1366 results about "Polyvinylidene difluoride" patented technology

The invention discloses a lithium ion battery composite diaphragm, a preparation method and a lithium ion battery, and relates to the technical field of lithium ion batteries. The lithium ion battery composite diaphragm comprises a base membrane and a functional coating arranged on the negative electrode side of the base membrane, the functional coating sequentially comprises an ion conducting layer, a thermal barrier layer and a self-repairing layer from the position close to the base film to the position far away from the base film; wherein the base membrane is a polyimide and aramid nanofiber blended electrostatic spinning membrane; the ion conducting layer comprises a compound of a modified fast ion conductor and polyvinylidene fluoride-hexafluoropropylene; the thermal barrier layer comprises a cross-linked network of boron nitride nanosheets and polybenzimidazole; the self-repairing layer comprises polyurethane microspheres loaded with dynamic disulfide bonds. The composite diaphragm provided by the invention can remarkably inhibit a purple area on the surface of a negative electrode, and enhance high-temperature self-protection and interface self-repairing of the lithium ion battery, so that the cycle and safety performance of the lithium ion battery are remarkably improved.

The invention provides a diaphragm and a preparation method thereof and a lithium ion battery, the diaphragm comprises a base membrane layer and a composite functional layer, the composite functional layer comprises hydrophobic SiO2 aerogel modified by a hydrophobic agent, a conductive ion polymer and a solid electrolyte, and the composite functional layer respectively accounts for 3-12wt%, 0.5-1.0 wt% and 0.5-1.5 wt% of the total mass of the diaphragm; the hydrophobic agent comprises trimethylchlorosilane, hexamethyldisilazane, perfluorooctyltriethoxysilane, polyvinylidene fluoride, polydimethylsiloxane and the like, the conductive ionic polymer comprises polyvinylpyrrolidone, lithium polymethacrylate, lithium polystyrene sulfonate, polyacrylamide and the like, and the solid electrolyte comprises lithium lanthanum titanium oxide, lithium lanthanum zirconium oxide, lithium lanthanum zirconium tantalum oxide and the like. The wettability is improved by the high porosity of the hydrophobic SiO2 aerogel, the stability and strong conductivity of a physical conductive network of the solid electrolyte and the ion affinity and amphoteric binding capacity of the conductive ion polymer are optimized, the electrochemical performance and thermal stability of the interface are optimized, and comprehensive optimization of the thermal-electric-interface performance of the diaphragm is realized through combination.

The utility model relates to a system for reducing the acid value of hydrolysate in the separation and washing process of dimethyl dichlorosilane hydrolysate. Comprising three stages of coalescers, dimethyl dichlorosilane acidic hydrolysate enters the system from the first stage of coalescer, process water enters the system from the third stage of coalescer, the acidic hydrolysate and diluted hydrochloric acid or process water are mixed in each stage of coalescer, oil-water two-phase separation is completed through multiple times of washing and coalescence, and meanwhile the acid value of the hydrolysate is reduced; each stage of coalescer comprises two static mixers connected in series, a group of prefilters and a large coalescer, the coalescer is Z-shaped, and four stages of filter elements are arranged in each stage of coalescer. Through repeated tests, a modified polyvinylidene fluoride filter element of Pall Company is finally selected, and after continuous three-stage coalescer treatment, the acid value of dimethyldichlorosilane hydrolysate can be reduced to 10 PPM or below.

The invention discloses a preparation method and application of a composite PVDF-HFP and polylysine nanofiber diaphragm, and belongs to the technical field of lithium batteries. The composite material is prepared by blending polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) and polylysine and then carrying out an electrostatic spinning process. The PVDF-HFP is utilized to provide excellent mechanical strength and chemical stability, rich polar amino functional groups in a polylysine molecular chain are utilized to improve the lyophilic property of the membrane, and anions in an electrolyte are fixed through an intermolecular acting force, so that the transference number of lithium ions is increased, and the lithium ions are induced to be uniformly deposited. The nanofiber membrane combines the characteristics of PVDF-HFP and polylysine, has high porosity, good thermal stability and excellent interface compatibility, can effectively inhibit the growth of lithium dendrites and prevent the diaphragm from being punctured, and can significantly prolong the cycle life and improve the safety performance of the lithium metal battery when being applied to the lithium metal battery.

The embodiment of the invention provides a polymer binder, a preparation method thereof and an all-solid-state sulfide lithium battery. The polymer binder is a modified polyvinylidene fluoride-trifluorochlor oethylene copolymer, and chlorine in the modified polyvinylidene fluoride-trifluorochlor oethylene copolymer is partially or completely substituted by bromine and / or iodine; in the modified polyvinylidene fluoride-trifluorochlor oethylene copolymer, the molar ratio of a corresponding repeating unit of polyvinylidene fluoride to a corresponding repeating unit of trifluorochlor oethylene is (1-9): (9-1); in the modified polyvinylidene fluoride-trifluorochlor oethylene copolymer, the weight of chlorine is a, the weight of bromine and / or iodine is b, and b / (a + b) * 100% is equal to 1%-100%. The technical effect of improving the cycling stability and safety of the battery is achieved, and then the technical problems that when a traditional binder is applied to the all-solid-state sulfide lithium battery, the interface is unstable, the binding power is insufficient, and the traditional binder reacts with electrolyte are solved.

The application discloses a preparation method of a hydrophilic oil-water separation anti-pollution membrane and the anti-pollution membrane and application thereof, and prepares MNRs material; the MNRs material is dispersed in dimethylacetamide, is uniformly stirred, polyvinylpyrrolidone is added, and stirring is continued, and a first mixture is obtained through ultrasonic treatment; the first mixture is mixed with polyvinylidene fluoride to obtain a second mixture, and the second mixture is stirred; the treated second mixture is dip-coated on a carrier, the dip-coated carrier is treated in deionized water to obtain an ultrafiltration membrane; the ultrafiltration membrane is soaked in a tea polyphenol solution with a Tris-HCl buffer solution, and is shaken to obtain the hydrophilic oil-water separation anti-pollution membrane. The hydrophilic oil-water separation anti-pollution membrane has excellent separation efficiency and flux recovery rate for four different oil-water mixtures of kerosene, gasoline, edible oil and n-hexane. The preparation process of the oil-water separation membrane is simple, the cost is low, and the reaction condition is mild; when the oil-water separation membrane is applied to organic wastewater separation, the oil-water separation membrane has the advantages of high efficiency, good removal performance and good recycling performance.

The invention relates to the technical field of flexible electronic sensing, and particularly discloses a composite fiber membrane-based capacitive flexible pressure sensor integrated system and a preparation method thereof. The sensor is composed of a composite fiber membrane sensitive layer, an interlayer type electrode structure, a multi-channel signal acquisition module and an intelligent data processing system. Wherein the composite fiber membrane is prepared through an electrostatic spinning technology, polyvinylidene fluoride serves as a matrix, ionic liquid with the mass ratio of 40%-70% is evenly dispersed, a three-dimensional porous structure is formed, and a pressure signal is converted into capacitance change through the double-electric-layer capacitance effect; the signal acquisition module adopts a high-precision capacitance digital converter to cooperatively work with a microcontroller, 9-channel parallel data acquisition is realized, the resolution reaches 6aF, and data is transmitted through an anti-interference bus protocol; and the data processing system dynamically analyzes the pressure-capacitance relationship based on an exponential function model, suppresses noise to be below 0.1 aF RMS in combination with a filtering algorithm, and synchronously generates a visual pressure distribution map.

The invention relates to a water treatment and membrane separation technology, and provides an integrated catalytic separation membrane, a preparation method thereof, and a water treatment method and system. According to the membrane, polyvinylidene fluoride is used as a continuous phase to form a porous matrix, and cerium dioxide is embedded and fixed in a mode of uniform dispersion in a membrane body in a phase inversion membrane forming process; in the presence of illumination and peroxysulfate, active species are generated through in-situ activation on a membrane-water interface, and membrane separation is completed synchronously. The water treatment method comprises the following steps: adding peroxymonosulfate or peroxydisulfate into a water body to be treated, and filtering through the membrane under illumination; the photothermal effect generated by organic matter degradation intermediates in operation inhibits membrane pollution and maintains flux. According to the invention, short-range coupling of active sites and mass transfer channels is realized, the medicament and energy utilization rate is improved, the coating stripping and metal dissolution risk is reduced, and the method is suitable for drinking water pretreatment, reclaimed water deep treatment and treatment of water containing natural organic matters / humic acid.

The invention discloses a preparation method of a catalytic membrane for organic wastewater treatment, which comprises the following steps: dissolving polyvinylidene fluoride (PVDF), a pore-forming agent and plant polyphenol in an organic solvent, and stirring to obtain a membrane casting solution, wherein the PVDF accounts for 12-20%, the pore-forming agent accounts for 1-8%, and the plant polyphenol accounts for 1-6%; standing and defoaming the membrane casting solution, blade-coating the membrane casting solution on a support body to form a membrane, and performing phase inversion in a water bath to obtain the plant polyphenol modified PVDF membrane; and immersing the membrane in a 3-10 mmol / L metal chloride aqueous solution, and reacting at 40-80 DEG C for 6-48 hours, so that metal ions and polyphenol are coordinated and crosslinked, and a metal-polyphenol network layer is formed on the surface of the membrane and the inner walls of membrane pores, thereby obtaining the catalytic membrane. The catalytic membrane can activate peroxymonosulfate (PMS) and synergistically degrade organic pollutants in water under a differential pressure filtration working condition, active sites are anchored stably, metal precipitation is reduced, and flux and catalytic efficiency are both considered.

The application belongs to the field of separation and specifically relates to a cellulose / PVDF electrostatic spinning oil-water separation membrane and a preparation method thereof. The preparation method comprises the following steps: S1: preparing cellulose stearate; S2: mixing cellulose stearate obtained in step S1 and polyvinylidene fluoride (PVDF) prepared into solutions respectively to obtain a spinning solution; and S3: defoaming the spinning solution obtained in step S2 and then electrostatic spinning to obtain a cellulose stearate / polyvinylidene fluoride (PVDF) hydrophobic oleophilic oil-water separation membrane. The mixed electrostatic spinning nanofiber membrane has better mechanical properties, and due to the addition of modified cellulose, the nanofiber membrane has greater separation flux, higher separation efficiency and greater porosity.

A device and method for representing the foam porosity state of foamed lightweight soil with self-adjusting beams, and relates to the technical field of sound absorption coefficients measurement; the device includes a standing wave tube, a plurality of polyvinylidene fluoride piezoelectric films, a sensor, an exciter, a push-pull handle, an adjustable telescopic tube, a foamed lightweight soil detection material, a charge amplifier, a data memory, a data adapter, a signal generator, an adaptive power amplifier board, and a PC computer; the device of the invention has low cost, long service life, high measurement accuracy, relatively simple production process, and can be applied to different scenarios.

The invention belongs to the technical field of preparation of phosphorus removal agents, and particularly relates to a composite phosphorus removal agent and a preparation method and application thereof. The composite phosphorus removal agent comprises a honeycomb carrier and microspheres, the microspheres are loaded on the honeycomb carrier; the microspheres are prepared from the following raw materials: polyvinylidene fluoride particles, graphene oxide, ZrOCl2 and phosphorus-accumulating bacteria. The composite phosphorus removal agent comprises a honeycomb carrier, microspheres and microcapsules, wherein the microspheres and the microcapsules are loaded on the honeycomb carrier; capturing phosphate radicals in a water body by the microspheres and carrying out biological phosphorus removal and adsorption phosphorus removal; the honeycomb carrier also has the effect of adsorbing phosphate; and the two synergistically remove phosphate in the water body, so that the phosphorus removal effect of the phosphorus removal agent is improved, and the burden of the water body is not increased.

Disclosed are a positive electrode slurry, a positive electrode sheet, and an electrochemical device containing same. The positive electrode slurry comprises a positive electrode active material, a binder, and a dispersant. The dispersant comprises component A and component B. Component A is an acidic dispersant, component B is an alkaline dispersant, and the mass ratio of component A to component B is (1-30):1. The positive electrode active material comprises carbon-coated lithium iron phosphate. The binder comprises polyvinylidene fluoride. The positive electrode slurry uses a composite dispersant comprising two different components, and has good coating performance and excellent bonding performance. A positive electrode sheet prepared using the positive electrode slurry has high peel strength, and the resulting electrochemical device (especially a lithium-ion battery) has excellent capacity retention.

The invention belongs to the field of biological medicine and material science, and particularly relates to an intelligent response type piezoelectric nanofiber dressing and a preparation method and application thereof. According to the preparation method, polyvinylidene fluoride-trifluoroethylene, a high polymer material and inorganic nanoparticles are blended and spun through an electrostatic spinning technology, and then a photo-thermal component coating is subjected to surface in-situ oxidation and self-polymerization, so that the composite fiber membrane is prepared. Under the stimulation of ultrasound (US) and near-infrared laser (Laser), the fiber membrane can cooperatively activate the piezoelectric effect and the photothermal effect, generate a dynamic electric field and local high temperature, realize multi-mode cooperative killing of bacteria (the antibacterial rate exceeds 99%), and simulate an endogenous electric field to promote cell migration and wound healing. The dressing has good mechanical properties (the Young modulus is 15-20 MPa), hydrophilicity (the contact angle is about 30 degrees), biocompatibility and stability, is suitable for treatment of chronic infected wounds such as diabetes mellitus and the like, and has the advantages of on-demand activation and intelligent response.

The invention discloses a high-temperature-resistant composite material for manufacturing a wafer chuck and a preparation method of the high-temperature-resistant composite material, and belongs to the technical field of composite materials. The high-temperature-resistant composite material for manufacturing the wafer chuck is characterized by comprising the following components in parts by weight: 40-60 parts of maleic anhydride grafted polyvinylidene fluoride, 10-20 parts of modified glass fibers, 20-40 parts of polyether-ether-ketone, 1-5 parts of a compatibilizer, 0.5-2 parts of a lubricant and 1-3 parts of an antistatic agent, wherein the modified glass fiber is polyimide coated modified glass fiber. By reasonably selecting and proportioning the maleic anhydride grafted polyvinylidene fluoride, the modified glass fiber, the polyether-ether-ketone and other components and adding the compatibilizer, the lubricant and the antistatic agent, the high temperature resistance of the material and the compatibility among the components are effectively improved, so that the service life of the composite material is remarkably prolonged.

The invention discloses a self-suspension ultrahigh-intensity pressure activated phase change sealing capsule for micro-leakage control and a preparation method thereof, and belongs to the technical field of leaking stoppage materials. The preparation raw materials comprise the following components in parts by weight: 50-100 parts of latex, 50-150 parts of water, 5-20 parts of an activating agent, 5-20 parts of a crystal phase change nano reinforcing agent, 5-20 parts of a defoaming agent, 1-10 parts of nano metal oxide, 0.5-5 parts of an anti-scorching agent, 0.5-5 parts of an accelerant and 50-150 parts of a terminating agent. The crystal phase change type nano reinforcing agent comprises at least one of polytetrafluoroethylene, polyvinylidene fluoride and a copolymer of the polytetrafluoroethylene and the polyvinylidene fluoride. The obtained phase-change sealing capsule is high in plugging speed, easy and convenient to construct, low in cost and high in plugging strength, can be applied to rapid repair and control of underground tubular column micron-scale to millimeter-scale crack leakage, and solves the problems that the plugging and repairing work flow is complex, the period is long, the cost is high, the risk is large, the one-time plugging success rate is low, and hidden dangers are difficult to eradicate.

The invention relates to a corrosion-resistant polypropylene modified plastic and a preparation method thereof, and belongs to the technical field of polypropylene plastic modification. The modified plastic is prepared from isotactic polypropylene, exfoliated montmorillonite, polyvinylidene fluoride powder, anhydride grafted polypropylene, a beta-crystal nucleating agent, diethyl aluminum chloride, peroxide, hindered phenol, phosphite ester and N, N-distearoyl hydroxylamine. The preparation method comprises the steps of low-shear melting and blending, high-shear supercritical COviscosity reduction, vacuum exhaust, bidirectional orientation, infrared local crosslinking, co-extrusion cooling and the like. The obtained material is excellent in tensile strength, elongation at break, low-temperature impact strength, strong acid corrosion resistance and the like.

The invention discloses a fluorinated COF enhanced PVDF-HFP composite gel polymer electrolyte. The fluorinated COF enhanced PVDF-HFP composite gel polymer electrolyte is prepared from the following raw materials: polyvinylidene fluoride-co-hexafluoropropylene, a fluorinated covalent organic framework containing an ether oxygen bond and a carbon-carbon unsaturated double bond, bis (trifluoromethylsulfonyl) imide anion ionic liquid and fluorine-containing imide lithium salt, the fluorinated covalent organic framework containing the ether-oxygen bond and the carbon-carbon unsaturated double bond is prepared by carrying out condensation reaction on a perfluorophenylene-containing module and the ether-oxygen bond-containing aromatic module. According to the electrolyte, PVDF-HFP is used as a polymer matrix, bis (trifluoromethylsulfonyl) imidogen ionic liquid is used as a functional phase and a plasticizer, imide lithium salt is used as a lithium ion source, fluorinated COF containing ether oxygen bonds and olefinic bonds is introduced, and the electrolyte has high ionic conductivity, high lithium ion transference number, excellent mechanical property and interface stability; the method is especially suitable for a high-safety lithium metal battery system.

The invention discloses a preparation method and application of a cationized composite paper-based material for filtering nano plastic, and belongs to the technical field of nano cellulose. The preparation method comprises the following steps: preparing cationized lignocellulose nanofibers through DES treatment, dissolving out lignin through DES treatment, fully mixing the lignin with a silane coupling agent KH-560 to obtain silanized lignocellulose nanofibers, and then loading a layer of nano lignocellulose material on the surface of a polyvinylidene fluoride filter membrane by adopting a vacuum suction filtration method, and finally, cross-linking polyethyleneimine to obtain the cationized composite paper-based material. The cationized composite paper-based material prepared by the invention is green and environment-friendly, has excellent hydrophilic, antibacterial and recycling performances, and has broad-spectrum effects on the size, concentration and type of carboxylated nano-plastics in efficient capture. The cationized composite paper-based material has the advantages that the carboxylated polystyrene nano-plastic filtering efficiency reaches 97.56%, the filtering flux reaches 1889.99 L.m <-2 >. H <-1 >. Bar <-1 >, the practical application performance of lignocellulose is further widened, and the cationized composite paper-based material has a good application prospect.

The invention discloses a preparation method and application of a vertically-oriented ferroelectric ceramic-polymer composite solid electrolyte, and belongs to the field of application of solid-state lithium metal batteries. The electrolyte membrane is composed of polyvinylidene fluoride, ferroelectric ceramic powder, lithium salt and the like. The ferroelectric ceramic can form dipoles under the action of an electric field, polyvinylidene fluoride conformation is induced to be converted from an alpha phase to a beta phase, the beta conformation has large dipole moment, dissociation of lithium salt can be promoted, and more free lithium ions are generated. Through multi-solvent blending, the freezing orientation technology can be adjusted, the ferroelectric ceramic-polymer composite solid electrolyte membrane of a vertical ordered structure is prepared, and the shortest path of transmission of lithium ions between a positive electrode and a negative electrode is achieved. The vertically oriented ferroelectric ceramic-polymer composite solid electrolyte can promote lithium salt dissociation, reduce the transportation tortuosity of lithium ions and increase the ionic conductivity. The battery assembled by the material can effectively inhibit the growth of lithium dendrites, and has excellent rate capability and cycling stability.

The invention belongs to the technical field of batteries, and particularly relates to an intelligent closed-pore composite diaphragm and a preparation method thereof, and a battery, the intelligent closed-pore composite diaphragm comprises a base membrane, a temperature-sensitive coating and a flame-retardant layer; the base film is provided with a first surface and a second surface which are oppositely arranged; the temperature-sensitive coating is arranged on the first surface of the base film; the temperature-sensitive coating comprises N-isopropylacrylamide-co-acrylic acid, polyvinylidene fluoride and aluminum oxide, and the N-isopropylacrylamide-co-acrylic acid is formed by cross-linking polymerization of N-isopropylacrylamide and acrylic acid; the flame-retardant layer is arranged on the second surface of the base film; the composite diaphragm realizes dynamic reversible hole closing along with temperature change. Compared with the prior art, the core defect that in the prior art, a passive flame-retardant material cannot dynamically respond to thermal runaway is overcome. According to the scheme, the polyimide base film and the temperature-sensitive coating are designed, and the flame-retardant layer is combined, so that precise regulation and control of the hole closing temperature, dynamic reversible hole closing and intrinsic flame retardance are realized, the high-temperature safety of the lithium battery is remarkably improved, and the cycle life of the lithium battery is remarkably prolonged.

The invention discloses a lignin-derived carbon fiber-based sodium metal battery negative electrode material which is prepared by the following steps: performing granulation and melt-blowing on lignin to obtain lignin fibers, performing pre-oxidation and carbonization treatment on the lignin fibers to obtain lignin-derived carbon fibers, soaking the lignin-derived carbon fibers in a silver nitrate saturated solution, taking out the lignin-derived carbon fibers, and drying to obtain the lignin-derived carbon fiber-based sodium metal battery negative electrode material. And carrying out flash burning treatment to obtain the silver nanoparticle / lignin derived carbon fiber composite material. The invention discloses a composite electrode plate for a sodium metal battery, which is prepared by the following steps: grinding a lignin-derived carbon fiber-based sodium metal battery negative electrode material into a short fiber shape, uniformly mixing with polyvinylidene fluoride and N-methyl pyrrolidone to prepare slurry, coating a negative current collector with the slurry, and cutting into pieces to obtain the lignin-derived carbon fiber-based composite electrode plate. The lignin-derived carbon fiber-based sodium metal battery negative electrode material has a three-dimensional interpenetrating network structure, has a high specific surface area, enables an electric field to be uniformly distributed, inhibits dendritic crystal growth, and is suitable for a sodium metal battery system.

The application discloses an anode catalyst layer and a preparation method thereof and a membrane electrode, relates to the technical field of proton exchange membrane water electrolysis, and the anode catalyst layer is a single-layer structure and is prepared from an anode catalyst slurry after drying, the anode catalyst slurry comprises the following components in parts by weight: 0.05-10 parts of a polymer compound; 0.5-10 parts of an iridium catalyst; 0.5-12 parts of a perfluorosulfonic acid resin; and 5-120 parts of a solvent; wherein the polymer compound is used to form a reinforcing structure in the anode catalyst layer, the polymer compound comprises at least one of sodium hydroxymethyl cellulose, polyvinylidene fluoride, polyacrylic acid, polyimide or butadiene styrene rubber, and the mass of the polymer compound is 20-100% of the mass of the anode catalyst. By introducing the polymer compound, the mechanical performance and electrochemical performance of the membrane electrode can be improved.

The application relates to the technical field of batteries, in particular to a high-safety separator for new energy batteries and a preparation method thereof. The separator is composed of a polyethylene microporous base film and a double-sided composite coating, and the coating contains core-shell nano-aluminum oxide and a polyvinylidene fluoride copolymer binder. The interface enhancement effect of the core-shell nanoparticles makes the separator have a lower thermal shrinkage rate at high temperatures, and the puncture strength is increased to above 430 N / mm. The application solves the contradiction between the thermal stability and the ion conduction performance of the traditional separator, and is particularly suitable for a high-energy-density power battery system, and effectively improves the battery safety and the cycle life.

The invention discloses a low-temperature high-conductivity composite solid-state electrolyte membrane and a preparation method and application thereof, and relates to the technical field of solid-state lithium battery materials, the low-temperature high-conductivity composite solid-state electrolyte membrane comprises: a polymer matrix composed of poly (1, 3-dioxolame) and a polyvinylidene fluoride-hexafluoropropylene copolymer; the ion conduction network is composed of a metal organic framework filler with the surface modified with-SO3Li groups and sulfonic acid lithiated carbon nanotubes arranged in the axial direction of the polymer matrix; a first anti-freezing interface layer and a second anti-freezing interface layer are arranged on the surfaces of the two opposite sides of the polymer matrix, and the first anti-freezing interface layer and the second anti-freezing interface layer are butanedinitrile-glutaronitrile eutectic plastic crystal layers composed of butanedinitrile, glutaronitrile, lithium salt and a nano reinforcing agent respectively. The solid electrolyte is suitable for polar scientific investigation equipment, spacecrafts and other low-temperature environments, and solves the industrial problems of sharp increase of low-temperature grain boundary impedance and interface contact failure of the traditional solid electrolyte.

The application relates to the technical field of batteries, in particular to a composite solid electrolyte membrane and a preparation method and application thereof. The composite solid electrolyte membrane comprises the following layers which are sequentially stacked: a first membrane layer comprising a polymer, a solid electrolyte and a lithium salt; a second membrane layer comprising a polymer, a solid electrolyte and a lithium salt; and a third membrane layer which is an interface layer; wherein the solid electrolyte and the lithium salt content of the second membrane layer are higher than those of the first membrane layer, and the polymer is formed by polymerization of raw materials comprising triacetyl cellulose (TCA) and polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP). The composite solid electrolyte membrane has improved high-temperature resistance and good ion transmission performance.

The invention discloses an ultrathin battery diaphragm with high cohesiveness and safety as well as a preparation method and application of the ultrathin battery diaphragm. The battery diaphragm comprises a polyolefin base material and polyvinylidene fluoride coatings arranged on the two sides of the polyolefin base material, wherein each polyvinylidene fluoride coating comprises aluminum oxide particles, a first polyvinylidene fluoride copolymer and a second polyvinylidene fluoride copolymer; the particle size of the aluminum oxide particles is below 0.4 micron; both the first polyvinylidene fluoride copolymer and the second polyvinylidene fluoride copolymer contain vinylidene fluoride and hexafluoropropylene monomer units, and the molar percentage of the hexafluoropropylene monomer unit in the first polyvinylidene fluoride copolymer is lower than that of the hexafluoropropylene monomer unit in the second polyvinylidene fluoride copolymer. The battery diaphragm has ultra-thin thickness, has high binding power with a metal electrode plate, and is high in battery safety when being used for a battery.

The invention discloses a preparation method of a piezoelectric response type hybrid ceramic membrane, which is characterized in that polyvinylidene fluoride powder is used as a base material of the membrane, propylene carbonate or ethylene carbonate is used as a diluent, negative-voltage-loaded piezoelectric ceramic modified nanoparticles are doped, and a proper amount of inorganic piezoelectric nanoparticles are doped, so that the electrical property of the pressed membrane is remarkably improved; a negative charge group introduced to the surface of the membrane through surface grafting is combined, so that the relative content of beta crystal forms of the polyvinylidene fluoride membrane is increased, and finally efficient interception and excellent anti-pollution effects on humic acid are achieved.

The invention discloses a gel electrolyte, a lithium ion battery and a preparation method of the lithium ion battery, and belongs to the technical field of lithium batteries. The invention discloses a gel electrolyte, which comprises a polymer main matrix, an initiator, a lithium salt, an organic solvent, a solid electrolyte and a coalescing agent, and the polymer main matrix comprises poly (vinylidene fluoride-hexafluoropropylene)-polyacrylonitrile-maleic anhydride-ethylene carbonate. The stability of the gel electrolyte is effectively improved.

The invention relates to the technical field of radiation refrigeration films, and discloses a porous polyvinylidene fluoride based composite radiation refrigeration film and a preparation method thereof. The method comprises the following steps: firstly, carrying out melt blending on PVDF, NaCl and ZnO nanoparticles and forming a film, then dissolving out NaCl through water washing, and constructing a continuous three-dimensional porous structure in a PVDF matrix; and immersing the obtained porous PVDF / ZnO membrane material into a methanol aqueous solution containing 2-methylimidazole, so that ZnO is subjected to a coordination reaction at the pore wall and is converted into the ZIF-8 nanocrystal in situ. In the thin film prepared by the steps, the micron-sized salt-induced pore structure, the nano-sized ZIF-8 particles and the interface of the ZIF-8 particles jointly form a multi-stage scattering network, so that the scattering ability of the thin film in the solar spectrum range of 0.25-2.5 microns can be remarkably enhanced, the high infrared emission performance of the PVDF matrix in an atmospheric window of 8-13 microns is maintained, and the thin film has high solar reflectivity and high infrared emissivity, and can be used for preparing the solar film. An excellent radiation refrigeration effect can be achieved, and the heat-dissipating material is suitable for being applied to building outer surfaces, equipment heat dissipation, individual heat management and the like.