CN120657241A - A Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte and its preparation method and application - Google Patents

Abstract

The invention discloses a polymer electrolyte with Lewis acid perovskite-hydrogen bond layer cooperative curing, a preparation method and application thereof, and relates to the technical field of new energy, comprising cyclic ether monomers, lewis acid perovskite-hydrogen bond layer composite initiator and lithium salt. The cyclic ether organic molecules are used as monomer precursors, lewis acid perovskite-hydrogen bond layer composite initiator is introduced, and the ring-opening polymerization of the monomer precursors is initiated in situ under the condition of normal temperature or medium-low temperature to form compact and uniform polymer skeleton. The perovskite-hydrogen bond collaborative initiation system not only can effectively induce the progress of monomer polymerization reaction, but also can regulate and control polymerization kinetics and a space network structure through Lewis acid-alkali action and hydrogen bond action, and a polymer electrolyte system with high ion conductivity and high lithium ion migration number is constructed.

Description

Polymer electrolyte with Lewis acid perovskite-hydrogen bond layer synergistically cured, and preparation method and application thereof

Technical Field

The invention relates to the technical field of new energy, in particular to a polymer electrolyte with Lewis acid perovskite-hydrogen bond layer cooperative curing, a preparation method and application thereof.

Background

Lithium metal batteries are widely considered as one of the core technologies of the new generation of high energy density energy storage devices due to the ultra-high theoretical specific capacity (3860 mAh/g) and the lowest electrochemical reduction potential (-3.04 v vs. However, in conventional organic liquid electrolyte systems, the high chemical activity of lithium metal is very susceptible to side reactions, leading to electrolyte consumption and thickening of the electrode/electrolyte interface. In addition, non-uniform deposition of lithium ions in the liquid electrolyte can induce lithium dendrite growth and dead lithium formation, thereby causing a series of potential safety hazards such as reduced coulomb efficiency, shortened cycle life, and even short circuit of the battery. Furthermore, the high volatility and flammability of conventional organic electrolytes further exacerbates the safety risk of lithium metal batteries.

To overcome the above problems, the solid electrolyte has great potential in inhibiting side reactions, inhibiting lithium dendrite growth, and improving battery safety due to its excellent chemical stability, high mechanical strength, and good flame retardant properties. Among them, solid polymer electrolytes are an important development direction of solid electrolytes by virtue of their good flexibility, easy processability, and controllability. Polymer systems represented by polyethylene oxide (PEO) and Polyacrylonitrile (PAN) have been widely studied. However, the contact interface between the traditional polymer electrolyte and the electrode still has obvious gaps, so that the interface impedance is higher, and the overall performance of the battery is affected.

In recent years, in-situ polymerization of solid electrolytes has become a research hotspot. The method adopts a liquid precursor, has the characteristics of low viscosity and excellent wettability, can effectively permeate an electrode structure, and is polymerized into a polymer electrolyte in situ after the battery is assembled, so that denser and stable interface contact is obtained, and the interface impedance is obviously reduced. Poly (1, 3-dioxolane) (PDOL) polymer systems based on 1, 3-Dioxolane (DOL) monomers are of great interest due to their high ionic conductivity, good compatibility with lithium metal and the property of being easy to polymerize in situ. Prior studies have often employed Lewis acids such as lithium hexafluorophosphate (LiPF ₆) or aluminum triflate (Al (OTf) ₃) as cationic ring-opening polymerization initiators to achieve rapid polymerization of PDOL. However, liPF ₆ is easy to decompose at high temperature to generate HF, has strong corrosiveness and seriously affects the stability of electrolyte, al (OTf) ₃ has too high reactivity, is easy to cause uneven polymerization rate and wide polymer molecular weight distribution, and part of Lewis acid initiator cannot stably form an effective Solid Electrolyte Interface (SEI), thus limiting the overall performance of the system. In addition, the PDOL polymer itself has low mechanical strength, and is difficult to effectively inhibit the growth of lithium dendrites, and the thermal stability of the PDOL polymer is also difficult to meet the requirements of a high-temperature working environment.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide the polymer electrolyte with the Lewis acid perovskite-hydrogen bond layer cooperative curing, which has good stability, aiming at the defects existing in the prior art.

In order to solve the first technical problem, the technical scheme of the invention is as follows:

a polymer electrolyte with Lewis acid perovskite-hydrogen bond layer cooperative curing comprises cyclic ether monomer, lewis acid perovskite-hydrogen bond layer composite initiator and lithium salt.

Preferably, the cyclic ether monomer comprises at least one of ethylene oxide EO, propylene oxide PO, tetrahydrofuran THF, 1,3 dioxane, 1,3 dioxolane DOL and trioxymethylene;

The lithium salt comprises at least one of LiTFSI, lithium triflate LiFSI, lithium hexafluorophosphate LiPF ₆ and lithium perchlorate LiClO ₄.

Preferably, the mass fraction of the Lewis acid perovskite-hydrogen bond layer synergistic composite initiator in the Lewis acid perovskite-hydrogen bond layer synergistic cured polymer electrolyte is 0.4-2wt%, and the molar ratio of the cyclic ether monomer to the lithium salt is 10-20:1.

Preferably, the lewis acid perovskite in the lewis acid perovskite-hydrogen bond layer composite initiator is lewis acid perovskite type or pseudo perovskite type fluoride, and the lewis acid perovskite is one of KCuF₃、KMnF₃、KFeF₃、CsCuF₃、RbCuF₃、CsNiF₃、KAgF₃、K₂NiFeF₆、Rb₂MnFeF₆. The metal ion (such as Cu ^{2 +}、Mn²⁺、Fe³⁺ and the like) and F ^- in the crystal structure form a stable hexacoordinated structural unit (such as CuF ₆、MnF₆ octahedron), and the crystal structure has high crystal order and rich Lewis acid sites.

Preferably, the hydrogen bond layer in the lewis acidic perovskite-hydrogen bond layer composite initiator is a hydrogen bond dielectric layer-shaped structural material with an M (OH) X metal oxyhalide structure, wherein M is a transition metal element, such as Cu, ni, co, mn, fe, and X is a halogen anion, and preferably, the hydrogen bond layer is one of CuOHF, coOHF, niOHF, mnOHF, feOHF, cu (OH) ₃F、Co2(OH)₃F、Ni₂(OH)₃ F. The material contains hydroxyl (OH ^-) and halogen ions (F ^-) at the same time, and has a typical M-OH-F bonding configuration. The crystal structure can be lamellar, chain or octahedral coordination.

The polymer electrolyte for the synergistic curing of the Lewis acid perovskite-hydrogen bond layer adopts cyclic ether organic molecules as monomer precursors, introduces a Lewis acid perovskite-hydrogen bond layer composite initiator, and initiates the ring-opening polymerization of the monomer precursors in situ under the condition of normal temperature or medium-low temperature to form a compact and uniform polymer skeleton. The perovskite-hydrogen bond collaborative initiation system not only can effectively induce the progress of monomer polymerization reaction, but also can regulate and control polymerization kinetics and a space network structure through Lewis acid-alkali action and hydrogen bond action, and a polymer electrolyte system with high ion conductivity and high lithium ion migration number is constructed.

The invention realizes the in-situ initiated polymerization of the cyclic ether monomer by constructing the Lewis perovskite-hydrogen bond layer synergistic composite initiator, and successfully prepares the compact and uniform polymer solid electrolyte membrane. The synergistic system has Lewis acidic catalytic property and high-strength hydrogen bond acting force, and effectively regulates and controls lithium ion transmission behavior and interface stability while improving the mechanical property of an electrolyte membrane.

The second technical problem to be solved by the invention is to provide a preparation method of the polymer electrolyte with Lewis perovskite-hydrogen bond layer cooperative curing aiming at the defects existing in the prior art, and the prepared polymer electrolyte has high stability.

In order to solve the second technical problem, the technical scheme of the invention is as follows:

A method for preparing a polymer electrolyte with Lewis acid perovskite-hydrogen bond layer cooperative curing, which comprises the following steps:

(1) Cu (NO ₃)₂·3H₂ O and KF) are dissolved in a solvent and mixed to form a uniform transparent solution, the uniform transparent solution is reacted for 2 hours at 100 ℃, the solution is centrifuged, a filter cake is washed for a plurality of times, and the solution is dried in vacuum at 60 ℃ overnight to obtain a Lewis acid perovskite-hydrogen bond layer composite initiator;

(2) Uniformly mixing a cyclic ether monomer, lithium salt and a Lewis acid perovskite-hydrogen bond layer composite initiator to obtain a mixed solution;

(3) Polymerizing the obtained mixed solution for 12 hours at room temperature to obtain high-viscosity gel without fluidity, and obtaining the polymer electrolyte with Lewis perovskite-hydrogen bond layer synergistically cured.

Preferably, the solvent is deionized water;

Cu (mol ratio of NO ₃)₂·3H₂ O to KF is 1:2, mol ratio of solvent to raw material is 2:0.003;

the mass ratio of the Lewis acid perovskite to the hydrogen bond layer is (60-67): 33-40.

In the invention, the adopted Lewis acid perovskite-hydrogen bond layer synergistic composite initiator is introduced into the lithium salt-cyclic ether monomer solution, so that not only is space domain limiting effect provided in the gel polymerization process, but also controllable polymerization reaction is induced between electrolyte molecules through Lewis acid metal centers (such as Cu ²⁺) in the perovskite structure of the lithium salt-cyclic ether monomer solution, and a viscous and stable gel system is formed. The initiator has an ordered skeleton layered hydrogen bond network of perovskite phase, and the synergistic effect of the initiator and the ordered skeleton layered hydrogen bond network can obviously enhance the three-phase coupling effect of ions, polymers and fillers in a system, so that the arrangement and the compactness of polymer chain segments are regulated, and the electrolyte membrane is endowed with excellent film forming property and ion conduction channel continuity.

Aiming at the defects existing in the prior art, the invention provides a lithium metal symmetrical battery system based on solid electrolyte, which has good stability.

In order to solve the third technical problem, the technical scheme of the invention is as follows:

A lithium metal symmetric battery system based on a solid electrolyte, comprising a polymer electrolyte with lewis acid perovskite-hydrogen bond layers cooperatively cured, and lithium metal sheets positioned on both sides of the polymer electrolyte with lewis acid perovskite-hydrogen bond layers cooperatively cured.

When the polymer electrolyte with the Lewis acid perovskite-hydrogen bond layer cooperatively cured is used for a lithium metal symmetrical battery, the polymer electrolyte has good interface stability and extremely low interface impedance, can obviously reduce voltage polarization difference in the metal lithium deposition/stripping process, enhances the cycling stability of the symmetrical battery, and the surface of the metal lithium of the symmetrical battery after long-term cycling is smooth and compact.

The solid-state lithium metal symmetrical battery system provided by the invention is a battery with metal lithium sheets at both sides. The current density of the lithium deposition and stripping cycle test of the lithium metal symmetrical battery system can be 0.1-6.4 mA/cm ², and the deposition or stripping time in each cycle can be 0.5-1 h.

Aiming at the defects of the prior art, the invention provides a lithium metal battery based on a polymer electrolyte with a Lewis acid perovskite-hydrogen bond layer cooperative curing function, which has high stability.

In order to solve the fourth technical problem, the technical scheme of the invention is as follows:

A lithium metal battery based on a lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte, comprising a positive electrode, a negative electrode, and a lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte between the positive and negative electrodes;

The negative electrode is a metal lithium sheet;

The positive electrode is at least one of FeF ₃、FeF₂, ferroferric oxide, cuF ₂, cuOHF, carbon-sulfur compound, feS ₂、LiMn₂O₄、LiFePO₄、LiCoO₂, nickel-rich ternary system and lithium-rich manganese-based solid solution.

The invention aims to solve the fifth technical problem of providing a solid lithium/fluoride battery with a soft package configuration based on a polymer electrolyte with a Lewis acid perovskite-hydrogen bond layer cooperatively cured, which has high stability.

In order to solve the fifth technical problem, the technical scheme of the invention is as follows:

provided is a solid state lithium/fluoride battery of soft pack configuration based on a polymer electrolyte with a lewis acidic perovskite-hydrogen bond layer co-cured, comprising a positive electrode, a negative electrode, and a polymer electrolyte with a lewis acidic perovskite-hydrogen bond layer co-cured between the positive electrode and the negative electrode;

The negative electrode is thin-layer metal lithium, and the positive electrode is at least one of FeF ₃、FeF₂, ferrite fluorine compound, cuF ₂, cuOHF, carbon-sulfur compound, feS ₂、LiMn₂O₄、LiFePO₄、LiCoO₂, nickel-rich ternary system and lithium-rich manganese-based solid solution.

The invention provides a transformation reaction type large-size fluorine-based solid state soft package battery based on a polymer electrolyte with a Lewis acid perovskite-hydrogen bond layer cooperatively cured, wherein a thin layer lithium belt (the thickness is about 45 mu m) is used as a negative electrode, and a positive electrode film comprises a fluoride positive electrode (active substance), a small amount of conductive carbon, a binder and lithium salt. A polymer electrolyte based on the co-curing of a lewis acidic perovskite-hydrogen bond layer is located between the anode and the cathode.

Due to the adoption of the technical scheme, the invention has the beneficial effects that:

1. The invention utilizes the Lewis perovskite-hydrogen bond layer composite initiator to cooperatively initiate the ring-opening polymerization of the cyclic ether monomer, thereby realizing the in-situ rapid polymerization strategy under the condition of no need of external heat source or high-energy irradiation. The synergistic initiation system has polymerization and hydrogen bond regulation functions, remarkably improves polymerization efficiency and spatial network uniformity, and enables the obtained electrolyte membrane to have excellent compactness and mechanical flexibility.

2. The Lewis acid perovskite-hydrogen bond layer composite initiator introduces a synergistically regulated ion transmission channel in a polymer network. The metal sites in the Lewis acid perovskite are selectively adsorbed with the TFSI ^-, so that the lithium salt is promoted to be dissociated while the anion migration is inhibited, a stable lithium ion conduction network is formed, and the layered structure mediated by hydrogen bonds provides a multidimensional diffusion channel for Li ⁺, so that the spatially distributed ion uniform flow is realized. The synergistic mechanism enables the composite polymer electrolyte to obtain ionic conductivity up to 1.4X10-4S.cm ^-1 and lithium ion migration number of 0.70 at room temperature.

3. The polymer electrolyte based on the Lewis acid perovskite-hydrogen bond layer cooperative curing in the invention can stably run for more than 5000 hours under the condition of no short circuit, thus showing the effective inhibition effect on lithium dendrites. In the construction of lithium/ferric fluoride batteries, the electrolyte can stabilize the interface reaction process, promote the efficient conversion of Fe ³⁺/Fe⁰, and realize the coulombic efficiency close to 100% and the ultra-long cycle life. The stable charge and discharge performance is maintained within the temperature range of-20-100 ℃, so that the lithium/ferric fluoride battery is maintained stably for 200 times at-20 ℃ and is maintained for 40 times at 100 ℃, the battery shows supernormal low-temperature and high-temperature performance, and the reliable operation capability of the battery in a wide temperature range is shown.

4. The lithium/ferric fluoride soft-package battery is successfully constructed based on the polymer electrolyte with the Lewis acid perovskite-hydrogen bond layer synergistically cured, the measured capacity is stably maintained at about 300mAh, the circulation stability is excellent, the battery components have the potential of amplifying preparation and practical integration, and the wide prospect of practical development of next-generation high-energy solid-state lithium metal batteries is shown.

Drawings

FIG. 1 is a scanning electron microscope image of a composite initiator with Lewis acid perovskite-hydrogen bond layer synergy;

FIG. 2 is an optical photograph of in situ curing of a liquid precursor into a solid polymer electrolyte;

FIG. 3 is a Raman spectrum of a polymer electrolyte based on Lewis acid perovskite-hydrogen bond layer co-curing before polymerization, after polymerization for 2 hours, and after polymerization for 12 hours, respectively;

FIG. 4 is a graph of the impedance of a polymer electrolyte based on the co-curing of a Lewis acid perovskite-hydrogen bond layer at different temperatures;

FIG. 5 is a constant current cycling performance and magnified graph of a Li symmetric cell at 0.2mA cm ^-2 for a polymer electrolyte based on a co-cure of a Lewis acid perovskite-hydrogen bond layer and a pure DOL liquid electrolyte;

FIG. 6 is an SEM image of the lithium metal deposition surface of a lithium metal symmetric cell based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte after 2500 hours of cycling;

FIG. 7 is a graph of the cycling performance of a Li||FeF ₃ cell based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte at a current density of 0.2C and a voltage range of 1.2-3.9V;

FIG. 8 is a graph of the cycling performance of a Li||FeF ₃ cell based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte at-20 ℃;

FIG. 9 is a graph of the cycling performance of a Li||FeF ₃ cell based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte at 60 ℃;

FIG. 10 is a graph of the cycling performance of a Li||FeF ₃ cell based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte under 100 ℃ extreme conditions;

FIG. 11 is an optical photograph and practical demonstration of a Li||FeF ₃ pouch cell based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte;

FIG. 12 is a graph of the cycling performance of a Li||FeF ₃ pouch cell at 60 ℃ based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte;

Fig. 13 is a graph of the cycling performance of a li||fef ₃ cell with a pure DOL liquid electrolyte at 0.2C.

Detailed Description

The invention is further illustrated by the following examples.

Example 1

(1) Polymer electrolyte with Lewis acid perovskite-hydrogen bond layer synergistically cured

(1) (A) preparation of Lewis acid perovskite-hydrogen bond layer synergistic composite initiator

Dissolving 0.242g of Cu (NO ₃)₂·3H₂ O) in 40mL of deionized water, adding 0.116g of KF, magnetically stirring, continuously reacting for 2 hours at 100 ℃, centrifuging the obtained solution, repeatedly washing with deionized water, and vacuum drying overnight at 60 ℃ to obtain Lewis acid perovskite-hydrogen bond layer composite initiator (KCF@COHF) powder, wherein the mass ratio of Lewis acid perovskite type or pseudoperovskite type fluoride to hydrogen bond dielectric layer structural material is 63.9:36.1, and a scanning electron microscope image shows the unique morphology of KCF@COHF particles.

(1) (B) preparation of a Polymer electrolyte with a Lewis acid perovskite-Hydrogen bond layer synergistically cured

Under the protection of argon, 0.574g of lithium bis (trifluoromethanesulfonyl) imide LiTFSI is dissolved in 2.0g of 1, 3-Dioxolane (DOL) to obtain a lithium salt solution uniformly, then 0.020g of KCF@COHF powder is added, stirring is carried out for 2 hours at room temperature, the system is gradually converted into a non-flowing high-viscosity gel-like liquid, and then the system is continuously reacted for 12 hours at room temperature, so that the opaque solid electrolyte gel KCF@COHF-PDOL is finally obtained, as shown in figure 2. The raman spectral characterization results in fig. 3 show that the characteristic peak at the position of about 937.1cm ^-1 associated with DOL almost disappears in the polymer matrix, indicating successful polymerization of kcf@coff-PDOL.

(2) Testing of ionic conductivity of polymer electrolyte with lewis acidic perovskite-hydrogen bond layer co-cured

The ss|kcf@coff-pdol|ss cell was assembled and measured in potentiostatic mode with a Solartron frequency analyzer (1296-1260) at 10 data points at frequency range 1MHz to 0.1Hz at frequency multiples of 10 per ten, and ion conductivity of the solid electrolyte was measured using 10mV ac perturbation. The solid polymer film was cut into 17mm diameter disks with two non-conductive stainless steel electrodes placed on either side of the electrolyte membrane. For temperature-dependent measurements, the cell was placed in an oven and impedance testing was performed in steps of 10 ℃ over the range of 80 ℃ to 30 ℃. Each temperature point was incubated for 1h to ensure steady state was reached. The ionic conductivity (ρ) of the solid polymer electrolyte is calculated by the following formula ρ=l/RS;

Where R is the resistance value, L is the film thickness, and S is the contact area of the electrode. FIG. 4 shows impedance plots of a polymer electrolyte co-cured with Lewis acid perovskite-hydrogen bond layers at different temperatures, calculated to have an ionic conductivity of 1.4X10 ^-4 S/cm at 30 ℃.

Example 2

Assembly and testing of lithium metal symmetric cells based on polymer electrolytes with lewis acidic perovskite-hydrogen bond layer co-curing:

the assembly of 2025 coin cells was performed in an argon glove box with water and oxygen values of less than 0.1 ppm. First, a metal lithium sheet (diameter 10 mm) was placed as a negative electrode in a button cell bottom case, then a piece of polymer electrolyte membrane (kcf@coff-PDOL in example 1) having a diameter of 17mm was placed, then another piece of metal lithium sheet having a diameter of 10mm was placed on the electrolyte membrane, and the cell was sealed after the assembly was completed. And (3) performing charge and discharge tests on the LAND electrochemical workstation, performing constant-current charging for 1h and then constant-current discharging for 1h under the current density of 0.2mA/cm ², detecting the voltage polarization difference of the metallic lithium in the deposition/stripping process, and unfolding the cycle in the step. As shown in fig. 5, symmetrical cells were tested at a current density of 0.2mA cm ^-2 and an area capacity of 0.2mAh cm ^-2. It can be seen that the polarization continues to increase after 1500 hours of operation of the cell based on the pure DOL electrolyte system, resulting in degradation of the cell. In contrast, polymer electrolyte cells based on co-curing of lewis acidic perovskite-hydrogen bond layers were able to successfully operate stably for more than 5000 hours, the cycling of the cell was very stable and the overpotential increase was almost negligible. In addition, after 2500 hours of cycling of the polymer electrolyte cell based on the co-curing of the lewis acidic perovskite-hydrogen bond layer, scanning electron microscope observation was performed on the metallic lithium surface on the deposition side, as shown in fig. 6. It can be seen that the surface of the lithium metal after circulation is smooth and compact, and no large needle-shaped lithium dendrites are formed. In the inset of fig. 6, the overall surface of the lithium appears bright and uniform, indicating that the composite electrolyte effectively inhibits non-uniform growth of lithium deposition during long-term cycling.

Example 3

Preparation and testing of lithium metal batteries based on lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolytes:

Preparation of positive electrode:

In this example, the positive electrode of FeF ₃ is described as a preferable object. In the preparation of the positive electrode, the active material was mixed with conductive carbon black (Super P), polyvinylidene fluoride (PVDF) in a weight ratio of 80:10:10, and then N-methylpyrrolidone was added to form a uniform mixture. The mixture was stirred at room temperature for 12h and then poured onto carbon coated aluminum foil. Wherein the loading of FeF ₃ is about 1.5mg cm ^-2.

Assembling and testing of li||fef ₃ cells based on lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolytes:

The assembly of 2025 coin cells was performed in an argon glove box with water and oxygen values of less than 0.1 ppm. First, a metallic lithium sheet (diameter 10 mm) was placed as a negative electrode in a button cell bottom case, then a piece of polymer electrolyte membrane (kcf@coff-PDOL in example 1) having a diameter of 17mm was placed, then a prefabricated FeF ₃ positive electrode sheet (diameter 8 mm) was placed on top of the electrolyte membrane as a cell positive electrode, and the cell was sealed after assembly was completed. Lithium/iron fluoride batteries based on lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolytes were tested for battery cycling performance at different specific currents at-20 ℃, room temperature, 60 ℃ and 100 ℃. The constant current measurement was performed using a Land battery tester. The test range of the lithium/ferric fluoride battery is 1.2-3.9V. Fig. 7 is a graph showing charge-discharge cycle performance of a lithium/iron fluoride battery at room temperature, the lithium/iron fluoride battery based on lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte still had a reversible capacity of 260mAh/g when cycled to 200 cycles at 0.2C, and the coulombic efficiency was nearly 100%. Fig. 8-10 show charge and discharge cycle performance of lithium/iron fluoride batteries based on lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolytes at different temperatures of-20 ℃,60 ℃ and 100 ℃, respectively. The li|kcf@coff-pdol|fef ₃ cell was stable cycled for 200 cycles at-20 ℃ and had a high capacity of above 500mAh/g at 60 ℃ and 100 ℃.

Example 4

Preparation and testing of a soft-pack type li||fef ₃ battery based on a lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte:

the preparation and measurement process of the Li||FeF ₃ pouch cell based on the Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte was such that the prepared FeF ₃ -based positive electrode (double-sided coating, preparation process as in example 3) was cut into sheets of 7X 10cm ² with a loading of active material of about 2mg cm ^-2. The lithium foil was cut to a slightly larger size, approximately 7.5 x 11cm ², and the composite polymer film was also cut to a larger size of 8 x 12cm ² to completely separate the FeF ₃ positive electrode and lithium metal negative electrode. These sheets were stacked to assemble a 10-layer pouch cell. Specifically, the functional sheets were stacked in the following structural order of FeF ₃ positive electrode/polymer electrolyte membrane (KCF@COHF-PDOL in example 1)/lithium metal negative electrode, to constitute a single cell in sequence. By repeatedly stacking the above structural units, a total of 10 layers of stacked soft package battery cells are finally assembled. Good alignment is maintained between each electrode layer and the electrolyte, ensuring continuity and interfacial uniformity of the charge transport path. Then placed in a laboratory designed clamping plate mold at a pressure of about 20KPa for one day before battery testing. Electrochemical testing was performed after standing in an oven at 60 ℃ for 4 hours. Fig. 11 shows a physical diagram of a li|fef ₃ pouch battery. The soft-packed battery shows about 25 continuous cycles of highly stable cycle performance at the current density of 100mA/g, the charge-discharge curve of the soft-packed battery is very similar to that of the button battery, and the discharge capacity of the soft-packed battery is up to 300mAh (figure 12), so that the reliability and the expandability of the Lewis perovskite-hydrogen bond layer cooperative curing polymer electrolyte in practical application are proved.

Comparative example

(1) Preparing pure DOL liquid electrolyte:

Dissolving 0.574g LiTFSI in 2.0g 1, 3-Dioxolane (DOL), and stirring uniformly to obtain pure DOL liquid electrolyte;

(2) Assembling and testing of a li||fef ₃ battery based on pure DOL liquid electrolyte:

The assembly of 2025 coin cells was performed in an argon glove box with water and oxygen values of less than 0.1 ppm. The specific process is that a metal lithium sheet, 40 mu L of pure DOL liquid electrolyte, celgard2500 and FeF ₃ positive electrode sheets are sequentially added into a battery shell to assemble the lithium metal battery. The cells were then tested for electrochemical cycling performance at room temperature at a LAND electrochemical workstation. Fig. 13 is a graph of li||fef ₃ cell cycle performance of a pure DOL electrolyte system. The capacity of the full battery decays faster in the circulation process, the coulomb efficiency is not maintained stable, large-amplitude fluctuation appears, and the reversibility of the system is poor.

It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the teachings of the present application, and such equivalents are intended to fall within the scope of the application as defined in the appended claims.

Claims (10)

1. A polymer electrolyte with Lewis acid perovskite-hydrogen bond layer cooperative curing is characterized by comprising cyclic ether monomers, a Lewis acid perovskite-hydrogen bond layer composite initiator and lithium salt.

2. A composition according to claim 1, wherein the cyclic ether monomer comprises at least one of ethylene oxide, propylene oxide, tetrahydrofuran, 1,3 dioxane, 1,3 dioxolane, and trioxymethylene;

The lithium salt comprises at least one of lithium bis (trifluoromethanesulfonyl) imide, lithium trifluoromethanesulfonate, lithium hexafluorophosphate and lithium perchlorate.

3. The polymer electrolyte cooperatively cured by Lewis acid perovskite-hydrogen bond layer according to claim 1, wherein the mass fraction of the Lewis acid perovskite-hydrogen bond layer cooperatively cured polymer electrolyte is 0.4-2wt%, and the molar ratio of the cyclic ether monomer to the lithium salt is 10-20:1.

4. The polymer electrolyte cooperatively cured by Lewis acid perovskite-hydrogen bond layer of claim 1 wherein the Lewis acid perovskite in the Lewis acid perovskite-hydrogen bond layer composite initiator is a Lewis acid perovskite type or a pseudo-perovskite type fluoride and the Lewis acid perovskite is one of KCuF₃、KMnF₃、KFeF₃、CsCuF₃、RbCuF₃、CsNiF₃、KAgF₃、K₂NiFeF₆、Rb₂MnFeF₆.

5. The polymer electrolyte cooperatively cured with the Lewis acid perovskite-hydrogen bond layer of claim 1 wherein the hydrogen bond layer of the Lewis acid perovskite-hydrogen bond layer composite initiator is a hydrogen bond mediating layer-like structural material and the hydrogen bond layer is one of CuOHF, coOHF, niOHF, mnOHF, feOHF, cu (OH) ₃F、Co2(OH)₃F、Ni₂(OH)₃ F.

6. A method of preparing a lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte as claimed in any one of claims 1 to 5 comprising the steps of:

(1) Cu (NO ₃)₂·3H₂ O and KF) are dissolved in a solvent and mixed to form a uniform transparent solution, the uniform transparent solution is reacted for 2 hours at 100 ℃, the solution is centrifuged, a filter cake is washed for a plurality of times, and the solution is dried in vacuum at 60 ℃ overnight to obtain a Lewis acid perovskite-hydrogen bond layer composite initiator;

(2) Uniformly mixing a cyclic ether monomer, lithium salt and a Lewis acid perovskite-hydrogen bond layer composite initiator to obtain a mixed solution;

(3) Polymerizing the obtained mixed solution for 12 hours at room temperature to obtain high-viscosity gel without fluidity, and obtaining the polymer electrolyte with Lewis perovskite-hydrogen bond layer synergistically cured.

7. The method for preparing a polymer electrolyte with a Lewis acid perovskite-hydrogen bond layer cooperative curing as claimed in claim 6, wherein the solvent is deionized water;

Cu (mol ratio of NO ₃)₂·3H₂ O to KF is 1:2, mol ratio of solvent to raw material is 2:0.003;

the mass ratio of the Lewis acid perovskite to the hydrogen bond layer is (60-67): 33-40.

8. A lithium metal symmetric battery system based on a solid electrolyte, which is characterized by comprising the polymer electrolyte with the Lewis acid perovskite-hydrogen bond layer cooperatively cured and metal lithium sheets positioned on two sides of the polymer electrolyte with the Lewis acid perovskite-hydrogen bond layer cooperatively cured according to any one of claims 1 to 5.

9. A lithium metal battery based on a polymer electrolyte with a cooperatively cured Lewis acid perovskite-hydrogen bond layer is characterized by comprising a positive electrode, a negative electrode and the polymer electrolyte with the cooperatively cured Lewis acid perovskite-hydrogen bond layer as set forth in any one of claims 1 to 5 between the positive electrode and the negative electrode;

The negative electrode is a metal lithium sheet;

The positive electrode is at least one of FeF ₃、FeF₂, ferroferric oxide, cuF ₂, cuOHF, carbon-sulfur compound, feS ₂、LiMn₂O₄、LiFePO₄、LiCoO₂, nickel-rich ternary system and lithium-rich manganese-based solid solution.

10. A solid lithium/fluoride battery of soft pack configuration based on a Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte, characterized by comprising a positive electrode, a negative electrode, and the Lewis acid perovskite-hydrogen bond layer co-cured polymer electrolyte of any one of claims 1-5 between the positive and negative electrodes;

The negative electrode is thin-layer metal lithium, and the positive electrode is at least one of FeF ₃、FeF₂, ferrite fluorine compound, cuF ₂, cuOHF, carbon-sulfur compound, feS ₂、LiMn₂O₄、LiFePO₄、LiCoO₂, nickel-rich ternary system and lithium-rich manganese-based solid solution.