Lewis acidic perovskite-hydrogen bond layer synergistically cured polymer electrolyte and preparation method and application thereof

Abstract

The invention discloses a Lewis acidic perovskite-hydrogen bond layer synergistically cured polymer electrolyte and a preparation method and application thereof, and relates to the technical field of new energy, and the Lewis acidic perovskite-hydrogen bond layer synergistically cured polymer electrolyte comprises cyclic ether monomers, a Lewis acidic perovskite-hydrogen bond layer composite initiator and a lithium salt. A cyclic ether organic molecule is adopted as a monomer precursor, a Lewis acidic perovskite-hydrogen bond layer composite initiator is introduced, and ring opening polymerization of the monomer precursor is initiated in situ under the condition of normal temperature or medium and low temperature, so that a compact and uniform polymer skeleton is formed. The perovskite-hydrogen bond synergistic initiation system not only can effectively induce monomer polymerization reaction, but also can regulate and control polymerization kinetics and a spatial network structure through Lewis acid-base action and hydrogen bond action to construct a polymer electrolyte system with high ionic conductivity and high lithium ion transference number.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte and a preparation method and application thereof. Background Art

[0002] Lithium metal batteries are widely considered to be one of the core technologies of the new generation of high-energy-density energy storage devices due to the ultra-high theoretical specific capacity (3860mAh / g) and the lowest electrochemical reduction potential (-3.04V vs.SHE) of their metallic lithium negative electrodes. However, in conventional organic liquid electrolyte systems, the high chemical activity of lithium metal can easily trigger side reactions, leading to electrolyte consumption and thickening of the electrode / electrolyte interface. In addition, the non-uniform deposition of lithium ions in the liquid electrolyte can induce lithium dendrite growth and dead lithium formation, leading to a series of safety hazards such as decreased coulombic efficiency, shortened cycle life, and even battery short circuit. Not only that, the high volatility and flammability of traditional organic electrolytes further exacerbate the safety risks of lithium metal batteries.

[0003] To overcome the above problems, solid electrolytes have shown great potential in inhibiting side reactions, inhibiting lithium dendrite growth and improving battery safety due to their excellent chemical stability, high mechanical strength and good flame retardant properties. Among them, solid polymer electrolytes have become an important development direction of solid electrolytes due to their good flexibility, easy processability and controllability. Polymer systems represented by polyethylene oxide (PEO) and polyacrylonitrile (PAN) have been widely studied. However, there are still obvious gaps at the contact interface between traditional polymer electrolytes and electrodes, resulting in high interfacial impedance, which affects the overall performance of the battery.

[0004] In recent years, in-situ polymerization of solid electrolytes has become a research hotspot. This method utilizes liquid precursors with low viscosity and excellent wettability, enabling efficient penetration of electrode structures and in-situ polymerization into polymer electrolytes after battery assembly, resulting in denser and more stable interfacial contacts and significantly reducing interfacial impedance. Poly(1,3-dioxolane) (PDOL) polymer systems based on 1,3-dioxolane (DOL) monomers have attracted widespread attention due to their high ionic conductivity, good compatibility with lithium metal, and ease of in-situ polymerization. Existing studies often use Lewis acids such as lithium hexafluorophosphate (LiPF6) or aluminum trifluoromethanesulfonate (Al(OTf)3) as cationic ring-opening polymerization initiators to achieve rapid polymerization of PDOLs. However, LiPF6 readily decomposes at high temperatures to produce HF, which is highly corrosive and severely impacts electrolyte stability. Al(OTf)3 is highly reactive, leading to uneven polymerization rates and a wide polymer molecular weight distribution. Furthermore, some Lewis acid initiators are unable to stably form an effective solid electrolyte interface (SEI), limiting the overall performance of the system. In addition, the mechanical strength of the PDOL polymer itself is low, making it difficult to effectively inhibit the growth of lithium dendrites, and its thermal stability is also difficult to meet the requirements of high-temperature working environments. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is: to address the deficiencies in the prior art and provide a Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte with good stability.

[0006] In order to solve the above-mentioned first technical problem, the technical solution of the present invention is:

[0007] A Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte comprises a cyclic ether monomer, a Lewis acidic perovskite-hydrogen bond layer composite initiator and a lithium salt.

[0008] Preferably, the cyclic ether monomer includes at least one of ethylene oxide EO, propylene oxide PO, tetrahydrofuran THF, 1,3-dioxane, 1,3-dioxolane DOL, and trioxymethylene;

[0009] The lithium salt includes at least one of LiTFSI, lithium trifluoromethanesulfonate LiFSI, lithium hexafluorophosphate LiPF6, and lithium perchlorate LiClO4.

[0010] Preferably, the mass fraction of the Lewis acidic perovskite-hydrogen bond layer cooperatively cured polymer electrolyte is 0.4 to 2 wt %, and the molar ratio of the cyclic ether monomer to the lithium salt is 10 to 20:1.

[0011] Preferably, the Lewis acidic perovskite in the Lewis acidic perovskite-hydrogen bond layer composite initiator is a Lewis acidic perovskite type or pseudoperovskite type fluoride, and the Lewis acidic perovskite is one of KCuF3, KMnF3, KFeF3, CsCuF3, RbCuF3, CsNiF3, KAgF3, K2NiFeF6, and Rb2MnFeF6. The metal ions (such as Cu 2 + 、Mn 2+ 、Fe 3+ etc.) and F - It forms stable six-coordinate structural units (such as CuF6 and MnF6 octahedra) with high crystal order and abundant Lewis acid sites.

[0012] Preferably, the hydrogen bonding layer in the Lewis acidic perovskite-hydrogen bonding layer composite initiator is a hydrogen bonding mediated layered structure material having a M(OH)X metal halide oxide structure, wherein M is a transition metal element such as Cu, Ni, Co, Mn, Fe, etc., and X is a halogen anion. Preferably, the hydrogen bonding layer is one of CuOHF, CoOHF, NiOHF, MnOHF, FeOHF, Cu2(OH)3F, Co2(OH)3F, and Ni2(OH)3F. This type of material also contains hydroxide (OH - ) and halogen ions (F - ), showing a typical M-OH-F bonding configuration. Its crystal structure can be layered, chain-like or octahedral coordination type.

[0013] The Lewis-acidic perovskite-hydrogen-bonding layer synergistically cured polymer electrolyte of the present invention utilizes cyclic ether organic molecules as monomer precursors and introduces a Lewis-acidic perovskite-hydrogen-bonding layer composite initiator to initiate in situ ring-opening polymerization of the monomer precursors at room temperature or at medium-low temperatures, forming a dense and uniform polymer backbone. This perovskite-hydrogen-bonding synergistic initiation system not only effectively induces monomer polymerization but also regulates polymerization kinetics and spatial network structure through Lewis acid-base interactions and hydrogen bonding, thereby constructing a polymer electrolyte system with high ionic conductivity and a high lithium ion transference number.

[0014] By constructing a Lewis-acidic perovskite-hydrogen-bonding layer synergistic composite initiator, this invention achieves in-situ polymerization of cyclic ether monomers, successfully preparing a dense and uniform polymer solid electrolyte membrane. This synergistic system combines Lewis-acidic catalytic properties with high-strength hydrogen bonding forces, effectively regulating lithium-ion transport behavior and interfacial stability while improving the mechanical properties of the electrolyte membrane.

[0015] The second technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a method for preparing a polymer electrolyte with Lewis acidic perovskite-hydrogen bond layer synergistic solidification is provided, and the prepared polymer electrolyte has high stability.

[0016] In order to solve the above second technical problem, the technical solution of the present invention is:

[0017] A method for preparing a Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte comprises the following steps:

[0018] (1) Cu(NO3)2·3H2O and KF were dissolved in a solvent and mixed to form a homogeneous transparent solution. The solution was reacted at 100°C for 2 h, centrifuged, the filter cake was washed several times, and vacuum dried at 60°C overnight to obtain a Lewis acidic perovskite-hydrogen bond layer composite initiator.

[0019] (2) uniformly mixing the cyclic ether monomer, the lithium salt, and the Lewis acidic perovskite-hydrogen bond layer composite initiator to obtain a mixed solution;

[0020] (3) The obtained mixed solution is polymerized at room temperature for 12 hours to obtain a high-viscosity gel without fluidity, that is, a polymer electrolyte with Lewis acidic perovskite-hydrogen bond layer synergistic solidification.

[0021] Preferably, the solvent is deionized water;

[0022] The molar ratio of Cu(NO3)2·3H2O to KF was 1:2, and the molar ratio of solvent to raw material was 2:0.003;

[0023] The mass ratio of Lewis acidic perovskite to hydrogen bonding layer is (60-67):(33-40).

[0024] In the present invention, the Lewis acidic perovskite-hydrogen bond layer synergistic composite initiator is introduced into the lithium salt-cyclic ether monomer solution, which not only provides a spatial confinement effect during the gel polymerization process, but also through the Lewis acidic metal center (such as Cu) in its perovskite structure. 2+ ) induces a controlled polymerization reaction between electrolyte molecules, forming a viscous and stable gel system. This type of initiator combines the ordered skeleton layered hydrogen bond network of the perovskite phase. The synergistic effect of the two can significantly enhance the ion-polymer-filler three-phase coupling within the system, thereby regulating the arrangement and density of the polymer chain segments, and endowing the electrolyte membrane with excellent film-forming properties and continuous ion conduction channels.

[0025] The third technical problem to be solved by the present invention is: to address the deficiencies in the existing technology and provide a lithium metal symmetric battery system based on a solid electrolyte with good stability.

[0026] In order to solve the third technical problem mentioned above, the technical solution of the present invention is:

[0027] A lithium metal symmetric battery system based on a solid electrolyte comprises a polymer electrolyte co-solidified by a Lewis acidic perovskite-hydrogen bond layer, and metal lithium sheets located on both sides of the polymer electrolyte co-solidified by a Lewis acidic perovskite-hydrogen bond layer.

[0028] When the polymer electrolyte with the Lewis acidic perovskite-hydrogen bond layer co-cured is used in a lithium metal symmetric battery, it has good interface stability and extremely low interface impedance, can significantly reduce the voltage polarization difference during the metal lithium deposition / stripping process, enhance the cycle stability of the symmetric battery, and the metal lithium surface of the symmetric battery remains smooth and dense after long-term cycling.

[0029] The solid-state lithium metal symmetric battery system provided by the present invention is a battery with lithium metal sheets on both sides. The current density of the lithium deposition and stripping cycle test of the lithium metal symmetric battery system can be 0.1 to 6.4 mA / cm 2 The deposition or stripping time in each cycle can be 0.5 to 1 hour.

[0030] The fourth technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a lithium metal battery with a polymer electrolyte based on Lewis acidic perovskite-hydrogen bond layer synergistic solidification is provided, which has high stability.

[0031] To solve the fourth technical problem, the technical solution of the present invention is:

[0032] 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 located between the positive electrode and the negative electrode;

[0033] The negative electrode is a metal lithium sheet;

[0034] The positive electrode is at least one of FeF3, FeF2, iron oxyfluoride, CuF2, CuOHF, carbon-sulfur composite, FeS2, LiMn2O4, LiFePO4, LiCoO2, nickel-rich ternary system and lithium-rich manganese-based solid solution.

[0035] The fifth technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a solid-state lithium / fluoride battery with a soft-pack configuration based on a polymer electrolyte synergistically solidified by a Lewis acidic perovskite-hydrogen bond layer is provided, and the battery has high stability.

[0036] To solve the fifth technical problem, the technical solution of the present invention is:

[0037] Provided is a solid-state lithium / fluoride battery with a soft-pack configuration 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 located between the positive electrode and the negative electrode;

[0038] The negative electrode is thin-layer metallic lithium, and the positive electrode is at least one of FeF3, FeF2, iron oxyfluoride, CuF2, CuOHF, carbon-sulfur complex, FeS2, LiMn2O4, LiFePO4, LiCoO2, nickel-rich ternary system and lithium-rich manganese-based solid solution.

[0039] The present invention provides a large-scale fluorine-based solid-state soft-pack battery using a conversion reaction, using a polymer electrolyte that is synergistically solidified by a Lewis-acidic perovskite and hydrogen-bonded layers. The negative electrode uses a thin-layer lithium ribbon (approximately 45 μm thick), and the positive electrode film contains a fluoride positive electrode (active material), a small amount of conductive carbon, a binder, and a lithium salt. The polymer electrolyte, which is synergistically solidified by a Lewis-acidic perovskite and hydrogen-bonded layers, is located between the positive and negative electrodes.

[0040] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0041] 1. This invention utilizes a Lewis-acidic perovskite-hydrogen-bonding layer composite initiator to synergistically initiate the ring-opening polymerization of cyclic ether monomers, achieving a rapid in-situ polymerization strategy without the need for external heat sources or high-energy irradiation. This synergistic initiation system combines polymerization and hydrogen-bonding regulation, significantly improving polymerization efficiency and spatial network uniformity, resulting in an electrolyte membrane with excellent density and mechanical flexibility.

[0042] 2. The Lewis acidic perovskite-hydrogen bond layer composite initiator of the present invention introduces a cooperatively regulated ion transport channel into the polymer network. The metal sites in the Lewis acidic perovskite and TFSI - Selective adsorption occurs, inhibiting the migration of anions while promoting the dissociation of lithium salts to form a stable lithium ion conduction network; the layered structure mediated by hydrogen bonds is Li + Providing multidimensional diffusion channels to achieve uniform ion flow in space. This synergistic mechanism enables the composite polymer electrolyte to achieve a high density of 1.4×10-4S·cm at room temperature. -1 The ionic conductivity and lithium ion transference number of 0.70.

[0043] 3. The polymer electrolyte based on the Lewis acidic perovskite-hydrogen bond layer synergistic solidification in the present invention can stably operate the symmetric lithium battery for more than 5000 hours without short circuit, indicating its effective inhibition of lithium dendrites. In the construction of lithium / iron fluoride batteries, the electrolyte can stabilize the interface reaction process and promote the Fe 3+ / Fe 0The battery maintains stable charge and discharge performance within a temperature range of -20 to 100°C, enabling the lithium / iron fluoride battery to maintain a stable cycle life of 200 cycles at -20°C and 40 cycles at 100°C, demonstrating exceptional low- and high-temperature performance and its reliable operation over a wide temperature range.

[0044] 4. The present invention successfully constructed a lithium / ferric fluoride soft-pack battery based on a polymer electrolyte synergistically solidified by a Lewis acidic perovskite-hydrogen bond layer. The measured capacity was stably maintained at around 300 mAh, with excellent cycle stability. The battery components all have the potential for scale-up preparation and practical integration, demonstrating broad prospects for the practical development of next-generation high-energy solid-state lithium metal batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a scanning electron micrograph of a Lewis acidic perovskite-hydrogen bond layer-coordinated composite initiator;

[0046] Figure 2 Optical photograph of liquid precursor in situ solidification into solid polymer electrolyte;

[0047] Figure 3 The Raman spectra of the polymer electrolyte based on Lewis acidic perovskite-hydrogen bond layer cooperative curing before polymerization, after polymerization for 2 hours, and after polymerization for 12 hours;

[0048] Figure 4 Impedance diagrams of polymer electrolytes based on Lewis acidic perovskite-hydrogen bond layer cooperative curing at different temperatures;

[0049] Figure 5 The performance of the polymer electrolyte based on Lewis acidic perovskite-hydrogen bond layer and the pure DOL liquid electrolyte at 0.2 mA cm -2 The constant current cycling performance and magnified image of the Li||Li symmetric battery below;

[0050] Figure 6 This is an SEM image of the lithium metal deposited surface of a lithium metal symmetric battery based on a Lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte after cycling for 2500 hours.

[0051] Figure 7 The cycling performance diagram of Li||FeF3 battery based on Lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte at a current density of 0.2C and a voltage range of 1.2-3.9V;

[0052] Figure 8 The cycling performance diagram of Li||FeF3 battery based on Lewis acidic perovskite-hydrogen bond layer synergistic solidified polymer electrolyte at -20℃;

[0053] Figure 9 The cycling performance diagram of Li||FeF3 battery based on Lewis acidic perovskite-hydrogen bond layer synergistic solidified polymer electrolyte at 60℃;

[0054] Figure 10 The cycling performance diagram of Li||FeF3 battery based on Lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte under extreme conditions of 100℃;

[0055] Figure 11 Optical photographs and practical application demonstration of Li||FeF3 soft-pack batteries based on Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte;

[0056] Figure 12 The cycling performance diagram of Li||FeF3 soft-pack battery based on Lewis acidic perovskite-hydrogen bond layer synergistic solidified polymer electrolyte at 60℃;

[0057] Figure 13 This is the cycling performance diagram of Li||FeF3 battery with pure DOL liquid electrolyte at 0.2C. DETAILED DESCRIPTION

[0058] The present invention will be further described below with reference to the embodiments.

[0059] Example 1

[0060] (1) Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte

[0061] (1) (a) Preparation of Lewis-acidic perovskite-hydrogen bond layer synergistic composite initiators

[0062] 0.242 g of Cu(NO3)2·3H2O was dissolved in 40 mL of deionized water, and then 0.116 g of KF was added. The mixture was stirred magnetically and reacted at 100°C for 2 h. The resulting solution was centrifuged, washed repeatedly with deionized water, and dried in a vacuum at 60°C overnight to obtain a Lewis acidic perovskite-hydrogen bond layer composite initiator (KCF@COHF) powder. The mass ratio of the Lewis acidic perovskite or pseudoperovskite fluoride to the hydrogen bond-mediated layered structure material was 63.9:36.1, as shown in FIG. Figure 1 As shown, the scanning electron microscopy image shows the unique morphology of KCF@COHF particles.

[0063] (1)(b) Preparation of Lewis-acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolytes

[0064] In an argon-protected glove box, 0.574 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was dissolved in 2.0 g of 1,3-dioxolane (DOL) to obtain a lithium salt solution. 0.020 g of KCF@COHF powder was then added and stirred at room temperature for 2 h. The system gradually transformed into a non-fluid, high-viscosity gel-like liquid. The system was then allowed to react at room temperature for 12 h to obtain an opaque solid electrolyte gel, KCF@COHF-PDOL. Figure 2 As shown. Figure 3 The Raman spectroscopy results showed that the DOL-related -1 The positional characteristic peaks almost disappeared in the polymer matrix, indicating the successful polymerization of KCF@COHF-PDOL.

[0065] (2) Testing of the ionic conductivity of the polymer electrolyte with Lewis acidic perovskite-hydrogen bond layer synergistic solidification

[0066] The SS|KCF@COHF-PDOL|SS battery was assembled and measured in constant potential mode using a Solartron frequency analyzer (1296-1260) in the frequency range of 1 MHz to 0.1 Hz and 10 data points per decade. The ionic conductivity of the solid electrolyte was measured using an AC perturbation of 10 mV. The solid polymer membrane was cut into discs with a diameter of 17 mm, and two non-conductive stainless steel electrodes were placed on both sides of the electrolyte membrane. For temperature-dependent measurements, the battery was placed in an oven and impedance tests were performed in steps of 10°C from 80°C to 30°C. Each temperature point was kept warm for 1 hour to ensure that a steady state was reached. The ionic conductivity (ρ) of the solid polymer electrolyte was calculated by the following formula: ρ = L / RS;

[0067] Where R is the resistance value, L is the film thickness, and S is the contact area of ​​the electrode. Figure 4 Impedance diagrams showing the Lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte at different temperatures. The calculated ionic conductivity at 30°C is 1.4×10 -4 S / cm.

[0068] Example 2

[0069] Assembly and testing of symmetric lithium metal batteries based on a polymer electrolyte with Lewis acidic perovskite-hydrogen bonding layer synergistic solidification:

[0070] The 2025 button cell was assembled in an argon glove box with a water and oxygen value of less than 0.1 ppm. First, a metal lithium sheet (10 mm in diameter) was placed as the negative electrode in the bottom shell of the button cell, and then a polymer electrolyte membrane with a diameter of 17 mm (KCF@COHF-PDOL in Example 1) was placed. Then, another metal lithium sheet with a diameter of 10 mm was placed on the electrolyte membrane. After assembly, the battery was sealed. Charge and discharge tests were carried out on a LAND electrochemical workstation at 0.2 mA / cm 2 At a current density of , first charge at constant current for 1 hour, then discharge at constant current for 1 hour, detect the voltage polarization difference of metal lithium during the deposition / stripping process, and then carry out the cycle in this step. Figure 5 As shown, 0.2 mA cm -2 The current density and 0.2 mAh cm -2 The symmetric battery was tested based on the area capacity of the battery. It can be seen that after 1500 hours of operation, the polarization of the battery based on the pure DOL electrolyte system continued to increase, resulting in battery degradation. In contrast, the polymer electrolyte battery based on the Lewis acidic perovskite-hydrogen bond layer co-curing can successfully and stably operate for more than 5000 hours. The battery cycle is very stable and the overpotential increase is almost negligible. In addition, after the polymer electrolyte battery based on the Lewis acidic perovskite-hydrogen bond layer co-curing cycle was 2500 hours, the metal lithium surface on the deposition side was observed by scanning electron microscopy, as shown in FIG. Figure 6 As shown. It can be seen that after the cycle, the surface of lithium metal is smooth and dense, and no large needle-shaped lithium dendrites are formed. Figure 6 In the inset, the overall surface of lithium appears bright and uniform, indicating that the composite electrolyte effectively suppresses the uneven growth of lithium deposition during long-term cycling.

[0071] Example 3

[0072] Preparation and testing of lithium metal batteries based on Lewis acidic perovskite-hydrogen bonded layer synergistically solidified polymer electrolytes:

[0073] Preparation of positive electrode:

[0074] In this example, the FeF3 positive electrode is used as the preferred material. During the positive electrode preparation process, the active material is mixed with conductive carbon black (Super P) and polyvinylidene fluoride (PVDF) in a weight ratio of 80:10:10. N-methylpyrrolidone is then added to form a uniform mixture. The mixture is stirred at room temperature for 12 hours and then cast onto carbon-coated aluminum foil. The FeF3 loading is 1.5 mg cm -2 about.

[0075] Assembly and testing of Li||FeF3 batteries based on Lewis acidic perovskite-hydrogen bonded layer synergistically solidified polymer electrolyte:

[0076] The assembly of 2025 button cells was carried out in an argon glove box with a water and oxygen value of less than 0.1ppm. First, a metal lithium sheet (10mm in diameter) was placed in the bottom shell of the button cell as the negative electrode, and then a polymer electrolyte membrane with a diameter of 17mm (KCF@COHF-PDOL in Example 1) was placed. Subsequently, a prefabricated FeF3 positive electrode sheet (8mm in diameter) was placed on the electrolyte membrane as the positive electrode of the battery. After assembly, the battery was sealed. The battery cycle performance of the lithium / iron fluoride battery based on the Lewis acidic perovskite-hydrogen bond layer co-cured polymer electrolyte was tested at different specific currents at -20℃, room temperature, 60℃ and 100℃. The constant current measurement was carried out using a Land battery tester. The test range of the lithium / iron fluoride battery is 1.2~3.9V. Figure 7 To demonstrate the charge and discharge cycle performance of lithium / iron fluoride batteries at room temperature, the lithium / iron fluoride battery based on Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte still has a reversible capacity of 260 mAh / g when cycled to 200 cycles at 0.2C, and the coulombic efficiency is close to 100%. Figure 8-10 The charge-discharge cycling performance of lithium / iron fluoride batteries based on a Lewis acidic perovskite-hydrogen bonded layer co-cured polymer electrolyte at -20°C, 60°C, and 100°C was demonstrated. The Li|KCF@COHF-PDOL|FeF3 battery was stably cycled for 200 cycles at -20°C and exhibited a high capacity exceeding 500 mAh / g at 60°C and 100°C.

[0077] Example 4

[0078] Preparation and testing of soft-pack Li||FeF3 batteries based on a polymer electrolyte with Lewis acidic perovskite-hydrogen bond layer synergistic solidification:

[0079] The preparation and measurement process of the Li||FeF3 soft pack battery based on Lewis acidic perovskite-hydrogen bond layer synergistic solidified polymer electrolyte is as follows: the prepared FeF3-based positive electrode (double-sided coating, the preparation process is the same as Example 3) is cut into 7×10 cm 2 The active material loading is about 2 mg cm -2 The lithium foil was cut into slightly larger size, approximately 7.5×11 cm 2 , the composite polymer film was also cut into larger sizes of 8×12 cm 2, to completely separate the FeF3 positive electrode and the lithium metal negative electrode. These sheets are stacked and assembled into 10 layers of soft-pack batteries. Specifically, the functional sheets are stacked in the following structural order: FeF3 positive electrode / polymer electrolyte membrane (KCF@COHF-PDOL in Example 1) / lithium metal negative electrode, which in turn form a single cell. By repeatedly stacking the above structural units, a total of 10 layers of stacked soft-pack battery cells are finally assembled. Good alignment is maintained between each electrode layer and the electrolyte to ensure the continuity of the charge transfer path and the uniformity of the interface. It was then placed in a plywood mold designed in the laboratory with a pressure of about 20KPa and left for one day before the battery test. Electrochemical testing was carried out after standing in an oven at 60°C for 4 hours. Figure 11 The actual picture of the Li||FeF3 soft pack battery is shown. The soft pack battery shows highly stable cycling performance for about 25 consecutive cycles at a current density of 100mA / g. Its charge and discharge curve is very similar to that of a button battery, and its discharge capacity is as high as 300mAh( Figure 12 ), confirming the reliability and scalability of Lewis-acidic perovskite-hydrogen bonded layer-synergistically solidified polymer electrolytes for practical applications.

[0080] Comparative Example

[0081] (1) Preparation of pure DOL liquid electrolyte:

[0082] 0.574 g of LiTFSI was dissolved in 2.0 g of 1,3-dioxolane (DOL) and stirred to obtain pure DOL liquid electrolyte.

[0083] (2) Assembly and testing of Li||FeF3 batteries based on pure DOL liquid electrolyte:

[0084] The 2025 coin cell battery was assembled in an argon glove box with water and oxygen concentrations below 0.1 ppm. The lithium metal sheet, 40 μL of pure DOL liquid electrolyte, Celgard 2500, and FeF3 cathode were sequentially added to the battery casing to assemble the lithium metal battery. The battery was then tested for electrochemical cycling performance at room temperature on a LAND electrochemical workstation. Figure 13 The cycling performance of a Li||FeF3 battery using a pure DOL electrolyte system is shown in Figure 2. The full battery exhibits rapid capacity decay during cycling, and the Coulombic efficiency fails to maintain stability, exhibiting significant fluctuations, reflecting the system's poor reversibility.

[0085] It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

Claims

1. A Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte, characterized in that: The invention comprises a cyclic ether monomer, a Lewis acidic perovskite-hydrogen bond layer composite initiator and a lithium salt.

2. A method according to claim 1, characterized in that: The cyclic ether monomer includes at least one of ethylene oxide, propylene oxide, tetrahydrofuran, 1,3-dioxane, 1,3-dioxolane, and trioxymethylene; The lithium salt includes at least one of lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium hexafluorophosphate, and lithium perchlorate.

3. The Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte according to claim 1, characterized in that: The mass fraction of the Lewis acidic perovskite-hydrogen bond layer cooperatively solidified 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 Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte according to claim 1, characterized in that: The Lewis-acidic perovskite in the Lewis-acidic perovskite-hydrogen bond layer composite initiator is a Lewis-acidic perovskite type or pseudoperovskite type fluoride, and the Lewis-acidic perovskite is one of KCuF3, KMnF3, KFeF3, CsCuF3, RbCuF3, CsNiF3, KAgF3, K2NiFeF6, and Rb2MnFeF6.

5. The Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte according to claim 1, characterized in that: The hydrogen bonding layer in the Lewis acidic perovskite-hydrogen bonding layer composite initiator is a hydrogen bonding mediated layered structure material, and the hydrogen bonding layer is one of CuOHF, CoOHF, NiOHF, MnOHF, FeOHF, Cu2(OH)3F, Co2(OH)3F, and Ni2(OH)3F.

6. A method for preparing a Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Cu(NO3)2·3H2O and KF were dissolved in a solvent and mixed to form a homogeneous transparent solution. The solution was reacted at 100°C for 2 h, centrifuged, the filter cake was washed several times, and vacuum dried at 60°C overnight to obtain a Lewis acidic perovskite-hydrogen bond layer composite initiator. (2) uniformly mixing the cyclic ether monomer, the lithium salt, and the Lewis acidic perovskite-hydrogen bond layer composite initiator to obtain a mixed solution; (3) The obtained mixed solution is polymerized at room temperature for 12 hours to obtain a high-viscosity gel without fluidity, that is, a polymer electrolyte with Lewis acidic perovskite-hydrogen bond layer synergistic solidification.

7. The method for preparing a Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte according to claim 6, characterized in that: The solvent is deionized water; The molar ratio of Cu(NO3)2·3H2O to KF was 1:2, and the molar ratio of solvent to raw material was 2:0.003; The mass ratio of Lewis acidic perovskite to hydrogen bonding layer is (60-67):(33-40).

8. A lithium metal symmetric battery system based on a solid electrolyte, characterized in that: The invention comprises the polymer electrolyte of any one of claims 1 to 5 in which the Lewis acidic perovskite and hydrogen bonding layer are cooperatively solidified, and metal lithium sheets are located on both sides of the polymer electrolyte of the Lewis acidic perovskite and hydrogen bonding layer cooperatively solidified.

9. A lithium metal battery based on a polymer electrolyte with Lewis acidic perovskite-hydrogen bond layer synergistic solidification, characterized in that: A polymer electrolyte comprising a positive electrode, a negative electrode, and the Lewis acidic perovskite-hydrogen bond layer cooperatively solidified according to any one of claims 1 to 5 located between the positive electrode and the negative electrode; The negative electrode is a metal lithium sheet; The positive electrode is at least one of FeF3, FeF2, iron oxyfluoride, CuF2, CuOHF, carbon-sulfur composite, FeS2, LiMn2O4, LiFePO4, LiCoO2, nickel-rich ternary system and lithium-rich manganese-based solid solution.

10. A solid-state lithium / fluoride battery with a soft-pack configuration based on a Lewis acidic perovskite-hydrogen bond layer synergistically solidified polymer electrolyte, characterized in that: A polymer electrolyte comprising a positive electrode, a negative electrode, and the Lewis acidic perovskite-hydrogen bond layer cooperatively solidified according to any one of claims 1 to 5 located between the positive electrode and the negative electrode; The negative electrode is thin-layer metallic lithium, and the positive electrode is at least one of FeF3, FeF2, iron oxyfluoride, CuF2, CuOHF, carbon-sulfur complex, FeS2, LiMn2O4, LiFePO4, LiCoO2, nickel-rich ternary system and lithium-rich manganese-based solid solution.

Images