2387 results about "Polyvinylidene fluoride" patented technology

The invention discloses a lithium battery diaphragm coating based on a nano material and application thereof, and relates to the technical field of lithium battery diaphragms. The coating comprises the following raw materials in parts by weight: 15-25 parts of polystyrene maleic anhydride copolymer modified polyvinylidene fluoride, 10-20 parts of polystyrene, 2-4 parts of nano silicon nitride, 3-6 parts of a boehmite / aluminum oxide and silicon dioxide composite material, 1-2 parts of a dispersing agent and 65-90 parts of a solvent, according to the lithium battery diaphragm coating provided by the invention, the wettability and absorptivity of a diaphragm to an electrolyte are remarkably improved, meanwhile, the lithium battery diaphragm coating also has excellent thermal stability, and the diaphragm can be effectively prevented from thermal shrinkage or melting under a high-temperature condition, so that the safety performance of a battery is remarkably enhanced.

The invention discloses a high-temperature-resistant, high-voltage-resistant and anti-breakdown capacitor base film and a preparation method thereof. The high-temperature-resistant, high-voltage-resistant and anti-breakdown capacitor base film is prepared from the following raw materials in parts by weight: 100 parts of polypropylene; 17 to 36 parts of polyvinylidene fluoride; 3-12 parts of enhanced and improved talcum powder; 1-6.5 parts of modified barium titanate; 1-6 parts of a cross-linking agent; 2-10 parts of a compatilizer; and 0.05-2 parts of an initiator. The capacitor base film is high in mechanical strength, and has excellent high temperature resistance, thermo-oxidative aging resistance, high voltage resistance and anti-breakdown performance; the enhanced and improved talcum powder is constructed by taking expanded layer modified talc as a carrier and titanium dioxide-carbon dot composite particles as a loading component and grafting and coating the organic matter, so that the defects of the talcum powder can be overcome, and the improvement effect of the talcum powder on heat resistance, high-voltage resistance and breakdown resistance can be fully exerted; meanwhile, the system can be endowed with excellent thermo-oxidative aging resistance.

The present invention relates to a lithium-ion battery diaphragm modified by high-temperature fluorine-containing liquid crystal polymer and polyvinylidene fluoride, and a preparation method and application thereof. The lithium-ion battery diaphragm of the present invention comprises a base diaphragm and a modified coating coated on the surface of the base diaphragm, wherein the modified coating comprises a fluorine-containing liquid crystal polymer and polyvinylidene fluoride. The present invention forms a modified coating by mixing and dissolving the two materials in a suitable solvent, which significantly improves the thermal stability, chemical stability, mechanical strength and ionic conductivity of the diaphragm, thereby improving the safety performance and cycle life of the battery.

The invention provides a PVDF (Polyvinylidene Fluoride) nanofiltration membrane constructed on the basis of microwave-enhanced bridging interfacial polymerization as well as a preparation method and application of the PVDF nanofiltration membrane. The method comprises the following steps: reacting PVDF powder with an organic alkali to prepare a modified film-forming solution, blade-coating the modified film-forming solution on a non-woven fabric supporting layer, placing the non-woven fabric supporting layer in an ethanol-water or methanol-water coagulating bath, and preparing a PVDF supporting film by virtue of assistance of an ice template; weighing the functionalized nano material and an amino silane coupling agent, performing ultrasonic dispersion, and adding a catalyst for reaction to obtain dispersion liquid; immersing a PVDF support membrane into the dispersion liquid to obtain a modified membrane; immersing the modified membrane into an aqueous solution containing an amine monomer and an organic solution containing an acyl chloride monomer, and carrying out microwave radiation. The interface reaction rate and selectivity are enhanced through the microwave excitation effect, and meanwhile, the hydrophilicity and reaction activity of the PVDF base membrane are cooperatively regulated and controlled, so that the separation efficiency and the anti-pollution capacity of the membrane are remarkably improved. The obtained PVDF nanofiltration membrane has high flux, high selectivity and excellent structural stability, and is suitable for efficient purification and resource recovery application in a complex water system.

The invention discloses a lithium ion battery positive electrode material and a preparation method thereof, the lithium ion battery positive electrode material comprises an active substance, a conductive additive, a binder and a thermal stability additive, the active substance is # imgabs0 # with a layered structure, x + y + z = 1, 0.5 < = x < = 0.8, 0.1 < = y < = 0.3, 0.1 < = z < = 0.3, the conductive additive is a compound of a carbon nanotube and graphene, and the thermal stability additive is a mixture of a carbon nanotube and graphene. The binder is a mixture of polyvinylidene fluoride and sodium carboxymethyl cellulose, the thermal stability additive is a mixture of lithium phosphate and aluminum oxide, the sum of the mass fraction of the lithium phosphate and the mass fraction of the aluminum oxide in the thermal stability additive is 0.5-10%, and the mass fraction of the lithium phosphate is 0.5-5%. According to the lithium ion battery positive electrode material and the preparation method thereof, the stability of the positive electrode material at high temperature can be improved, the thermal runaway risk is reduced, and the cycle life of the battery is prolonged.

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 discloses a microporous diaphragm for a low-electrical-impedance lithium battery and a preparation method of the microporous diaphragm. The diaphragm comprises: a base film layer, wherein the base film layer is of a microporous structure formed by biaxially stretching polypropylene and / or polyethylene; the surface of the base film layer is coated with the functional coating, and the functional coating contains mixed slurry of inorganic nanoparticles and a binder; the surface modification layer is formed by introducing a hydrophilic electrolyte group on the surface of the functional coating through plasma treatment or chemical grafting. The base membrane layer forms a uniform micropore structure through a two-way stretching process, the functional coating is formed by compounding nano silicon dioxide or aluminum oxide and polyvinylidene fluoride according to a specific proportion, a porous layer with gradient pore diameter is formed, the pore size of the porous layer is smaller than that of the base membrane layer, and efficient permeation of electrolyte is ensured. Electrolyte-philic groups such as sulfonic groups are introduced into the surface modification layer, so that the wettability of the diaphragm to an electrolyte is remarkably improved. During preparation, the base membrane is formed through melt blending, two-way stretching and pore-forming agent extraction, and then the functional layer is constructed through slurry coating and a low-temperature plasma treatment or sulfonation process. The diaphragm combines gradient aperture design, inorganic filler enhancement and surface chemical modification, and realizes low impedance, high thermal stability and excellent mechanical strength.

The invention provides a polyvinylidene fluoride-based nanofiber yarn wave-absorbing fabric as well as a preparation method and application thereof, and belongs to the technical field of preparation of wave-absorbing composite materials. The preparation method comprises the following steps: preparing nanofiber yarns or nanofiber core-spun yarns by adopting a conjugate electrostatic spinning technology, directly adding a conductive substance into a spinning solution to form conductive nanofibers, and further coating the nanofiber yarns or the nanofiber core-spun yarns with a PDA shell layer to improve the wear resistance and reduce silver nanoparticles in situ; finally, the yarns are woven into fabric through a weaving or knitting technology, and the fabric is applied to the fields of buildings, electromagnetic protective clothing, flexible electronics and the like. Compared with an existing microwave absorbing material, the fabric-based material is light in weight and good in mechanical flexibility and processability. Fabrics formed of nanofiber yarns or nanofiber core spun yarns facilitate the induction of interfacial polarization and multiple reflections, and can deeply design material properties. The material provided by the invention has better wear resistance, wearability and microwave absorption performance, and is suitable for actual production and application.

The invention relates to the field of electromagnetic functional composite materials, and particularly discloses a multi-layer composite structure flexible frequency selective surface material and a preparation method thereof. The ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced band-pass frequency selection array sequentially comprises an acrylic acid polyvinylidene fluoride organic polymer coating environment-resistant layer, a metal oxide organic film isolation layer, an ultra-high molecular weight polymer fiber-reinforced polymer-based composite material thin-film mechanical enhanced layer, a band-pass frequency selection layer and a packaging protection layer from top to bottom, and the band-pass frequency selection layer is a hexagonal / circular ring nested band-pass frequency selection pattern array. The packaging protection layer is formed by printing a conductive coating composed of conductive filler / polymer resin matrix, and the packaging protection layer is an ink coating. The flexible frequency selective surface material has the characteristics of light weight, high strength, salt fog / rain / ultraviolet and other severe environments, frequency selective wave transmission and multiple functions, has good gas barrier property, is beneficial to maintaining the shape of an inflatable hangar made of a skin and ensuring normal operation of radar equipment, and has good practical engineering application value.

The invention discloses a polyion liquid / polyvinylidene fluoride-hexafluoropropylene-based solid electrolyte with a microscopic liquid phase and a preparation method and application thereof, and the preparation method comprises the following steps: adding a lithium salt into N-methyl-2-pyrrolidone, and stirring until the lithium salt is completely dissolved; then adding imidazolyl polyion liquid to prepare a solution A; adding polyvinylidene fluoride-hexafluoropropylene into N-methyl-2-pyrrolidone to prepare a solution, adding the solution into the solution A, continuously stirring until the solution is fully dissolved to obtain a precursor solution of the solid electrolyte, casting the precursor solution onto a polytetrafluoroethylene mold, and carrying out vacuum drying to obtain the solid electrolyte. And the polyvinylidene fluoride-hexafluoropropylene polymer-based solid electrolyte added with the imidazolyl polyion liquid is prepared by adding the imidazolyl polyion liquid into the polyvinylidene fluoride-hexafluoropropylene polymer-based solid electrolyte. The polymer-based solid electrolyte with a microscopic liquid phase is obtained through an electrolyte preparation process which is mild in condition, simple to operate and easy for large-scale production, and the solid electrolyte has good conductivity and mechanical properties.

The invention discloses a silicon dioxide reinforced high-hydrophobicity polyvinylidene fluoride membrane as well as a preparation method and application thereof, SiO2 nanoparticles are taken as a mechanical reinforcing agent and a structure regulator and are directly added into a membrane casting solution system, and solid-liquid phase separation is preliminarily induced on the surface of a primary membrane in combination with non-solvent spraying ethanol, so that the high-hydrophobicity PVDF membrane is successfully prepared. A unique multi-stage micro-nano structure consisting of mutually connected spherocrystals is constructed on the surface of the membrane, the hydrophobicity, aperture, porosity and mechanical property of the membrane are effectively improved, and the membrane shows excellent and stable separation performance in performance tests of seawater desalination and erythritol concentration, and has good application prospects in seawater desalination and erythritol concentration. The method shows huge application potential in the fields of wastewater treatment, food production and the like.

The invention belongs to the technical field of lithium battery materials, and particularly relates to an integrated positive electrode / solid-state electrolyte sheet, a preparation method thereof and application of the integrated positive electrode / solid-state electrolyte sheet in a solid-state lithium battery. When the integrated positive electrode / solid electrolyte sheet provided by the invention is prepared, polyvinylidene fluoride-hexafluoropropylene is used as a flexible framework, poly (1, 3-dioxolame) is used as an additive, and an ionic liquid is used as an ionic conductor, solid electrolyte slurry is prepared by mixing, then the slurry is directly coated on the positive electrode sheet, and the integrated positive electrode / solid electrolyte sheet is obtained. The thickness of the solid-state electrolyte layer in the obtained integrated positive electrode / solid-state electrolyte sheet is less than 20 [mu] m, so that the requirement on high energy density of a solid-state lithium battery in industry is met. Meanwhile, the integrated positive electrode / solid-state electrolyte sheet can be randomly bent under the condition of keeping high ionic conductivity and mechanical modulus, so that the solid-state lithium battery assembled by adopting the electrolyte sheet at room temperature has higher specific capacity and good cycling stability, and has good popularization and application prospects in high-energy-storage lithium batteries.

The invention relates to a preparation technology of a gel polymer lithium ion battery cell electrolyte, and belongs to the field of battery preparation technologies, the preparation technology comprises the following steps: mixing methacrylate monomers and silane monomers according to a mass ratio of 3: 1-5: 1, adding 1-3% of an initiator, and carrying out prepolymerization at 60-80 DEG C for 1-3 h to prepare a prepolymer solution; mixing with a non-aqueous solvent containing lithium hexafluorophosphate according to a mass ratio of (1: 4)-(1: 6) to form a precursor mixed solution, and controlling the injection rate to be 1.5-2.5 g / Ah to a gap between a battery cell pole piece and a diaphragm; after standing for 2-4 hours at the vacuum degree of less than or equal to-0.08 MPa, curing for 3-6 hours at the temperature of 60-70 DEG C to form a gel polymer electrolyte; the wettability is improved through pole piece surface hydrophilic treatment, 1-5% of vinylene carbonate is added to optimize an SEI film, the prepolymerization temperature fluctuation is controlled to be smaller than or equal to + / -2 DEG C through microwave-assisted heating, the pressure of 0.2-0.5 MPa is applied after injection to promote uniform permeation, a polyvinylidene fluoride coating of 5-10 microns is coated after curing to enhance protection, and the interface performance is ensured through an alternating-current impedance test.

A piezoelectric sensing module includes a polyvinylidene fluoride (PVDF) piezoelectric film, a first electrode layer that includes multiple receiver electrodes arranged in a first pattern enabling a sensing of a position of an input object on a touch surface using the PVDF piezoelectric film, and a second electrode layer that includes at least one common electrode. The PVDF piezoelectric film is arranged between the first electrode layer and the second electrode layer, with the second electrode layer between the PVDF piezoelectric film and the touch surface.

The invention discloses an aircraft shell surface quality detection method. According to the method, a passenger cabin pressure difference curve and a shell outer surface temperature curve are calculated to obtain a pressure difference change node and a temperature difference change node respectively, and then partitioning is carried out to obtain phase thermoelastic coupling partitions; when a temperature difference change node reaches a phase change threshold value, performing beta-phase to alpha-phase transformation on the polyvinylidene fluoride microcapsule premixed in the finish paint, and forming a polarized memory cavity at a defect cementing position; when a voltage difference change node reaches a peak value, triggering a polarized memory hole to release charges, exciting a high-order thin film elastic wave, and performing integer ratio phase locking on the high-order thin film elastic wave and a natural vibration wave of a machine body to obtain a defect harmonic signal; carrying out acoustic-mechanical coupling calculation according to the amplitude of the defect harmonic signal to obtain a virtual work increment, and recording the virtual work increment to a damage matrix; and performing multi-leg accumulation calculation on the virtual work increment, and outputting a defect early warning signal when an accumulation value exceeds a material fatigue critical value. According to the invention, the hidden fatigue defect of the surface of the aircraft shell under the dynamic load can be detected.

The invention provides a high-temperature-resistant fast-charging PVDF-HFP-based all-solid-state electrolyte membrane as well as a preparation method and application thereof, and relates to the technical field of power batteries. The preparation method comprises the following steps: uniformly mixing a polyvinylidene fluoride-hexafluoropropylene copolymer, a lithium salt and a polar solvent to obtain a PVDF-HFP solution; then uniformly mixing the PVDF-HFP solution with a cross-linking agent and a 2, 2-bis (4-allyloxy-3, 5-dibromophenyl) propane monomer, so as to obtain a precursor solution; uniformly mixing an initiator with the precursor solution to obtain a reaction solution; and finally, coating a substrate with the reaction solution, and heating at 70-80 DEG C for 12-16 hours to obtain the high-temperature-resistant fast-charging PVDF-HFP-based all-solid-state electrolyte membrane. When the high-temperature-resistant and fast-charging PVDF-HFP-based all-solid-state electrolyte membrane is applied to a lithium metal battery, the thermal safety and the high-temperature-resistant and fast-charging performance can be 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 invention discloses a lignin-monofluoroacrylic polymer high-voltage lithium ion binder as well as preparation and application thereof. The binder is prepared from lignin, polyfluoroacrylic acid and copolymer thereof through esterification reaction. The preparation method comprises the following steps: firstly, preparing a monofluoroacrylic polymer through free radical polymerization, and then grafting lignin into a side chain of the monofluoroacrylic polymer by utilizing esterification reaction to form a three-dimensional network structure; the binder has the free radical scavenging capacity of lignin, and the characteristics of chelating transition metal ions and stabilizing a CEI interface of polymonofluoroacrylic acid. Compared with a commercial PVDF (Polyvinylidene Fluoride) binder, the binder material disclosed by the invention has the advantages that the adhesive force is improved by 5.6 times, and the voltage resistance reaches 4.93 V which is obviously higher than that of PVDF (4.58 V). Therefore, the binder can be used for preparing the positive electrode of the high-voltage lithium ion battery, and has remarkable performance advantages.

The invention discloses lithium ion battery slurry and a coating process thereof, and belongs to the technical field of battery diaphragms. The lithium ion battery slurry comprises the following raw materials in parts by weight: 40-50 parts of ceramic powder, 10-15 parts of bio-based semi-aromatic polyamide, 10-15 parts of polyvinylidene fluoride, 35-45 parts of a solvent and 1-4 parts of a dispersing agent. The coating process comprises the following steps: A1, sequentially adding a solvent and a dispersing agent into a stirring tank, then adding ceramic powder, bio-based semi-aromatic polyamide and polyvinylidene fluoride, and uniformly stirring and mixing to obtain bio-based coating slurry; a2, feeding a polyethylene-based membrane into a coating device, coating by using the bio-based coating slurry prepared in the step A1, coating at least one side of a battery diaphragm by adopting a micro-concave roller coating mode, and drying and rolling the coated battery diaphragm to obtain a finished product of the ceramic-coated lithium battery composite diaphragm. The dispersing agent is used in the process of preparing the coating slurry, so that the mechanical property, the heat resistance and the adhesion property of the diaphragm can be improved.

The invention provides a lithium supplement composite layer and a preparation method thereof, a lithium supplement method, a pre-lithiated negative pole piece, a secondary battery and an electronic device, the lithium supplement composite layer comprises an interface layer and a lithium supplement layer which are laminated, the interface layer comprises interface particles and a binder, the interface particles comprise a lithium intercalation material and / or a conductive agent, and the binder comprises a lithium intercalation material and / or a conductive agent. The lithium intercalation material is selected from at least one of artificial graphite, natural graphite, hard carbon, a silicon-carbon material, a silicon-oxygen material, lithium titanate, tin and a tin-copper alloy, and the conductive agent is selected from at least one of conductive carbon black, carbon fiber, graphene and a carbon nanotube; the binder is selected from at least one of polytetrafluoroethylene, an ethylene-tetrafluoroethylene copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride and polyoxyethylene; the lithium supplementing layer comprises lithium metal and / or lithium alloy. The lithium supplement composite layer meets the above characteristics, lithium supplement is carried out on the negative pole piece, the first coulombic efficiency of the secondary battery can be improved, the cycle capacity attenuation is reduced, and the energy density of the secondary battery is improved.

The invention relates to the technical field of recycling and reusing of solar back plates of photovoltaic modules, and discloses a recycling method of a solar back plate. The recovery method of the solar back panel is characterized by comprising the following steps: (1) in the presence of a protective gas and a catalyst, carrying out alcoholysis reaction on the solar back panel and alcohol to obtain a depolymerized mixed solution; and (2) carrying out purification treatment on the depolymerized mixed solution obtained in the step (1) to obtain bis (2-hydroxyethyl) terephthalate (BHET), polyvinylidene fluoride and polyolefin. According to the method, the PET middle layer in the solar panel can be completely depolymerized into the BHET monomer, the yield is greater than or equal to 78%, and the purity is greater than or equal to 98%; pVDF and PP (or PE) products can be respectively obtained after the PVDF and PP (or PE) materials which do not participate in depolymerization are separated and purified; the whole chemical recovery process is simple in operation method and high in efficiency, and has good economic benefits.

The invention provides a microwave-transmitting and infrared-compatible low-emissivity coating, and belongs to the technical field of camouflage materials. The microwave-transmitting and infrared-compatible low-emissivity coating is of a double-layer structure composed of a bottom microwave transparent layer and a surface infrared functional layer. The microwave transparent layer is made of hollow dielectric microbeads and polyvinylidene fluoride; the infrared functional layer is made of modified flaky aluminum powder, modified hexagonal boron nitride nanosheets and polyvinylidene fluoride. The microwave-transmitting compatible infrared low-emissivity coating provided by the invention has an infrared radiation inhibition effect in two atmospheric window wave bands of 3-5 microns and 8-14 microns, and has high transmissivity in an electromagnetic wave band of 2-18 GHz; the method is especially suitable for the scenes, such as stealth unmanned aerial vehicles, ship decks and 5G base station shells, where infrared characteristics need to be suppressed and microwave signal transmission needs to be kept at the same time.

The invention relates to the technical field of dielectric materials, in particular to a diamine monomer crosslinking modified fluorine-containing ferroelectric polymer, a preparation method and a device. The diamine monomer cross-linked modified fluorine-containing ferroelectric polymer comprises the following components: a semi-crystalline thermoplastic fluorine-containing ferroelectric polymer and a diamine cross-linking agent, the semi-crystalline thermoplastic fluorine-containing ferroelectric polymer is polyvinylidene fluoride with ferroelectricity and a copolymer derivative thereof; the diamine cross-linking agent is short-chain diamine containing a rigid structure; the mass fraction of the diamine cross-linking agent is 0.25%-10% compared with the total mass fraction. The thin film prepared by the invention meets the application requirements of improvement of dielectric constant, reduction of dielectric loss, reduction of leakage current, improvement of breakdown field strength and the like in a high electric field.

The invention provides a rigid-flexible metal-organic framework diaphragm with high selectivity as well as a preparation method and application of the rigid-flexible metal-organic framework diaphragm. Through a seed secondary growth strategy, the problems that MOF particles are easy to fall off and are incompatible with a substrate film are successfully avoided. On one hand, grain seeds embedded in the polyvinylidene fluoride (PVDF) substrate film in advance provide stable anchoring points for growth of MOF, and MOF particles are not prone to falling off due to the high adhesive force of the grain seeds. The high Young modulus of the MOF crystal also effectively improves the thermal shrinkage resistance of the diaphragm, the excellent flexibility of PVDF is complementary with the diaphragm in mechanical property, and the battery diaphragm shows excellent mechanical property and thermal stability due to the rigid-flexible combination strategy. The invention provides an efficient diaphragm construction strategy for developing a lithium metal battery with long cycle life and high safety, and shows a wide application prospect in a next-generation high-safety battery.

The invention discloses a gradient membrane based on continuous distribution of PVDF-HFP-silicon dioxide electronic injection microspheres and a construction method of the gradient membrane, and belongs to the field of gradient membranes, an improved electrostatic spinning and electrostatic spraying technology is utilized, a PVDF-HFP fiber membrane is prepared through the electrostatic spinning technology, PVDF-HFP / SiO2 composite microspheres are electrostatically sprayed, and a collector receiving device is combined, so that the gradient membrane is obtained. The traction speed change of the substrate film is controlled on the blade electrode, and a wettability gradient film with the continuously-changed surface appearance is constructed; on the surface of the prepared fiber membrane, the distribution form of the polyvinylidene fluoride-hexafluoropropylene / silicon dioxide composite microspheres on the surface of the membrane is in gradient change, a microstructure with continuous change is constructed, the contact angle of the fiber membrane is increased from 128 degrees to 153 degrees along with the change of the surface position, and a gradient surface gradually changing from hydrophobicity to super-hydrophobicity is obtained. And the preparation method has an excellent application prospect in the field of gradient films, bubble transmission and bubble micro-reaction.

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 relates to the technical field of chemical production equipment, and discloses polyvinylidene fluoride powder wet powder purification equipment and a use method.The polyvinylidene fluoride powder wet powder purification equipment comprises a main body, the inner top wall of the main body is fixedly connected with a telescopic linkage assembly capable of stretching out and drawing back, and the outer wall of the telescopic linkage assembly is connected with an overturning assembly capable of overturning in the main body in a meshed mode; a filter pressing assembly capable of sliding up and down in the main body is fixedly connected to the bottom end of the telescopic linkage assembly, a cleaning assembly is fixedly connected to the inner wall of the end, located outside the main body, of the filter pressing assembly through a hose, and an output assembly capable of rotating in the main body is fixedly connected to the inner top wall of the cleaning assembly; the hydraulic telescopic machine drives the overturning gear to rotate through the linkage toothed plate, the polyvinylidene fluoride powder wet powder obtained after filter pressing of the water distribution table and the ultrafiltration plate can be overturned into the discharging bin, a worker does not need to open the device to take out the polyvinylidene fluoride powder wet powder, and the interior of the device is prevented from being polluted.

To provide a separator for a non-aqueous secondary battery which is excellent in thermal dimensional stability and adhesion to an electrode, and improves battery cycle characteristics and impact resistance.SOLUTION: A separator for a non-aqueous secondary battery includes a porous base material, a heat-resistant layer which is arranged on one side or both sides of the porous base material, and contains inorganic particles and a binder resin, and an adhesive layer which is arranged on one side or both sides of the laminate of the porous base material and the heat-resistant layer, and contains a polyvinylidene fluoride-based resin, wherein the mass ratio of the inorganic particles in the heat-resistant layer is 95 mass% or more, the average primary particle diameter of the inorganic particles contained in the heat-resistant layer is 0.01 μm to 0.30 μm, and the adhesive layer has a porous structure such that fibrils containing the polyvinylidene fluoride-based resin are connected to each other in three-dimensional meshes.SELECTED DRAWING: Figure 1

The invention belongs to the technical field of lithium battery materials, and particularly relates to a preparation method of a polyvinylidene fluoride-hexafluoropropylene-based solid-state lithium battery, and the preparation method comprises the steps of preparing a composite solid electrolyte membrane and assembling the battery. Polyvinylidene fluoride hexafluoropropylene, lithium salt and nitrogen-methyl pyrrolidone are used as raw materials, and the plasticizer and the dendritic mesoporous nano silicon dioxide are added to prepare the composite solid electrolyte membrane, so that more conductive channels are provided for migration of lithium ions, and the electric capacity of the electrolyte is improved; according to the preparation method, the interface compatibility between the PVDF-HFP and the dendritic mesoporous nano silicon dioxide is improved, the electrochemical performance is improved, the crystallinity of the PVDF-HFP is reduced, and short circuit and explosion caused by the fact that dendritic crystals pierce the diaphragm are avoided; the invention solves the potential safety hazards caused by the traditional liquid electrolyte, such as leakage, combustion, explosion and the like, and has the advantages of simple preparation method and low cost, and is suitable for industrial large-scale production.

The invention discloses positive electrode slurry for preventing formation of gel and a preparation method of the positive electrode slurry. The method comprises the following steps: S1, drying a positive electrode active material under the protection of inert gas; s2, carrying out surface modification by using a functionalized silane coupling agent; s3, drying the conductive agent under a high-temperature vacuum condition; s4, under the protection of inert gas, lithium alkyl sulfonate, a polyhydric alcohol chelating agent and polyvinylidene fluoride are subjected to a reaction to prepare a modified binder; s5, mixing and dispersing the modified active material, the conductive agent, the modified binder and the acidic buffer agent in a low-dew-point drying chamber; s6, performing ultrasonic treatment on the slurry under a vacuum condition; and S7, adding a cross-linked fluorosilane coupling agent, mixing at a low speed and precisely filtering to obtain the anti-gel positive electrode slurry. According to the invention, through a multi-synergistic anti-gel mechanism, the problem that the positive electrode material slurry is easy to form gel is solved, and the prepared slurry has excellent stability, rheological property and coating performance, so that the electrochemical performance of the battery is improved.