42results about How to "Improve volume change" patented technology

The invention discloses a method for preparing nano tin / carbon composite nanofibers through the electrospinning technology. The method includes the steps that first, stannous chloride, polymethyl methacrylate and polyacrylonitrile are prepared into composite nanofibers through the electrospinning technology; then calcination is conducted under the nitrogen atmosphere, so that the polyacrylonitrile is carbonized, SnCl2 is decomposed, the polymethyl methacrylate is subjected to pyrolysis, accordingly, a porous structure is formed, and the nano tin / carbon composite nanofibers are obtained. The method has the advantages that the preparation technology is simple, the reaction condition is easy to control, and the repetitive rate is high; obtained Sn particles are only 1-2 nm and are evenly inlaid N-doped porous carbon nanofibers, and the mass percent of the Sn can reach 60-65%. The composite material is of a three-dimensional net structure which is formed by interweaving nanofibers from the microcosmic view, the composite material can be directly used as the negative electrode of a sodium-ion battery without a binding agent, high electrochemistry sodium storage reversible capacity can be achieved, excellent rate capability and cycling stability are achieved, and the application prospect is very bright.

A set volume control device for an on-vehicle audio system includes: a volume control switch to which a vehicle occupant can arbitrarily give an operational input; and a controller for controlling a set volume changer based on a vehicle speed detected by a vehicle speed detector and the operational input to the volume control switch so that a set volume of an audio system becomes a low vehicle speed region set volume fixed independently of vehicle speed change in a low vehicle speed region; becomes a high vehicle speed region set volume fixed independently of the vehicle speed change in a high vehicle speed region; and changes according to the vehicle speed change along a predetermined medium vehicle speed region set volume change line connecting the low vehicle speed region set volume and the high vehicle speed region set volume in a medium vehicle speed region between the low vehicle speed region and the high vehicle speed region. The controller changes a setting of the low vehicle speed region set volume according to an operational input to the volume control switch within a first volume setting range set up in advance when the volume control switch is operated in the low vehicle speed region, and changes a setting of the high vehicle speed region set volume according to an operational input to the volume control switch within a millisecond volume setting range set up in advance when the volume control switch is operated in the high vehicle speed region. A lower limit of the millisecond volume setting range is set higher than an upper limit of the first volume setting range. Thus, it is possible to accurately control the volume of the audio system and improve feeling of volume change.

A current collector includes a first principal plane and a second principal plane. In the current collector, the roughness of the first principal plane and second principal plane being mutually different.

The invention discloses a three-dimensional porous lithium ion battery anode material of a graphene composite material and a preparation method of the lithium ion battery anode material. The preparation method of the three-dimensional porous lithium ion battery anode material comprises the following steps: dissolving oxidized graphene, semiconductor nanoparticles and polyvinyl alcohol into water, and mixing the raw materials evenly; carrying out freeze drying on the mixture obtained from the previous step in a mold, and obtaining a solid oxidized graphene / semiconductor nanoparticle / polyvinyl alcohol three-dimensional porous nano-material; carrying out thermal treatment reduction on the product which is obtained from the previous step, restoring the electrical conductivity of the product, and obtaining a high-elasticity solid oxidized graphene / semiconductor nanoparticle / polyvinyl alcohol three-dimensional porous graphene composite material; and cutting the material obtained from the previous step into slices to serve as the anode material assembling battery of a lithium ion battery, and obtaining the three-dimensional porous lithium ion battery anode material of the graphene composite material. According to the three-dimensional porous lithium ion battery anode material disclosed by the invention, the electrical conductivity of the graphene material can be restored; the three-dimensional porous lithium ion battery anode material has a three-dimensional continuous conductive network and the cycling stability; and the mechanical property of the material can be adjusted.

The invention belongs to the field of energy storage research, and particularly relates to a silicon-carbon negative electrode material. The particle diameter D1 of the silicon-carbon negative electrode material is 1 micron to 200 microns, the silicon-carbon negative electrode material comprises secondary particle structures, the secondary particles consist of primary particles and an electron conduction component, the particle diameters D2 of the primary particles are smaller than or equal to 0.5D1; the electron conduction component comprises graphene slice layers, and the primary particles and the graphene slice layers are uniformly dispersed; strong binding force exists among the graphene slice layers; a conductive network structure with flexibility can be constructed, and a silicon-based material is fixed in the network structure, so that the silicon-carbon negative electrode material with good performance is obtained.

The invention provides a pitch-based porous carbon material and a preparation method thereof, a silicon-carbon negative electrode material and a secondary battery, which relate to the technical fieldof carbon material preparation. The preparation method of the pitch-based porous carbon material comprises the following steps of: calcining the mixture of the pitch obtained after ball milling and apore forming agent to obtain the pitch-based porous carbon material. The preparation method can alleviate the technical problems of complex process steps, high production cost and low production efficiency when producing porous carbon by using the pitch as a raw material in the prior art, thereby achieving the technical effects of reducing production cost, improving production efficiency and improving porosity of the porous carbon material.

The invention discloses a self-supporting silicon-carbon anode material and a preparation method thereof, and the self-supporting silicon-carbon anode material is obtained by adopting a uniaxial electrostatic spinning method to prepare a nanofiber membrane, and performing drying, heat treatment and carbonization treatment on the nanofiber membrane. The prepared self-supporting silicon-carbon anodematerial is a composite material of composite nanofibers and carbon, and has a three-dimensional network structure, so that the dispersity of nano silicon can be improved, the volume change of silicon can be effectively relieved, a conductive network can be formed, and transfer of electrons and ions is facilitated. The method is simple, stable, continuous and controllable in operation, low in energy consumption and low in cost. The prepared self-supporting silicon-carbon anode material can be directly used as a lithium ion battery, shows better cycle performance in a Si / C battery anode, and has a good application prospect.

The invention discloses a preparation method and application of graphite and cobalt-based metal organic framework composite materials for negative electrode of a lithium ion battery. The method comprises the following steps of mixing cobalt acetate with organic matrix isophthalic acid and uniformly dispersing the mixture, fully mixing the mixture with graphite to obtain a cobalt acetate-organic matrix isophthalic acid graphite mixture; adding N-N dimethylformamide to the graphite mixture, pouring into a hydrothermal reaction kettle after uniform stirring for hydrothermal reaction; taking out the reactant obtained in the hydrothermal reaction kettle for washing and sedimentation to discard the supernatant and retain the precipitate for further centrifugation; and drying the precipitate obtained after centrifugation after being ultrasonically dispersed at room temperature to obtain a graphite and cobalt-based metal organic framework composite. The preparation method and application of graphite and cobalt-based metal organic framework composite materials for negative electrode of a lithium ion battery have the advantages that the preparation method is simple and easy to operate, and the obtained graphite and cobalt-based metal organic framework composite material can effectively improve the volume change brought about by the charging and discharging process of the graphite by being used as an active material of the negative electrode of a lithium ion battery, thereby improving the cycle life of the battery.

The invention relates to the technical field of sodium ion battery materials, and in particular to a preparation method of a sodium vanadium phosphate sodium ion battery composite material. The preparation method provided by the invention comprises the following steps of 1: mixing, ball milling and drying a sodium source, a vanadium source and a phosphorus source to obtain sodium vanadium phosphate precursor powders; 2: pre-sintering and sintering the sodium vanadium phosphate precursor powders is a non-oxidizing atmosphere to obtain sodium ion battery cathode material sodium vanadium phosphate; 3: dissolving a organic carbon source in a dispersant, adding the sodium vanadium phosphate and stirring the mixture in a water bath, evaporating the mixture until a gel is formed, and drying and milling the gel to obtain mixed powders; and 4, mixing and grinding a compound containing the Y element and the mixed powders obtained in the step 3, sintering the mixture at 300 to 500 degrees centigrade for 0.5 to 3 hours to obtain the sodium vanadium phosphate sodium ion battery composite material. The method can solve the technical problem that the existing sodium vanadium phosphate has low electronic conductivity and thus seriously limits its rate performance and cycle performance.

The invention discloses a preparation method of a silicon-carbon composite material. The preparation method comprises the following specific steps of dissolving a water-soluble saccharide compound and a water-soluble polymer into water, adding organic acid or alkali, then adding highly purified nanoscale silicon powder, reacting at 140-300 DEG C, and carrying out dehydration and calcination, thereby obtaining the silicon carbon composite. The preparation method of a silicon carbon composite provided by the invention has the advantages of easily available raw material, lower price, simple preparation method, the silicon carbon composite prepared by using water as a solvent and using the water-soluble saccharide compound as a precursor in a one-pot method has the advantages of fine ductility, elasticity, high porosity and controllable size and the like, and the conductivity of an electron of silicon material is improved, the prepared silicon carbon composite can be used in fields of batteries and semiconductor materials.

The invention relates to a silicon-carbon composite assembled battery. The silicon-carbon composite assembled battery is prepared by steps: (1) adding silicon powder into NaOH solution containing various mixtures and being smaller than 30% in mass ratio, vibrating ultrasonically, filtering and drying to remove surface impurities and oxides of silicon, wherein the mixtures include carbohydrates, high polymers, silicon powder and organic solvents in a mass ratio of 1:1:0.5:5-1:0.1:0.1:0.5; (2) dissolving citric acid in absolute ethyl alcohol to obtain citric acid / ethanol solution with concentration being 0.4g / ml; adding the silicon powder processed at the step 1 into the citric acid / ethanol solution according to an addition quantity of 2g / ml, ultrasonically stirring for reaction for 30min, and subjecting the mixed solution to spray pyrolysis in air at 400 DEG C to obtain the silicon-carbon composite assembled battery. Easiness in raw material acquisition, low cost and simplicity in preparation are realized, and the prepared silicon-carbon composite is small and controllable in size.

The invention discloses a tremella-shaped nanosphere material assembled by inlaying molybdenum dioxide nanoparticles into carbon nanosheets, preparation of the tremella-shaped nanosphere material andapplication of the tremella-shaped nanosphere material in a sodium ion battery. In the material, MoO2 nanoparticles are inlaid in amorphous carbon nanosheets, the carbon nanosheets are interwoven andassembled into tremella-shaped nanospheres, and a large number of mesopores and other pores exist between the carbon nanosheets. The preparation method comprises the following steps of polymerizing ammonium molybdate and dopamine hydrochloride to form a precursor, and calcining to decompose and carbonize, thereby obtaining the final product. The electrochemical activity, the structural stability and the cycling stability of MoO2 can be improved, so that MoO2 has higher specific capacity and more stable cycling performance. The tremella-shaped nanosphere assembled by inlaying MoO2 nanoparticlesinto carbon nanosheets has a remarkable application value when being used as an electrode material of a sodium-ion battery.

The invention discloses a carbon / titanium dioxide coated tin oxide nano particle / carbon assembled mesoporous sphere material as well as preparation and application thereof in a lithium ion battery negative electrode material. In the material, SnO2 nano particles are assembled into mesoporous spheres through carbon, and the surfaces of the SnO2 mesoporous spheres are coated with a layer of TiO2 nano crystals and a layer of amorphous carbon. The preparation method comprises the following steps: firstly, synthesizing SnO2 nano particle / carbon assembled mesoporous spheres by a hydrothermal method,then coating TiO2 by a hydrolysis method, finally coating a layer of resorcinol-formaldehyde resin, and carbonizing to obtain a final product. According to the invention, the electrochemical activity, the structural stability and the cycling stability of SnO2 can be improved, so that SnO2 has high specific capacity and stable cycling performance. The carbon / TiO2 coated SnO2 nano particle / carbon assembled mesoporous sphere has an important application value as a lithium ion battery negative electrode material.

The invention relates to a preparation method for a silicon-carbon composite material, and belongs to the technical field of carbon composite material preparation. The preparation method comprises the specific steps that carbohydrate, high polymer, silicon powder and organic solvent are subjected to reaction in a sealed vessel at the temperature ranging from 150 DEG C-250 DEG C, and the silicon-carbon composite material is obtained through drying and calcination. The preparation method for the silicon-carbon composite material has the advantages that the needed material is easy to acquire, the cost is low, and the preparation process is easy. The prepared silicon-carbon composite material has the advantages of being small and controllable in size, high in the specific capacity and excellent in the cycle performance.

The invention discloses a concrete crack repair material and a preparation method and an application method thereof, and solves the problems of properties to be improved and limited adaptive range of the existing concrete crack repair materials. The preparation method comprises the steps: mixing waste glass, mineral powder, portland cement, a water reducer and molasses according to proportions by weight, then putting the mixture into a wet mill and adding water for milling to prepare slurry; and adding triethanolamine, warm round glue, azobisformamide, a defoamer, a poly-propionate emulsion, dispersible latex powder and fine sand proportionally to the slurry and uniformly mixing the materials. The preparation method has a simple process, convenient control, low production cost and environmental friendliness, and the prepared concrete crack repair material has high strength, high liquidity, low bleeding rate, high cohesiveness and certain swelling property.

The invention provides a Fe2O3 / FeF3-2xOx / Fe<3+>,Co<2+> doped bismuth fluoride layer structure positive electrode material of a lithium battery and a preparation method thereof. According to the method, Fe<3+>,Co<2+> doped bismuth fluoride is prepared through solid-phase synthesis; then on the basis of the characteristic that FeF3 is prone to gradual oxidation into Fe2O3 at a high temperature, FeF3-2xOx (wherein 0<x<0.3) and a Fe2O3 layer successively coat Fe<3+>,Co<2+> doped bismuth fluoride particles so as to improve surface electron conduction capability of Fe<3+>,Ce<4+> doped bismuth fluoride and to resist harmful effect of an organic electrolyte on particle surfaces; and comprehensive electrochemical performance of bismuth fluoride is greatly improved through Fe<3+>,Co<2+> doping.

Hydraulic fluid is supplied from a hydraulic fluid supply opening to a hydraulic fluid supply portion. The hydraulic fluid in the hydraulic fluid supply portion is supplied to a primary hydraulic fluid storage chamber and to a secondary hydraulic fluid storage chamber via a hydraulic fluid supply passage. An oblong cylinder-shaped portion that has a chamber is formed between the hydraulic fluid supply opening and the hydraulic fluid supply portion. Further, a volume-augmented chamber forming portion that has a volume-augmented chamber that is communicated with the chamber is disposed in this oblong cylinder-shaped portion. In that case, at least part of the volume-augmented chamber is positioned above a MAX line of the hydraulic fluid.

A mount apparatus (20) for supporting a vibration source on a base is provided. The mount apparatus (20) includes a moving member (134) that is partially disposed in a pumping chamber (64) for moving within the pumping chamber (64) along a first axis (A) to create a volume change in the pumping chamber (64) to maintain the volume of the pumping chamber (64) to prevent a pressure increase in the pumping chamber (64) during the deformation of a flexible body (46) in response to an external excitation to effectively cancel the external excitation. The moving member (134) includes a moveable wall (144) of a flexible material, having a generally hour glass-shape in steady state, and extending between moving member upper and lower ends (140, 142). The moveable wall (144) flexes radially outwardly and inwardly relative to the first axis (A) in response to relative axial movement between the moving member upper and lower ends (140, 142), to amplify the volume change in the pumping chamber (64).

The invention belongs to the field of anode materials for lithium ion batteries and discloses a graphene-coated silicon composition material as well as a preparation method and application thereof. The preparation method comprises the following preparation steps: carrying out ultrasonic exfoliation dispersion on graphite oxide in deionized water to form oxidized graphene suspension; mixing Si powder with Zn powder, then carrying out ball mill and dispersing into the deionized water to obtain an Si@Zn particle mixed solution; mixing the Si@Zn particle mixed solution with the oxidized graphene suspension, and carrying out stirring reaction at normal temperature to obtain Si@ZnOx@RGO, then soaking with acid to remove ZnOx, washing and drying to obtain a Si@ RGO composite material. The obtained Si@RGO composite material disclosed by the invention has the advantages of improving the conductivity of the composite material while volume change of silicon is inhibited, and has excellent cyclingstability and rate discharge performance.

The invention belongs to the technical field of environmental geotechnics and discloses a mud high-pressure filtering and compressed dewatering testing cavity. The mud high-pressure filtering and compressed dewatering testing cavity comprises a force application pushrod, a top cover, a cylinder barrel, a piston, a lower porous plate, a base and a first water pressure transmitter, wherein the forceapplication pushrod is embedded inside a through hole formed in the top cover and can move axially; the top cover is detachably arranged on the top opening of the cylinder barrel in a sealed mode; the piston abuts against the inner wall of the cylinder barrel and is fixedly connected with the first end of the force application pushrod and driven by the force application push rod to move axially along the inner wall of the cylinder barrel; the base is arranged on the bottom opening in a sealed mode on the cylinder barrel; the lower porous plate is arranged in the lower portion of the inner cavity of the cylinder barrel and abuts against the base; the sensing end of the first water pressure transmitter is fixed inside the inner cavity of the cylinder barrel; the base is provided with a lower drainage channel and communicated with the liquid outlet of the lower porous plate. The mud high-pressure filtering and compressed dewatering testing cavity can in real time convert data of transmission pressure application change, liquid drainage and liquid pressure, thereby increasing diversity of testing data.

The invention discloses a self-supporting silicon-carbon negative electrode material and a preparation method thereof. The invention adopts a uniaxial electrostatic spinning method to prepare a nanofiber film, and then dries, heats and carbonizes the film. The prepared self-supporting silicon-carbon anode material is a composite material of composite nanofibers and carbon, and has a three-dimensional network structure, which can not only improve the dispersion of nano-silicon, but also effectively alleviate the volume change of silicon, and can also form a conductive network. Facilitate the transfer of electrons and ions. The method is simple in operation, stable, continuous, controllable, low in energy consumption and low in cost. The prepared self-supporting silicon-carbon anode material can be directly used as a lithium-ion battery, and it exhibits better cycle performance in the Si / C battery anode, and has a good application prospect.

The invention discloses a concrete crack repair material and a preparation method and an application method thereof, and solves the problems of properties to be improved and limited adaptive range of the existing concrete crack repair materials. The preparation method comprises the steps: mixing waste glass, mineral powder, portland cement, a water reducer and molasses according to proportions by weight, then putting the mixture into a wet mill and adding water for milling to prepare slurry; and adding triethanolamine, warm round glue, azobisformamide, a defoamer, a poly-propionate emulsion, dispersible latex powder and fine sand proportionally to the slurry and uniformly mixing the materials. The preparation method has a simple process, convenient control, low production cost and environmental friendliness, and the prepared concrete crack repair material has high strength, high liquidity, low bleeding rate, high cohesiveness and certain swelling property.