1911 results about "Polymer composites" patented technology

The invention discloses a positive electrode material and a preparation method thereof, a battery and a power utilization device. The positive electrode material comprises an inner core; the first coating layer comprises a first coating material, and the first coating material comprises at least one of an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte and a polymer composite solid electrolyte; the first coating layer coats the inner core, the second coating layer coats the inner core, the first coating layer coats the second coating layer, the second coating layer comprises a second coating material, and the second coating material comprises a halide solid electrolyte. The coating layer plays a certain role in isolating the material of the inner core from the external environment, and the situation that the material in the inner core has side reaction with external substances or the property of the material is changed due to other reasons is reduced. Therefore, the performance stability of the positive electrode material is kept.

The invention relates to a polymeric composite comprising poly(ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), waterborne polyurethane (WPU) and a sugar alcohol, wherein the sugar alcohol is selected from the group consisting of glycerol, erythritol, threitol, arabitol, xylitol, ribitol, mannitol, sorbitol, galactitol, fucitol, iditol, inositol, volemitol, isomalt, maltitol, lactitol, maltotriitol, maltotetraitol, polyglycitol, or a combination thereof, and wherein the sugar alcohol is 20 wt % to 50 wt % of the polymer composite; an electrical device comprising such composite. The present invention also relates to methods of fabricating and its uses thereof. In particular, the present invention relates to intrinsically conductive polymer composites suitable for use in efficient dry / wet epidermal biopotential monitoring. The polymer composites are advantageously self-adhesive and stretchable, and can be used as dry electrodes.

A biodegradable polymer composite, a method of making the same and use for same are provided. The biodegradable polymer composite has about 30 to 99.5% by weight of a polymer selected from a group consisting of polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) grafted with a compatibilizer selected from a group consisting of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate; and about 0.5 to 50 % by weight a nano-filler or a micro-filler. The biodegradable polymer composite does not contain polylactic acid. Surfaces of the nano-filler or the micro-filler may be modified using a grafting agent so that the biodegradable polymer composite has enhanced mechanical properties, increased heat resistance, compostablity and / or improved processability. The biodegradable polymer composite may be used to make flexible articles, such as a freezer wrap and a farming sheet.

The invention provides a nano / micron particle polymer composite fiber and a preparation method thereof, a mixed solution of nano / micron particles and a polymer is extruded by wet spinning to form a liquid fiber, and a coaxial shell layer water flow is applied to the periphery of the liquid fiber while the liquid fiber is extruded, so that the nano / micron particle polymer composite fiber is obtained. The flow velocity of the coaxial shell layer water flow is greater than that of the liquid fiber, and the liquid fiber is stretched and cured under the action of the coaxial shell layer water flow to form the nano / micron particle polymer composite fiber. According to the preparation method of the nano / micron particle polymer composite fiber, the micron fiber can be directly prepared, the method has the advantages that the method is simple, the diameter of the fiber is easy to adjust, and the universality is good, and the problems that only millimeter fiber can be prepared and micron fiber is difficult to prepare in the current wet spinning method are solved.

The invention discloses preparation of DOPO-based hollow polymer microspheres and application of the DOPO-based hollow polymer microspheres in flame-retardant polymers, and belongs to the technical field of high polymer materials. The preparation method of the DOPO-based hollow polymer microspheres comprises the following steps: preparing a template core through self-stable precipitation polymerization, then polymerizing a DOPO-based flame-retardant monomer, an anhydride monomer and a cross-linking agent on the surface of the template core to construct a cross-linking shell layer in situ to obtain copolymer microspheres with a core-shell structure, and finally removing the template through solvent etching to obtain the DOPO-based hollow polymer microspheres. And the DOPO-based hollow polymer microspheres are prepared. The compatibility between the DOPO-based hollow polymer microspheres and a polymer matrix is greatly improved through rich anhydride groups on the surfaces of the DOPO-based hollow polymer microspheres, the flame retardant property of the polymer composite material is improved, the mechanical property of the polymer composite material is greatly improved, and due to the unique hollow structure of the polymer composite material, the flame retardant property of the polymer composite material is greatly improved. The polymer material is endowed with excellent transparency and low dielectric property.

The invention discloses a manufacturing process of a circuit board structure of aviation equipment, which comprises the following steps of: providing a carbon fiber reinforced ceramic substrate, after desizing process treatment, coating high-temperature ceramic slurry on the carbon fiber reinforced ceramic substrate, forming a high-temperature-resistant base material layer through vacuum drying, coating an electromagnetic shielding material on the surface of the base material layer, and forming the circuit board structure of the aviation equipment. Designing a circuit pattern, and transferring the circuit pattern to the electromagnetic shielding layer through a laser cutting or etching process to form a circuit layout; wiring the copper alloy film according to the circuit pattern, and combining the copper alloy film with the polymer composite material middle layer through a lamination process to form an electrical connection layer; coating the surface of the circuit board with a resin material, performing curing treatment, mounting a metal connecting piece in the edge area of the circuit board, performing connection in a crimping manner, then performing a 3D printing process, and printing connecting points on the surface of the circuit board; the circuit board provided by the invention has the advantages of high temperature resistance, electromagnetic interference resistance, support and excellent protection performance.

The invention belongs to the technical field of polymer composite materials, and particularly relates to a composite material for a high-strength pipeline and a preparation method of the composite material. The composite material comprises the following components in parts by weight: 70-80 parts of long-carbon-chain semi-aromatic nylon, 15-20 parts of glass fibers, 3-10 parts of carboxylated carbon nanotubes, 1-6 parts of nano silicon dioxide particles, 2-4 parts of an amino silane coupling agent, 0-3 parts of a lubricant and 0-3 parts of an antioxidant. And the long-carbon-chain semi-aromatic nylon is adopted as matrix resin, so that the dual requirements on strength and toughness of the composite material are met. The mechanical property of the material is improved through the glass fiber, the carboxylated carbon nano tube and the nano silicon dioxide particle composite reinforcing filler, and the compatibility of the composite reinforcing filler and the resin and the interaction between molecular chains can be improved by combining a proper amount of the amino silane coupling agent, so that the reinforcing and toughening effects of the filler are fully exerted; the rigidity and toughness of the final product are integrally improved, and the problem of floating fibers on the surface of the glass fibers is solved.

The invention relates to the field of civil engineering waterproof materials, in particular to a nano bentonite-polymer composite material with high salt tolerance and a preparation method thereof, and the nano bentonite-polymer composite material is especially suitable for a sodium-based bentonite waterproof blanket in a saline soil area or a marine environment, and the preparation method comprises the following steps: (1) preparing nano bentonite lamellar colloidal dispersion liquid; (2) introducing and mixing an electrostatic screening agent and a polymerizable monomer; (3) carrying out in-situ free radical polymerization reaction; and (4) post-treatment and finished product preparation. By constructing a three-dimensional interpenetrating hierarchical structure composed of a covalent grafted polymer network, a physically anchored electrostatic screening agent and a stripped bentonite nanosheet layer, effective protection of a bentonite core anti-seepage unit is realized, so that the adaptability and long-term stability of the material under a complex water quality condition are remarkably improved.

The invention discloses a composite copper foil current collector and a preparation method thereof, a negative electrode, a lithium ion battery and electric equipment, and belongs to the technical field of batteries. The composite copper foil current collector comprises a polymer composite layer which comprises a polymer layer and a conductive material layer, the polymer layer has two opposite surfaces, and the conductive material layer is attached to at least one surface of the polymer layer; the polymer composite layer is provided with a first surface and a second surface which are opposite; and the copper layer is attached to the first surface and the second surface of the polymer composite layer. The conductive material is introduced to the surface of the polymer base material and then copper plating is performed, so that the binding force is stronger compared with the binding force between the polymer and copper; meanwhile, the conductive material is compounded on the polymer base material and replaces part of the polymer insulating material to form a coherent conductive network, so that the composite copper foil current collector has higher conductivity; volume expansion hardly occurs in the charging and discharging process, active substances are prevented from falling off from the current collector, and the cycling stability of the battery is improved.

The invention discloses a conductive and heat-conducting hydrophobic polymer composite membrane as well as a preparation method and application thereof. The method comprises the following steps: preparing a PU nanofiber membrane through an electrostatic spinning technology; then AgNPs is adsorbed on the surface of the PU nanofiber through an interface hydrogen bond, contact thermal resistance and resistance are effectively reduced, MWCNTs are attached to the upper surface and the lower surface of the composite film through suction filtration and hot pressing, a sandwich structure is formed, and hydrophobicity is guaranteed while the resistance and the thermal resistance are further reduced. The resistance and the heat conductivity of the polymer composite film respectively reach 14.8 m omega / sq and 7.9 W (m K) <-1 >, and the water contact angle is 132.8 degrees. The excellent durability of the composite film is guaranteed through strong interface interaction, and the composite film has potential application prospects in multifunctional electric conduction and heat conduction composite materials.

A liquid crystal element includes two substrates with a transparent conductive film, the substrates being arranged such that transparent conductive films face each other, and a liquid crystal-polymer composite film which is sandwiched between the two substrates with a transparent conductive film, in which the liquid crystal-polymer composite film contains an acetylene alcohol.

The invention relates to the field of road building materials, and particularly discloses recycled asphalt concrete and a preparation method thereof, and the recycled asphalt concrete comprises the following raw materials: a waste asphalt mixture, matrix asphalt, aggregate, mineral powder, hydroxyl modified polyester fibers, a polymer composite modifier, modified nano silicon dioxide and a regenerant; the preparation method comprises the following steps: preheating the waste asphalt mixture; mixing and preheating the aggregate and the mineral powder; preheating matrix asphalt and mixing the matrix asphalt with the preheated aggregate to prepare a primary mixture; preheating a regenerant, mixing with the primary mixture, and then mixing and stirring with the preheated waste asphalt mixture to obtain a mixture; mixing the hydroxyl modified polyester fiber, the polymer composite modifier and the modified nano silicon dioxide, and then stirring and mixing with the mixture to prepare the recycled asphalt concrete. The method has the characteristics that the later cracking problem of the recycled asphalt concrete is relieved, and the durability of the recycled asphalt concrete is improved.

The invention relates to an injectable skin filler. The injectable skin filler comprises hydrophilic modified adhesive polyester microspheres, a suspending agent and a synergist, the mass ratio of the hydrophilic modified adhesive polyester microspheres to the suspending agent to the synergist is (1-5): 1: (0.1-2); the hydrophilic modified adhesive polyester microsphere is an amphiphilic polymer composite polyester microsphere, and the amphiphilic polymer is a catechol-terminated amphiphilic polymer. The invention further provides a preparation method of the injectable skin filling agent. Polyester microspheres are modified through the amphiphilic polymer terminated by catechol. The device can be widely applied to medical cosmetology.

The invention relates to a vertical orientation ceramic fiber / polymer composite solid electrolyte membrane and a preparation method and application thereof, the vertical orientation ceramic fiber / polymer composite solid electrolyte membrane is composed of an inorganic framework material with a vertical orientation structure and a toughening matrix material filled in the inorganic framework material, the inorganic framework material is an inorganic ceramic nanofiber with high lithium ion conductivity, the toughening matrix material is a polymer / lithium salt compound with relatively high lithium ion conductivity. The composite solid electrolyte membrane combines high modulus of an inorganic skeleton and high toughness of a polymer, has excellent mechanical properties, and can form good contact with a positive electrode and a negative electrode of a battery. More importantly, the unique vertical orientation fiber structure of the inorganic skeleton can greatly reduce the actual transmission path of ions in the operation process of the battery, and the ionic conductivity of the composite solid electrolyte membrane is greatly improved.

The invention discloses a fluoride-free reinforced wear-resistant polyketone composite material as well as a preparation method and application thereof, and relates to the technical field of polymer composite materials. The fluoride-free reinforced wear-resistant polyketone composite material comprises polyketone resin, glass fibers, modified ultra-high molecular weight polyethylene, an antioxidant and a lubricant, wherein the modified ultra-high molecular weight polyethylene is obtained by modifying branched-chain-free linear polyethylene with the molecular weight of 2 million or more, and the dosage of the modifier is 1%-5% of that of the ultra-high molecular weight polyethylene. The modified ultra-high molecular weight polyethylene, the glass fiber and the polyketone resin are subjected to blending modification, and the characteristics of good wear resistance of the polyketone resin and high strength of the glass fiber are combined; meanwhile, the friction coefficient is low after the ultra-high molecular weight polyethylene is modified, the compatibility with the polyketone resin is enhanced, the dispersion is more uniform, and the heat resistance and friction performance of the polyketone resin are comprehensively improved. In addition, due to the use of fluorine-free, the safety of the polyketone composite material is improved, and meanwhile, the application market of the polyketone composite material is expanded.

The invention relates to the technical field of solid waste treatment and recycling, and discloses a waste incineration fly ash geopolymer composite material and a preparation method thereof, and the composite material is prepared from waste incineration fly ash, apatite minerals, zero-valent iron powder, persulfate and an alkali activator. The preparation method comprises the following steps: mixing the waste incineration fly ash, apatite minerals, zero-valent iron powder and persulfate to obtain composite powder; performing frequency conversion mechanochemical synergistic activation on the composite powder, wherein the activation process comprises a low-temperature activation stage and a high-energy pulse activation stage; and finally, mixing the activated powder with an alkali activator, pouring, molding and curing. According to the method, the reduction reaction and the oxidation reaction are driven step by step in the same system by regulating and controlling the mechanical energy input time sequence, the compatibility problem of a reducing agent and an oxidizing agent is solved, different types of persistent organic pollutants are synergistically degraded, meanwhile, heavy metal is stabilized, and the treatment effect is good. And the fly ash is recycled to prepare a geopolymer material with mechanical properties.

Composite materials with noble metal coated silver nanowires loaded into polymer are described. The composite materials may have resistivities of no more than about 100 Ohm-cm, or from about 100 Ohm-cm to about 1×1011 Ohm-cm depending on the amount of noble metal coated silver nanowires loaded into the polymer. The noble metal coated silver nanowires may be platinum coated silver nanowires. Metal particulates such as silver flakes or silver particles may be added to the composite materials in order to obtain desired properties. Composite precursor compositions and methods for preparing the composite materials are described.

The invention belongs to the technical field of composite material design, and discloses a polymer composite material design method based on LLM knowledge database construction and reasoning optimization, and the method comprises the following steps: S1, target performance setting; s2, constructing a knowledge database; s3, constructing a reverse design model; s4, constructing a performance verification module; and S5, performing multi-round test-verification design loop optimization. According to the method, an intelligent design method integrating target setting, semantic knowledge database construction, a design assistant, a performance verifier, a prompt engineering module and a language model material knowledge system is provided, closed-loop reasoning and feedback of structure-mechanism-performance are achieved through multiple rounds of DA-VM collaborative optimization, and the design efficiency is improved. The method has the advantages of high design efficiency, strong structure generation rationality, accurate performance prediction, knowledge evolvable and the like, and is suitable for intelligent rapid development of the high thermal conductivity-wave absorbing-shielding-mechanical integrated functional polymer composite material.

The invention relates to the technical field of 3D printing building materials, in particular to a 3D printing geopolymer composite material with low drying shrinkage and a preparation method thereof.The 3D printing geopolymer composite material is prepared from, by mass, 400 parts of slag powder, 320 parts of fly ash, 80 parts of steel slag micro powder, 1200 parts of quartz sand, 5.1-25.6 parts of sodium hydroxide, 46.4-66.9 parts of sodium silicate, 8 parts of barium chloride and 296 parts of water. The preparation method comprises the following steps: fully mixing the slag powder, the fly ash, the steel slag micro-powder and the quartz sand according to a preset mass ratio to obtain a uniform basic powder mixture; adding an alkali activator and barium chloride into the basic powder mixture, and continuously mixing until the mixture is uniform to obtain a first mixture; and adding water into the first mixture according to a preset water-binder ratio, and carrying out stirring treatment according to a preset stirring method to obtain the 3D printing geopolymer composite material with low drying shrinkage. According to the invention, the drying shrinkage can be reduced.

The invention relates to a hollow mesoporous carbon sphere prepared based on a confinement polymerization method and a preparation method of a platinum alloy catalyst loaded by the hollow mesoporous carbon sphere and doped with rare earth metal. The method comprises the following steps: by taking mesoporous silica as a template, introducing an initiator and a small molecular organic matter precursor into mesopores, and carrying out confinement polymerization in the mesopores to obtain a silica / polymer composite; carrying out high-temperature calcination and etching treatment on the complex to obtain hollow mesoporous carbon spheres; the carbon sphere is used as a carrier to load a platinum alloy doped with rare earth metal. The hollow mesoporous carbon spheres prepared by the method have good spherical morphology and mesoporous channels and high specific surface area, and the problems of non-uniform morphology, unobvious mesopores and the like in a traditional method are solved. After platinum alloy particles doped with rare earth metal are loaded on the carbon spheres, the problems of agglomeration, wide particle size distribution, poor performance and the like of the platinum alloy particles are solved.

The invention discloses a wide-temperature energy storage aerogel / polymer composite material and a preparation method thereof.The preparation method comprises the steps that oxide aerogel with a three-dimensional skeleton structure is subjected to silanization treatment to obtain hydrophobic oxide aerogel, then the hydrophobic oxide aerogel is dispersed into a solvent to obtain dispersion liquid, and then the dispersion liquid is subjected to ultrasonic treatment to obtain the wide-temperature energy storage aerogel / polymer composite material. The preparation method comprises the following steps: sequentially adding a diamine monomer and an anhydride monomer into a dispersion liquid, reacting under stirring to obtain a polyamide acid precursor solution dispersed with hydrophobic oxide aerogel, carrying out film casting on the polyamide acid precursor solution to obtain a dry film, and carrying out imidization treatment on the dry film to obtain the aerogel / polymer composite material. The obtained aerogel / polymer composite material can still maintain high energy storage performance and stability even at extreme ambient temperature.

The invention belongs to the technical field of three-dimensional micro-nano manufacturing, and discloses a three-dimensional composite film and a preparation method thereof.The method comprises the steps that a conductive functional structure is prepared on the surface of a prepared high-molecular polymer composite double-layer stress film; the high-molecular polymer composite double-layer stress film comprises a first high-molecular polymer film and a second high-molecular polymer film arranged on the surface of the first high-molecular polymer film, and the swelling ratio of the first high-molecular polymer film is different from that of the second high-molecular polymer film; the conductive functional layer is prepared on the surface of the second high-molecular polymer film; then cutting to obtain a planar composite double-layer stress film; and the planar composite double-layer stress film is subjected to swelling deformation in a solvent, and the three-dimensional composite film in a preset shape is obtained. According to the method, a stress difference introduction strategy based on a swelling mechanism is utilized, so that integrated curling forming manufacturing of the flexible polymer functional film is realized.

The invention provides a preparation method of an HNT modified polymer composite membrane. The preparation method comprises the following steps: S1, preparing dealuminated HNT; s2, preparing modified HNT by using the dealuminated HNT; s3, preparing sulfonated polyether ether ketone; s4, performing ionization treatment on the sulfonated polyether ether ketone; and S5, preparing the HNT modified polymer composite membrane by using the modified HNT and the sulfonated polyetheretherketone or perfluorosulfonic acid membrane obtained in the step S4. The problems that an existing flow battery diaphragm is poor in comprehensive performance, high in cost and not suitable for various systems are solved.

A firearm suppressor is provided, including a tubular core, a baffle carried within the core, and a tubular mount. The core may be attached end-to-end to the mount. A cap may be attached end-to-end to the core opposite the mount. An intermediate member may be included, extending between the mount and the cap, and residing outboard of the core. The intermediate member may be welded to the mount and to the cap. The mount, the cap, and the intermediate member may be composed of one or more of titanium, aluminum, resins, polymers, composites, carbon fiber, and ceramics, whereas the core and the baffle may be composed of one or more of cobalt, nickel alloy, steel, stainless steel, and cobalt alloy.

The invention provides a diaphragm and a preparation method thereof, and relates to the technical field of lithium batteries, the diaphragm comprises: a first isolation layer used for contacting with a positive plate of a lithium battery; the third isolating layer is used for being in contact with a negative plate of the lithium battery; the second isolation layer is arranged between the first isolation layer and the third isolation layer; wherein the first isolation layer comprises a ceramic material, the second isolation layer comprises a polymer layer material, and the third isolation layer comprises a modified polymer composite layer material.By means of the diaphragm, the problem that the temperature rise of a capsule endoscope lithium battery is too high during short circuit is solved, a response can be made rapidly when the battery is short-circuited, and the service life of the capsule endoscope lithium battery is prolonged. And the short-circuit temperature rise temperature is reduced to be within 50 DEG C.

The invention relates to the technical field of flexible steel wire ropes, and discloses a durability-enhanced flexible steel wire rope and a processing technology thereof.The durability-enhanced flexible steel wire rope comprises, by mass, 98-105 parts of an alloy steel wire core; 5 to 15 parts of a ceramic nano composite outer coating; 2 to 10 parts of a self-repairing polymer middle coating layer; 1-5 parts of a high-adhesion polymer inner coating; 1-8 parts of a polymer composite lubricant; 0.5 to 3 parts of nanometer lubricating particles; according to the process, through collaborative design of multiple functional coatings and a lubricating system and combination of a heat treatment process, the corrosion resistance and the wear resistance of the steel wire rope are remarkably improved, and the service life is remarkably prolonged. Through the collaborative design of the high alloy steel core, the ceramic nano coating, the self-repairing middle layer, the three-layer coating structure and the polymer nano lubricating system, the corrosion resistance, the fatigue resistance, the wear resistance and the self-repairing capacity of the steel wire rope are improved, the service life is prolonged, and the maintenance cost is reduced.

The invention belongs to the technical field of polymer composite materials, and discloses a carbon fiber interface modifier aided design method and system based on collaborative optimization, and the method is used for designing a carbon fiber interface modifier based on collaborative optimization of machine learning and molecular dynamics simulation. By constructing a closed loop iteration process of generation-prediction-verification-learning, interfacial modifier molecules meeting multi-target performance requirements are quickly and accurately obtained under the condition that a large amount of early-stage chemical synthesis and experimental screening are not needed. According to the method, through deep combination of high-throughput prediction of machine learning and virtual experiment verification of molecular dynamics, efficient and automatic design of the interface modifier molecules is achieved, experimental synthesis and trial and error links are greatly reduced, the research and development efficiency is improved, and the method is widely suitable for design and optimization of the interface modifier molecules of the carbon fiber / resin-based composite material.

The invention belongs to the technical field of flow batteries, and discloses a flexible graphite bipolar plate with a self-repairing function and a preparation method and application thereof. The flexible graphite bipolar plate comprises a flexible graphite-polymer composite matrix, microcapsules and a graphene conductive layer, wherein the graphene conductive layer is arranged on the surface of the flexible graphite-polymer composite matrix; the microcapsule is dispersed in the flexible graphite-polymer composite matrix, the core of the microcapsule is a liquid metal alloy, the liquid metal alloy contains Ga, and the shell of the microcapsule is polyurethane. The microcapsules containing the liquid metal alloy are introduced into the flexible graphite bipolar plate in situ, and when the flexible graphite bipolar plate generates microcracks due to mechanical stress, thermal cycle and the like, the internal microcapsules are broken at the first time to release the liquid metal and fill the cracks, so that the graphite bipolar plate still keeps relatively high mechanical strength and air tightness, and the service life of the flexible graphite bipolar plate is prolonged. Therefore, the conductive stability and the use durability of the flow battery are improved.

A polymer-nanocellulose-lignin composite as disclosed comprises a polymer, nanocellulose, and lignin, wherein lignin forms a hydrophobic interface between the polymer and the nanocellulose. In some variations, a process is disclosed for producing a polymer-nanocellulose-lignin composite material, comprising: fractionating lignocellulosic biomass in the presence of an acid, a solvent for lignin, and water, to generate cellulose-rich solids and a liquid containing hemicellulose and lignin, wherein lignin deposits onto fiber surfaces or into fiber pores; mechanically treating the cellulose-rich solids to form a hydrophobic nanocellulose material comprising cellulose fibrils and / or cellulose crystals; hydrolyzing the hemicellulose to generate fermentable hemicellulosic sugars; fermenting the fermentable hemicellulosic sugars to generate a monomer or monomer precursor; polymerizing the monomer to produce a polymer; and combining the polymer with the lignin-coated nanocellulose to generate a polymer-nanocellulose-lignin composite material for use in a wide variety of products.

The invention relates to a composite diaphragm with a functional gradient coating and a preparation method of the composite diaphragm. The composite diaphragm comprises a porous base membrane, a solid electrolyte coating attached to one side or two sides of the porous base membrane, a mixed functional coating attached to the surface of the solid electrolyte coating, and a polymer composite coating on the outermost layer, the solid electrolyte coating comprises a first solid electrolyte and a first binder; the mixed functional coating comprises a second solid electrolyte, a high dielectric constant nano material and a second binder; the polymer composite coating comprises an in-situ polymerized polymer of a three-dimensional network structure, and a lithium salt and a third solid electrolyte which are filled in gaps of the three-dimensional network structure; the polymer is formed by initiating in-situ polymerization of polymerizable monomers through a photoinitiator. When the composite diaphragm is applied to the lithium battery, the cycle performance of the lithium battery can be improved.