An amorphous polyether composite electrolyte based on oxygen-vacancy cerium oxide nanofiller and its preparation method

Abstract

This invention discloses an amorphous polyether composite electrolyte based on oxygen-vacancy cerium oxide nanofiller and its preparation method, relating to the field of solid-state battery technology. The preparation method of the amorphous ether composite electrolyte based on oxygen-vacancy cerium oxide nanofiller includes the following steps: mixing 1,3-dioxolane with a metal salt and an initiator in a solvent; adding oxygen-vacancy cerium oxide nanofiller to form a prepolymer solution; and under initiator conditions, polymerizing the 1,3-dioxolane in the prepolymer solution to obtain the amorphous ether composite electrolyte based on oxygen-vacancy cerium oxide nanofiller; wherein the metal salt is a lithium salt and / or a sodium salt. This invention, through the synergistic design of high-oxygen-vacancy cerium oxide nanofiller and amorphous poly(1,3-dioxolane) matrix, comprehensively improves the ionic conductivity, high-voltage resistance, fast-charging capability, and cycle stability of the composite electrolyte, providing a key material solution for the practical application of high-performance lithium / sodium-ion batteries.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, and in particular to an amorphous polyether composite electrolyte based on oxygen vacancy cerium oxide nanofiller and its preparation method. Background Technology

[0002] With the development of automotive electrification and the popularization of emerging electronic products such as wearable devices, the market demand for energy storage devices with high energy density, long cycle life, and intrinsic safety continues to rise. Solid-state electrolytes, as a key breakthrough direction for lithium batteries, have become a core research object for next-generation battery technology due to their superior safety characteristics compared to liquid electrolytes (such as eliminating the risk of leakage and thermal runaway), wider electrochemical window, and adaptability to lithium metal / sodium anode and high-voltage cathode materials. Within the solid-state electrolyte system, composite polymer electrolytes, with their flexible three-dimensional ion transport network, good interfacial contact with electrodes, and engineerable processing advantages, have become an ideal choice balancing performance and practicality.

[0003] Poly(1,3-dioxolane) (PDOL), as a promising polymer, has attracted much attention in the field of solid-state electrolytes due to its unique molecular structure. However, existing research shows that pure PDOL-based electrolytes still have significant limitations: for example, their room-temperature ionic conductivity cannot meet commercial requirements, they have poor compatibility with electrode interfaces, and their electrochemical window is difficult to match commercial high-voltage cathodes, leading to the continuous decomposition of cathode materials during battery cycling. Although researchers have modified PDOL by enhancing chain segment mobility through chemical crosslinking and introducing inorganic fillers such as alumina (Al2O3) to construct ion transport channels, the inherent defects of PDOL still make it difficult for composite systems to achieve withstand voltages above 4.5V and high-rate charge-discharge requirements. The incompatibility between PDOL-based electrolytes and high-voltage cathode materials, as well as the poor power density of PDOL-based batteries, significantly restrict their industrialization process. Summary of the Invention

[0004] The purpose of this invention is to provide an amorphous polyether composite electrolyte based on oxygen vacancy cerium oxide nanofiller and its preparation method, so as to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy cerium oxide nanofiller, comprising the following steps:

[0007] S1. Mix 1,3-dioxolane (DOL) with a metal salt and an initiator in a solvent, and add oxygen-vacant cerium oxide nanofiller to form a prepolymer solution;

[0008] S2. Under initiation conditions, the polymerization of 1,3-dioxolane in the prepolymer solution is achieved to obtain the amorphous ether composite electrolyte based on oxygen vacancy cerium oxide nanofiller;

[0009] The metal salt is a sodium salt and / or a lithium salt.

[0010] The amorphous ether composite electrolyte in this invention has an amorphous structure.

[0011] As a further preferred embodiment of the present invention, the amorphous ether composite electrolyte based on oxygen-vacancy cerium oxide nanofiller can be prepared in situ. The oxygen vacancies are precisely in an electron-deficient state, yet possess the ability to gain electrons; therefore, they are also called Lewis acids. Lewis acids can improve the conversion rate of DOL. The in-situ preparation steps include:

[0012] S1. DOL is mixed with metal salt and initiator in a solvent, and oxygen vacancy cerium oxide nanofiller is added to form a prepolymer solution;

[0013] S2. The prepolymer liquid is injected between the positive and negative electrodes of the battery or coated on the electrode surface, and a separator is used for support.

[0014] S3. Under initiation conditions, the polymerization of 1,3-dioxolane in the prepolymer solution is achieved to obtain the amorphous ether composite electrolyte based on oxygen vacancy cerium oxide nanofiller.

[0015] As a further preferred embodiment of the present invention, the oxygen-vacancy cerium oxide nanofiller is:

[0016] Fluorite-type Gd x Ce 1-x O 2-δ Where 0.4 ≥ x ≥ 0, δ represents oxygen vacancies, ranging from 0.15 ≥ δ ≥ 0.05; or perovskite-type BaCeO 3-δ δ represents oxygen vacancies, with a range of 0.1 ≥ δ ≥ 0.01.

[0017] As a further preferred embodiment of the present invention, the fluorite mineral type is Gd. 0.2 Ce 0.8 O 1.9 The perovskite type is BaCeO 2.95 .

[0018] The fluorite mineral type Gd 0.2 Ce 0.8 O 1.9 Preparation method: Gd₂O₃ was dissolved in dilute nitric acid in a 50℃ water bath, and Ce(NO₃)₃·6H₂O was added to prepare a nitrate mixed solution with a total metal ion concentration of 0.1 mol / L (Gd₂O₃). 3+ :Ce 3+=0.02:0.08mol / L). In a 60℃ water bath, 0.1mol / L NH4HCO3 solution was added dropwise to the mixed solution at a molar ratio of NH4HCO3:metal ions = 3:1 until the pH reached 8, forming a milky white precipitate. The precipitate was washed three times by centrifugation with deionized water and anhydrous ethanol, and dried at 70℃. It was pre-calcined at 750℃ for 2 hours in air to obtain oxygen vacancies, and then calcined at 800℃ for 5 hours in Ar atmosphere to obtain Gd. 0.2 Ce 0.8 O 1.9 Powder.

[0019] The perovskite-type BaCeO 2.95 Preparation method: Dissolve BaO in dilute nitric acid at 50℃, add Ce(NO3)3·6H2O, and prepare a nitrate mixed solution with a total metal ion concentration of 0.1mol / L (BaO). 2+ :Ce 3+ =0.05:0.05mol / L). In a 60℃ water bath, 0.1mol / L NH4HCO3 solution was added dropwise to the mixed solution at a molar ratio of NH4HCO3:metal ions = 3:1 until the pH reached 8, forming a milky white precipitate. The precipitate was washed three times by centrifugation with deionized water and anhydrous ethanol, and dried at 70℃. It was pre-calcined at 750℃ for 2 hours in air to obtain oxygen vacancies, and then calcined at 1000℃ for 5 hours in Ar atmosphere to obtain BaCeO. 2.95 Powder.

[0020] As a further preferred embodiment of the present invention, the initiator is one or two of lithium hexafluorophosphate (LiPF6) and aluminum trifluoromethanesulfonate (Al(OTf)3); and / or, the metal salt is one or more of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluoromethanesulfonyl)imide (LiFSI), lithium tetrafluoroborate (LiBF4), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), sodium bis(oxalateborate)borate (NaBOB), and sodium tetrafluoroborate (NaBF4). As a further preferred embodiment of the present invention, the initiator is initiated by heating, light irradiation, or electrochemical initiation.

[0021] As a further preferred embodiment of the present invention, the mass concentration of the oxygen vacancy cerium oxide nanofiller in the prepolymer solution is 0.1%-10%; and / or, the concentration of the metal salt in the prepolymer solution is 0.1M-1.0M; and / or, the concentration of the initiator in the prepolymer solution is 0.1M-1.0M.

[0022] As a further preferred embodiment of the present invention, the solvent is dimethyl ethylene glycol (DME); more preferably, the volume ratio of 1,3-dioxolane to DME is (1-2):(1-2).

[0023] The second technical solution of the present invention is to provide an amorphous ether composite electrolyte based on oxygen vacancy cerium oxide nanofiller prepared by the above preparation method.

[0024] The third technical solution of this invention is to provide the application of the above-mentioned amorphous ether composite electrolyte based on oxygen vacancy cerium oxide nanofiller in lithium-ion batteries or sodium-ion batteries.

[0025] The fourth technical solution of this invention provides a lithium-ion battery or a sodium-ion battery comprising the aforementioned amorphous ether composite electrolyte based on oxygen vacancy cerium oxide nanofiller; wherein the positive electrode material is lithium iron phosphate (LiFePO4, LFP) or nickel-cobalt-manganese ternary material (LiNi). x Mn y Co z O2, NMC, x+y+z=1) or sodium vanadium phosphate (Na3V2(PO4)3, NVP), the anode material includes one or more of artificial graphite, natural graphite, silicon and its alloys, tin and its alloys, lithium and its alloys, sodium and its alloys, transition metal oxides, lithium titanate or hard carbon.

[0026] This invention achieves multiple performance enhancements through the synergistic effect of high-oxygen-vacancy cerium oxide-based nanofillers and amorphous PDOL matrix: On the one hand, high-oxygen-vacancy cerium oxide-based nanofillers can significantly improve the conversion rate of DOL and promote the formation of a denser polymer network structure; at the same time, they can effectively regulate the microstructure of PDOL, promote the uniform distribution of ceramic particles and polymer substrate, provide an efficient path for lithium-ion / sodium-ion transport, and, combined with the rapid ion transport characteristics of the amorphous PDOL substrate itself, enable the composite electrolyte to have high ionic conductivity over a wide temperature range (including room temperature), providing core support for rapid charging and discharging of batteries.

[0027] The present invention discloses the following technical effects:

[0028] This invention comprehensively improves the ionic conductivity, high voltage resistance, fast charging capability, and cycle stability of composite electrolytes through the synergistic design of high oxygen vacancy cerium oxide nanofiller and amorphous PDOL matrix, providing a key material solution for the practical application of high-performance lithium / sodium ion batteries. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1The images show the DSC diagrams of the amorphous electrolyte prepared in Example 1 of this invention and the conventional PDOL electrolyte in Comparative Example 3.

[0031] Figure 2 The ionic conductivity diagrams are for the amorphous electrolyte prepared in Example 1 of this invention and the conventional PDOL electrolyte in Comparative Example 3.

[0032] Figure 3 The above are the proton NMR spectra of the amorphous electrolytes prepared in Examples 1 and 2 of this invention, the amorphous PDOL electrolyte of Comparative Example 1, and the DOL liquid.

[0033] Figure 4 Linear scanning voltammetry (LSV) test results of amorphous PDOL prepared in Examples 1-4 and electrolytes prepared in Comparative Examples 1-3 of this invention.

[0034] Figure 5 The rate performance diagrams show the Li / / LFP cells constructed using the amorphous PDOL prepared in Examples 1-4 of this invention and the electrolytes prepared in Comparative Examples 1-3.

[0035] Figure 6 The graph shows the cycle performance of Li / / LFP batteries constructed using amorphous PDOLs prepared in Examples 1-4 of this invention and electrolytes prepared in Comparative Examples 1-2.

[0036] Figure 7 The rate performance diagram shows the Li / / NMC622 battery constructed using the amorphous PDOL prepared in Example 1 of this invention and the electrolyte prepared in Comparative Example 1.

[0037] Figure 8 The graph shows the cycle performance of Li / / NMC622 batteries constructed using the amorphous PDOL prepared in Example 1 of this invention and the electrolyte prepared in Comparative Example 1.

[0038] Figure 9 The image shows the cycle performance of a Na / / NVP battery constructed using amorphous PDOL as the electrolyte, prepared in Example 5 of this invention. Detailed Implementation

[0039] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0041] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0042] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0043] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0044] In this invention, the room temperature is 25°C.

[0045] It should be noted that any aspects not described in detail in this invention are conventional practices in the field and are not the focus of this invention.

[0046] The oxygen-vacancy cerium oxide nanofiller Gd used in the following embodiments of the present invention 0.2 Ce 0.8 O 1.9 It was prepared by the following method:

[0047] (1) Press Gd 0.2 Ce 0.8 O 1.9 Weigh out 34.73 g of cerium nitrate (Ce(NO3)3·6H2O, analytical grade) and 3.63 g of gadolinium oxide (Gd2O3, analytical grade) in stoichiometric ratio.

[0048] (2) In a constant temperature water bath at 50℃, dissolve Gd2O3 with dilute nitric acid, then add weighed Ce(NO3)3·6H2O to the obtained gadolinium nitrate (Gd(NO3)3) solution, and add a certain amount of deionized water to prepare a nitrate solution with a total concentration of 0.1mol / L of Gd ions and Ce ions (Gd ion concentration 0.02mol / L, Ce ion concentration 0.08mol / L), and add it to a beaker for later use.

[0049] (3) Dissolve a certain amount of ammonium bicarbonate (NH4HCO3) in deionized water to prepare a solution with a concentration of 0.1 mol / L. In a water bath at 60°C, add the NH4HCO3 solution dropwise to the beaker in step (2) while stirring, according to a molar ratio of NH4HCO3 to metal ions (Gd ions and Ce ions) of 3:1, until the solution pH=8. After the reaction is complete, wash the milky white precipitate three times by centrifugation with deionized water and anhydrous ethanol, respectively, and dry it in an oven at 70°C. Then, pre-calcine it at 750°C for 2 hours in an air atmosphere, and finally calcine it at 800°C for 5 hours under argon (Ar) conditions to obtain oxygen vacancy cerium oxide nanofiller Gd 0.2 Ce 0.8 O 1.9 The yield is >95%. Theoretical Gd 0.2 Ce 0.8 O 1.9 The yield was 17.39g, and the actual yield was 16.52g.

[0050] The oxygen-vacancy cerium oxide nanofiller BaCeO used in the following embodiments of the present invention 2.95 It was prepared by the following method:

[0051] (1) Press BaCeO 2.95 The stoichiometric ratio of Ce(NO3)3·6H2O (analytical grade) 21.71g and barium oxide (BaO, analytical grade) 7.67g was weighed.

[0052] (2) In a constant temperature water bath at 50℃, dissolve BaO with dilute nitric acid, then add weighed Ce(NO3)3·6H2O to the obtained barium nitrate (Ba(NO3)2) solution, and add a certain amount of deionized water to prepare a nitrate solution with a total concentration of Ba ions and Ce ions of 0.1mol / L (Ba ion concentration is 0.05mol / L, Ce ion concentration is 0.05mol / L), and add it to a beaker for later use.

[0053] (3) Dissolve a certain amount of NH4HCO3 in deionized water to prepare a solution with a concentration of 0.1 mol / L. In a water bath at 60°C, add the NH4HCO3 solution dropwise to the beaker in step (2) while stirring, according to a molar ratio of NH4HCO3 to metal ions (Ba ions and Ce ions) of 3:1, until the solution pH=8. After the reaction is complete, wash the milky white precipitate three times by centrifugation with deionized water and anhydrous ethanol, respectively, and dry it in an oven at 70°C. Then, pre-calcine it at 750°C for 2 hours in an air atmosphere, and finally calcine it at 1000°C for 5 hours under Ar conditions to obtain oxygen vacancy cerium oxide nanofiller BaCeO. 2.95 The yield is >90%. Theoretical BaCeO 2.95 The yield was 16.27g, and the actual yield was 14.64g.

[0054] Example 1

[0055] A method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy cerium oxide nanofiller, comprising the following steps:

[0056] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add LiPF6 and LiTFSI, stir until homogeneous, and then add Gd to the mixture. 0.2 Ce 0.8 O 1.9 The prepolymer solution is obtained;

[0057] In the prepolymer solution, the concentration of LiPF6 was 0.75 M, the concentration of LiTFSI was 0.5 M, and the concentration of Gd was... 0.2 Ce 0.8 O 1.9 The concentration was 0.2 wt.%.

[0058] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is lithium iron phosphate (LFP) or lithium nickel cobalt manganese oxide (LiNi). 0.6 Mn 0.2 Co 0.2 O2 (NMC622), the negative electrode is lithium, using 2.00cm -2 The PP2500 separator was then subjected to polymerization of 1,3-dioxolane monomers at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL-0.2wt.% GDC) based on oxygen vacancy cerium oxide nanofiller. The resulting batteries were either Li / / LFP batteries or Li / / NMC622 batteries.

[0059] Example 2

[0060] A method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy cerium oxide nanofiller, comprising the following steps:

[0061] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add LiPF6 and LiTFSI, stir until homogeneous, and then add BaCeO to the mixture. 2.95 The prepolymer solution is obtained;

[0062] The prepolymer solution contained 0.75 M LiPF6, 0.5 M LiTFSI, and BaCeO4. 2.95 The concentration was 0.2 wt.%.

[0063] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is LFP and the negative electrode is lithium, a 2.00cm... -2 The PP2500 separator was then subjected to polymerization of 1,3-dioxolane monomers at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL-0.2wt.%BAC) based on oxygen vacancy cerium oxide nanofiller, and the resulting battery was a Li / / LFP battery.

[0064] Example 3

[0065] A method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy cerium oxide nanofiller, comprising the following steps:

[0066] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add LiPF6 and LiTFSI, stir until homogeneous, and then add Gd to the mixture. 0.2 Ce 0.8 O 1.9 The prepolymer solution is obtained;

[0067] In the prepolymer solution, the concentration of LiPF6 was 0.75 M, the concentration of LiTFSI was 0.5 M, and the concentration of Gd was... 0.2 Ce 0.8 O 1.9 The concentration was 0.1 wt.%.

[0068] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is LFP and the negative electrode is lithium, a 2.00cm... -2The PP2500 separator was then subjected to polymerization of 1,3-dioxolane monomers at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL-0.1wt.%GDC) based on oxygen vacancy cerium oxide nanofiller, and the resulting battery was a Li / / LFP battery.

[0069] Example 4

[0070] A method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy cerium oxide nanofiller, comprising the following steps:

[0071] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add LiPF6 and LiTFSI, stir until homogeneous, and then add BaCeO to the mixture. 2.95 The prepolymer solution is obtained;

[0072] The prepolymer solution contained 0.75 M LiPF6, 0.5 M LiTFSI, and BaCeO4. 2.95 The concentration was 0.1 wt.%.

[0073] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is LFP and the negative electrode is lithium, a 2.00cm... -2 The PP2500 separator was then subjected to polymerization of 1,3-dioxolane monomers at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL-0.1wt.%BAC) based on oxygen vacancy cerium oxide nanofiller. The resulting battery is a Li / / LFP battery.

[0074] Example 5

[0075] A method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy cerium oxide nanofiller, comprising the following steps:

[0076] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add NaPF6 and NaTFSI, stir until homogeneous, and then add Gd to the mixture. 0.2 Ce 0.8 O 1.9 The prepolymer solution is obtained;

[0077] In the prepolymer solution, the concentration of NaPF6 was 0.75 M, the concentration of NaTFSI was 0.5 M, and the concentration of Gd was... 0.2 Ce 0.8 O 1.9 The concentration was 0.2 wt.%.

[0078] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is sodium vanadium phosphate (NVP) and the negative electrode is sodium, using a 2.00 cm... -2 The PP2325 separator was then used; subsequently, 1,3-dioxolane monomer polymerization was initiated at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL-0.2wt.% GDC-Na) based on oxygen vacancy cerium oxide nanofiller, and the resulting battery was a Na / / NVP battery.

[0079] Comparative Example 1

[0080] The preparation steps of an amorphous ether-based composite electrolyte are as follows:

[0081] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add LiPF6 and LiTFSI, stir until homogeneous, and obtain a prepolymer solution; in the prepolymer solution, the concentration of LiPF6 is 0.75M and the concentration of LiTFSI is 0.5M.

[0082] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is LFP or NMC622 and the negative electrode is lithium, using a 2.00cm... -2 The PP2500 separator was then used; subsequently, 1,3-dioxolane monomer polymerization was initiated at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL), and the corresponding batteries were Li / / LFP batteries or Li / / NMC622 batteries.

[0083] Comparative Example 2

[0084] A method for preparing an amorphous ether-based composite electrolyte based on oxygen-vacancy-free nanofillers, comprising the following steps:

[0085] (1) Mix 1,3-dioxolane and ethylene glycol dimethyl ether at a volume ratio of 1:1, then add LiPF6 and LiTFSI, stir until homogeneous, and then add Al2O3 to the mixture to obtain a prepolymer solution;

[0086] The concentration of LiPF6 in the prepolymer solution was 0.75 M, the concentration of LiTFSI was 0.5 M, and the concentration of Al2O3 was 0.2 wt.

[0087] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2Between the positive and negative electrodes, where the positive electrode is LFP and the negative electrode is lithium, a 2.00cm... -2 The PP2500 separator was then subjected to polymerization of 1,3-dioxolane monomers at 25°C to obtain an amorphous ether composite electrolyte (amorphous PDOL-0.2wt.%Al2O3) based on oxygen-free vacancy nanofillers. The resulting battery is a Li / / LFP battery.

[0088] Comparative Example 3

[0089] The preparation steps of a conventional PDOL electrolyte are as follows:

[0090] (1) Add 1,3-dioxolane to LiPF6 and stir until homogeneous to obtain a prepolymer solution; the concentration of LiPF6 in the prepolymer solution is 1.25M;

[0091] (2) Take 60 μL of the obtained prepolymer solution and inject it into a 1.96 cm channel. -2 Lithium sheet and 1.13cm -2 Between the positive and negative electrodes, where the positive electrode is LFP and the negative electrode is lithium, a 2.00cm... -2 The PP2500 separator was used; then, 1,3-dioxolane monomer polymerization was initiated at 25°C to obtain a conventional PDOL electrolyte, and the corresponding battery was a Li / / LFP battery.

[0092] Figure 1 The DSC diagrams are for the amorphous PDOL-0.2wt.% GDC electrolyte prepared in Example 1 of this invention and the conventional PDOL electrolyte (conventional PDOL polymer) in Comparative Example 3. Figure 1 The DSC test results showed that the conventional PDOL electrolyte in Comparative Example 3 exhibited a crystallization temperature of 19.8°C. The crystallization region restricts the chain movement of PDOL, thus affecting its ionic conductivity. In contrast, the amorphous PDOL-0.2wt.% GDC electrolyte in Example 1 did not show a crystallization temperature. This indicates that the introduction of DME and oxygen-vacancy cerium oxide nanofillers weakened the intermolecular forces of PDOL molecules, preventing the polymer from arranging itself in an orderly manner at room temperature, thus resulting in an amorphous state at room temperature. This leads to a faster lithium-ion migration rate.

[0093] Figure 2 The diagram shows the ionic conductivity of the amorphous PDOL-0.2wt.% GDC electrolyte prepared in Example 1 and the amorphous PDOL electrolyte in Comparative Example 1. Within the temperature range of -30 to 30°C, the ionic conductivity of the amorphous PDOL-0.2wt.% GDC electrolyte is greater than 1 mS / cm. -1 It far exceeds that of amorphous PDOL electrolytes, and its ionic conductivity increases with increasing temperature, showing a clear linear relationship with temperature.

[0094] Figure 3 The images show the 1H NMR spectra of the amorphous PDOL-0.2wt.% GDC electrolyte and amorphous PDOL-0.2wt.% BAC electrolyte prepared in Examples 1 and 2 of this invention, as well as the amorphous PDOL electrolyte and DOL liquid in Comparative Example 1. The 1H NMR spectra demonstrate that the oxygen-vacancy cerium oxide nanofiller has a certain influence on the conversion rate of DOL monomers. The chemical environment of H in DOL monomers at 3.78 ppm and 4.78 ppm changed to 3.59 ppm and 4.63 ppm respectively after polymerization. Figure 3 The H positions at positions a and b in the DOL monomer are changed to c and d, which closely matches the structure of -O-CH2-O-CH2-CH2- in PDOL. a and b correspond to hydrogen atoms in different chemical environments within the -O-CH2-CH2- and -O-CH2-O- groups of the DOL monomer. Calculate the DOL monomer conversion rate: Formula, c is Figure 3 The peak area is at 3.59 ppm, and a is... Figure 3 The peak area is 3.78 ppm. Substituting this into the formula, we find that C in PDOL with only an initiator added... m It is 68.1%.

[0095] Furthermore, 0.2 wt.% Gd was added to this mixture. 0.2 Ce 0.8 O 1.9 Example 1: Electrolyte and 0.2 wt.% BaCeO 2.95 In Example 2, the Cm of DOL in the electrolyte increased to 74.7% and 70.4%, respectively. This indicates that the filler containing oxygen vacancies successfully promoted the ring-opening polymerization of DOL due to the Lewis acidity of its surface, thereby improving its conversion rate. It is worth noting that Example 1 more significantly promoted the conversion of DOL, ensuring that no excess DOL would affect the oxidative stability of the electrolyte under high pressure.

[0096] Figure 4 For LSV testing:

[0097] Using the electrolytes prepared in Examples 1-4 and Comparative Examples 1-3 respectively, lithium metal was used as the reference electrode, and a stainless steel gasket was used as the working electrode to assemble "Li|electrolyte|SS" coin cells for testing. The results are shown in [Figure 1]. Figure 4Compared to the amorphous PDOL in Comparative Example 1 and the conventional PDOL in Comparative Example 3, the addition of DME and LiTFSI to form an amorphous electrolyte reduces the electrochemical window, mainly due to the poor voltage tolerance of carbonate solvents (DME). Compared to Comparative Example 2, the addition of filler also increases the oxidation potential of the electrolyte. Compared to Comparative Examples 1-3, the electrolyte systems of Examples 1-4 all exhibit a wider electrochemical window, with their average oxidation potential significantly increasing from 4.5V to 5.1V, and the current growth curve is smoother. This phenomenon can be attributed to the multiple synergistic effects caused by the introduction of cerium oxide additives. First, cerium dioxide with a low oxidation state is used to generate a high concentration of oxygen vacancies. These oxygen vacancies are usually positively charged and can act as Lewis acids in composite polymer electrolytes, capturing lithium anions, increasing the lithium-ion migration rate, and improving fast-charging performance. Simultaneously, it can catalyze the polymerization of DOL monomers, increasing their conversion rate and enhancing the oxidative stability of the electrolyte.

[0098] Li / / LFP battery performance testing:

[0099] Performance testing at different rates: The lithium-ion battery was charged to 4.2V at a constant current of 0.2C at 25°C room temperature, with a cutoff current of 0.02C. It was then discharged to 2.5V at a constant current of 0.2C, and this cycle was repeated 10 times. Then, under the same conditions, it was cycled 10 times each at different rates (0.5C, 1C, 3C, and 5C) to test the battery capacity. Afterwards, the above conditions were repeated, gradually returning to 3C-1C-0.5C-0.2C at different rates to test the battery stability. The results are shown in […]. Figure 5 Under low-rate conditions of 0.2C, Examples 1-4, all with gadolinium-doped cerium oxide, exhibited significantly improved discharge specific capacity, with Example 1 reaching 160.78 mAh g⁻¹. -1 This is significantly higher than the corresponding values ​​of 120.88 mAh g in Comparative Examples 1 and 2. -1 and 121.42mAh g -1 Furthermore, Comparative Example 3 failed to cycle normally at 5C. Of particular note is that, under the harsh conditions of high-rate 5C, Example 1 still maintained 98.23 mAh g⁻¹. -1 The high discharge specific capacity of the sample, while the comparative sample 1 could only maintain 56.86 mAh g. -1The discharge capacity and capacity retention rate were significantly reduced. This result fully demonstrates that the introduction of gadolinium-doped cerium oxide significantly improves the ion transport kinetics of the electrolyte and optimizes the electrode / electrolyte interface characteristics, thereby endowing the battery with excellent rate performance and fast charging capability. Experiments show that the addition of gadolinium-doped cerium oxide not only improves the ionic conductivity of the electrolyte, but also effectively reduces the polarization effect under high-rate conditions by promoting uniform lithium-ion deposition and suppressing interfacial side reactions, enabling the battery to maintain stable electrochemical performance during rapid charge and discharge.

[0100] Cycle performance test: The lithium-ion battery was charged to 4.2V at a constant current of 5C at room temperature (25°C), with a cutoff current of 0.02C, and then discharged to 2.5V at a constant current of 5C, cycling 500 times to test the battery's cycle life. The results are shown below. Figure 6 .Depend on Figure 6 As can be seen, under 5C long-term cycling in Li / / LFP, Examples 1-4 and Comparative Examples 1-2 clearly show that the battery with added gadolinium-doped cerium oxide has a higher discharge specific capacity than the battery without added gadolinium-doped cerium oxide. Furthermore, after 500 cycles, Example 1 still retains 101.01 mAh g⁻¹. -1 The discharge specific capacity of [the sample] is [higher], while that of Comparative Example 1 is only 76.18 mAh g. -1 Comparative Example 2 has only 77.93 mAh g. -1 This demonstrates that the gadolinium-doped cerium oxide electrolyte battery can maintain a high discharge specific capacity even under high-rate cycling.

[0101] Battery performance test of Li / / NMC622:

[0102] Performance testing at different rates: The lithium-ion battery was charged to 4.3V at a constant current of 0.2C at 25°C room temperature, with a cutoff current of 0.02C. It was then discharged to 2.8V at a constant current of 0.2C, and this cycle was repeated 10 times. The same conditions were then applied to different rates (0.5C, 1C, 2C, 3C, 5C, and 10C) for 10 cycles each, and the battery capacity was tested. The above conditions were then repeated, gradually returning to 5C-3C-2C-1C-0.5C-0.2C, to test the battery stability. The results are shown in [Figure number missing]. Figure 7 .like Figure 7 As shown, Example 1, with the addition of 0.2% gadolinium-doped cerium oxide under low-rate conditions of 0.2C, exhibited a throughput of 201.66 mAh g. -1 Example 1 exhibits superior initial discharge capacity, significantly outperforming Comparative Example 1; even at an ultra-high rate of 10C, Example 1 still maintains 119.57 mAh g⁻¹. -1 The high discharge capacity, compared to Comparative Example 1 (117.39 mAh g), is significantly higher. -1It exhibits more stable electrochemical performance. It demonstrates that the electrolyte battery with 0.2% gadolinium-doped cerium oxide still maintains high discharge specific capacity under high voltage and high rate conditions.

[0103] Cyclic performance testing: The lithium-ion battery was charged to 4.3V at a constant current of 1C at room temperature (25°C), with a cutoff current of 0.02C, and then discharged to 2.8V at a constant current of 1C, cycling 500 times to test the battery's cycle life. The results are shown below. Figure 8 .like Figure 8 As shown, Example 1, with the addition of 0.2% gadolinium-doped cerium oxide, exhibited significantly better cycling performance than Comparative Example 1: after 500 cycles, Example 1 still maintained 112.36 mAh g⁻¹. -1 The reversible capacity (capacity retention rate of 62.02%) is significantly higher than that of Comparative Example 1 (73.24 mAh g). -1 (Capacity retention rate 42.77%). This result fully demonstrates that gadolinium-doped cerium oxide modified electrolyte effectively suppresses side reactions and electrode material degradation under high voltage conditions by constructing a stable electrode / electrolyte interface, enabling the battery to exhibit excellent capacity retention and structural stability during long-term cycling.

[0104] Na / / NVP battery performance test:

[0105] Cyclic performance testing: The sodium-ion battery was charged to 4.1V at a constant current of 1C at room temperature (25°C), with a cutoff current of 0.02C, and then discharged to 2.5V at a constant current of 1C, cycling 500 times to test the battery's cycle life. The results are shown below. Figure 9 .like Figure 9 As shown, Example 5, with the addition of 0.2% gadolinium-doped cerium oxide, exhibited significant cycling performance: after 500 cycles, Example 5 still maintained 94.98 mAh g⁻¹. -1 The reversible capacity (capacity retention rate of 90.95%) is demonstrated. This result fully proves that gadolinium-doped cerium oxide modified electrolyte, by constructing a stable electrode / electrolyte interface, is also suitable for sodium-ion batteries, enabling sodium-ion batteries to exhibit excellent capacity retention and stability during long-term cycling.

[0106] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing an amorphous ether-based composite electrolyte based on ceria nanofillers based on oxygen vacancies, characterized in that, The method comprises the following steps: S1. mixing 1,3-dioxolane with a metal salt and an initiator in a solvent, adding an oxygen vacancy ceria nano-filler to form a prepolymer solution; S2. under an initiation condition, polymerizing 1,3-dioxolane in the prepolymer solution to obtain the amorphous ether-based composite electrolyte based on the oxygen vacancy ceria nano-filler; The oxygen vacancy ceria nano-filler is: fluorite-type Gd x Ce 1-x O 2-δ wherein 0.4 > x > 0, and δ is an oxygen vacancy in the range of 0.15 > δ > 0.05; or a perovskite-type BaCeO 3-δ wherein δ is an oxygen vacancy in the range of 0.1 > δ > 0.01; The initiator is one or both of lithium hexafluorophosphate and aluminum trifluoromethyl sulfonate; the metal salt is one or several of lithium bistrifluoromethyl sulfonimide, lithium bistrifluorosulfonimide, lithium tetrafluoroborate, sodium bistrifluoromethyl sulfonimide, sodium bisoxalate borate and sodium tetrafluoroborate; The mass concentration of the oxygen vacancy ceria nano-filler in the prepolymer solution is 0.1%-10%; and / or, the concentration of the metal salt in the prepolymer solution is 0.1M-1.0M; and / or, the concentration of the initiator in the prepolymer solution is 0.1M-1.0M.

2. The production method according to claim 1, characterized by, The initiation condition is thermal initiation, and the temperature of the thermal initiation is 25-60℃.

3. The method of claim 1, wherein, The solvent is ethylene glycol dimethyl ether.

4. The amorphous ether-based composite electrolyte based on the oxygen vacancy ceria nano-filler prepared by the preparation method according to any one of claims 1-3.

5. The application of the amorphous ether-based composite electrolyte based on the oxygen vacancy ceria nano-filler according to claim 4 in a lithium ion battery or a sodium ion battery.

6. A lithium-ion battery or a sodium-ion battery, characterized in that, The amorphous ether-based composite electrolyte based on the oxygen vacancy ceria nano-filler according to claim 4; wherein the positive electrode material is lithium iron phosphate, nickel-cobalt-manganese ternary material or sodium vanadium phosphate; and / or, the negative electrode material comprises one or more of graphite, silicon and its alloy, tin and its alloy, lithium and its alloy, sodium and its alloy, transition metal oxide, lithium titanate or hard carbon.

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