Polymer electrolyte material containing ether-based plasticizer and preparation method and application thereof

Abstract

The application relates to the technical field of solid electrolytes, and particularly discloses a polymer electrolyte material containing ether plasticizers as well as a preparation method and application thereof, the molecular formula of the polymer electrolyte material is MgBr2-PEO-xTEGDME-H2O, the addition amount of TEGDME is 0 wt%-10 wt% (not 0), and the addition amount of H2O molecules is 10 wt%. Raw materials, i.e. magnesium bromide, polyethylene oxide and tetraethylene glycol dimethyl ether, are dissolved in anhydrous ethanol under a protective atmosphere, then are dried under vacuum, and finally, the solid electrolyte is exposed to air to absorb water molecules in the air, thereby obtaining a polymer electrolyte material containing ether plasticizers. The polymer electrolyte material containing ether plasticizers prepared by the application has an ionic conductivity of 1.25*10 ‑2 S cm ‑1 at room temperature, and can stably charge and discharge for 420 times at a low overpotential (<1.5 V). The application is suitable for magnesium ion batteries and other solid-state or quasi-solid-state batteries, and has excellent ionic conductivity and cycle stability.

Description

Technical Field

[0001] This invention relates to the field of solid-state electrolyte technology, and more particularly to a polymer electrolyte material containing ether-based plasticizers, its preparation method, and its applications. This material is suitable for magnesium-ion batteries and other solid-state or quasi-solid-state batteries, exhibiting excellent ionic conductivity and cycle stability. Background Technology

[0002] Solid-state electrolytes have attracted widespread attention due to their high safety, lack of leakage risk, and good thermal stability. Especially in large-scale energy storage and electric vehicle applications, solid-state electrolytes are considered an ideal alternative to traditional liquid electrolytes. Among them, magnesium-based electrolytes, with their abundant magnesium resources, high theoretical capacity, and lack of dendrite growth, are expected to become a next-generation alternative to lithium-ion batteries.

[0003] Currently, magnesium-based solid electrolytes mainly fall into two categories: inorganic solid electrolytes and organic polymer solid electrolytes. Inorganic magnesium ion solid electrolytes primarily include materials of the phosphate, hydride, and sulfide types. However, due to the high charge density and strong polarization of magnesium ions, their migration barrier in the solid lattice is relatively high, resulting in the low ionic conductivity of most inorganic magnesium-based solid electrolytes at room temperature, generally below 10. -4 S‧cm -1 Furthermore, magnesium ions are prone to side reactions during charge-discharge cycles, increasing interfacial impedance and severely affecting the long-term cycle stability of the battery. Among organic polymer solid electrolytes, polyethylene oxide (PEO)-based polymer electrolytes have been widely studied due to their excellent mechanical properties and low glass transition temperature. By combining magnesium salts such as magnesium chloride (MgCl2), magnesium bromide (MgBr2), and magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) with PEO, magnesium ions can be rapidly conducted in the amorphous regions of PEO. However, the room-temperature ionic conductivity of this type of electrolyte remains low, typically below 10. -4 S‧cm -1 Furthermore, its poor interfacial stability with the electrodes limits its practical application.

[0004] The introduction of magnesium halides can suppress the formation of a passivation layer at the electrolyte-electrode interface, thereby improving the long-term cycle stability of the battery. (Leong et al. Reversibility of a high-voltage, Cl...) –-regulated, aqueous mg metal battery enabled by a water-in-saltelectrolyte[J]. ACS Energy Letters, 2022, 7(8): 2657-2666.) By Cl - The process involves regulating the use of a MgCl2-based "salt-in-water" electrolyte to suppress the hydrogen evolution reaction. This transforms the passivation film on the magnesium anode surface, which cannot conduct magnesium ions, into a conductive magnesium-magnesium oxide composite layer, enabling the full cell to operate at 0.5 A g / L. -1 It can stably cycle for more than 700 times at current density. However, it still has the problem of proton co-intercalation during charge and discharge, which affects the voltage plateau. Wang et al. (Wang Q, Li H, Xu T, et al. Understanding Mg-ion deposition behavior on MgBi alloy in solid-stateform[J]. Energy Materials, 2025, 5(2).) found that adding MgBr2‧2NH3 nanoparticles to Mg(BH4)2‧1.9NH3 can utilize Br - The etching effect of ions inhibits the formation of a passivation layer at the MgBi alloy interface. This electrolyte operates at 0.1 mA cm⁻¹. -2 At current densities of [specific value], it can achieve more than 1200 reversible dissolution / deposition cycles, with the overpotential maintained at approximately 0.05 V. However, its ionic conductivity is limited, at 2.1 × 10⁻⁶ at 50 °C. -4 S cm -1 .

[0005] Composite polymers are often used to improve the ionic conductivity and stability of electrolytes. Leong et al. (Leong K W, Pan W, Yi X, et al. Next-generation magnesium-ion batteries: The quasi-solid-state approach to multivalent metal ion storage[J]. Science advances,2023, 9(32): eadh1181.) combined magnesium chloride aqueous solution with PEO, utilizing PEO to anchor water molecules and confine the hydrated hydrogen bond network, achieving an ionic conductivity as high as 1.24 mS / cm. -1A quasi-solid-state electrolyte with an electrochemical window up to 5 V enables true metal ion storage. (Xu et al. Tailoring Hydrogen Bonds Enabling Fast Mg...) 2+ Migration in Hydrate Salt-Based Solid-State Electrolytes[J]. Electrochimica Acta, 2025: 147655.) A small amount of water molecules was introduced into the MgBr2‧4.67H2O-PEO system. The hydrogen bonding between PEO and H2O promoted the migration of magnesium ions, increasing its ionic conductivity at 40 °C to 1.2 × 10⁻⁶. -4 S cm -1 Meanwhile, the binding of H2O molecules by PEO inhibits the decomposition of H2O at low potentials, broadening the electrochemical window to 5.58 V. However, the interfacial stability between this type of electrolyte and the magnesium anode is still not ideal, with large overpotential fluctuations during magnesium dissolution / deposition, and reversibility needs to be improved.

[0006] To further improve the compatibility between the electrolyte and the magnesium anode, a strategy of adding plasticizers such as tetraethylene glycol dimethyl ether (TEGDME) is often adopted. Mesallam et al. (Mesallam M, Kamar EM, Sharma N, et al. Synthesis and characterization of polyvinylidene fluoride / magnesium bromide polymerelectrolyte for magnesium battery application[J]. Physica Scripta, 2020, 95(11): 115805.) added TEGDME to PVDF-MgBr2 electrolyte, which made it exhibit low overpotential and reversible magnesium deposition / dissolution behavior in the initial cycle. Wang et al. (Wang T, Zhao X, Liu F, et al. Porous polymer electrolytes for long-cycle stable quasi-solid-state magnesium batteries[J]. Journal of Energy Chemistry, 2021, 59: 608-614.) immersed porous PVDF-HFP membranes in MgCl2-AlCl3 / TEGDME electrolytes, and the resulting magnesium symmetric batteries assembled with porous polymer electrolytes could achieve reversible deposition / dissolution under an overvoltage of approximately 0.13V. Nevertheless, the room-temperature ionic conductivity of these electrolytes remains insufficient; for example, PVDF-MgBr2-TEGDME only has a conductivity of 1.2 × 10⁻⁶. -6 S cm -1 The room temperature ionic conductivity of the PVDF-HFP membrane that adsorbs the electrolyte is 4.72 × 10⁻⁶. -4 S cm -1 However, it still falls short of meeting the needs of practical applications.

[0007] In view of the above shortcomings, a polymer electrolyte material that can solve the problems of low ionic conductivity and poor stability to magnesium anode in existing polyethylene oxide / magnesium bromide solid electrolytes is urgently needed in the industry. Summary of the Invention

[0008] Based on the above analysis, the present invention provides a polymer electrolyte material containing ether plasticizer, its preparation method and application. This material can effectively improve the interfacial stability between electrolyte and magnesium, thereby achieving stable cycling at low overpotential for 420 cycles.

[0009] To achieve the above-mentioned technical effects, the present invention adopts the following technical solution:

[0010] This invention first discloses a polymer electrolyte material containing an ether-based plasticizer, the molecular formula of which is MgBr2-PEO-χTEGDME-H2O, wherein:

[0011] χ is 0 wt% to 10 wt%, and χ is not 0.

[0012] Furthermore, the χ is 2 wt%.

[0013] This invention also discloses a method for preparing the above-mentioned polymer electrolyte material containing ether plasticizer, comprising the following steps:

[0014] Step 1: Dissolve magnesium bromide and polyethylene oxide in anhydrous ethanol (H2O < 50 ppm) under a protective atmosphere, then add tetraethylene glycol dimethyl ether to obtain a homogeneous mixed solution. Pour the solution into a polytetrafluoroethylene petri dish and dry it under vacuum to obtain a gel-like solid I.

[0015] Step 2: Expose gel-like solid I to air to absorb water molecules from the air, thus obtaining a polymer electrolyte material containing ether plasticizer.

[0016] Furthermore, in step 1, the stirring speed is 300 rpm, the stirring temperature is 60 ℃, and the stirring time is not less than 24 hours.

[0017] Furthermore, the vacuum drying conditions described in step 1 are drying at 80 °C for 6 h, with a vacuum degree of approximately 21 kPa.

[0018] Furthermore, the environmental conditions for air exposure in step 2 are a temperature of 25°C, a humidity of 50%, and an exposure time of 30 minutes.

[0019] Further, in step 1, the mass ratio of magnesium bromide to polyethylene oxide is 7:3, and the mass fraction of tetraethylene glycol dimethyl ether is χ.

[0020] The present invention also discloses a polymer electrolyte material containing ether plasticizer prepared by any of the above preparation methods.

[0021] The present invention also discloses the application of the above-mentioned polymer electrolyte material containing ether plasticizer in the preparation of rechargeable batteries.

[0022] Furthermore, the rechargeable battery includes: a magnesium-ion battery, a solid-state battery, or a quasi-solid-state battery.

[0023] The technical principle of this technical solution is as follows:

[0024] 1. The technical solution of this invention solves the problems of low ionic conductivity and poor compatibility with magnesium ion solid electrolytes by adding tetraethylene glycol dimethyl ether to a water / polyethylene oxide / magnesium bromide solid electrolyte, thereby obtaining a polymer electrolyte material containing ether plasticizers. The room temperature ionic conductivity of this electrolyte is increased to [value missing]. It has the ability to efficiently and rapidly conduct Mg 2+ The migration path.

[0025] 2. This invention uses water / polyethylene oxide / magnesium bromide as the solid electrolyte matrix for magnesium-ion batteries and adds tetraethylene glycol dimethyl ether as a plasticizer, enabling the magnesium|water / tetraethylene glycol dimethyl ether / polyethylene oxide / magnesium bromide|magnesium symmetric battery to cycle stably for 420 times with an overpotential of less than 1.5 V, thereby improving the stability of the magnesium bromide-based solid electrolyte to the magnesium anode.

[0026] 3. To improve the stability of the electrolyte with respect to the magnesium anode, it is necessary to suppress the hydrogen evolution reaction that occurs in liquid water during charge and discharge, and simultaneously suppress the side reactions between liquid water and the magnesium anode to form a passivation layer such as magnesium hydroxide, thereby enabling the electrolyte to cycle stably. This invention proposes a water / plasticizer composite method that can effectively improve the interfacial stability between the electrolyte and magnesium, thereby achieving stable cycling at low overpotential for 420 cycles.

[0027] The beneficial effects of this invention are as follows:

[0028] This invention significantly improves the room-temperature ionic conductivity of the polymer electrolyte material by introducing the ether plasticizer tetraethylene glycol dimethyl ether (TEGDME) into the MgBr2-PEO-H2O system, reaching [value missing]. The efficiency is significantly higher than that of existing magnesium-based solid-state electrolyte materials and quasi-solid-state electrolyte materials. Simultaneously, the addition of TEGDME effectively suppresses the hydrogen evolution reaction and side reactions between water molecules and the magnesium anode, reduces the formation of passivation layers such as magnesium hydroxide, and significantly improves the interfacial stability between the electrolyte and the magnesium anode. Magnesium symmetric batteries assembled using the ether-containing plasticizer polymer electrolyte material prepared according to this invention can stably cycle 420 times with an overpotential below 1.5 V, exhibiting excellent cycle stability and low-level characteristics. Furthermore, the preparation method of this invention is simple, operates under mild conditions, requires no complex equipment, and is suitable for magnesium-ion batteries, solid-state batteries, or quasi-solid-state batteries, showing broad application prospects. Attached Figure Description

[0029] Figure 1 X-ray diffraction patterns of polymer electrolyte materials (MgBr2-PEO-χTEGDME-H2O) containing ether plasticizers obtained in Examples 1-6 and Comparative Example 1 of the present invention;

[0030] Figure 2Differential scanning calorimetry (DSC) of the polymer electrolyte material (MgBr2-PEO-2%TEGDME-H2O) containing ether plasticizer obtained in Example 1 of the present invention;

[0031] Figure 3 The infrared spectra of the polymer electrolyte materials containing ether plasticizers obtained in Examples 1-6 and Comparative Example 1 of this invention are shown below.

[0032] Figure 4 The images show the nuclear magnetic resonance (NMR) spectra of the polymer electrolyte materials containing ether plasticizers obtained in Examples 1-6 and Comparative Example 1 of this invention.

[0033] Figure 5 The Nyquist spectrum of the polymer electrolyte material (MgBr2-PEO-2%TEGDME-H2O) containing ether plasticizer obtained in Example 1 of the present invention at 25°C;

[0034] Figure 6 This is a graph showing the temperature-ionic conductivity relationship of the polymer electrolyte material (MgBr2-PEO-2%TEGDME-H2O) containing ether plasticizer obtained in Example 1 of the present invention.

[0035] Figure 7 The graph shows the temperature-ionic conductivity relationship of the polymer electrolyte materials containing ether plasticizers obtained in Examples 1-6 and Comparative Example 1 of this invention.

[0036] Figure 8 The cyclic voltammetry diagram is shown for the polymer electrolyte material (MgBr2-PEO-2%TEGDME-H2O) containing ether plasticizer obtained in Example 1 of this invention.

[0037] Figure 9 The images show the constant current charge-discharge curves of the counter electrode of the polymer electrolyte materials containing ether plasticizers obtained in Examples 1-6 and Comparative Example 1 of this invention. Detailed Implementation

[0038] The following detailed description illustrates the specific implementation method:

[0039] Example 1:

[0040] A polymeric electrolyte material containing an ether-based plasticizer, wherein the molecular formula of the quasi-solid electrolyte is MgBr2-PEO-2%TEGDME-H2O, and the amount of TEGDME added is 2% (mass fraction).

[0041] The preparation method of the above-mentioned quasi-solid-state electrolyte material includes the following steps:

[0042] Step 1: Under vacuum conditions, take 0.7 g magnesium bromide and 0.3 g polyethylene oxide (1 g total raw material) and add them to a 50 mL reaction flask in a glove box. Seal the flask with a rubber stopper and sealing film, and then remove it. Under an argon atmosphere, add 10 mL of anhydrous ethanol (H2O < 50 ppm) using a syringe. After the solid dissolves, add 0.02 mL of tetraethylene glycol dimethyl ether using a syringe. Stir at 60 °C for 24 hours at a speed of 300 rpm.

[0043] Step 2: Pour the solution from Step 1 into a polytetrafluoroethylene petri dish, transfer it to a vacuum oven and dry it for 6 hours at 80 ℃. Transfer the dried solid to a glove box to obtain gelatinous solid I (MgBr2-PEO-2%TEGDME).

[0044] Step 3: Expose the MgBr2-PEO-2%TEGDME solid from Step 2 to air in a constant temperature and humidity chamber for 30 min at a temperature of 25 ℃ and a humidity of 50% to obtain a polymer electrolyte material containing ether plasticizer (MgBr2-PEO-2%TEGDME-H2O).

[0045] Differential scanning calorimetry (DSC) plots, Nyquist plots at 25 °C, and cyclic voltammetry curves at 50 °C for polymer electrolyte materials containing ether plasticizers are shown in the appendix. Figure 2 , 5 6 and 8.

[0046] Figure 2 This is the DSC curve of the MgBr2-PEO-2%TEGDME-H2O composite electrolyte material in Example 1. After adding 2% TEGDME, the first endothermic peak of 2TEGDME-H2O is located at 147 °C, indicating that the thermal stability of the composite is improved. Furthermore, no endothermic peaks related to the liquid water phase transition were observed near 0 °C and 100 °C in the DSC curves of all samples, proving that the water molecules absorbed by MgBr2 in the composite are not in a free state, but are tightly bound to PEO or TEGDME.

[0047] Figure 5 This is the Nyquist plot of the MgBr2-PEO-2%TEGDME-H2O electrolyte in Example 1 at 25 °C. Due to the high ionic conductivity of the electrolyte, its Nyquist plot consists of a curve crossing the real axis Z' in the high-frequency region, a semicircle in the mid-frequency region, and a slanted line with an angle of approximately 45° in the low-frequency region, indicating that it is a typical ionic conductor. The curve crossing the real axis in the high-frequency region corresponds to the bulk resistance of the electrolyte, the semicircle in the mid-frequency region corresponds to the interfacial resistance between the electrolyte and the electrode, and the slanted line in the low-frequency region corresponds to the MgBr2-PEO-2%TEGDME-H2O electrolyte. 2+ The diffusion (Warburg) process between the electrolyte and the electrode.

[0048] Figure 6 This is the ionic conductivity change curve of the MgBr2-PEO-2%TEGDME-H2O electrolyte in Example 1 during heating and cooling. During heating, the ionic conductivity of the electrolyte shows a steady upward trend as the temperature increases from 25 °C to 80 °C. During cooling, the ionic conductivity of the electrolyte decreases synchronously and steadily as the temperature drops from 80 °C to 25 °C, and the ionic conductivity at each temperature point during cooling is basically consistent with that during heating. This result demonstrates that the MgBr2-PEO-2%TEGDME-H2O electrolyte has excellent thermal stability, and its ion transport channels do not undergo irreversible changes due to temperature fluctuations.

[0049] Figure 8 This is the cyclic voltammogram of a Mg|MgBr2-PEO-2%TEGDME-H2O|Mg symmetric cell at 50 °C. The current begins to increase significantly near 1 V and -1 V, and reaches oxidation and reduction peaks near 2 V and -2 V, respectively, corresponding to the oxidation dissolution and reduction deposition processes of magnesium. The results demonstrate that this electrolyte has good interfacial compatibility with the magnesium anode. 2+ Magnesium deposition / dissolution processes can occur on the surface of magnesium anodes.

[0050] Examples 2-6:

[0051] The only difference from Example 1 is the amount of tetraethylene glycol dimethyl ether added, as shown in Table 1 below.

[0052] Table 1 shows the different amounts (mass fraction%) of tetraethylene glycol dimethyl ether added in Examples 2-6.

[0053] Tetraethylene glycol dimethyl ether addition amount 1% 4% 6% 8% 10%

[0054] Examples 1-6 are polymer electrolyte materials containing ether-based plasticizers with different mass fractions of tetraethylene glycol dimethyl ether. X-ray diffraction patterns, infrared spectra, nuclear magnetic resonance spectra, temperature-ionic conductivity graphs, and constant current charging curves of the counter electrode are shown in the appendix. Figure 1 , 3 4, 7 and 9.

[0055] Comparative Example 1:

[0056] The difference from Example 1 is that Comparative Example 1 did not include TEGDME. Comparisons are made with Examples 1-6. X-ray diffraction patterns, infrared spectra, nuclear magnetic resonance spectra, temperature-ionic conductivity graphs, and constant current charging curves of the counter electrode are shown in the appendix. Figure 1 , 3 4, 7 and 9.

[0057] according to Figure 1 The results showed that the diffraction peak intensities of all examples and comparative examples were very weak. Only the spectra of Comparative Example 1 and Example 4 showed some weak MgBr2 diffraction peaks. The MgBr2 diffraction peaks of the other samples disappeared completely, indicating that the addition of water molecules promoted the formation of the amorphous structure of the complex.

[0058] according to Figure 3 The results show that the atlas is located at approximately 1600 cm. -1 and 3300 cm -1 Both peaks exhibit broad absorption peaks, and the distribution of these two characteristic peaks corresponds to the bending and stretching vibrations of the HO bonds in water molecules, mainly originating from the large amount of H2O molecules added to the sample.

[0059] according to Figure 4 The results show that in Comparative Example 1, the water molecules... 1 The H NMR signal was at 4.89 ppm. After adding 1% and 2% TEGDME, 1 The H NMR signal shifts to a lower field, indicating a decrease in the electron cloud density around the hydrogen nuclei of water molecules and a weakening of the shielding effect. This demonstrates that when low concentrations of TEGDME are added, there is a strong interaction between water molecules and PEO and TEGDME, and the original H2O−H2O hydrogen bond network of water molecules is largely disrupted. When the TEGDME content increases to 4% and 6%, 1 The H NMR signal shifted to a higher field, indicating enhanced electron cloud shielding of hydrogen nuclei compared to the 1% and 2% samples. This suggests a weakening of the interaction between water molecules and TEGDME and PEO, with a gradual increase in free water content. When the TEGDME content was further increased to 8% and 10%, 1 The H NMR signal shifted further to a higher field, and the electron shielding effect was further enhanced, indicating that the interaction between the component and water molecules continued to weaken and the free water content increased.

[0060] Figure 9 The magnesium symmetric cells assembled for Examples 1-6 and Comparative Example 1 were tested at 50 °C and 0.1 mA cm⁻¹. -2 Constant current charge-discharge cycle curves at current density. In Comparative Example 1, the initial charge-discharge overpotential of the symmetrical cell was 0.2 V. During continuous charge-discharge cycles, the overpotential showed a rapid increasing trend, exceeding 5 V in a short time, indicating that its Mg... 2+ The deposition / dissolution process is highly unstable. After adding 1% TEGDME, the initial overpotential of the symmetric cell was 0.7 V. During the first 60 hours of cycling, the overpotential slowly increased to 2 V, exhibiting some cycling stability. However, after 60 hours, the overpotential increased sharply to over 5 V, and Mg... 2+The deposition / dissolution of Mg becomes unstable. The 2TEGDME-H2O sample with 2% TEGDME added exhibits the best cycling stability, with an initial charge-discharge overpotential of 0.6 V. During the first 60 hours of cycling, the overpotential remained stable without significant change. After 60 h, the overpotential increased slowly, but only increased to 1.5 V by 280 h (420 cycles). Furthermore, the charge-discharge curves showed good symmetry throughout the cycling process, indicating that Mg... 2+ The deposition / dissolution process was consistently reversible and stable, with good interfacial stability between the electrolyte and the magnesium anode. However, samples with 4%, 6%, and 8% TEGDME showed a sharp increase in overpotential during the initial charge / discharge phase, exhibiting extremely poor cycle stability. The 6TEGDME-H2O sample showed the fastest overpotential increase, exceeding 5V within a short time, demonstrating highly unstable magnesium deposition / dissolution. When the TEGDME addition reached 10%, the symmetric cell exhibited better cycle stability, with an initial overpotential of approximately 2V, higher than the 2TEGDME-H2O sample. However, during 280 hours of cycling, the overpotential remained stable without significant increase, achieving long-term stable cycling. But compared to the 2TEGDME-H2O sample, the symmetry of the charge / discharge curve of this electrolyte gradually deteriorated with cycling, indicating incomplete magnesium deposition / dissolution. 2+ The deposition / dissolution process, and the overpotential difference during charging and discharging gradually increased, resulting in slightly lower overall cycle stability compared to the 2TEGDME-H2O sample.

[0061] Comparative Example 2:

[0062] The difference from Example 1 is that the polymer electrolyte material containing ether-based plasticizers (MgBr2-PEO-2%TEGDME-H2O) was prepared using a conventional method: MgBr2, PEO, TEGDME, and H2O were simultaneously added to a reaction flask, solvent was added, the mixture was stirred, and then dried. See the attached diagram for the temperature-ionic conductivity relationship. Figure 7 . Figure 7 The results showed that the addition of TEGDME significantly improved the ionic conductivity of MgBr2-PEO-H2O, and the ionic conductivity of all samples increased with increasing temperature. At 25 ℃, the ionic conductivity of the 0TEGDME-H2O electrolyte in Comparative Example 1 (without TEGDME) was 1.72 × 10⁻⁶. -5 S cm -1 After adding 1% TEGDME, the ionic conductivity was significantly increased to 5.12 × 10⁻⁶. -3 S cm -1 With the addition of 2% TEGDME, the ionic conductivity was further increased to 9.95 × 10⁻⁶. -3 S cm -1The ionic conductivity was 4.98 × 10⁻⁶ after adding 4% TEGDME. -3 S cm -1 When the TEGDME content increased to 6%, the ionic conductivity of the electrolyte reached its maximum value of 1.24 × 10⁻⁶. -2 S cm -1 Further increasing the TEGDME content did not significantly change the ionic conductivity. Comparative Example 2, prepared using conventional methods, exhibited a relatively lower ionic conductivity compared to the examples.

[0063] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific materials and properties is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A polymer electrolyte material containing an ether-based plasticizer, the polymer electrolyte material having the molecular formula MgBr2-PEO-χTEGDME-H2O, wherein: χ is 0 wt% to 10 wt%, and χ is not 0.

2. The polymer electrolyte material containing ether-based plasticizer according to claim 1, wherein: χ is 2 wt%.

3. A method for preparing a polymer electrolyte material containing an ether-based plasticizer according to claim 1 or 2, comprising the following steps: Step 1: Dissolve magnesium bromide and polyethylene oxide in anhydrous ethanol under a protective atmosphere, then add tetraethylene glycol dimethyl ether to obtain a homogeneous mixed solution. Pour the solution into a polytetrafluoroethylene petri dish and dry it under vacuum to obtain a gel-like solid I. Step 2: Expose gel-like solid I to air to absorb water molecules from the air, thus obtaining a polymer electrolyte material containing ether plasticizer.

4. The preparation method according to claim 3, wherein: The stirring speed in step 1 is 300 rpm, the stirring temperature is 60 ℃, and the stirring time is not less than 24 hours.

5. The preparation method according to claim 3, wherein: The vacuum drying conditions described in step 1 are: drying at 80 ℃ for 6 h, with a vacuum degree of 21 kPa.

6. The preparation method according to claim 3, wherein: The environmental conditions for air exposure in step 2 are: temperature 25℃, humidity 50%, and exposure time 30 min.

7. The preparation method according to claim 3, wherein: In step 1, the mass ratio of magnesium bromide to polyethylene oxide is 7:3, and the mass fraction of tetraethylene glycol dimethyl ether is χ.

8. A polymer electrolyte material containing an ether plasticizer prepared by the preparation method according to any one of claims 3 to 7.

9. The application of a polymer electrolyte material containing an ether-based plasticizer according to claim 1, 2 or 8 in the preparation of a rechargeable battery.

10. The application according to claim 9, wherein: The rechargeable battery includes: magnesium-ion battery, solid-state battery, or quasi-solid-state battery.

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