1050 results about "Polymer electrolytes" patented technology

The invention discloses a high-interface-stability composite solid electrolyte membrane as well as a preparation method and application thereof. The composite solid electrolyte membrane comprises a gradient aperture three-dimensional porous skeleton formed by sintering inorganic solid electrolyte particles, a polymer electrolyte filled in a pore channel, and a plastic interface stable layer positioned between the electrolyte membrane and an electrode. The preparation method comprises the following steps: preparing a gradient aperture porous framework through a pore-forming agent template method and a tape casting technology, dipping and filling a polymer electrolyte precursor solution in a solution, accelerating in-situ polymerization by adopting electric induction, and performing hot-pressing treatment. The composite solid-state electrolyte membrane has high ionic conductivity, excellent interface compatibility and high mechanical strength, can effectively inhibit the growth of lithium dendrites, can be applied to solid-state batteries such as lithium metal batteries, lithium sulfur batteries and lithium air batteries, and can remarkably prolong the cycle life and improve the safety performance of the batteries, and the preparation process is suitable for large-scale production.

The invention discloses a multi-scale synergistically enhanced self-healing solid polymer electrolyte and a preparation method thereof, and belongs to the technical field of electrolyte materials. The preparation method of the electrolyte comprises the following steps: S1, adding the eight-arm star polymer, the carborane lithium salt, the neutral plastic crystal additive, the ionic liquid monomer and the crown ether functionalized boron alkene two-dimensional filler into a mixed solvent to form electrolyte slurry; s2, uniformly coating a base material with the electrolyte slurry to form a wet film, and drying the wet film; s3, transferring the dried membrane to an environment filled with inert gas, and initiating in-situ polymerization of an ionic liquid monomer by using ultraviolet irradiation to form a polyionic liquid nanofiber network; and S4, placing the membrane under a vacuum condition at a constant temperature of 120 DEG C for 5 hours to obtain the solid polymer electrolyte membrane. The solid polymer electrolyte membrane provided by the invention overcomes the problems of low ionic conductivity, low lithium ion transference number, insufficient mechanical properties, poor interface stability, narrow electrochemical window and the like of the existing solid polymer electrolyte.

The invention relates to the technical field of polymer electrolyte, in particular to a self-repairing type gel polymer electrolyte membrane, a preparation method and application in an energy storage battery, the self-repairing type gel polymer electrolyte membrane is prepared by the following steps: dissolving amino-terminated polyethylene glycol in an organic solvent, adding trimesic acid under the protection of an inert atmosphere, heating, stirring and reacting to form a pre-polymerized solution, cooling, and then adding trimesic acid into the pre-polymerized solution to prepare a self-repairing type gel polymer electrolyte membrane; the preparation method comprises the following steps: adding glyoxylic acid and glacial acetic acid, carrying out a constant temperature reaction to obtain a solution A, adding LiTFSI into the solution A, carrying out ultrasonic dispersion to a homogeneous phase, pouring the obtained slurry onto a template, and carrying out a drying curing reaction to obtain the self-repairing gel polymer electrolyte membrane. A rigid aromatic cross-linking agent is used for inhibiting polymer crystallization and improving mechanical integrity, an imine bond-based dynamic covalent network is introduced to realize an autonomous interface repairing function at the working temperature of the battery, and meanwhile, a polyethylene glycol ether oxygen chain is used for constructing an efficient lithium ion transmission channel; therefore, the technical boundary that the conductivity, the mechanical strength and the interface stability of the traditional GPE are difficult to collaboratively optimize is broken through.

The invention belongs to the technical field of new energy materials, and particularly relates to siloxane crosslinking modified polyether solid electrolyte and a preparation method thereof. According to the solid electrolyte, the electrophilic ring-opening polymerization reaction of a polymer monomer with an epoxy group is utilized, siloxane is used as a cross-linking agent, polyether chain structures are connected together to form a cross-linked network structure, the ionic conductivity can be increased, and the mechanical strength and the high-temperature dimensional stability can be improved; the lithium ion transference number is increased, the polarization is reduced, and the battery rate capability is improved; the oxidation stability of the electrolyte is improved; the decomposition reaction of polyether at high temperature is inhibited; the thermal stability and the flame retardant property of the polymer electrolyte are remarkably improved, so that the safety of a solid-state battery is improved.

The lithium secondary battery comprises a positive electrode, a negative electrode, a diaphragm and a polymer electrolyte, the polymer electrolyte contains the flame-retardant microcapsule, the flame-retardant microcapsule has a core-shell structure, a copolymer material containing one or more of an amide group, an ester group and an ether group is taken as a shell layer, and a flame retardant is taken as a core; the rupture collapse temperature of the flame-retardant microcapsule shell material is 60-120 DEG C, the melting point of the flame retardant is 20-120 DEG C, and the rupture collapse temperature of the copolymer material is higher than the melting point of the flame retardant. The lithium secondary battery disclosed by the invention has excellent flame retardance, the flame-retardant microcapsule added in the lithium secondary battery can be broken and collapsed when the battery is in thermal runaway, and the flame retardant is quickly released, so that the thermal runaway is actively defended in advance from the interior of the battery, and the electrochemical performance of the battery is not reduced.

The invention belongs to the technical field of polymer electrolyte membrane materials, and particularly relates to a high-ionic-conductivity polymer electrolyte membrane and a preparation method thereof.The preparation method comprises the steps that 1, PEO and lithium salt are added into a polar aprotic solvent, and the mixture is rapidly and violently stirred to be completely dissolved; (2) adding a cross-linking agent and a photoinitiator into the mixed solution, and violently stirring to obtain a mixed solution; and (3) coating the mixed solution in a polytetrafluoroethylene template, heating to remove the solvent, and performing ultraviolet radiation. According to the invention, a three-dimensional cross-linked network is formed by photocuring of an acrylate group of the cross-linking agent, PEO chain segment crystallization is inhibited, and lithium salt anions (such as TFSI-) are physically embedded. A benzene ring structure in a cross-linked network endows the electrolyte membrane with flexibility, mechanical property deterioration caused by a plasticizer or a diluent is avoided, the compact structure of the electrolyte membrane can inhibit lithium dendrite growth, the ionic conductivity reaches 1.7 * 10 <-4 > S / cm, and the electrochemical window reaches 4.9 V. The method is simple in process and suitable for large-scale preparation of the high-energy-density solid-state lithium battery.

The invention belongs to the field of functional material preparation, and relates to an MOFs crystal film and a preparation method and application thereof. According to the MOFs crystal film, a porous polymer supporting film is used as a carrier, a high-crystallinity, compact and continuous rigid MOFs crystal layer grows on the surface of the porous polymer supporting film in situ, and a solid / quasi-solid electrolyte system is formed by matching polymer electrolyte or electrolyte. The MOFs ordered pore channel ion screening effect and metal ion sites are used for limiting anions, so that the ion transference number is increased; a physical-chemical synergistic dendritic crystal inhibiting mechanism is realized by utilizing high mechanical strength and a high crystal structure; the low-tortuosity compact ordered MOFs crystal film is used for improving the conductivity, the MOFs electrolyte with wide temperature range stability and high voltage resistance is obtained, and a support is provided for realizing a secondary battery with high energy density and high safety.

An exemplary embodiment of the present disclosure provides a method for making an electrolyte, comprising: providing a solid polymer electrolyte (SPE); incorporating boron nitride with the SPE to form a composite polymer electrolyte (CPE), wherein the boron nitride is at least one of exfoliated hexagonal boron nitride (ex-BN) or fluorine-fimctionalized hexagonal boron nitride (BN-F).

A preparation method for a dual-enhanced interface solid polymer electrolyte by means of step-by-step polymerization, the preparation method comprising: mixing a matrix monomer and a first photoinitiator to obtain a mixed slurry, and illuminating same to obtain a pre-polymerized slurry; adding a lithium salt and a second photoinitiator to the pre-polymerized slurry, mixing same to obtain a polymer slurry, dividing the polymer slurry into a first polymer slurry and a second polymer slurry, adding a nitrogen-containing functional monomer to the first polymer slurry to obtain a polymer slurry A, and adding a fluorine-containing functional monomer to the second polymer slurry to obtain a polymer slurry B; and pouring the polymer slurry A on a first face of a base membrane, performing a treatment on same, pouring the polymer slurry B on a second face of the base membrane, and performing a treatment on same, so as to obtain a stepwise-polymerized dual-enhanced interface solid polymer electrolyte. The solid polymer electrolyte is prepared by means of using a step-by-step polymerization method, thereby optimizing a positive electrode side interface and a negative electrode side interface, and realizing continuous large-scale production of a solid polymer electrolyte.

The present invention provides a composition for forming a gel polymer electrolyte which includes a lithium salt; an organic solvent; and a crosslinking compound represented by Formula 1. wherein in Formula 1, L1, L2, L3, and L4 are each independently selected from a direct bond or an alkylene group having 1 to 3 carbon atoms, L5 and L6 are each independently an alkylene group having 1 to 20 carbon atoms in which at least one methylene group is optionally substituted with an ether group and at least one hydrogen is substituted with fluorine, and R1 and R2 are each independently selected from hydrogen, an alkyl group having 1 to 3 carbon atoms, or a halogen.

The invention discloses a polymer electrolyte composite material for a high-temperature-resistant solid-state battery and a preparation method of the polymer electrolyte composite material, and belongs to the technical field of solid-state battery materials. The preparation method comprises the following steps: preparation of key functional components, preparation of a precursor solution, dispersion and compounding of the filler, film casting and heat treatment, and post-treatment. A dynamic thioether bond is introduced into a main chain to construct an oxygen-sulfur synergistic coordination network, and a multi-component interface chemical bonding and gradient curing process is combined, so that the problems that the ionic conductivity and the mechanical strength of the traditional polymer electrolyte cannot be considered at a high temperature, the filler is easy to agglomerate, the membrane has many defects and the like are solved; the obtained material still keeps high ionic conductivity and excellent mechanical stability at 150 DEG C, has a wide electrochemical window, and is suitable for high-safety and high-energy-density solid-state batteries.

The invention provides a phosphorus-based ionic liquid flame-retardant polymer solid electrolyte and a preparation method and application thereof, belongs to the technical field of polymer solid electrolyte materials, and relates to a phosphorus-containing group flame-retardant ionic liquid polymer electrolyte and a preparation method thereof. The invention aims to overcome the problems that the polymer electrolyte in the prior art is poor in safety and the battery performance needs to be further improved, and provides the ionic liquid polymer electrolyte with the flame-retardant characteristic, the polymer electrolyte can greatly improve the safety performance of the battery while improving the battery performance, and the service life of the battery is prolonged. The phosphate group-containing ionic liquid has the advantages that the phosphate group-containing ionic liquid can be used as a polymer matrix of a polymer solid electrolyte, so that enough mechanical strength is ensured, phosphate radicals play a flame-retardant effect in a reaction process, a combustion reaction can be interrupted, and the safety performance of a battery can be greatly improved while the performance of the battery is improved.

The invention belongs to the field of polymer electrolyte. Polyurethane (PU) which is high in strength, good in elasticity, convenient to form and capable of being self-repaired is selected as a substrate of the solid electrolyte. A deep eutectic solvent (DES) which can be copolymerized with the lithium salt is selected to enhance the polarity of the system and promote dissociation of the lithium salt, so that the conductivity of the solid electrolyte is improved. The invention provides a preparation method of a DES copolymerization modified self-repairing polyurethane-based solid electrolyte. The preparation method comprises the following steps: preparing a long-chain polyurethane prepolymer; preparing a self-repairing prepolymer; performing double-bond modification on the self-repairing prepolymer; preparing DES containing lithium salt and double bonds; uniformly mixing the self-repairing polyurethane prepolymer with the end capped by double bonds and DES (diethylbenzene sulfonate); pouring into a mold and curing to obtain the DES / polyurethane-based solid electrolyte membrane; and preparing the solid-state lithium battery. The solid electrolyte disclosed by the invention is free from slag falling and liquid leakage, capable of self-repairing, high in ion mobility, simple in preparation process, low in cost and outstanding in performance, and has a wide market application prospect.

The invention relates to the technical field of polymer electrolytes, in particular to a composite solid electrolyte based on aramid nanofibers and a lithium-sulfur battery. The composite solid electrolyte is prepared by taking a composite aramid nanofiber membrane with a double-layer three-dimensional structure as a base material, an upper polyaniline base material provides good interface contact stability with a lithium negative electrode, and a lower aramid nanofiber skeleton provides good mechanical support performance for the fiber membrane; and meanwhile, the electrochemical performance of the composite solid electrolyte is comprehensively improved by doping the special porous structure of the composite solid electrolyte with the core-shell porous carbon.

The invention belongs to the field of batteries, and particularly relates to a solid-state polymer electrolyte composite membrane, a preparation method thereof and a solid-state battery. The solid polymer electrolyte composite membrane comprises an MOF functional layer, an anti-reduction coating and an anti-oxidation coating, wherein the anti-reduction coating and the anti-oxidation coating are arranged on the two sides of the MOF functional layer respectively; the MOF functional layer comprises an intermediate layer base material formed by an organic polymer, and an inorganic solid electrolyte and an MOF-based ionic conductor MOF-ILE which are dispersed in the intermediate layer base material; the MOF-based ionic conductor MOF-ILE comprises an MOF material, an ionic liquid and a lithium salt. The electrolyte membrane can meet the multifunctional requirements of all-solid-state batteries, including high ionic conductivity of the electrolyte membrane, good electrode-solid electrolyte membrane interface compatibility, high electrochemical window, excellent mechanical strength and electrochemical stability, so that the electrical performance of the all-solid-state batteries is remarkably improved.

The invention discloses an in-situ cross-linked flame-retardant polymer electrolyte and a precursor solution and a battery thereof, and belongs to the technical field of new energy batteries. The precursor solution comprises an ester-based electrolyte, an alkylene oxide monomer and an initiator, wherein the alkylene oxide monomer and the initiator are used for in-situ cross-linking curing to form a gel polymer; the mass ratio of the alkylene oxide monomer to the ester-based electrolyte is (0.5-2): 100; the alkylene oxide monomers comprise a first monomer and a second monomer, the epoxy functionality of the first monomer is greater than or equal to 3, and the second monomer contains a perfluoro chain segment. The precursor solution is a gel polymer which can be cross-linked and cured in situ to form a locking solution by adding a small amount of monomers into an ester-based electrolyte, and can improve the electrical property and safety of a battery system.

The invention relates to the technical field of lithium metal batteries, and discloses a silane coupling agent modified Mxene-based solid-state polymer electrolyte, a solid-state lithium battery and a preparation method of the solid-state lithium battery. The silane coupling agent modified Mxene-based solid polymer electrolyte is prepared by uniformly mixing the raw materials and then heating and curing; the raw materials comprise the following components in percentage by weight: 0.2-1.6 wt% of silane coupling agent modified Mxene; 8-15 wt% of a lithium salt; 3 to 6 wt% of an acrylate unsaturated monomer; 0.01 to 0.05 wt% of an initiator; and the balance of solvent. According to the invention, the two-dimensional material MXene is introduced, so that the growth of lithium dendrites is effectively inhibited; abundant functional groups on the surface of MXene and a polymer skeleton generate a synergistic effect, rapid migration of Li < + > can be promoted, and a film is formed at an interface of a positive electrode and a negative electrode, so that the solid-state lithium battery can stably operate under extreme conditions of high and low temperatures, high magnification and the like; the MXene is subjected to surface modification through siloxane, so that the compatibility of the MXene in an electrolyte precursor solution can be improved, and the electronic conductivity of the MXene can be remarkably reduced, thereby enhancing the safety of the battery.

The invention discloses a polymer solid electrolyte, which is composed of the following components: a polymer substrate; a lithium salt; the composite filler is IL (at) ZIF-67 formed by compounding ZIF-67 and an ionic liquid; and a solvent. The ionic liquid is used as a plasticizer, and the EmimTFSI can effectively weaken the intermolecular acting force between polymer chains and increase the free volume and movement ability of the polymer chains. ZIF-67 has abundant Lewis acid sites (Co < + >), and the sites can form weak coordination with LiTFSI, so that the ionic conductivity is further improved. The introduction of the composite filler is beneficial to improving the interface stability of the polymer electrolyte and the lithium metal negative electrode and inhibiting the growth of lithium dendrites, so that the cycle life of the battery is prolonged. The polymer solid electrolyte membrane prepared on the basis of the preparation method is applied to a solid-state lithium-sulfur battery, and the cycling stability, the rate capability and the coulombic efficiency of the battery can be remarkably improved.

The invention provides a polymer electrolyte, a secondary battery and a preparation method of the polymer electrolyte and the secondary battery. The non-aqueous electrolyte comprises an organic solvent, an electrolyte salt, a borate derivative with the mass fraction of 0.1%-15%, a sulfonyl-containing cross-linking agent A with the mass fraction of 0.1%-4%, a cross-linking agent B at least containing three carbon-carbon double bonds and an initiator, the mass ratio of the cross-linking agent B to the cross-linking agent A is (1-100): 1, the mass fraction of the borate derivative is 0.1%-15%, the mass fraction of the sulfonyl-containing cross-linking agent A is 0.1%-4%, and the mass fraction of the initiator is 0.1%-1%. The mass ratio of the sum of the mass of the borate derivative, the cross-linking agent A and the cross-linking agent B to the mass of the initiator is (1000-20): 1. The polymer electrolyte provided by the invention has high ionic conductivity, can improve the safety performance of a battery in a high proportion state, and can maintain good cycle performance at the same time.

The invention provides a gel electrolyte with a controllable polymerization degree, a preparation method of the gel electrolyte, a semi-solid lithium ion secondary battery and a preparation method of the semi-solid lithium ion secondary battery, and relates to the technical field of lithium ion batteries. Raw materials for preparing the gel electrolyte comprise a cyclic ether monomer, an initiator and a polymerization inhibitor; the cyclic ether monomer is subjected to ring opening polymerization to obtain an ether polymer; the polymerization inhibitor is an inorganic lithium salt, and the polymerization degree of the gel electrolyte is determined by the dosage of the polymerization inhibitor and the dosage of the initiator. The gel electrolyte provided by the invention has the fluidity advantage of a liquid electrolyte and the flexibility advantage of a solid polymer electrolyte, and is beneficial to maintaining a stable contact interface between the electrolyte and an electrode, reducing interface impedance and improving ion transmission.

The invention provides a Lewis acid metal ion-piperazine modified nanocellulose film as well as a preparation method and application thereof, and belongs to the technical field of battery materials. The preparation method comprises the following steps: mixing carboxylated nanocellulose with Lewis acidic metal salt in a solution, and carrying out pre-crosslinking reaction to obtain Lewis acidic metal ion modified carboxylated nanocellulose; a piperazine ligand compound and dopamine hydrochloride are added into the Lewis acidic metal ion modified carboxylated nano-cellulose, a cross-linking reaction is carried out with Lewis acidic metal ions as the center, suction filtration is carried out, and a film is formed. The metal in the Lewis acid metal salt is metal cations with the valence of more than bivalent. The carboxylated nanocellulose, the Lewis acid metal ion-piperazine complex and the solid polymer electrolyte are organically combined together for the first time and are applied to the lithium metal battery, the unique advantages of the lithium metal battery in the field of batteries are shown, and the rate capability and the cycling stability are greatly improved.

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 provides an ultrathin aramid nanofiber-based composite solid electrolyte and a preparation method and application thereof, and belongs to the technical field of polymer electrolytes and metal secondary batteries, the method comprises the following steps: adding LLZTO into anhydrous acetonitrile, stirring, then carrying out ultrasonic dispersion, then adding PEO and LiTFSI, carrying out constant-temperature stirring treatment, and then carrying out vacuum drying to obtain the ultrathin aramid nanofiber-based composite solid electrolyte. A mixed electrolyte solution is obtained; a porous aramid nanofiber aerogel film is soaked in the mixed electrolyte solution, and a soaked aramid nanofiber-based composite solid electrolyte is obtained; and placing the impregnated aramid nanofiber-based composite solid electrolyte on a polytetrafluoroethylene film, and carrying out vacuum drying and stripping to obtain the ultrathin aramid nanofiber-based composite solid electrolyte. The problems that an existing solid electrolyte is poor in mechanical property, low in ionic conductivity and unstable in electrochemical performance can be solved.

The invention discloses a polyphosphazene flame-retardant electrolyte, a lithium ion battery containing the electrolyte and a preparation method of the lithium ion battery, and belongs to the technical field of lithium ion batteries. The electrolyte comprises a lithium salt, an organic solvent, a cosolvent, an additive, a cross-linking agent, a polymer monomer and a polymerization initiator, and is prepared in an in-situ or ex-situ polymerization mode. According to the polymer electrolyte or gel electrolyte provided by the invention, on the basis of various flame-retardant mechanisms of a phosphazene structure and a polymer network structure of a three-dimensional network structure, the overall thermal stability is improved, the intrinsic safety of a battery is improved, the safety risk caused by abuse, overcharge and overdischarge, needling, collision and the like is reduced, and the service life of the battery is prolonged. And a new direction is provided for further developing a multi-element composite flame-retardant material and promoting the safety of a lithium ion battery.

The invention belongs to the technical field of development and manufacturing of solid-state electrolyte materials and solid-state lithium batteries, and particularly relates to an all-solid-state oxide-polymer electrolyte membrane as well as a preparation method and application thereof. The electrolyte membrane comprises a polymer matrix, a lithium salt, butanedinitrile, lithium lanthanum zirconium tantalum oxide and graphite phase carbon nitride, the polymer matrix, the lithium salt, the butanedinitrile, the lithium lanthanum zirconium tantalum oxide and the graphite phase carbon nitride are uniformly mixed to form a solid film; the polymer matrix is polyacrylonitrile and forms a framework of the electrolyte membrane; the lithium salt, the butanedinitrile, the lithium lanthanum zirconium tantalum oxide and the graphite phase carbon nitride are at least physically and uniformly dispersed in the polymer matrix. The electrolyte membrane can be prepared through the steps of slurry preparation, defoaming treatment, membrane forming processing, drying and curing and the like, and can be used in a solid-state lithium battery, so that the contact between the electrolyte membrane and an electrode interface is improved, side reaction is inhibited, the ion transmission efficiency and mechanical property are improved, the interface impedance is reduced, and the cycling stability and safety of the solid-state lithium battery are enhanced.

The invention discloses a solid electrolyte membrane, a preparation method and a lithium battery. The solid electrolyte membrane comprises a polymer electrolyte, the structure of the polymer electrolyte is a hyperbranched polymer, a molecular chain of the polymer electrolyte contains a polyoxyethylene chain segment, ether oxygen atoms in an amorphous phase region can form coordination with lithium ions, migration of the lithium ions is facilitated, and the ionic conductivity of the solid electrolyte membrane is improved; besides, a nitrogen and sulfur element annular structure is introduced into the hyperbranched polymer, so that the mechanical strength of the solid electrolyte membrane can be effectively improved, the ionic conductivity of the solid electrolyte membrane can be further improved, the interface impedance can be reduced, and the comprehensive performance of the battery on safety performance and electrical performance is improved.

The invention discloses a sulfur-containing all-solid-state polymer electrolyte membrane, a preparation method and a lithium metal battery, and belongs to the technical field of polymer electrolytes.The method comprises the steps that 1, 4-phenylene-diacrylate and dimethyl tetrasulfide are evenly mixed and cooled to the room temperature after a reverse vulcanization reaction, and a polymer solid is obtained; the preparation method comprises the following steps: dissolving a polymer solid in dimethyl sulfoxide, adding bis (trifluoromethanesulfonyl) lithium imide, uniformly stirring and mixing, casting in a PTFE (Polytetrafluoroethylene) mold, uniformly spreading, and carrying out vacuum drying to obtain the sulfur-containing all-solid-state polymer electrolyte membrane. The ion transmission function of a liquid electrolyte is replaced by the solid ion conduction property, and the physical isolation function of a diaphragm is replaced by a compact and firm physical structure, so that the Li < + > diffusion energy barrier is reduced, the electrochemical window is widened, the interface impedance is reduced, and the interface compatibility between the positive and negative electrode materials and the solid electrolyte is improved; the lithium metal battery assembled by the electrolyte has excellent electrochemical performance and cycle performance.

The invention relates to the technical field of lithium battery electrolyte, in particular to a composite enhanced solid electrolyte membrane and a preparation method thereof. The polymer solid electrolyte is a polycarbonate-based solid electrolyte such as a poly (ethylene carbonate)-based solid electrolyte PVC, a poly (vinylene carbonate)-based solid electrolyte PEC, a poly (propylene carbonate)-based solid electrolyte PPC, a poly (propylene carbonate)-based solid electrolyte PTMC and a polyoxyethylene-based solid electrolyte. The electrolyte is one or more of polysiloxane-based polymer electrolyte and single-lithium-ion conductive polymer electrolyte materials. The composite enhanced solid electrolyte membrane is disclosed. The preparation method comprises the following steps: preparing the three-dimensional nanofiber skeleton through electrostatic spinning, loading the two surfaces of mixed slurry of the polymer electrolyte and the lithium salt on the base membrane in an inert atmosphere, and carrying out vacuum curing molding. The composite membrane has high safety and a wide electrochemical window, the process of the composite membrane is compatible with an existing lithium battery production line, the raw material cost is controllable, and the composite membrane has large-scale commercial application potential.

The invention discloses a fluorinated polymer and application thereof in an electrode protection layer and a solid electrolyte, and belongs to the technical field of lithium metal secondary batteries, and the fluorinated polymer is obtained by reacting acrylate functionalized polyethylene glycol, HFBA and an initiator. When the fluorinated polymer is used as a lithium metal negative electrode protective layer, the LiFePO4 / Li total battery protected by the polymer shows more excellent cycle performance compared with an unprotected total battery. And the battery is stable in cycle performance, high in capacity retention rate and low in capacity fading speed. When the fluorinated polymer is applied to the solid-state electrolyte, the polymer solid-state electrolyte in which a polymer network wraps an ionic conductive plastic crystal can be formed through an in-situ reaction, so that the growth of Li dendritic crystals is effectively inhibited, and the stability of the polymer electrolyte and a lithium negative electrode is ensured. Moreover, the solid electrolyte can be adapted to a high-nickel ternary positive electrode material, and a thought is provided for realizing a stable and safe high-energy-density battery.

The invention relates to a preparation method of a gel polymer electrolyte and the gel polymer electrolyte, and the method comprises the following steps: dissolving a polymer matrix in a fluorinated solvent, and adding a lithium salt, an initiator and an additive into the fluorinated solvent; stirring the fluorinated solvent through an ultrasonic dispersion technology to form a homogeneous precursor solution; injecting the precursor solution into a battery shell, carrying out thermal polymerization at a preset polymerization temperature for a preset polymerization time, and forming an electrolyte membrane with a three-dimensional cross-linked network structure in the battery shell; after a residual solvent in a battery shell is removed through vacuum drying, an electrolyte membrane with a three-dimensional cross-linked network structure is used as a flexible self-supporting gel polymer electrolyte. The gel polymer electrolyte is an electrolyte membrane with a three-dimensional cross-linked network structure, can inhibit the growth of lithium dendrites and improve the ion migration efficiency, is superior to the existing electrolyte in ionic conductivity and Li < + > transference number, and is suitable for high-energy-density energy storage lithium batteries.