1872 results about "Battery electrolyte" patented technology

Systems and apparatus may carry out analysis of battery physical phenomena, and characterize batteries based on phenomena occurring in particular time and / or frequency domains. These systems may be additionally responsible for charging and / or monitoring a rechargeable battery. Examples of battery physical phenomena include mass transport (e.g., diffusion and / or migration) in battery electrolytes, mass transport in battery electrodes, and reactions on battery electrodes.

The invention belongs to the technical field of battery electrolytes, and particularly relates to a gel polymer electrolyte as well as a preparation method and application thereof. The gel polymer electrolyte is prepared through in-situ polymerization, and the electrolyte is composed of a monomer, a cross-linking agent, an initiator, an organic solvent and a lithium salt. The monomer is selected from fluorine-containing monomers such as trifluoroethyl acrylate, 2, 2, 3, 3-tetrafluoropropyl methacrylate and the like, and the cross-linking agent is selected from NH-containing cross-linking agents such as N, N '-methylene bisacrylamide, hexamethylene bisacrylamide and the like, so that a polymer side chain fluorine-containing functional group is formed in situ and interacts with lithium ions, and lithium ion transmission is promoted; and the NH functional group on the main chain limits the migration of anions, so that the ion migration number is increased. Therefore, the copolymerized fluorine-containing monomer and nitrogen-containing cross-linking agent gel polymer electrolyte enables the battery to show good specific discharge capacity and cycling stability under high current density.

Systems and apparatus may carry out analysis of battery physical phenomena, and characterize batteries based on phenomena occurring in particular time and / or frequency domains. These systems may be additionally responsible for charging and / or monitoring a rechargeable battery. Examples of battery physical phenomena include mass transport (e.g., diffusion and / or migration) in battery electrolytes, mass transport in battery electrodes, and reactions on battery electrodes.

The invention discloses a complex electrolyte additive for a battery, an aqueous zinc ion battery electrolyte and an aqueous zinc ion battery. The electrolyte additive is a complex containing metal complex ions; the complex is composed of a central ion and an internal ligand. The electrolyte additive can respectively form metal and alloy electrode-electrolyte interfaces on the surface of a zinc negative electrode through replacement and electrochemical reaction, and regulate and control the deposition behavior of zinc ions to inhibit the generation of zinc dendrites and accelerate deposition / dissolution kinetics, so that the service life of the zinc negative electrode is remarkably prolonged, and the rate capability is enhanced; a solvation structure of zinc ions can be regulated and controlled, side reactions such as hydrogen evolution, corrosion and passivation are slowed down, and capacity fading of the water-based zinc ion battery can be remarkably delayed when the positive electrode is coupled with a high-efficiency positive electrode; meanwhile, the aqueous zinc ion battery electrolyte additive is low in price, green, environment-friendly, high in functionality and beneficial to development of an aqueous zinc ion battery electrolyte and an aqueous zinc ion battery which are excellent in performance, safe, environment-friendly and low in cost.

The invention provides a sodium ion battery electrolyte additive and a composition thereof, an electrolyte and a sodium ion battery containing the electrolyte. The additive is a fluorine-containing cyclic sulfate compound, the composition comprises fluorine-containing cyclic sulfate and other additives, and the fluorine-containing cyclic sulfate has a structure as shown in a formula (I): # imgabs0 # formula (I); the sodium-ion battery electrolyte comprises an organic solvent, a sodium salt electrolyte, the additive and any one composition of the additive, the sodium-ion battery comprises a positive electrode material, a negative electrode material and any one of the combined electrolyte. As the fluorine-containing additive has a relatively low HOMO energy level, the oxidation resistance of the non-aqueous electrolyte can be improved, and the electrochemical window of the non-aqueous electrolyte is widened; meanwhile, the cyclic sulfate participates in the formation of a negative electrode SEI film, so that the electrode interface is stabilized, and the impedance of the negative electrode surface can be remarkably reduced, thereby reducing the overall impedance of the battery, improving the rate capability and high-temperature performance of the battery, and prolonging the cycle life of the battery.

The invention discloses Zn-I2 battery electrolyte as well as a preparation method and application thereof. The Zn-I2 battery electrolyte comprises an additive, zinc salt and a composite solvent, the additive contains halogen groups and polar functional groups; the halogen group is selected from one or more than two of F, Cl and Br. Through halogen groups in the additive, the iodine negative ion intermediate is effectively stabilized, so that a Zn-I2 battery is subjected to multi-electron transfer, and the specific capacity of the photoelectric storage integrated battery is improved; the polar functional groups in the additive can homogenize the electric field distribution on the Zn surface, reduce the nucleation overpotential corrosion current and hydrogen evolution current of Zn, change the diffusion path of Zn < 2 + > on an anode interface and improve the cycle stability of the Zn-I2 battery, the Zn-I2 battery with high specific capacity and long cycle life can be obtained by matching the two functional groups, and the Zn-I2 battery is coupled with a solar battery, so that the service life of the Zn-I2 battery is prolonged. Therefore, the overall conversion efficiency and the service life of the photoelectric storage integrated battery are improved.

The invention discloses a novel semi-solid battery and a preparation method thereof, and belongs to the technical field of lithium ion batteries. According to the novel electrolyte, a sulfur-containing cyclic compound is added into a lithium ion battery electrolyte, and the semi-solid-state battery contains the novel electrolyte and a composite positive electrode comprising a current collector layer, an active material layer and a solid-state electrolyte layer. The sulfur-containing cyclic compound in the novel electrolyte can form a layer of sulfur-containing organic film with nanoscale thickness on the surface of the solid electrolyte layer, so that high-temperature side reaction of the solid electrolyte and the electrolyte is effectively avoided, and the service life of a battery under a high-temperature condition is greatly prolonged.

The invention discloses a lithium ion battery electrolyte high temperature resistance determination system, which relates to the technical field of battery electrolyte determination, and comprises a central control system, a data acquisition and analysis module and an electrochemical performance test module, the system is characterized in that the central control system is connected with a data acquisition and analysis module and an electrochemical performance test module through a laboratory local area network, the data acquisition module is connected to the electrochemical performance test module through a data line, and the electrochemical performance test module is used for detecting the electrochemical performance change of the battery electrolyte; the electrochemical performance test module comprises a cyclic voltammetry unit, an alternating current impedance spectroscopy unit and a charge and discharge test unit. By installing the electrochemical performance test module, the electrochemical performance test function of the electrolyte is realized, the problem that the electrochemical performance of the electrolyte in a high-temperature environment cannot be accurately evaluated is solved, performance data of the electrolyte under an actual battery working condition is provided, and battery design and optimization are supported.

The invention relates to an electrolyte additive, an electrolyte and a battery. The electrolyte additive comprises a first additive and lithium trifluoromethanesulfinate, the structural formula of the first additive is as shown in a formula (I): # imgabs0 # formula (I), and in the electrolyte additive, the mass ratio of the first additive to the lithium trifluoromethanesulfinate is 0.02-10. When the electrolyte additive is added into the electrolyte of the battery, the rate capability and the high-temperature performance of the battery can be effectively improved.

The invention discloses an anion-regulated weak-solvation sulfuryl electrolyte and a preparation method thereof, and belongs to the technical field of battery electrolytes. The electrolyte comprises a common lithium salt, a high-donor-number lithium salt and a sulfone solvent. The coordination of lithium ions and sulfone solvents is effectively weakened through anions of the lithium salt with the high donor number, and the interaction between the lithium ions and common lithium hydrochloride ions is enhanced. By constructing the weak solvation structure, the lithium ion desolvation process and the decomposition of common lithium salt are promoted, and meanwhile, the solid electrolyte interface SEI layer rich in inorganic matters is formed through the oxidation reduction of negative ions of the weak solvation structure, so that the problem of poor compatibility of a sulfone solvent with lithium metal and a graphite negative electrode is solved; meanwhile, good electrochemical performance and wide temperature range adaptability are achieved. The electrolyte has wide application prospects in the aspects of lithium ion batteries, energy storage lithium battery systems and the like.

The embodiment of the invention provides an electrolyte formula generation method, a storage medium and a processor, and belongs to the technical field of secondary batteries. The electrolyte formula generation method comprises the following steps: determining a target physical property parameter index of an electrolyte and at least one battery performance index according to an application requirement of a battery; according to the electrolyte component prediction model, screening out a formula conforming to a target physical property parameter index from the electrolyte component feasible region, and taking the formula as a group of candidate electrolyte formulas; estimating a performance index estimation value of each of the group of candidate electrolyte formulas according to a performance index estimation model, and solving a weighted sum of the performance index estimation values in the at least one battery performance index; and taking the corresponding electrolyte formula of which the weighted sum meets a preset standard as a recommended electrolyte formula. According to the electrolyte formula generation method disclosed by the invention, the optimal battery electrolyte formula can be recommended by comprehensively considering cost, physical property factors and battery performance, and high-efficiency and low-cost design of the electrolyte is realized.

The invention provides an ionic liquid additive for a solid-state lithium metal battery electrolyte and a method for preparing the solid-state lithium metal battery electrolyte by using the ionic liquid additive. The bistrifluoromethanesulfonyl imide salt containing terphenyl and lithium carboxylate obtained through Michael addition reaction is captured by open metal sites of the MOF material UiO-66-NH2, the structural stability of the material can be improved, more transmission channels are provided for lithium ions, and therefore the transference number of the lithium ions is increased, the performance of the lithium metal battery is improved, and the service life of the lithium metal battery is prolonged. Especially in the aspect of charge and discharge rate. The electrolyte material disclosed by the invention has good stability with lithium metal, so that electrolyte decomposition can be prevented, and an unstable phenomenon, such as lithium dendrite growth, on the surface of an electrode can be avoided, so that a lithium metal battery can show excellent electrochemical performance, including better cycling stability, high coulombic efficiency and longer battery life.

The invention discloses a modified lithium borohydride solid electrolyte and a preparation method thereof, and belongs to the field of all-solid-state battery electrolyte preparation, the method comprises the following steps: mixing LiBH4 and lithium halide according to a formula ratio, and carrying out ball milling and heating to obtain an xLiBH4-LiX (x = 1-5) solid solution; then mixing and ball-milling B2O3 and the LiBH4-lithium halide solid solution to obtain a doped and composite synergistically modified (xLiBH4-LiX) y-B2O3 (y is equal to 10 to 20) solid electrolyte; a LiBH4 phase is stabilized by doping lithium halide, and grain gaps are densified by compounding B2O3, so that the grain boundary impedance is reduced, the lithium dendrite inhibition capability of the lithium borohydride-based solid electrolyte is improved, the stable operation of the lithium borohydride-based solid electrolyte at high voltage is ensured, and the lithium borohydride-based solid electrolyte has relatively high ionic conductivity, relatively low electronic conductivity and a relatively wide electrochemical window; and the lithium borohydride-based solid electrolyte has good stability and compatibility with a lithium metal negative electrode, and development of the lithium borohydride-based solid electrolyte in commercial application of a lithium ion battery is facilitated.

The invention provides an electrolyte for improving the interface stability of a four-electron aqueous zinc-iodine battery, and belongs to the technical field of zinc-iodine battery electrolyte additives, the electrolyte comprises N, N-dihydroxyethyl glycine, zinc sulfate, an additive and water; in the electrolyte, the concentration of the N, N-dihydroxyethyl glycine is 0.5 + / -0.2 mol / L; the molar ratio of the additive to the zinc sulfate is 1: 3; the additive comprises any one of methyl triethyl ammonium chloride, betaine hydrochloride and triethylamine hydrobromide. The electrolyte can enhance the interface stability of the electrode electrolyte, improve the cycling stability and electrochemical performance of the aqueous zinc-iodine battery, inhibit side reactions, and improve the safety and reliability of the battery. The invention also provides a high-capacity aqueous zinc-iodine battery.

The invention discloses deep eutectic gel polymer electrolyte as well as preparation and application thereof, belongs to the technical field of battery electrolyte, solves the problems of low thermal stability, low ionic conductivity and poor mechanical property in the prior art, and comprises a bimetallic salt-eutectic solvent and a polymer chain which are dynamically crosslinked and constructed, the bimetallic salt-eutectic solvent comprises lithium ions, heterogeneous metal salt and Lewis base, and the polymer chain is formed by free radical polymerization, atom transfer radical polymerization (ATRP) or reversible addition-fragmentation chain transfer radical polymerization (RAFT). According to the invention, the deep eutectic solvent is introduced as a reaction solution, so that the organic gel monomer is subjected to photopolymerization or thermal polymerization in the solution, the elongation at break can reach more than 500%, the organic gel has excellent mechanical stretchability, a polymer network is formed by utilizing a long-chain molecular formula of a polymer chain, the deep eutectic solution is wrapped in the polymer network, and the organic gel has excellent thermal stability; and the good ionic conductivity of the electrolyte is ensured.

The invention belongs to the technical field of sodium-ion battery electrolyte, and particularly discloses negative-electrode-free sodium metal battery electrolyte as well as a preparation method and application thereof. The negative-electrode-free sodium metal battery electrolyte comprises an organic solvent, sodium salt and a sodium supplementing additive; the sodium supplementing additive comprises at least one of sodium trimethylsilanolate and sodium amide. According to the electrolyte disclosed by the invention, through reasonable configuration, a compact solid electrolyte interface film (SEI film) is formed on an electrode-electrolyte interface of the negative-electrode-free sodium metal battery, so that irreversible loss of active sodium in an SEI forming stage is effectively compensated, reversible capacity loss in a circulating process is reduced, and the circulating stability and safety of the battery are improved.

The invention belongs to the technical field of zinc battery electrolyte, and discloses application of pyridine hydrochloride as an electrolyte additive in stabilizing a zinc negative electrode and realizing four-electron transfer of a zinc-iodine secondary battery. The hydrochloride containing the pyridine structure is used as an electrolyte additive, molecules of the pyridine structure are adsorbed on the surface of the zinc negative electrode to form a shielding layer, the deposition / stripping reversibility of the zinc negative electrode is improved, stabilization of the zinc negative electrode can be achieved, and the problems of zinc dendritic crystal, corrosion and hydrogen evolution are solved. Meanwhile, molecules with pyridine structures can activate and stabilize I- / I0 / I < + > four-electron redox reaction, inhibit I < + > hydrolysis side reaction and improve the energy density and cycling stability of the zinc-iodine battery. The problem of poor electrochemical deposition / stripping reversibility of a zinc negative electrode and the problem of poor stability of positive valence I < + > species of an iodine positive electrode of a four-electron transfer reaction are solved. The electrolyte containing the additive is low in cost, simple in method, easy to produce and high in practical value.

The invention belongs to the technical field of battery electrolyte additives, and particularly discloses a sulfonamide / sulfonamide ester additive and application thereof in a sodium-ion battery electrolyte, the sulfonamide / sulfonamide ester additive is a compound with the structural formula shown in the formula (I): # imgabs0 #, the sulfonamide / sulfonamide ester additive provided by the invention can remove trace hydrofluoric acid and water existing in a battery by introducing amido; a group containing an F element is introduced, so that a compact passivation protection film can be formed on the surface of the electrode material, and further reaction of an electrolyte and the electrode material is isolated; a sulfonate group is introduced, the ionic conductivity of the electrolyte is improved, and a low-impedance electrode-electrolyte interface film can be formed, so that a sodium-ion battery electrolyte additive system with long service life and high safety is obtained; and the bottleneck problems of poor rate capability, short cycle life and the like of the sodium ion battery in the traditional carbonic ester and ether electrolyte are solved in a targeted manner.

The utility model discloses a continuous cooling crystallization device for recovering and extracting sodium sulfate in waste battery electrolyte. The continuous cooling crystallization device comprises a crystallizer shell and a crystallizer jacket, the crystallizer jacket is fixedly arranged on the outer wall of the crystallizer shell in a sleeving manner; a circulating cooling medium is introduced into the crystallizer jacket, a coaxial sleeve-shaped guide cylinder is arranged in the crystallizer shell, two layers of stirring blades are arranged in the guide cylinder, and the stirring blade at the lower layer is flush with the lower edge of the guide cylinder; one end of a first channel serving as a feeding hole of the crystallizer is positioned on the side wall of the guide cylinder, and extends out of the outer wall of the crystallizer jacket after sequentially passing through a cylinder body of the crystallizer shell and the crystallizer jacket; one end of a second channel serving as a turbidimeter and thermometer port extends into the barrel of the crystallizer shell and extends out of the outer wall of the crystallizer jacket after passing through the crystallizer jacket, and one end of a first channel located on the side wall of the guide cylinder is located between the double-layer stirring blades.

The invention relates to the field of sodium-ion battery electrolytes, and discloses a fluorine-rich combined additive, an electrolyte and application of the fluorine-rich combined additive and the electrolyte in inhibition of gas production of a sodium-ion battery. The fluorine-rich additive comprises sodium difluoro (oxalato) borate (NaDFOB), fluoroethylene carbonate (FEC) and bis (trifluoroethyl) carbonate (TFEC), and the electrolyte comprises sodium salt NaPF6, a cyclic / linear carbonate solvent combination and the fluorine-rich additive combination. A positive electrode electrolyte membrane (CEI) and a negative electrode solid electrolyte membrane (SEI) are cooperatively constructed by utilizing preferential oxidation and echelon reduction characteristics of different components in the combined additive, so that on one hand, dissolution of transition metal on the surface of a positive electrode and crystal structure transformation are inhibited, on the other hand, SEI dissolution of the negative electrode is inhibited, gas production of the sodium ion battery is cooperatively inhibited, and the stability of the sodium ion battery is improved. Therefore, the oxide positive electrode / hard carbon negative electrode sodium ion battery system has excellent cycling stability.

The present invention relates to a process for preparing lithium bis(fluorosulfonyl)imide, comprising the following steps of: contacting of bis(fluorosulfonyl)imide with a lithium base in a solvent selected from carbonates, ethers and nitriles, to obtain a mixture comprising lithium bis(fluorosulfonyl)imide and water; diafiltration of the mixture on a nanofiltration membrane so as to obtain, firstly, a concentrate enriched in lithium bis(fluorosulfonyl)imide and depleted in water and, secondly, a permeate depleted in lithium bis(fluorosulfonyl)imide and enriched in water. The present invention also relates to a process for preparing an Li-ion battery electrolyte.

The invention relates to an aqueous zinc-iodine battery electrolyte containing a phenolic additive, and a preparation method and application thereof, and belongs to the technical field of aqueous zinc-iodine batteries. The invention aims to solve the technical problems of serious multi-iodide shuttling and negative electrode by-products of the existing aqueous zinc-iodine battery. The preparation method of the aqueous zinc-iodine battery electrolyte containing the phenolic additive comprises the following steps: dissolving zinc salt and the phenolic additive in deionized water, and fully stirring and mixing to obtain the aqueous zinc-iodine battery electrolyte containing the phenolic additive. The phenolic additive used in the application can accelerate conversion from I3-to I-, accelerate iodine conversion reaction kinetics and reduce generation of polyiodide, so that shuttling of the polyiodide is effectively inhibited, a phenolic additive monomer is adsorbed on the surface of a zinc negative electrode, contact between Zn < 2 + > and water molecules is reduced, and generation of zinc negative electrode by-products is inhibited; the zinc-iodine battery also has the advantages of being easy to manufacture and low in cost.

The invention relates to a high-performance lithium-rich manganese-based lithium ion battery electrolyte with a flame-retardant function and a preparation method thereof, the high-performance lithium-rich manganese-based lithium ion battery electrolyte comprises a lithium salt and an electrolyte organic solvent, the lithium salt is a composite lithium salt, the composite lithium salt comprises lithium hexafluorophosphate and lithium salt additive lithium difluoro (oxalato) borate, and the electrolyte solvent comprises the electrolyte organic solvent and an additive, the additive comprises a positive electrode film-forming additive tris (trimethylsilane) phosphate and a flame-retardant additive ethyoxyl (pentafluoro) cyclotriphosphazene. The electrolyte has the advantages that the electrolyte not only has excellent cycle performance, but also has a flame-retardant function.

The invention discloses a lithium ion battery electrolyte, a preparation method and application. The lithium ion battery electrolyte comprises a lithium salt and an organic solvent, wherein the lithium salt comprises a combination of at least two of lithium hexafluorophosphate, lithium difluoro bis (oxalato) phosphate, lithium bis (fluorosulfonyl) imide and lithium bis (oxalato) borate, and the organic solvent comprises 30 wt%-50 wt% of hydrofluoroether, 10 wt%-30 wt% of acetate and 20 wt%-60 wt% of carbonate. The lithium ion battery electrolyte provided by the invention can keep the diaphragm structure complete, realizes filling of pores with lithium salt, and reduces the permeability of the diaphragm, thereby controlling possible shrinkage of the diaphragm in a temperature change process under a low-temperature or high-temperature condition; the crosstalk problem caused by gas penetration between the positive electrode and the negative electrode is inhibited, and the battery prepared by utilizing the lithium ion battery electrolyte provided by the invention has good cycle performance and rate capability under a low-temperature condition and has relatively high safety under a high-temperature condition.

The invention provides a low-molar-concentration I < + > stabilizer / zinc salt aqueous zinc-iodine battery electrolyte and an aqueous zinc-iodine battery, and belongs to the technical field of aqueous zinc-iodine battery electrolytes.The electrolyte comprises the following chemical components: an I < + > stabilizer, other zinc salts, a multi-iodide ion complexing agent, a diluent and water; in the electrolyte, the concentration of the I + stabilizer is 0.5-1.5 mol / L, the concentration of the other zinc salt is 0.5-2.5 mol / L, the mass fraction of the multi-iodide ion complexing agent is 3-15%, and the volume ratio of the diluent to the water is 1: (3-19); the multi-iodide ion complexing agent comprises at least one of polyvinyl alcohol, polyethylene glycol and polyvinylpyrrolidone. The electrolyte can still realize high coulombic efficiency of the aqueous zinc-iodine battery in the presence of a low-molar-concentration I < + > stabilizer / zinc salt, and also can inhibit side reaction at one end of a zinc negative electrode in the cyclic process of the aqueous zinc-iodine battery, shuttle effect of multi-iodide ions in the I- / I2 conversion process at one end of an iodine positive electrode and hydrolysis of I < + > in the I2 / I < + > process, so that the cycle life of the battery is prolonged, and the service life of the battery is prolonged. And the working temperature range is widened, so that the device can stably operate under severe conditions.

The invention belongs to the field of secondary batteries, and particularly relates to an aqueous zinc ion battery electrolyte additive and an electrolyte. The additive is a beta-diketone organic reagent. When the additive is added into the zinc salt-containing electrolyte, dendritic crystal growth and hydrogen evolution corrosion of zinc can be remarkably inhibited, so that the cycle performance and coulombic efficiency of the zinc ion battery are improved. According to the invention, the zinc ion battery has good cycle performance, is easy for industrial production, and has an application prospect in the technical field of energy storage.

The embodiment of the invention relates to a negative-electrode-free sodium-ion battery electrolyte and a preparation method and application thereof, and the negative-electrode-free sodium-ion battery electrolyte comprises a non-fluorinated conventional ether substance, a fluoroether substance and a sodium salt; the mass percent of the non-fluorinated conventional ether substance, the fluoroether substance and the sodium salt is (5%-85%): (5%-85%): (5%-30%); wherein the non-fluorinated conventional ether substances comprise linear ether and / or cyclic ether. Compared with the traditional carbonic ester electrolyte, the negative-electrode-free sodium ion battery electrolyte provided by the embodiment of the invention has the advantages that the transmission rate of sodium ions can be improved, the sodium ions can be subjected to reversible deposition with high coulombic efficiency on a pure current collector, and the overall oxidation stability of the electrolyte is improved; the prepared sodium ion battery without the negative electrode can stably operate under high working voltage and has excellent electrochemical performance.

The invention provides eutectic aqueous aluminum ion battery electrolyte as well as a preparation method and application thereof, and relates to the technical field of aluminum ion batteries. According to the invention, the eutectic aqueous aluminum ion battery electrolyte is prepared by solid-solid mixing and dissolving of aluminum metal salt and eutectic substances; the aluminum metal salt is selected from at least one of aluminum chloride hexahydrate, aluminum perchlorate nonahydrate, aluminum nitrate nonahydrate and aluminum sulfate octadecahydrate; the eutectic substance is an organic small molecule compound containing amino and ester groups. By screening hydrated aluminum metal salt and eutecticevaporate substances and regulating and controlling the proportion, the prepared electrolyte is applied to aqueous aluminum ion batteries, such as symmetrical batteries and total batteries, and shows excellent performance. According to the electrolyte, the stability of the aluminum ion battery can be improved, a solvation structure dominated by anions is formed, and meanwhile, a compact anion-rich solid electrolyte interface layer is formed on the surface of an aluminum negative electrode to protect the aluminum negative electrode. The problem that an existing water-based aluminum ion battery negative electrode is poor in stability is solved.

The invention relates to the technical field of battery electrolytes, in particular to a flame-retardant solid polymer electrolyte and a preparation method and application thereof and a gel polymer electrolyte.The preparation method comprises the steps that a lithium salt, a polymer monomer, a cross-linking agent, an initiator, an additive and an organic solvent are mixed, heated and stirred to be uniform, and a precursor is obtained; and introducing a catalyst into the precursor to polymerize and cure the precursor to obtain the solid polymer electrolyte. The solid polymer electrolyte prepared by the invention has extremely strong flame retardant property; a unique cross-linked structure enhances the mechanical strength, and destroys the regularity of a polyether chain segment, so that the polyether chain segment is in an amorphous state, and therefore, the polyether chain segment has high ionic conductivity; due to the introduction of bicyclic carbonate, the oxidation stability is enhanced, high stability is shown on a high-voltage positive electrode, and the lithium ion transference number of the electrolyte is also increased to a certain extent; and finally, the assembled battery shows excellent cycling stability and rate capability.

The invention provides a secondary battery electrolyte additive and a preparation method thereof. The additive is obtained by bonding oxygen atoms of four hydroxyl groups on R1-R5 groups in a compound as shown in a structural formula I with a group A and a group B through any one of the following modes: (1) bonding with two groups A; (2) bonding with two B groups; (3) bonding with one A group and one B group: # imgabs0 # wherein n is 0 or 1; r1 to R5 are independently selected from H, alkoxy of C1 to C5, hydroxyl and alkyl of C1 to C5 substituted by hydroxyl, and at least four hydroxyl are contained in R1 to R5; * represents a bonding position. The additive can form a stable, cross-linked and tough SEI film, and battery impedance is further reduced. The additive is cheap and easily available in preparation raw materials, low in cost, short in reaction route, simple in purification process, high in production efficiency and wide in application prospect in the secondary battery electrolyte.