1065 results about "Polyvinylidene fluoride" 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 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.

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 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 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 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 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 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.

The invention discloses an Ag / Fe3O4 synergistically modified basalt fiber and PVDF (Polyvinylidene Fluoride) composite material and a preparation method thereof, Ag nano particles and Fe3O4 nano particles are simultaneously modified on basalt fibers, and the limitation of a traditional single modification function is broken; the modified basalt is used for preparing the oriented PVDF composite material, so that the piezoelectric property and the electromagnetic shielding property of the prepared PVDF composite material are synchronously improved, the PVDF composite material can be directly used as a material for preparing structural parts such as equipment shells, cabins and automobiles, self-sensing and self-shielding intelligent structures are manufactured, and the PVDF composite material can be used as a novel PVDF composite material product. Good application prospects and economic values are realized.

The invention belongs to the technical field of radiation refrigeration, and discloses a modified PVDF and HFP composite porous membrane and a preparation method thereof. The modified PVDF and HFP composite porous membrane comprises a substrate layer, a porous bottom layer and a compact top layer. Wherein the porous bottom layer is prepared from acetone, deionized water, a PVDF-HFP copolymer, a mixed dispersion liquid and a modified nanosheet dispersion liquid; the compact top layer is prepared from acetone, deionized water, a PVDF-HFP (Polyvinylidene Fluoride-Hexafluoropropylene) copolymer, synergistic microspheres and a modified nanosheet dispersion liquid; the mixed dispersion liquid is prepared from acetone, silicon carbide, synergistic microspheres and polyvinylpyrrolidone. The radiation refrigeration capacity, hydrophobicity, dimensional stability and aging resistance of the modified PVDF and HFP composite porous membrane are effectively improved by introducing the modified nanosheet dispersion liquid and the synergistic microspheres. Therefore, the method has a wider application prospect.

The invention provides a preparation method of fluororesin foam with high foaming ratio, and relates to the technical field of foaming materials, and the preparation method comprises the following steps: S1, carrying out melt blending on raw materials containing 90-100 parts of polyvinylidene fluoride (PVDF) and 0-5 parts of an inorganic nucleating agent to prepare a precursor; s2, performing supercritical fluid foaming treatment on the precursor to obtain a micro-foaming nucleation sample; s3, carrying out irradiation crosslinking treatment on the micro-foaming nucleation sample; s4, the irradiated sample is subjected to secondary supercritical fluid foaming treatment, and fluororesin foam is prepared; the nucleating agent is added to cooperate with a low-temperature and high-pressure infiltration process, so that the nucleating efficiency of a PVDF matrix is improved, the nucleation density is improved, PVDF molecular chains can be subjected to a cross-linking reaction through irradiation cross-linking to form a net structure, meanwhile, the melt strength of a micro-foaming precursor is improved, cell collapse and combination are inhibited in the foaming process in the second step, and the foaming performance of the PVDF matrix is improved. And a uniform and compact foam structure is prepared.

The invention discloses a high-power lithium iron phosphate battery and a preparation method thereof. The high-power lithium iron phosphate battery comprises a positive plate, a negative plate, a diaphragm and electrolyte. The positive plate comprises a positive material layer and a positive current collector; the negative plate comprises a negative electrode material layer and a negative electrode current collector; the diaphragm is coated with an adhesive layer composed of ceramic and polyvinylidene fluoride, and the porosity of the diaphragm is 45%-50%; the electrolyte comprises a lithium salt, an organic solvent and an additive, and the mass ratio of the lithium salt to the organic solvent to the additive is (13-18): (75-80): (3-8). By optimizing the positive plate, the negative plate, the diaphragm and the electrolyte, the prepared high-power lithium iron phosphate battery has high reliability, long cycle life and wide temperature range under high-power discharge.

A method for preparing a flexible lead-free piezoelectric composite film, in which a rare-earth-doped SrSbxSc2-xTaCl2O8 precursor powder is prepared and coated with a BaTiO3 shell to form core-shell nanoparticles, and the core-shell nanoparticles are dispersed in a polyvinylidene fluoride (PVDF) matrix to obtain the flexible lead-free piezoelectric composite film. An electronic device including such piezoelectric composite film is also provided.

The invention relates to the technical field of lithium batteries, in particular to a preparation method of a positive plate and a battery comprising the positive plate. The invention discloses a positive plate preparation method and a battery comprising the positive plate, and the positive plate preparation method comprises the following steps: firstly, pre-mixing a pretreated NCM811 positive plate material, a composite conductive agent composed of super conductive carbon black and the like, and hydroxyl-containing modified polyvinylidene fluoride in proportion, adding polystyrene microspheres to prepare a slurry, coating a modified aluminum foil with the slurry, and carrying out vacuum drying to obtain a positive plate; performing segmented drying, gradient rolling and the like to obtain a positive plate; and finally, winding, packaging and injecting liquid according to the sequence of the positive plate, the diaphragm treated by dopamine and the negative plate, standing and forming to obtain the battery, and mainly improving the performances of conductivity, interface stability, low-temperature discharge and the like.

The invention discloses a flame-retardant and electric leakage protection energy storage system cable which comprises two cables, exposed cable cores are arranged at the close ends of the two cables and are twisted and welded, a silver-plated copper woven belt is pressed outside the cable cores, an insulating layer is wrapped outside the cable cores, sealing rings are wrapped at the two ends of the cable cores, then a flame-retardant sheath layer is wrapped outside the cable cores, a protection box is fixed at the close ends of the two cables, the protection box is hollow, and the opposite ends of the protection box are opened and fixed; an annular groove embedded expansion rubber strip is arranged on the butt joint face. The inner walls of the protection boxes are connected with arc-shaped supporting blocks through first springs to abut against the flame-retardant sheath layer, the two protection boxes are clamped and fixed through clamping strips, clamping grooves, second springs and clamping blocks, a cable penetrates through the protection boxes, and hose clamps are arranged at the ends, away from the boxes, of the protection boxes to fix the cable. The insulating layer is made of a silicone rubber composite insulating material, the sealing ring is made of a rubber and expanded vermiculite composite material, the flame-retardant sheath layer is made of polyvinylidene fluoride, and the two ends of the flame-retardant sheath layer are in hot melting welding with the cable. According to the cable, through cooperation of a multi-layer structure and materials, the problem of combustion electric leakage caused by poor contact and untight insulation of connection parts is solved, and safety and reliability are improved.