere-like porous carbon skeleton is provided with a plurality of asymmetric faces, fillets are formed between the faces, and the radius of the fillets does not exceed 20 microns. The problem of structural damage of the material under the action of external force such as rolling can be effectively relieved, good mechanical stability is kept, excellent bonding performance can be achieved in the electrode coating process, the ion transmission path of the material is improved, and the electronic conductivity and the lithium ion diffusion performance are improved.

The invention discloses a porous silicon-carbon composite negative electrode material, a one-step preparation method, a lithium ion battery and application, and belongs to the technical field of lithium ion battery materials, the method comprises the following steps: mixing a silicon source, magnesium powder, a carbon source and a soluble pore forming agent to obtain mixed powder; performing high-energy mechanical ball milling on the mixed powder in an inert atmosphere, and performing acid pickling, high-temperature carbonization treatment, cooling, water washing, suction filtration and drying to obtain the porous silicon-carbon composite negative electrode material; the porous silicon-carbon composite negative electrode material comprises a porous shell formed by amorphous porous carbon and a porous core formed by silicon nanoparticles embedded in the porous shell, the mechanical collision energy generated in the high-energy mechanical ball milling process triggers the low-temperature magnesiothermic reduction reaction between the silicon source and the magnesium powder, the carbon source is attached to the surfaces of silicon particles while the silicon particles are generated, and silicon synthesis, carbon coating and pore forming are synchronously achieved. The silicon-based negative electrode has the advantages of high initial coulombic efficiency, high specific capacity, excellent cycle stability and rate capability, and effectively solves the problems of volume expansion and large-scale preparation of the silicon-based negative electrode.

The invention provides a silicon-based material and a preparation method thereof, a lithium ion battery monomer, a battery device and a power utilization device, the silicon-based material comprises a porous carbon matrix and silicon nanoparticles located in pores of the porous carbon matrix, the surface of each silicon nanoparticle is provided with a silicon oxide passivation layer formed through a passivation reaction, the ratio of the ID / IG of the silicon-based material to the ID / IG of the porous carbon matrix before the passivation reaction is (0.95-1.05): 1; the mass multiple of the Si element and the C element in the silicon-based material is recorded as A, the mass multiple of the Si element and the C element before the passivation reaction is recorded as B, and the ratio of A to B is (0.95-1.05): 1. According to the invention, the thermal safety performance, the cycle performance and the rate capability of the lithium ion battery monomer can be improved.

The invention discloses a porous silicon carbon negative electrode material, a preparation method thereof and a battery. A matrix of the porous silicon carbon negative electrode material is porous carbon, a conductive layer is deposited in pores of the porous carbon, a fast ion layer is deposited on the surface of the conductive layer, a silicon nanoparticle layer is deposited on the outer side of the fast ion layer, and carbon coating layers are deposited on the surface of the porous carbon and among silicon nanoparticles. According to the method, the conductive layer is firstly deposited, then the fast ion layer is deposited, and a Li reaction place is changed from point-to-point contact of silicon particles and porous carbon into surface-to-surface contact of the conductive layer and the conductive ion layer, so that a Li < + > desolvation barrier and electronic impedance of a substrate are greatly reduced.

The invention discloses a solid-state battery negative electrode material and a preparation method and application thereof, and relates to the technical field of solid-state batteries. The preparation method comprises the following steps: uniformly mixing silicon nanowires, silicon nanoparticles, a carbon nanofiber precursor material and a solvent, preparing a negative electrode material precursor by adopting electrostatic spinning, and carrying out pre-oxidation treatment and carbonization treatment to prepare the solid-state battery negative electrode material, wherein the mass ratio of the silicon nanowires to the silicon nanoparticles is 1: (0.1-4). According to the invention, the silicon nanowires and the silicon nanoparticles are cooperated, and the carbon nanofibers are used as a carrier to form a three-dimensional network structure, so that the diffusion path, anisotropic stress distribution and crushing resistance of Li can be shortened, the cycle performance is improved, and the carbon nanofibers not only improve the mechanical stability of Si in the cycle process, but also provide good conductivity for the electrode. The problems of volume change and low conductivity of the silicon negative electrode material in the use process are effectively solved, and the interface stability of the silicon negative electrode material and a solid electrolyte material is enhanced.

The invention discloses a silicon-carbon composite negative electrode material with silicon coated by porous carbon as well as a preparation method and application of the silicon-carbon composite negative electrode material, silicon nanoparticles (50-100nm) are taken as a core and are uniformly coated by a porous carbon layer derived from a zeolite imidazate framework material to form a core-shell structure (Si-C), and a silicon / carbon dual-phase coexisting composite material is constructed. The material is further doped with Ni, Co or Zn elements in situ, so that the conductivity and the catalytic activity are improved. The preparation method comprises the following steps: (1) carrying out solvothermal synthesis on a Ni / Co / Zn-ZIF precursor; (2) mixing the silicon nanoparticles with a ZIF precursor, and performing gradient carbonization (350-800 / 900 DEG C) to form a carbon-coated silicon structure; and (3) compounding with a conductive agent and a binder to prepare the negative pole piece. The silicon-carbon composite material disclosed by the invention has high silicon loading capacity (40-60wt%), and the first-circle discharge capacity reaches 1650mAh / g. The material is suitable for high-energy-density lithium ion batteries, and has the advantages of simple process, low cost and large-scale production.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly discloses a nanometer silicon / high-entropy alloy oxide / carbon composite lithium ion battery negative electrode material with a honeycomb-like three-dimensional hierarchical nanometer structure and a preparation method of the nanometer silicon / high-entropy alloy oxide / carbon composite lithium ion battery negative electrode material. The preparation method comprises the following steps: respectively adding PVP and silicon nanoparticles into deionized water, and stirring for 12-24 hours; adding oxysalts of iron, nickel, cobalt, chromium and manganese with equal molar weight, stirring for 12-24 hours, and then freeze-drying for 24-48 hours; and finally, putting the freeze-dried product into a tubular furnace, and calcining at high temperature in an inert atmosphere to obtain the composite lithium ion battery negative electrode material. A half battery prepared from the composite lithium ion battery negative electrode material prepared by the method has high initial specific discharge capacity and excellent capacity retention ratio, and the preparation method of the composite material is simple and convenient to operate, low in cost and suitable for large-scale production, and provides a new idea for preparation of a silicon-based composite electrode.

The invention discloses a silicon-carbon composite material, a preparation method thereof, a negative plate and a lithium ion battery, and belongs to the technical field of lithium ion batteries. When the silicon-carbon composite material is prepared, the carbon nanotubes and the silicon nanoparticles on which the vertical graphene grows are dispersed in a dispersing agent to form dispersion liquid, and the dispersion liquid is subjected to spray drying to obtain the silicon-carbon composite material. The silicon-carbon composite material comprises a core body on which vertical graphene grows and a carbon nanotube coating layer coating the surface of the core body. The silicon-carbon composite material is applied to a battery negative electrode, and the two-dimensional vertical structure of the vertical graphene and the one-dimensional linear structure of the carbon nanotube are effectively compounded, so that the electron and ion transmission rate can be improved, and the probability of deformation or pulverization and falling of a negative electrode plate caused by the volume change of silicon is reduced; furthermore, the rate capability and the cycle performance of the lithium ion battery can be improved.

The invention discloses a long-circulation lithium battery and a preparation method thereof, and relates to the technical field of lithium battery preparation, the long-circulation lithium battery comprises a gradient doped ternary material-spinel composite structure positive electrode material, a designed porous carbon skeleton confined silicon nanoparticle (Si-C) negative electrode material, and a lithium bis (fluorosulfonyl) imide (LiFSI)-based high-concentration electrolyte, the surface of the polyimide (PI)-based composite diaphragm is coated with a boron nitride nanosheet (BNNS) and polydopamine (PDA), and a three-dimensional porous current collector and a gradient porosity electrode are introduced into the battery structure; through gradient doping and composite coating of a positive electrode material, negative electrode porous carbon confinement silicon and pre-lithiation, collaborative optimization of a high-concentration electrolyte, a high-heat-resistance self-repairing diaphragm and design of a three-dimensional porous current collector and a gradient porosity electrode, remarkable improvement of the battery in the aspects of high energy density, ultra-long cycle life, high safety and rapid charge and discharge performance is realized.

The invention provides a spherical silicon-based composite material and a preparation method thereof, a negative electrode and a battery, and relates to the technical field of silicon-based composite materials, the spherical silicon-based composite material comprises phenolic resin microspheres, a conductive agent and silicon nanoparticles, the phenolic resin microspheres are doped with the conductive agent to form a matrix of the spherical silicon-based composite material, and the silicon nanoparticles are doped with the conductive agent to form the spherical silicon-based composite material. The phenolic resin microspheres are of a regular spherical structure, grooves or protrusions or the combination of the grooves and the protrusions are arranged on the outer surfaces of the phenolic resin microspheres, the conductive agent is evenly dispersed in the phenolic resin microspheres, and part of the conductive agent is dispersed on the outer surfaces of the phenolic resin microspheres. The matrix is activated to form porous carbon microspheres with discontinuous porous channels or pores, and the silicon nanoparticles are deposited in the porous channels or pores. The problems that the ion conduction rate of the spherical silicon-based composite material is reduced and the conductivity is reduced can be solved, so that the first efficiency and the cycle stability of the spherical silicon-based composite material are improved.

A silicon-carbon composite material, a negative electrode sheet and a battery. The silicon-carbon composite material comprises a hierarchically porous carbon material, silicon nanoparticles dispersed in pore channels of the hierarchically porous carbon material, and an amorphous carbon layer that coats a surface of the hierarchically porous carbon material, wherein the porous structure of the hierarchically porous carbon material comprises micropores, mesopores and macropores, the pore volume is 0.4 cm3 / g to 1.5 cm3 / g, and the pore volume of the micropores accounts for 60% to 92% of the total pore volume. The silicon-carbon composite material can effectively inhibit the aggregation of the silicon nanoparticles and reduce the phenomenon of stress concentration; and when the silicon-carbon composite material is used as a negative electrode active material for the preparation of a battery, better first-cycle efficiency, a lower expansion rate and a higher cycling stability can be obtained.

The invention provides a silicon-based negative electrode material and a preparation method and application thereof, and particularly relates to the field of negative electrode materials, the negative electrode material comprises an inner core and a coating layer coating the surface of the inner core, the inner core is composed of a porous carbon matrix and silicon nano-particles deposited in pore channels of the porous carbon matrix, the coating layer is a short-range ordered high-texture carbon layer, and the coating layer is a silicon nano-particle coating layer. The thickness of the high-texture carbon layer is 0.5-30 nm, the length-diameter ratio of the carbon lines is 1-10, and the interlayer spacing is 0.33-0.37 nm. According to the technical scheme, through the synergistic effect of the surface oxygen passivation layer and the high-texture carbon coating layer formed at a high temperature, silicon volume expansion is effectively inhibited, side reactions are reduced, and meanwhile the electrode conductivity and cycling stability are remarkably improved.

The invention relates to the technical field of nano-particle preparation, and discloses preparation and application of a hollow porous yolk shell structure silicon-carbon nano-composite material. According to the hollow porous yolk shell structure silicon-carbon nano-particle provided by the invention, a silicon nano-sphere is used as a core, and a hollow layer between a carbon shell layer and the core is based on a carbon-coated porous channel; the volume change of the silicon nanoparticles in the charging and discharging process is fully released, and the mechanism stability of the electrode material is kept; meanwhile, the hollow structure and the porous structure are beneficial to de-intercalation migration of lithium ions in the silicon nanoparticles, and the rate capability is increased; in addition, the carbon coating layer can avoid direct contact between the silicon nanoparticles and an electrolyte, so that the electronic and ionic conductivity of the material is ensured, and the first coulombic efficiency is improved. When the carbon-silicon composite material prepared by the method is used as a negative electrode, the battery capacity is relatively high, and the rate capability is relatively long.

A method for directly coating silicon nanoparticles onto a solid substrate uses a VHFLPP process that collects silicon nanoparticles in a trapping fluid when preparing the silicon nanoparticles and is also characterized in that the solid substrate is immersed in the trapping fluid during collection of the silicon nanoparticles.

The application relates to a composite sodium ion battery anode material and a preparation method and application thereof, and belongs to the technical field of sodium ion batteries. The preparation method comprises the following steps: S1, dissolving polyacrylonitrile and tetrabutyl titanate in a solvent II, uniformly mixing to obtain a shell layer solution; dissolving multi-walled carbon nanotubes and styrene-acrylonitrile copolymer in a solvent III, uniformly mixing to obtain a core layer solution; stirring and heating gallium, silicon and silicon dioxide, then adding a solvent I to obtain gallium-silicon nanoparticles through ultrasonic treatment, adding the gallium-silicon nanoparticles into the core layer precursor solution to obtain an intermediate layer solution; S2, performing three-axis electrostatic spinning on the three solutions through a concentrically shaped channel nozzle to obtain a composite film; and S3, carbonizing the composite film to obtain the composite sodium ion battery anode material. The composite sodium ion battery anode material can make the electrode have high capacity and excellent cycle stability, prolong the service life of the battery, and is a self-healing and self-repairing battery anode.

The present invention relates to a silicon-nanographite aerogel for use as an anode in a battery, such as a lithium ion battery, comprising a matrix of nanographite flakes consisting of a mixture of graphene, multilayer graphene and graphite nanoplatelets, and silicon nanoparticles having a diameter between 1 nm and 100 nm, whereby the aerogel has a three-dimensional structure with pores between the flakes, whereby the specific surface area accommodates a volume expansion of the silicon nanoparticles of at least 400% during lithiation, and wherein the surfaces of the nanographite flakes are for 10 to 90% covered with nanoparticles of silicon or wherein the aerogel has a specific surface area between 10 and 500 m2 / g as measured using a BET (Braunauer-Emmett-Teller). The invention also relates to a method of making the aerogel and an electrode comprising the aerogel.

The application discloses a preparation method of nitrogen-doped carbon-silicon nanofibers and application of the nitrogen-doped carbon-silicon nanofibers in a lithium ion battery negative electrode material, and belongs to the technical field of lithium ion battery negative electrode materials. The method comprises the following steps: mixing silicon nanoparticles and a carbon source, performing electrostatic spinning, stabilization treatment and carbonization treatment, and obtaining carbon-silicon nanofibers; and then mixing the carbon-silicon nanofibers with a nitrogen source, performing heat treatment under an inert atmosphere, making nitrogen elements doped into a carbon skeleton, and obtaining nitrogen-doped carbon-silicon nanofibers. The material obtained by the application is a one-dimensional nanofiber structure, silicon particles are uniformly wrapped in carbon fibers, and nitrogen elements are uniformly distributed in the carbon skeleton. The method can realize uniform nitrogen doping while maintaining the microstructure of the material, and significantly improves the electronic conductivity and interface stability of the material. The material obtained by the application is used as a lithium ion battery negative electrode, and exhibits high reversible capacity and excellent cycle stability.

This application provides fluorescent silicon nanoparticles, their preparation method, and a water-soluble fluorescent anti-counterfeiting ink, relating to the field of silicon nanomaterials technology. The preparation method of the fluorescent silicon nanoparticles includes: mixing and reacting a silicon source, a reducing agent, and water to obtain the fluorescent silicon nanoparticles; wherein the silicon source includes 3-aminopropyltriethoxysilane; and the reducing agent includes humic acid. The fluorescent silicon nanoparticles prepared in this application appear green under 365nm ultraviolet light irradiation and can be applied to water-soluble fluorescent anti-counterfeiting inks. This application uses a low-cost, simple, readily available, rapid, convenient, and mild preparation method to prepare fluorescent silicon nanoparticles with excellent acid and alkali resistance, light resistance, and salt resistance. When applied to fluorescent anti-counterfeiting inks, they can produce clear and bright fluorescent patterns.

This invention relates to a silicon-based anode material with a self-healing layer, its preparation method, and its application, belonging to the field of lithium-ion battery technology. By mixing and drying silicon nanoparticles, a carbon source, and a gallium source in the liquid phase, followed by a one-step high-temperature annealing, a hierarchical structure of "core-buffered intermediate layer-shell" is obtained. This structure consists of a silicon nanoparticle core, a gallium oxide intermediate layer covering the core surface, and a carbon shell layer covering the intermediate layer. The in-situ transformation and alloying reaction of the gallium oxide intermediate layer during lithium intercalation buffers the expansion stress of the internal silicon core, fundamentally preventing the outermost carbon shell from cracking. Simultaneously, the liquid metal network generated in the intermediate layer bridges the broken silicon particles, achieving self-healing of the electrode, thereby achieving high specific capacity, long cycle life, and low macroscopic expansion rate.

A negative electrode active material comprising: a composite that includes a carbon-based material and silicon nanoparticles. The silicon nanoparticles have a pipe-shaped structure extending in one direction by a length. A wall portion of the silicon nanoparticles includes an inner wall forming a through hole having a diameter, and the wall portion has a thickness from the inner wall to an outer wall. Also disclosed is a negative electrode comprising a current collector having a negative electrode active material layer comprising the negative electrode active material on it. Further disclosed is a rechargeable lithium battery comprising the negative electrode and a positive electrode.

This invention relates to the preparation and application of silicon-carbon anode materials, and discloses a silicon-carbon anode material modified with lithium phosphide nanoparticles, its preparation method, and a secondary battery. The material has a core-shell structure, with the core comprising porous carbon and lithium phosphide nanoparticles and silicon nanoparticles generated in situ within the micropores of the porous carbon; the shell comprises a composite coating layer composed of amorphous carbon and carbon nanotubes; silicon accounts for 45-65 wt% of the modified silicon-carbon anode material by mass, and the P / Si molar ratio of the lithium phosphide nanoparticles to the silicon nanoparticles is 2:98~30:70. A small amount of phosphorus source is first deposited in the porous carbon micropores, followed by lithiation treatment to convert the phosphorus in the porous carbon into lithium phosphide nanoparticles, then a second deposition of silicon nanoparticles, and finally overall carbon coating. This invention's modified silicon-carbon anode material improves the problem of rapid impedance increase in the low-charge range of silicon-carbon anode materials, significantly enhancing the user experience.

The present invention provides a lubricant additive composition for reducing a friction coefficient and improving wear resistance, and more specifically, the lubricant additive composition is characterized by containing an emulsion solution in which silicon nanoparticles, zinc nanoparticles, and cerium nanoparticles are dispersed. As described above, the lubricating oil additive containing the emulsion solution in which the silicon, zinc, and cerium nanoparticles are dispersed reduces the friction coefficient of the lubricating oil, thereby improving fuel efficiency, reducing exhaust gas, and improving the lifespan of a vehicle.

According to an exemplary embodiment of the present invention, a silicon-carbon composite that can improve the lifespan characteristics of a secondary battery is provided. The silicon-carbon composite is a silicon-carbon composite for use as a negative electrode active material, comprising a carbon matrix and silicon nanoparticles trapped in the carbon matrix, wherein the surface roughness (Rq) of the silicon-carbon composite can be 4-50 nm.

A negative electrode active material for a lithium secondary battery, according to the present invention, includes a silicon-carbon composite including silicon nanoparticles and a carbon-based matrix, wherein the silicon-carbon composite includes 0.5-7 parts by weight of polyvinyl butyral (PVB) based on 100 parts by weight of the silicon nanoparticles.

A negative electrode active material for a lithium secondary battery according to the present invention includes a silicon-carbon-based composite including: silicon nanoparticles; a carbon-based matrix; and a conductive additive, wherein the content of the conductive additive may be 0.2-10 wt% relative to the silicon nanoparticles in the composite.

A lithium-ion solid-state battery component includes an electrode with a current collector and a silicon-based active layer. The active layer is made of silicon nanoparticles encapsulated within an interwoven carbon nanotube network. The carbon nanotube network is configured to maintain electrical connectivity and mechanically stabilize the silicon nanoparticles during volume expansion and contraction of the electrode during charge cycling.

The invention relates to the technical field of gas separation, and discloses a composite hollow fiber membrane for efficient separation of ship tail gas SO2, and the composite hollow fiber membrane comprises the following components in parts by weight: 8-12 parts of polyether sulfone, 1-3 parts of montmorillonite, 0.5-2 parts of silicon nanoparticles, 0.1-1 part of a carbon nanomaterial, 0.5-2 parts of polyvinyl alcohol and 5-15 parts of a functional compound, the invention also provides a preparation method of the composite hollow fiber membrane for efficient separation of SO2 in ship tail gas, and the preparation method comprises the following steps: adding polyether sulfone, montmorillonite silicon nanoparticles, a carbon nanomaterial and polyvinyl alcohol into a proper amount of solvent to form a mixture solution, and stirring the mixture at 60-80 DEG C for 3-6 hours to prepare a composite solution. According to the composite hollow fiber membrane disclosed by the invention, the gas separation efficiency is remarkably improved by optimizing the formula and structural design of the material, and the selectivity of the membrane is enhanced by the introduced nano carbon material and montmorillonite.

The present disclosure relates to single-crystal spherical silicon nanoparticles which are monocrystalline are spherical and have an average particle diameter of 1 nm to 20 nm as well as a method of producing the same. The single-crystal spherical silicon nanoparticles of the present invention can produce fluorescence at a high fluorescence quantum efficiency upon excitation by light in a wide range of wavelengths from deep ultraviolet light having a wavelength of 200 nm to 300 nm to visible light, and can increase the conventionally known fluorescence quantum efficiency of silicon nanoparticles from around 1% to 10% or more.

This invention belongs to the field of food and agricultural product safety testing technology, specifically relating to a rapid detection method for parathion and its application. Based on the parathion-induced blue shift in fluorescence of silicon nanoparticles, ascorbic acid is reacted with 3-aminopropyltriethoxysilane to generate green fluorescent silicon nanoparticles. During the formation of silicon nanoparticles, parathion can embed itself into the porous structure of the silicon nanoparticles through host-guest interactions, causing a change in the excited state of the silicon nanoparticles. This affects the fluorescence emission of the silicon nanoparticles, resulting in a blue shift in the fluorescence emission peak, changing from green fluorescence to blue fluorescence, specifically manifested as an increase in fluorescence intensity at 422 nm and a decrease in fluorescence intensity at 520 nm. By establishing the relationship between ratiometric fluorescence signal or fluorescence color change and parathion concentration, specific detection of parathion is achieved. This invention requires no enzymes or antibodies for parathion detection, is inexpensive, fast, easy to operate, highly sensitive, and has good specificity.

The invention belongs to the technical field of detection of pests in food, and particularly relates to a rapid staphylococcus aureus detection method based on a nano double-fluorescent probe. The method comprises the following steps: synthesizing carbon dots, preparing silicon nanoparticles, carrying out surface functional modification (introducing vancomycin and an antibody), and constructing a ratio-type fluorescent biosensor. The prepared sensor has double emission fluorescence peaks (492 nm and 529 nm), is good in repeatability and high in sensitivity, and quantitatively analyzes the content of staphylococcus aureus by measuring the ratio (F492 / F529) of the two fluorescence peaks. The detection linear range is wide, and the correlation regression coefficient can reach 0.98. The standard recovery rate in actual sample detection is 94-102.9%, and the relative standard deviation is less than 5%. The method is high in specificity and excellent in anti-interference capability, can be widely applied to rapid, accurate and quantitative detection of staphylococcus aureus in complex matrixes such as dairy products and the like, and has a wide application prospect.